<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e6aa8-6560-7760-ada7-467fab424839,g:a3240d7f-b31c-4839-b2a3-645c0f3f8a74-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.gwresources.com/role/CondensedConsolidatedBalanceSheetsunaudited" xlink:type="simple" xlink:href="gwrs-20260630.xsd#CondensedConsolidatedBalanceSheetsunaudited"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/CondensedConsolidatedBalanceSheetsunaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019fa843-c716-7a1d-ad1d-418e41a22f20" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019fa843-c716-78e2-8fd1-5078326941b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019fa843-c716-7a1d-ad1d-418e41a22f20" xlink:to="loc_us-gaap_StatementTable_019fa843-c716-78e2-8fd1-5078326941b6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019fa843-c716-71af-b390-70633118186b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019fa843-c716-78e2-8fd1-5078326941b6" xlink:to="loc_us-gaap_CreditFacilityAxis_019fa843-c716-71af-b390-70633118186b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019fa843-c716-71af-b390-70633118186b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019fa843-c716-71af-b390-70633118186b" xlink:to="loc_us-gaap_CreditFacilityDomain_019fa843-c716-71af-b390-70633118186b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019fa843-c716-750a-a3c1-0f1bf3efb555" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019fa843-c716-71af-b390-70633118186b" xlink:to="loc_us-gaap_CreditFacilityDomain_019fa843-c716-750a-a3c1-0f1bf3efb555" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019fa843-c716-73b0-9bf5-9e3d56d79507" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019fa843-c716-750a-a3c1-0f1bf3efb555" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019fa843-c716-73b0-9bf5-9e3d56d79507" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_019e6aa8-67ba-7867-9b00-b74b07ca9e5f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fa843-c716-7a1d-ad1d-418e41a22f20" xlink:to="loc_us-gaap_AssetsAbstract_019e6aa8-67ba-7867-9b00-b74b07ca9e5f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService_019e6aa8-67ba-7dc2-93d4-2431e4249447" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e6aa8-67ba-7867-9b00-b74b07ca9e5f" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService_019e6aa8-67ba-7dc2-93d4-2431e4249447" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation_019e6aa8-67ba-72d4-a658-091c8d14d97c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e6aa8-67ba-7867-9b00-b74b07ca9e5f" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation_019e6aa8-67ba-72d4-a658-091c8d14d97c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_019e6aa8-67ba-7575-83c4-65fd5442fcb6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e6aa8-67ba-7867-9b00-b74b07ca9e5f" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_019e6aa8-67ba-7575-83c4-65fd5442fcb6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_019e6aa8-67ba-7c2b-8473-08d45594f089" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e6aa8-67ba-7867-9b00-b74b07ca9e5f" xlink:to="loc_us-gaap_AssetsCurrentAbstract_019e6aa8-67ba-7c2b-8473-08d45594f089" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e6aa8-67ba-7d4d-ba8c-1026822327a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019e6aa8-67ba-7c2b-8473-08d45594f089" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e6aa8-67ba-7d4d-ba8c-1026822327a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019e6aa8-67ba-7485-9a26-f702d28a4dd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019e6aa8-67ba-7c2b-8473-08d45594f089" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019e6aa8-67ba-7485-9a26-f702d28a4dd3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedFeesAndOtherRevenueReceivable_019e6aa8-67ba-71fe-aeee-9cb1c5fc1207" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedFeesAndOtherRevenueReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019e6aa8-67ba-7c2b-8473-08d45594f089" xlink:to="loc_us-gaap_AccruedFeesAndOtherRevenueReceivable_019e6aa8-67ba-71fe-aeee-9cb1c5fc1207" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019e6aa8-67ba-7731-84c3-6590b77cfde7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019e6aa8-67ba-7c2b-8473-08d45594f089" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_019e6aa8-67ba-7731-84c3-6590b77cfde7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019e6aa8-67ba-7b5b-889c-80bbafd2fc35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_019e6aa8-67ba-7c2b-8473-08d45594f089" xlink:to="loc_us-gaap_AssetsCurrent_019e6aa8-67ba-7b5b-889c-80bbafd2fc35" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e6aa8-67ba-7867-9b00-b74b07ca9e5f" xlink:to="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019e6aa8-67ba-7723-b723-a98ba4765f55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:to="loc_us-gaap_Goodwill_019e6aa8-67ba-7723-b723-a98ba4765f55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019e6aa8-67ba-719e-b3b5-7e3d0fb788df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019e6aa8-67ba-719e-b3b5-7e3d0fb788df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAssetsNoncurrent_019e6aa8-67ba-75bd-9b0c-91d14d4df7ac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatoryAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:to="loc_us-gaap_RegulatoryAssetsNoncurrent_019e6aa8-67ba-75bd-9b0c-91d14d4df7ac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsNoncurrent_019e6aa8-67ba-75d0-a346-3bb6af1304bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsNoncurrent_019e6aa8-67ba-75d0-a346-3bb6af1304bc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_LeaseRightOfUseAsset_019e6aa8-67ba-7fee-89b4-d345079f4db7" xlink:href="gwrs-20260630.xsd#gwrs_LeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:to="loc_gwrs_LeaseRightOfUseAsset_019e6aa8-67ba-7fee-89b4-d345079f4db7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMiscellaneousNoncurrent_019e6aa8-67ba-7bfe-95ff-1c1bca9620bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsMiscellaneousNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:to="loc_us-gaap_OtherAssetsMiscellaneousNoncurrent_019e6aa8-67ba-7bfe-95ff-1c1bca9620bc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019e6aa8-67ba-7ac4-8609-5dc1bc6aef35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsAbstract_019e6aa8-67ba-78ad-b3f8-1cdc02eba253" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019e6aa8-67ba-7ac4-8609-5dc1bc6aef35" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019e6aa8-67ba-744c-be2b-454f1eb89386" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019e6aa8-67ba-7867-9b00-b74b07ca9e5f" xlink:to="loc_us-gaap_Assets_019e6aa8-67ba-744c-be2b-454f1eb89386" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019e6aa8-67ba-7214-a008-4970c2048acc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fa843-c716-7a1d-ad1d-418e41a22f20" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019e6aa8-67ba-7214-a008-4970c2048acc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizationLongtermDebtAndEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019e6aa8-67ba-7214-a008-4970c2048acc" xlink:to="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019e6aa8-67ba-7ff7-be65-0231ab8a82e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:to="loc_us-gaap_CommonStockValue_019e6aa8-67ba-7ff7-be65-0231ab8a82e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_019e6aa8-67ba-71d4-a3b2-d45abc49083b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:to="loc_us-gaap_TreasuryStockCommonValue_019e6aa8-67ba-71d4-a3b2-d45abc49083b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019e6aa8-67ba-7e0f-9313-3f724ce49046" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019e6aa8-67ba-7e0f-9313-3f724ce49046" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019e6aa8-67ba-75d9-a26f-7c7690340793" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019e6aa8-67ba-75d9-a26f-7c7690340793" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e6aa8-67ba-785f-914a-f9046bf08bf1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:to="loc_us-gaap_StockholdersEquity_019e6aa8-67ba-785f-914a-f9046bf08bf1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019e6aa8-67ba-7191-9f51-5f2f54602a94" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019e6aa8-67ba-7191-9f51-5f2f54602a94" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizationLongtermDebtAndEquity_019e6aa8-67ba-743c-8808-5a891b264183" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizationLongtermDebtAndEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizationLongtermDebtAndEquityAbstract_019e6aa8-67ba-7a74-89b0-d75e30e94be2" xlink:to="loc_us-gaap_CapitalizationLongtermDebtAndEquity_019e6aa8-67ba-743c-8808-5a891b264183" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_019e6aa8-67ba-76d0-a390-2089ff267c72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019e6aa8-67ba-7214-a008-4970c2048acc" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_019e6aa8-67ba-76d0-a390-2089ff267c72" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_019e6aa8-67ba-7020-98a1-d6c6d46b724f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019e6aa8-67ba-76d0-a390-2089ff267c72" xlink:to="loc_us-gaap_AccountsPayableCurrent_019e6aa8-67ba-7020-98a1-d6c6d46b724f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_CustomerAndMeterDepositsCurrent_019e6aa8-67ba-7546-8e28-590f31a9e3b3" xlink:href="gwrs-20260630.xsd#gwrs_CustomerAndMeterDepositsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019e6aa8-67ba-76d0-a390-2089ff267c72" xlink:to="loc_gwrs_CustomerAndMeterDepositsCurrent_019e6aa8-67ba-7546-8e28-590f31a9e3b3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019e6aa8-67ba-7e51-961b-14f06c660b56" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019e6aa8-67ba-76d0-a390-2089ff267c72" xlink:to="loc_us-gaap_LongTermDebtCurrent_019e6aa8-67ba-7e51-961b-14f06c660b56" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_LeaseLiabilityCurrent_019e6aa8-67ba-73bf-98cf-f0ec3d9daac6" xlink:href="gwrs-20260630.xsd#gwrs_LeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019e6aa8-67ba-76d0-a390-2089ff267c72" xlink:to="loc_gwrs_LeaseLiabilityCurrent_019e6aa8-67ba-73bf-98cf-f0ec3d9daac6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_AccruedLiabilitiesAndOtherCurrentLiabilities_019e6aa8-67ba-71db-bec1-c931cdcffb00" xlink:href="gwrs-20260630.xsd#gwrs_AccruedLiabilitiesAndOtherCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019e6aa8-67ba-76d0-a390-2089ff267c72" xlink:to="loc_gwrs_AccruedLiabilitiesAndOtherCurrentLiabilities_019e6aa8-67ba-71db-bec1-c931cdcffb00" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019e6aa8-67ba-7ef6-a2bc-b11ca41afaeb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_019e6aa8-67ba-76d0-a390-2089ff267c72" xlink:to="loc_us-gaap_LiabilitiesCurrent_019e6aa8-67ba-7ef6-a2bc-b11ca41afaeb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesNoncurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019e6aa8-67ba-7214-a008-4970c2048acc" xlink:to="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019fa843-c716-7227-8664-9371cefe5e28" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_us-gaap_LineOfCredit_019fa843-c716-7227-8664-9371cefe5e28" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_LeaseLiabilityNoncurrent_019e6aa8-67ba-7655-b092-b976bf351eb3" xlink:href="gwrs-20260630.xsd#gwrs_LeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_gwrs_LeaseLiabilityNoncurrent_019e6aa8-67ba-7655-b092-b976bf351eb3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredRevenueNoncurrent_019e6aa8-67ba-7810-874d-76d6662fe93c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredRevenueNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_us-gaap_DeferredRevenueNoncurrent_019e6aa8-67ba-7810-874d-76d6662fe93c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryLiabilityNoncurrent_019e6aa8-67ba-7b2f-986a-3906f3833649" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatoryLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_us-gaap_RegulatoryLiabilityNoncurrent_019e6aa8-67ba-7b2f-986a-3906f3833649" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_AdvancesInAidOfConstruction_019e6aa8-67ba-707e-a857-a0d42c578c79" xlink:href="gwrs-20260630.xsd#gwrs_AdvancesInAidOfConstruction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_gwrs_AdvancesInAidOfConstruction_019e6aa8-67ba-707e-a857-a0d42c578c79" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContributionsInAidOfConstruction_019e6aa8-67ba-76db-a879-173c62821a06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContributionsInAidOfConstruction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_us-gaap_ContributionsInAidOfConstruction_019e6aa8-67ba-76db-a879-173c62821a06" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019e6aa8-67ba-71d5-8e99-e11797070aab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019e6aa8-67ba-71d5-8e99-e11797070aab" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_HookUpFeeLiabilities_019e6aa8-67ba-77aa-a076-b350b8a23850" xlink:href="gwrs-20260630.xsd#gwrs_HookUpFeeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_gwrs_HookUpFeeLiabilities_019e6aa8-67ba-77aa-a076-b350b8a23850" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_019e6aa8-67ba-788d-afa2-2b6bfeaf1f6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_019e6aa8-67ba-788d-afa2-2b6bfeaf1f6c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrent_019e6aa8-67ba-7508-a547-494bc1cac529" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract_019e6aa8-67ba-7887-968f-13220bb1f854" xlink:to="loc_us-gaap_LiabilitiesNoncurrent_019e6aa8-67ba-7508-a547-494bc1cac529" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019e6aa8-67ba-77b5-8f9f-5c9c54be2914" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019e6aa8-67ba-7214-a008-4970c2048acc" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019e6aa8-67ba-77b5-8f9f-5c9c54be2914" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6aa8-67ba-7925-96b5-4d87f9d0a4e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019e6aa8-67ba-7214-a008-4970c2048acc" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6aa8-67ba-7925-96b5-4d87f9d0a4e8" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/CondensedConsolidatedStatementsofOperationsunaudited" xlink:type="simple" xlink:href="gwrs-20260630.xsd#CondensedConsolidatedStatementsofOperationsunaudited"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/CondensedConsolidatedStatementsofOperationsunaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019e6aa8-67ba-7dcf-92bc-ef998dbf54c2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_StatementTable_019e6aa8-67ba-7dcf-92bc-ef998dbf54c2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019e6aa8-67ba-7a33-aa1a-483718b1b7a9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e6aa8-67ba-7dcf-92bc-ef998dbf54c2" xlink:to="loc_srt_ProductOrServiceAxis_019e6aa8-67ba-7a33-aa1a-483718b1b7a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e6aa8-67ba-7a33-aa1a-483718b1b7a9_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019e6aa8-67ba-7a33-aa1a-483718b1b7a9" xlink:to="loc_srt_ProductsAndServicesDomain_019e6aa8-67ba-7a33-aa1a-483718b1b7a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e6aa8-67ba-739a-82e5-4ff63ad1967d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019e6aa8-67ba-7a33-aa1a-483718b1b7a9" xlink:to="loc_srt_ProductsAndServicesDomain_019e6aa8-67ba-739a-82e5-4ff63ad1967d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_WaterServicesMember_019e6aa8-67ba-760e-ae3e-5f7ac21675d9" xlink:href="gwrs-20260630.xsd#gwrs_WaterServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e6aa8-67ba-739a-82e5-4ff63ad1967d" xlink:to="loc_gwrs_WaterServicesMember_019e6aa8-67ba-760e-ae3e-5f7ac21675d9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_WastewaterAndRecycledWaterMember_019e6aa8-67ba-7356-b2a0-db2fa90b0343" xlink:href="gwrs-20260630.xsd#gwrs_WastewaterAndRecycledWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e6aa8-67ba-739a-82e5-4ff63ad1967d" xlink:to="loc_gwrs_WastewaterAndRecycledWaterMember_019e6aa8-67ba-7356-b2a0-db2fa90b0343" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_UnregulatedRevenueMember_019f4be3-e438-7dca-975d-21acbd3fbefa" xlink:href="gwrs-20260630.xsd#gwrs_UnregulatedRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e6aa8-67ba-739a-82e5-4ff63ad1967d" xlink:to="loc_gwrs_UnregulatedRevenueMember_019f4be3-e438-7dca-975d-21acbd3fbefa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_019e6aa8-67ba-7ea7-875d-b0c73556a75d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_RevenuesAbstract_019e6aa8-67ba-7ea7-875d-b0c73556a75d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e6aa8-67ba-7c31-b4e5-f2cdb859835a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_019e6aa8-67ba-7ea7-875d-b0c73556a75d" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e6aa8-67ba-7c31-b4e5-f2cdb859835a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-67ba-767b-85f4-b860295ba2a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-67ba-767b-85f4-b860295ba2a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations_019e6aa8-67ba-7d06-9886-cc419c8b3c32" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-67ba-767b-85f4-b860295ba2a8" xlink:to="loc_us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations_019e6aa8-67ba-7d06-9886-cc419c8b3c32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019e6aa8-67ba-76eb-a74d-e780b55a412b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-67ba-767b-85f4-b860295ba2a8" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019e6aa8-67ba-76eb-a74d-e780b55a412b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAmortizationAndAccretionNet_019e6aa8-67ba-7767-af90-c203e7be013c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationAmortizationAndAccretionNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-67ba-767b-85f4-b860295ba2a8" xlink:to="loc_us-gaap_DepreciationAmortizationAndAccretionNet_019e6aa8-67ba-7767-af90-c203e7be013c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019e6aa8-67ba-7e72-bd7b-33758c6d9c91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-67ba-767b-85f4-b860295ba2a8" xlink:to="loc_us-gaap_OperatingExpenses_019e6aa8-67ba-7e72-bd7b-33758c6d9c91" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019e6aa8-67ba-7d3d-9d29-ce630505dfb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_OperatingIncomeLoss_019e6aa8-67ba-7d3d-9d29-ce630505dfb8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019e6aa8-67ba-72a0-917d-fdbbe8d52d34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019e6aa8-67ba-72a0-917d-fdbbe8d52d34" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019e6aa8-67ba-7707-9eb7-ee256b5fc837" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019e6aa8-67ba-72a0-917d-fdbbe8d52d34" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019e6aa8-67ba-7707-9eb7-ee256b5fc837" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_019e6aa8-67ba-7865-9342-bb0deca8d023" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019e6aa8-67ba-72a0-917d-fdbbe8d52d34" xlink:to="loc_us-gaap_InterestExpenseDebt_019e6aa8-67ba-7865-9342-bb0deca8d023" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019e6aa8-67ba-7ffe-8705-cc776ff0bda1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019e6aa8-67ba-72a0-917d-fdbbe8d52d34" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019e6aa8-67ba-7ffe-8705-cc776ff0bda1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019e6aa8-67ba-74d8-b1cb-30bc7730aca8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019e6aa8-67ba-72a0-917d-fdbbe8d52d34" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019e6aa8-67ba-74d8-b1cb-30bc7730aca8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e6aa8-67ba-7231-96c8-30eeb2f19ab9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e6aa8-67ba-7231-96c8-30eeb2f19ab9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019e6aa8-67ba-76a8-afee-f176fa3fd211" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019e6aa8-67ba-76a8-afee-f176fa3fd211" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6aa8-67ba-7a29-8d4e-d1bc8a7f13e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_NetIncomeLoss_019e6aa8-67ba-7a29-8d4e-d1bc8a7f13e5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019e6aa8-67ba-7607-aa85-f939fbf65d87" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_EarningsPerShareBasic_019e6aa8-67ba-7607-aa85-f939fbf65d87" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019e6aa8-67ba-7b72-9bc9-e9bcc07c2607" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019e6aa8-67ba-7b72-9bc9-e9bcc07c2607" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019e6aa8-67ba-7494-ab44-947f65f82b75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019e6aa8-67ba-7494-ab44-947f65f82b75" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019e6aa8-67ba-725e-9c29-47652e3a2ea2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-7766-8ca5-1882349ad819" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019e6aa8-67ba-725e-9c29-47652e3a2ea2" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e6aa8-67ba-7b4e-92b1-8e39299a79a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019e6aa8-67ba-725e-9c29-47652e3a2ea2" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e6aa8-67ba-7b4e-92b1-8e39299a79a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019e6aa8-67ba-7e43-a163-de8c3143ab94" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019e6aa8-67ba-725e-9c29-47652e3a2ea2" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019e6aa8-67ba-7e43-a163-de8c3143ab94" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/CondensedConsolidatedStatementsofShareholdersEquityunaudited" xlink:type="simple" xlink:href="gwrs-20260630.xsd#CondensedConsolidatedStatementsofShareholdersEquityunaudited"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/CondensedConsolidatedStatementsofShareholdersEquityunaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019e6aa8-67ba-76dd-a6d7-48ba93272ca2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019e6aa8-67ba-7de5-ae96-8066835d95ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-76dd-a6d7-48ba93272ca2" xlink:to="loc_us-gaap_StatementTable_019e6aa8-67ba-7de5-ae96-8066835d95ec" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019e6aa8-67ba-7b6b-baa5-e76ee2b145ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e6aa8-67ba-7de5-ae96-8066835d95ec" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019e6aa8-67ba-7b6b-baa5-e76ee2b145ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e6aa8-67ba-7b6b-baa5-e76ee2b145ca_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e6aa8-67ba-7b6b-baa5-e76ee2b145ca" xlink:to="loc_us-gaap_EquityComponentDomain_019e6aa8-67ba-7b6b-baa5-e76ee2b145ca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e6aa8-67ba-7402-bfd6-e74de3334da1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e6aa8-67ba-7b6b-baa5-e76ee2b145ca" xlink:to="loc_us-gaap_EquityComponentDomain_019e6aa8-67ba-7402-bfd6-e74de3334da1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019e6aa8-67ba-704d-b813-b8e64bff353b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e6aa8-67ba-7402-bfd6-e74de3334da1" xlink:to="loc_us-gaap_CommonStockMember_019e6aa8-67ba-704d-b813-b8e64bff353b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019e6aa8-67ba-75ff-9146-c87cb1c7c53c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e6aa8-67ba-7402-bfd6-e74de3334da1" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019e6aa8-67ba-75ff-9146-c87cb1c7c53c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019e6aa8-67ba-756f-a756-aee46a1f9961" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e6aa8-67ba-7402-bfd6-e74de3334da1" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019e6aa8-67ba-756f-a756-aee46a1f9961" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019e6aa8-67ba-799d-8f87-0d60248343ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e6aa8-67ba-7402-bfd6-e74de3334da1" xlink:to="loc_us-gaap_RetainedEarningsMember_019e6aa8-67ba-799d-8f87-0d60248343ca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e6aa8-67ba-76dd-a6d7-48ba93272ca2" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019e6aa8-67ba-7558-bdbc-5c7ac9003b92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_CommonStockSharesIssued_019e6aa8-67ba-7558-bdbc-5c7ac9003b92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e6aa8-67ba-7157-a980-70edb659ad8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_StockholdersEquity_019e6aa8-67ba-7157-a980-70edb659ad8b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019e6aa8-67ba-7dfe-a2d0-058903cf7a0d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_TreasuryStockCommonShares_019e6aa8-67ba-7dfe-a2d0-058903cf7a0d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings_019e6aa8-67ba-7370-ad4b-1bf1c80ad80e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings_019e6aa8-67ba-7370-ad4b-1bf1c80ad80e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019e6aa8-67ba-7f13-bf49-b4d9993f1787" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019e6aa8-67ba-7f13-bf49-b4d9993f1787" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_019e6aa8-67ba-7119-adde-8e23e88496ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_019e6aa8-67ba-7119-adde-8e23e88496ba" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019e6aa8-67ba-76f8-ab57-df1c530c0de9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019e6aa8-67ba-76f8-ab57-df1c530c0de9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019e6aa8-67ba-7b22-b70b-7ee4855e4067" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019e6aa8-67ba-7b22-b70b-7ee4855e4067" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6aa8-67ba-7732-8eef-2009d5a7b4b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e6aa8-67ba-7fca-b86e-6ae2fded375a" xlink:to="loc_us-gaap_NetIncomeLoss_019e6aa8-67ba-7732-8eef-2009d5a7b4b0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019e6aa8-67ba-7400-b4ee-efdc03d4bd92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e6aa8-67ba-7761-9afd-652ca1fca59a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019e6aa8-67ba-7726-a7cc-63ff0baabd55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/AcquisitionsNarrativeDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#AcquisitionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/AcquisitionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7e43-9c28-cb701479155c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-67bb-7b7a-a671-4dec21cf0863" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7e43-9c28-cb701479155c" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-67bb-7b7a-a671-4dec21cf0863" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-67bb-7b31-ab0b-da5a387cdc3d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-67bb-7b7a-a671-4dec21cf0863" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-67bb-7b31-ab0b-da5a387cdc3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-7b31-ab0b-da5a387cdc3d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-67bb-7b31-ab0b-da5a387cdc3d" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-7b31-ab0b-da5a387cdc3d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-7ede-aab1-f26b742e46fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-67bb-7b31-ab0b-da5a387cdc3d" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-7ede-aab1-f26b742e46fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_TucsonWaterMember_019e6aa8-67bb-7c59-bd2b-b2e8682662d2" xlink:href="gwrs-20260630.xsd#gwrs_TucsonWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-7ede-aab1-f26b742e46fb" xlink:to="loc_gwrs_TucsonWaterMember_019e6aa8-67bb-7c59-bd2b-b2e8682662d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019e6aa8-67bb-78ed-9b95-34b305ee3e41" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-67bb-7b7a-a671-4dec21cf0863" xlink:to="loc_srt_CounterpartyNameAxis_019e6aa8-67bb-78ed-9b95-34b305ee3e41" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019e6aa8-67bb-78ed-9b95-34b305ee3e41_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_019e6aa8-67bb-78ed-9b95-34b305ee3e41" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019e6aa8-67bb-78ed-9b95-34b305ee3e41_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019e6aa8-67bb-7a41-bc36-ac47d5fb3d23" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_019e6aa8-67bb-78ed-9b95-34b305ee3e41" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019e6aa8-67bb-7a41-bc36-ac47d5fb3d23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GWOcotilloMember_019e6aa8-67bb-7286-ad8c-0bcabaef227d" xlink:href="gwrs-20260630.xsd#gwrs_GWOcotilloMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019e6aa8-67bb-7a41-bc36-ac47d5fb3d23" xlink:to="loc_gwrs_GWOcotilloMember_019e6aa8-67bb-7286-ad8c-0bcabaef227d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfBusinessesAcquired_019e6aa8-67bb-7cc3-b060-b925dae893b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfBusinessesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7e43-9c28-cb701479155c" xlink:to="loc_us-gaap_NumberOfBusinessesAcquired_019e6aa8-67bb-7cc3-b060-b925dae893b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019e6aa8-67bb-718f-9d74-1ae5534a017b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7e43-9c28-cb701479155c" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019e6aa8-67bb-718f-9d74-1ae5534a017b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ActiveWaterConnections_019e6aa8-67bb-7a77-9e8f-1602e30e2751" xlink:href="gwrs-20260630.xsd#gwrs_ActiveWaterConnections"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7e43-9c28-cb701479155c" xlink:to="loc_gwrs_ActiveWaterConnections_019e6aa8-67bb-7a77-9e8f-1602e30e2751" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PublicUtilitiesPropertyPlantAndEquipmentEstimatedRateBase_019e6aa8-67bb-79e1-b84e-a353bf4f43bb" xlink:href="gwrs-20260630.xsd#gwrs_PublicUtilitiesPropertyPlantAndEquipmentEstimatedRateBase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7e43-9c28-cb701479155c" xlink:to="loc_gwrs_PublicUtilitiesPropertyPlantAndEquipmentEstimatedRateBase_019e6aa8-67bb-79e1-b84e-a353bf4f43bb" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/AcquisitionsRecognizedIdentifiedAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#AcquisitionsRecognizedIdentifiedAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/AcquisitionsRecognizedIdentifiedAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-67bb-78e9-9c22-cb6eeb1acdb4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-67bb-78e9-9c22-cb6eeb1acdb4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-67bb-75bf-a4bb-77da5d9af7cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-67bb-78e9-9c22-cb6eeb1acdb4" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-67bb-75bf-a4bb-77da5d9af7cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-75bf-a4bb-77da5d9af7cb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-67bb-75bf-a4bb-77da5d9af7cb" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-75bf-a4bb-77da5d9af7cb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-75d5-87d7-0a6d6c2e6fd6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-67bb-75bf-a4bb-77da5d9af7cb" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-75d5-87d7-0a6d6c2e6fd6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_TucsonWaterMember_019e6aa8-67bb-79e1-8f06-2f00f031ea18" xlink:href="gwrs-20260630.xsd#gwrs_TucsonWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-67bb-75d5-87d7-0a6d6c2e6fd6" xlink:to="loc_gwrs_TucsonWaterMember_019e6aa8-67bb-79e1-8f06-2f00f031ea18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019e6aa8-67bb-7e3d-86e1-42be063cb924" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019e6aa8-67bb-7e3d-86e1-42be063cb924" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019e6aa8-67bb-718c-bfd2-ceebc6016c41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019e6aa8-67bb-718c-bfd2-ceebc6016c41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019e6aa8-67bb-7d27-9b2a-6b8a963e1143" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019e6aa8-67bb-7d27-9b2a-6b8a963e1143" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOtherAccruedLiabilities_019e6aa8-67bb-7795-be2b-9dd65cf5dbdb" xlink:href="gwrs-20260630.xsd#gwrs_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOtherAccruedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:to="loc_gwrs_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOtherAccruedLiabilities_019e6aa8-67bb-7795-be2b-9dd65cf5dbdb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_019e6aa8-67bb-75f1-8fe9-0167fdf8d1c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_019e6aa8-67bb-75f1-8fe9-0167fdf8d1c4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019e6aa8-67bb-70a6-b655-dc66c325a3af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:to="loc_us-gaap_Goodwill_019e6aa8-67bb-70a6-b655-dc66c325a3af" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019e6aa8-67bb-7aed-80be-aaca34e0802b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-67bb-7858-8d11-b1076622828a" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019e6aa8-67bb-7aed-80be-aaca34e0802b" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/RegulatoryMattersDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#RegulatoryMattersDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/RegulatoryMattersDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesGeneralDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesGeneralDisclosuresTable_019e6aa8-67bb-7cef-8275-b3fc8752964b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesGeneralDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_us-gaap_PublicUtilitiesGeneralDisclosuresTable_019e6aa8-67bb-7cef-8275-b3fc8752964b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAgencyAxis_019e6aa8-67bb-75f7-8ec9-6e21c7a7e931" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatoryAgencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresTable_019e6aa8-67bb-7cef-8275-b3fc8752964b" xlink:to="loc_us-gaap_RegulatoryAgencyAxis_019e6aa8-67bb-75f7-8ec9-6e21c7a7e931" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAgencyDomain_019e6aa8-67bb-75f7-8ec9-6e21c7a7e931_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatoryAgencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RegulatoryAgencyAxis_019e6aa8-67bb-75f7-8ec9-6e21c7a7e931" xlink:to="loc_us-gaap_RegulatoryAgencyDomain_019e6aa8-67bb-75f7-8ec9-6e21c7a7e931_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryAgencyDomain_019e6aa8-67bb-76fe-a725-30996ff4349a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatoryAgencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RegulatoryAgencyAxis_019e6aa8-67bb-75f7-8ec9-6e21c7a7e931" xlink:to="loc_us-gaap_RegulatoryAgencyDomain_019e6aa8-67bb-76fe-a725-30996ff4349a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ArizonaCorporationCommissionACCMember_019e6aa8-67bb-78f6-a838-873a129d1e5e" xlink:href="gwrs-20260630.xsd#gwrs_ArizonaCorporationCommissionACCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryAgencyDomain_019e6aa8-67bb-76fe-a725-30996ff4349a" xlink:to="loc_gwrs_ArizonaCorporationCommissionACCMember_019e6aa8-67bb-78f6-a838-873a129d1e5e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesRegulatoryProceedingAxis_019e6aa8-67bb-7cb8-bab6-25130d193bc0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesRegulatoryProceedingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresTable_019e6aa8-67bb-7cef-8275-b3fc8752964b" xlink:to="loc_us-gaap_PublicUtilitiesRegulatoryProceedingAxis_019e6aa8-67bb-7cb8-bab6-25130d193bc0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesRegulatoryProceedingDomain_019e6aa8-67bb-7cb8-bab6-25130d193bc0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesRegulatoryProceedingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilitiesRegulatoryProceedingAxis_019e6aa8-67bb-7cb8-bab6-25130d193bc0" xlink:to="loc_us-gaap_PublicUtilitiesRegulatoryProceedingDomain_019e6aa8-67bb-7cb8-bab6-25130d193bc0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesRegulatoryProceedingDomain_019e6aa8-67bb-77b5-95b6-fce0c45977aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesRegulatoryProceedingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilitiesRegulatoryProceedingAxis_019e6aa8-67bb-7cb8-bab6-25130d193bc0" xlink:to="loc_us-gaap_PublicUtilitiesRegulatoryProceedingDomain_019e6aa8-67bb-77b5-95b6-fce0c45977aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GWSantaCruzRateCaseMember_019e6aa8-67bb-72d4-9a15-33549a4d164c" xlink:href="gwrs-20260630.xsd#gwrs_GWSantaCruzRateCaseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesRegulatoryProceedingDomain_019e6aa8-67bb-77b5-95b6-fce0c45977aa" xlink:to="loc_gwrs_GWSantaCruzRateCaseMember_019e6aa8-67bb-72d4-9a15-33549a4d164c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilityAxis_019e6aa8-67bb-7004-920b-12ba8fa987cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresTable_019e6aa8-67bb-7cef-8275-b3fc8752964b" xlink:to="loc_us-gaap_PublicUtilityAxis_019e6aa8-67bb-7004-920b-12ba8fa987cb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UtilityPlantDomain_019e6aa8-67bb-7004-920b-12ba8fa987cb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UtilityPlantDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilityAxis_019e6aa8-67bb-7004-920b-12ba8fa987cb" xlink:to="loc_us-gaap_UtilityPlantDomain_019e6aa8-67bb-7004-920b-12ba8fa987cb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UtilityPlantDomain_019e6aa8-67bb-78f6-b334-ecd2332af74a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UtilityPlantDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilityAxis_019e6aa8-67bb-7004-920b-12ba8fa987cb" xlink:to="loc_us-gaap_UtilityPlantDomain_019e6aa8-67bb-78f6-b334-ecd2332af74a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WaterPlantMember_019e6aa8-67bb-7c20-b606-6b29626196c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WaterPlantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_UtilityPlantDomain_019e6aa8-67bb-78f6-b334-ecd2332af74a" xlink:to="loc_us-gaap_WaterPlantMember_019e6aa8-67bb-7c20-b606-6b29626196c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PublicUtilitiesNumberOfRegulatoryRateCases_019e6aa8-67bb-7ba6-b08b-29544e491144" xlink:href="gwrs-20260630.xsd#gwrs_PublicUtilitiesNumberOfRegulatoryRateCases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_gwrs_PublicUtilitiesNumberOfRegulatoryRateCases_019e6aa8-67bb-7ba6-b08b-29544e491144" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInterimRateIncreaseDecreaseAmount_019fc6d2-6d6c-741f-a5e9-8c5ee43c6b16" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesInterimRateIncreaseDecreaseAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_us-gaap_PublicUtilitiesInterimRateIncreaseDecreaseAmount_019fc6d2-6d6c-741f-a5e9-8c5ee43c6b16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount_019e6aa8-67bb-7042-adb3-9dff70bd2b49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount_019e6aa8-67bb-7042-adb3-9dff70bd2b49" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PublicUtilitiesPropertyPlantAndEquipmentPlantHeldForFutureUse_019e6aa8-67bb-7814-80f4-a81415a79f44" xlink:href="gwrs-20260630.xsd#gwrs_PublicUtilitiesPropertyPlantAndEquipmentPlantHeldForFutureUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_gwrs_PublicUtilitiesPropertyPlantAndEquipmentPlantHeldForFutureUse_019e6aa8-67bb-7814-80f4-a81415a79f44" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfDisallowedCostsForRecentlyCompletedPlant_019e6aa8-67bb-7e69-86dd-fb92e2c8bad7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfDisallowedCostsForRecentlyCompletedPlant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfDisallowedCostsForRecentlyCompletedPlant_019e6aa8-67bb-7e69-86dd-fb92e2c8bad7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesRequestedReturnOnEquityPercentage_019e6aa8-67bb-70bf-8b45-5ed82786fc49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesRequestedReturnOnEquityPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_us-gaap_PublicUtilitiesRequestedReturnOnEquityPercentage_019e6aa8-67bb-70bf-8b45-5ed82786fc49" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PublicUtilitiesRequestedRatePhaseInPeriod_019e6aa8-67bb-7de0-ad90-c666617afefe" xlink:href="gwrs-20260630.xsd#gwrs_PublicUtilitiesRequestedRatePhaseInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_gwrs_PublicUtilitiesRequestedRatePhaseInPeriod_019e6aa8-67bb-7de0-ad90-c666617afefe" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesRequestedEquityCapitalStructurePercentage_019e6aa8-67bb-77d8-a7f1-a194aece14f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesRequestedEquityCapitalStructurePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_us-gaap_PublicUtilitiesRequestedEquityCapitalStructurePercentage_019e6aa8-67bb-77d8-a7f1-a194aece14f1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PublicUtilitiesRequestedDeferralOfRecoveryOfAcquisitionPremiumAmount_019e6aa8-67bb-759b-8e8f-992317843f33" xlink:href="gwrs-20260630.xsd#gwrs_PublicUtilitiesRequestedDeferralOfRecoveryOfAcquisitionPremiumAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_gwrs_PublicUtilitiesRequestedDeferralOfRecoveryOfAcquisitionPremiumAmount_019e6aa8-67bb-759b-8e8f-992317843f33" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfConstructionWorkInProcessIncludedInRateBase_019e6aa8-67bb-7c3c-b48c-84dce99b3314" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfConstructionWorkInProcessIncludedInRateBase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfConstructionWorkInProcessIncludedInRateBase_019e6aa8-67bb-7c3c-b48c-84dce99b3314" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_RevenueCredits_019e6aa8-67bb-7a54-93c2-0cd904776f0b" xlink:href="gwrs-20260630.xsd#gwrs_RevenueCredits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesGeneralDisclosuresLineItems_019e6aa8-67bb-76d8-a210-90b5a634ed0a" xlink:to="loc_gwrs_RevenueCredits_019e6aa8-67bb-7a54-93c2-0cd904776f0b" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/RevenueRecognitionDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#RevenueRecognitionDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/RevenueRecognitionDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019e6aa8-67bb-7bee-b595-cb28e68141d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019e6aa8-67bb-7e1a-8093-0368d3ceea53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e6aa8-67bb-7bee-b595-cb28e68141d2" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019e6aa8-67bb-7e1a-8093-0368d3ceea53" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilityRegulatedOrUnregulatedStatusAxis_019e6aa8-67bb-7e38-aabc-079d2ae08fed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilityRegulatedOrUnregulatedStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e6aa8-67bb-7e1a-8093-0368d3ceea53" xlink:to="loc_us-gaap_PublicUtilityRegulatedOrUnregulatedStatusAxis_019e6aa8-67bb-7e38-aabc-079d2ae08fed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatedAndUnregulatedOperationDomain_019e6aa8-67bb-7e38-aabc-079d2ae08fed_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatedAndUnregulatedOperationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilityRegulatedOrUnregulatedStatusAxis_019e6aa8-67bb-7e38-aabc-079d2ae08fed" xlink:to="loc_us-gaap_RegulatedAndUnregulatedOperationDomain_019e6aa8-67bb-7e38-aabc-079d2ae08fed_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatedAndUnregulatedOperationDomain_019e6aa8-67bb-7841-b5b8-6791659fc7ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatedAndUnregulatedOperationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilityRegulatedOrUnregulatedStatusAxis_019e6aa8-67bb-7e38-aabc-079d2ae08fed" xlink:to="loc_us-gaap_RegulatedAndUnregulatedOperationDomain_019e6aa8-67bb-7841-b5b8-6791659fc7ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatedOperationMember_019e6aa8-67bb-7c40-8bc0-863192aaf958" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatedOperationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatedAndUnregulatedOperationDomain_019e6aa8-67bb-7841-b5b8-6791659fc7ec" xlink:to="loc_us-gaap_RegulatedOperationMember_019e6aa8-67bb-7c40-8bc0-863192aaf958" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnregulatedOperationMember_019fa84f-0e0e-76cd-9bf6-8f252a9443a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnregulatedOperationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatedAndUnregulatedOperationDomain_019e6aa8-67bb-7841-b5b8-6791659fc7ec" xlink:to="loc_us-gaap_UnregulatedOperationMember_019fa84f-0e0e-76cd-9bf6-8f252a9443a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019e6aa8-67bb-7bdb-9d9f-3424a2bb3d0d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e6aa8-67bb-7e1a-8093-0368d3ceea53" xlink:to="loc_srt_ProductOrServiceAxis_019e6aa8-67bb-7bdb-9d9f-3424a2bb3d0d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-7bdb-9d9f-3424a2bb3d0d_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019e6aa8-67bb-7bdb-9d9f-3424a2bb3d0d" xlink:to="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-7bdb-9d9f-3424a2bb3d0d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-7949-a6c6-fe9bfb739922" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019e6aa8-67bb-7bdb-9d9f-3424a2bb3d0d" xlink:to="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-7949-a6c6-fe9bfb739922" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_WaterServicesMember_019e6aa8-67bb-70b8-bbdd-c0d455e43016" xlink:href="gwrs-20260630.xsd#gwrs_WaterServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-7949-a6c6-fe9bfb739922" xlink:to="loc_gwrs_WaterServicesMember_019e6aa8-67bb-70b8-bbdd-c0d455e43016" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_WasteWaterAndRecycledWaterMember_019e6aa8-67bb-7bd6-a6c7-ec90fceeec3e" xlink:href="gwrs-20260630.xsd#gwrs_WasteWaterAndRecycledWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-7949-a6c6-fe9bfb739922" xlink:to="loc_gwrs_WasteWaterAndRecycledWaterMember_019e6aa8-67bb-7bd6-a6c7-ec90fceeec3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019e6aa8-67bb-7fea-88e4-093fcdea9923" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e6aa8-67bb-7e1a-8093-0368d3ceea53" xlink:to="loc_srt_MajorCustomersAxis_019e6aa8-67bb-7fea-88e4-093fcdea9923" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7fea-88e4-093fcdea9923_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_019e6aa8-67bb-7fea-88e4-093fcdea9923" xlink:to="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7fea-88e4-093fcdea9923_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_019e6aa8-67bb-7fea-88e4-093fcdea9923" xlink:to="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ResidentialMember_019e6aa8-67bb-79bf-abf5-f4c86fe70fcc" xlink:href="gwrs-20260630.xsd#gwrs_ResidentialMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:to="loc_gwrs_ResidentialMember_019e6aa8-67bb-79bf-abf5-f4c86fe70fcc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_IrrigationMember_019e6aa8-67bb-7c4d-bc2e-027478ce4f20" xlink:href="gwrs-20260630.xsd#gwrs_IrrigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:to="loc_gwrs_IrrigationMember_019e6aa8-67bb-7c4d-bc2e-027478ce4f20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_CommercialMember_019e6aa8-67bb-7614-9f37-02f47d223e62" xlink:href="gwrs-20260630.xsd#gwrs_CommercialMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:to="loc_gwrs_CommercialMember_019e6aa8-67bb-7614-9f37-02f47d223e62" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_MultiFamilyCustomerMember_019e6aa8-67bb-7224-acf4-3d7103d92afc" xlink:href="gwrs-20260630.xsd#gwrs_MultiFamilyCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:to="loc_gwrs_MultiFamilyCustomerMember_019e6aa8-67bb-7224-acf4-3d7103d92afc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ConstructionWaterServicesMember_019e6aa8-67bb-78de-92d9-4f97f006aa74" xlink:href="gwrs-20260630.xsd#gwrs_ConstructionWaterServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:to="loc_gwrs_ConstructionWaterServicesMember_019e6aa8-67bb-78de-92d9-4f97f006aa74" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_OtherWaterRevenuesMember_019e6aa8-67bb-7e54-8010-243143ffe8a4" xlink:href="gwrs-20260630.xsd#gwrs_OtherWaterRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:to="loc_gwrs_OtherWaterRevenuesMember_019e6aa8-67bb-7e54-8010-243143ffe8a4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_RecycledWaterRevenuesMember_019e6aa8-67bb-75b5-bb85-42d367008f45" xlink:href="gwrs-20260630.xsd#gwrs_RecycledWaterRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:to="loc_gwrs_RecycledWaterRevenuesMember_019e6aa8-67bb-75b5-bb85-42d367008f45" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_OtherWastewaterRevenuesMember_019e6aa8-67bb-759e-94b3-e9d53043c235" xlink:href="gwrs-20260630.xsd#gwrs_OtherWastewaterRevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019e6aa8-67bb-7863-915f-eb683d2dc6a4" xlink:to="loc_gwrs_OtherWastewaterRevenuesMember_019e6aa8-67bb-759e-94b3-e9d53043c235" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e6aa8-67bb-7b18-827b-2cbd4a3c455b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e6aa8-67bb-7bee-b595-cb28e68141d2" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e6aa8-67bb-7b18-827b-2cbd4a3c455b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/RevenueRecognitionDeferredRevenueICFADetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#RevenueRecognitionDeferredRevenueICFADetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/RevenueRecognitionDeferredRevenueICFADetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019e6aa8-67bb-7433-97ad-af77ba318e1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019e6aa8-67bb-7038-8959-f8b184b94369" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e6aa8-67bb-7433-97ad-af77ba318e1f" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019e6aa8-67bb-7038-8959-f8b184b94369" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019e6aa8-67bb-76c6-9de0-c8ea7867b089" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e6aa8-67bb-7038-8959-f8b184b94369" xlink:to="loc_srt_ProductOrServiceAxis_019e6aa8-67bb-76c6-9de0-c8ea7867b089" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-76c6-9de0-c8ea7867b089_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019e6aa8-67bb-76c6-9de0-c8ea7867b089" xlink:to="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-76c6-9de0-c8ea7867b089_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-73c3-935d-d0d070fe4b3e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019e6aa8-67bb-76c6-9de0-c8ea7867b089" xlink:to="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-73c3-935d-d0d070fe4b3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_InfrastructureCoordinationAndFinancingAgreementsMember_019e6aa8-67bb-7c82-931f-448429a57a3b" xlink:href="gwrs-20260630.xsd#gwrs_InfrastructureCoordinationAndFinancingAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e6aa8-67bb-73c3-935d-d0d070fe4b3e" xlink:to="loc_gwrs_InfrastructureCoordinationAndFinancingAgreementsMember_019e6aa8-67bb-7c82-931f-448429a57a3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_DeferredRevenueRollForwardRollForward_019e6aa8-67bb-7bec-a743-baf11472719e" xlink:href="gwrs-20260630.xsd#gwrs_DeferredRevenueRollForwardRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e6aa8-67bb-7433-97ad-af77ba318e1f" xlink:to="loc_gwrs_DeferredRevenueRollForwardRollForward_019e6aa8-67bb-7bec-a743-baf11472719e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019e6aa8-67bb-7300-bebf-bee34e26c778" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gwrs_DeferredRevenueRollForwardRollForward_019e6aa8-67bb-7bec-a743-baf11472719e" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019e6aa8-67bb-7300-bebf-bee34e26c778" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ContractWithCustomerLiabilityAdditions_019e6aa8-67bb-7790-bd46-a85c391f5963" xlink:href="gwrs-20260630.xsd#gwrs_ContractWithCustomerLiabilityAdditions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gwrs_DeferredRevenueRollForwardRollForward_019e6aa8-67bb-7bec-a743-baf11472719e" xlink:to="loc_gwrs_ContractWithCustomerLiabilityAdditions_019e6aa8-67bb-7790-bd46-a85c391f5963" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ContractWithCustomerLiabilityReclassificationFromHUF_019fa868-d5fe-7e8a-80d1-6ff14bb58e63" xlink:href="gwrs-20260630.xsd#gwrs_ContractWithCustomerLiabilityReclassificationFromHUF"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gwrs_DeferredRevenueRollForwardRollForward_019e6aa8-67bb-7bec-a743-baf11472719e" xlink:to="loc_gwrs_ContractWithCustomerLiabilityReclassificationFromHUF_019fa868-d5fe-7e8a-80d1-6ff14bb58e63" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019fa866-d872-7fd1-abf7-f9a0a2faa61d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gwrs_DeferredRevenueRollForwardRollForward_019e6aa8-67bb-7bec-a743-baf11472719e" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019fa866-d872-7fd1-abf7-f9a0a2faa61d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_019e6aa8-67bb-79d6-9abc-73048d6af7e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/EarningsPerShareDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#EarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/EarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicLineItems_019e6aa8-67bb-783e-8171-c07ea8c05642" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasicLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019e6aa8-67bb-7f1d-8261-c39bf8fba4f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019e6aa8-67bb-783e-8171-c07ea8c05642" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019e6aa8-67bb-7f1d-8261-c39bf8fba4f9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e6aa8-67bb-7806-a23f-6bc7d92b5825" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019e6aa8-67bb-7f1d-8261-c39bf8fba4f9" xlink:to="loc_us-gaap_AwardTypeAxis_019e6aa8-67bb-7806-a23f-6bc7d92b5825" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-67bb-7806-a23f-6bc7d92b5825_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e6aa8-67bb-7806-a23f-6bc7d92b5825" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-67bb-7806-a23f-6bc7d92b5825_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-67bb-7138-95b2-4c6fd0eb73ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e6aa8-67bb-7806-a23f-6bc7d92b5825" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-67bb-7138-95b2-4c6fd0eb73ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019e6aa8-67bb-7570-960a-d2f35ba0f4bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-67bb-7138-95b2-4c6fd0eb73ae" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019e6aa8-67bb-7570-960a-d2f35ba0f4bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019e6aa8-67bb-7e2d-94a0-4d83b8843ea9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-67bb-7138-95b2-4c6fd0eb73ae" xlink:to="loc_us-gaap_RestrictedStockMember_019e6aa8-67bb-7e2d-94a0-4d83b8843ea9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e6aa8-67bb-7dd4-b0f3-f58d64ca4d74" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019e6aa8-67bb-783e-8171-c07ea8c05642" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e6aa8-67bb-7dd4-b0f3-f58d64ca4d74" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019e6aa8-67bb-7a7d-b5c3-546cc7913fe3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019e6aa8-67bb-783e-8171-c07ea8c05642" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019e6aa8-67bb-7a7d-b5c3-546cc7913fe3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019e6aa8-67bb-72d4-a3d9-4ec1036dfa57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019e6aa8-67bb-783e-8171-c07ea8c05642" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019e6aa8-67bb-72d4-a3d9-4ec1036dfa57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019e6aa8-67bb-71ea-be32-717c8ead8d1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019e6aa8-67bb-783e-8171-c07ea8c05642" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019e6aa8-67bb-71ea-be32-717c8ead8d1a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/EquityDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#EquityDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/EquityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019e6aa8-67bb-78a5-9ad0-c7b09988578e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019e6aa8-67bb-7c82-a702-00c8db23051f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e6aa8-67bb-78a5-9ad0-c7b09988578e" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019e6aa8-67bb-7c82-a702-00c8db23051f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_019e6aa8-67bb-7617-a79b-aee157042b00" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019e6aa8-67bb-7c82-a702-00c8db23051f" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_019e6aa8-67bb-7617-a79b-aee157042b00" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-67bb-7617-a79b-aee157042b00_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_019e6aa8-67bb-7617-a79b-aee157042b00" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-67bb-7617-a79b-aee157042b00_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-67bb-7954-91f1-3b6cff35e2e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_019e6aa8-67bb-7617-a79b-aee157042b00" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-67bb-7954-91f1-3b6cff35e2e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PublicOfferingMember_019e6aa8-67bb-7eef-b3f6-e31edbcf38e0" xlink:href="gwrs-20260630.xsd#gwrs_PublicOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-67bb-7954-91f1-3b6cff35e2e4" xlink:to="loc_gwrs_PublicOfferingMember_019e6aa8-67bb-7eef-b3f6-e31edbcf38e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OverAllotmentOptionMember_019e6aa8-67bb-7eb7-ac5f-882b2359dc06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-67bb-7954-91f1-3b6cff35e2e4" xlink:to="loc_us-gaap_OverAllotmentOptionMember_019e6aa8-67bb-7eb7-ac5f-882b2359dc06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PrivatePlacementOfferingMember_019fee43-5072-75b8-9862-f12b64fc6e8b" xlink:href="gwrs-20260630.xsd#gwrs_PrivatePlacementOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-67bb-7954-91f1-3b6cff35e2e4" xlink:to="loc_gwrs_PrivatePlacementOfferingMember_019fee43-5072-75b8-9862-f12b64fc6e8b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e6aa8-67bb-74b7-ba06-2538ad934027" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019e6aa8-67bb-7c82-a702-00c8db23051f" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e6aa8-67bb-74b7-ba06-2538ad934027" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019e6aa8-67bb-74b7-ba06-2538ad934027_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e6aa8-67bb-74b7-ba06-2538ad934027" xlink:to="loc_us-gaap_RelatedPartyDomain_019e6aa8-67bb-74b7-ba06-2538ad934027_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019e6aa8-67bb-75d2-a893-c18d7e052603" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e6aa8-67bb-74b7-ba06-2538ad934027" xlink:to="loc_us-gaap_RelatedPartyDomain_019e6aa8-67bb-75d2-a893-c18d7e052603" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AffiliatedEntityMember_019e6aa8-67bb-713b-8205-17455de9ac70" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AffiliatedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019e6aa8-67bb-75d2-a893-c18d7e052603" xlink:to="loc_srt_AffiliatedEntityMember_019e6aa8-67bb-713b-8205-17455de9ac70" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019e6aa8-67bb-74a5-b625-152a1a7ed6aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e6aa8-67bb-78a5-9ad0-c7b09988578e" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019e6aa8-67bb-74a5-b625-152a1a7ed6aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_019e6aa8-67bb-7a96-a57b-a4a2938ba21a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e6aa8-67bb-78a5-9ad0-c7b09988578e" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_019e6aa8-67bb-7a96-a57b-a4a2938ba21a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_019e6aa8-67bb-7547-8a6f-5eecdb0f3fd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e6aa8-67bb-78a5-9ad0-c7b09988578e" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_019e6aa8-67bb-7547-8a6f-5eecdb0f3fd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_019e6aa8-67bb-7e19-a5a4-b7b1aca07e9c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e6aa8-67bb-78a5-9ad0-c7b09988578e" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_019e6aa8-67bb-7e19-a5a4-b7b1aca07e9c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_SaleOfStockNumberOfSharesToBeIssuedInTransaction_019fee43-599c-73a3-ad09-39446ed6f535" xlink:href="gwrs-20260630.xsd#gwrs_SaleOfStockNumberOfSharesToBeIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e6aa8-67bb-78a5-9ad0-c7b09988578e" xlink:to="loc_gwrs_SaleOfStockNumberOfSharesToBeIssuedInTransaction_019fee43-599c-73a3-ad09-39446ed6f535" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/DebtDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#DebtDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/DebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019e6aa8-67bb-7126-9ef2-dc303f4f1468" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019e6aa8-67bb-7cf4-80b6-8eaaa2d33138" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e6aa8-67bb-7126-9ef2-dc303f4f1468" xlink:to="loc_us-gaap_DebtInstrumentTable_019e6aa8-67bb-7cf4-80b6-8eaaa2d33138" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019e6aa8-67bb-7ec8-9f97-cc1609665e4c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019e6aa8-67bb-7cf4-80b6-8eaaa2d33138" xlink:to="loc_us-gaap_CreditFacilityAxis_019e6aa8-67bb-7ec8-9f97-cc1609665e4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019e6aa8-67bb-7ec8-9f97-cc1609665e4c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019e6aa8-67bb-7ec8-9f97-cc1609665e4c" xlink:to="loc_us-gaap_CreditFacilityDomain_019e6aa8-67bb-7ec8-9f97-cc1609665e4c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019e6aa8-67bb-7ee8-b8ac-8d06a5335143" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019e6aa8-67bb-7ec8-9f97-cc1609665e4c" xlink:to="loc_us-gaap_CreditFacilityDomain_019e6aa8-67bb-7ee8-b8ac-8d06a5335143" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019e6aa8-67bb-7007-907d-df3dcb74ab58" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019e6aa8-67bb-7ee8-b8ac-8d06a5335143" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019e6aa8-67bb-7007-907d-df3dcb74ab58" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019e6aa8-67bb-7e44-a224-c3411595ea91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019e6aa8-67bb-7cf4-80b6-8eaaa2d33138" xlink:to="loc_us-gaap_DebtInstrumentAxis_019e6aa8-67bb-7e44-a224-c3411595ea91" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019e6aa8-67bb-7e44-a224-c3411595ea91_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019e6aa8-67bb-7e44-a224-c3411595ea91" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019e6aa8-67bb-7e44-a224-c3411595ea91_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019e6aa8-67bb-77e1-b62a-4b91b6554272" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019e6aa8-67bb-7e44-a224-c3411595ea91" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019e6aa8-67bb-77e1-b62a-4b91b6554272" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_NorthernTrustLoanAgreementMember_019e6aa8-67bb-73ef-95cb-de7a8e6b015a" xlink:href="gwrs-20260630.xsd#gwrs_NorthernTrustLoanAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019e6aa8-67bb-77e1-b62a-4b91b6554272" xlink:to="loc_gwrs_NorthernTrustLoanAgreementMember_019e6aa8-67bb-73ef-95cb-de7a8e6b015a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019e6aa8-67bb-78e2-8b7a-71d729da1483" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e6aa8-67bb-7126-9ef2-dc303f4f1468" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019e6aa8-67bb-78e2-8b7a-71d729da1483" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_019e6aa8-67bb-77ad-abf3-45c83acd89bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e6aa8-67bb-7126-9ef2-dc303f4f1468" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_019e6aa8-67bb-77ad-abf3-45c83acd89bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019e6aa8-67bb-7d66-90fb-06acc94a989f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e6aa8-67bb-7126-9ef2-dc303f4f1468" xlink:to="loc_us-gaap_LineOfCredit_019e6aa8-67bb-7d66-90fb-06acc94a989f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/FairValueFairValueofFinancialInstrumentsDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#FairValueFairValueofFinancialInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/FairValueFairValueofFinancialInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e6aa8-687c-7c5f-8561-70aa4419eea7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e6aa8-687c-7c03-8a4d-ab885fe90cb2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e6aa8-687c-7c5f-8561-70aa4419eea7" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e6aa8-687c-7c03-8a4d-ab885fe90cb2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6aa8-687c-7a32-ab84-2cf37be95d8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e6aa8-687c-7c03-8a4d-ab885fe90cb2" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6aa8-687c-7a32-ab84-2cf37be95d8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-7a32-ab84-2cf37be95d8b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6aa8-687c-7a32-ab84-2cf37be95d8b" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-7a32-ab84-2cf37be95d8b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-74f8-800e-43d16b8c41a5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6aa8-687c-7a32-ab84-2cf37be95d8b" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-74f8-800e-43d16b8c41a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019e6aa8-687c-7821-84b9-79ff22e0a029" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-74f8-800e-43d16b8c41a5" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019e6aa8-687c-7821-84b9-79ff22e0a029" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019e6aa8-687c-7665-8394-4d1b61f6ceec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-74f8-800e-43d16b8c41a5" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019e6aa8-687c-7665-8394-4d1b61f6ceec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019e6aa8-687c-7820-a750-92309c420ac7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-74f8-800e-43d16b8c41a5" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019e6aa8-687c-7820-a750-92309c420ac7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019e6aa8-687c-703c-b989-0807eff8dd6a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e6aa8-687c-7c5f-8561-70aa4419eea7" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019e6aa8-687c-703c-b989-0807eff8dd6a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019e6aa8-687c-7f93-831d-88cc7e094797" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019e6aa8-687c-703c-b989-0807eff8dd6a" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019e6aa8-687c-7f93-831d-88cc7e094797" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_019e6aa8-687c-7ea1-975c-f3e1adc0ad24" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_019e6aa8-687c-703c-b989-0807eff8dd6a" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_019e6aa8-687c-7ea1-975c-f3e1adc0ad24" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/FairValueCarryingAmountandEstimatedFairValuesDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#FairValueCarryingAmountandEstimatedFairValuesDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/FairValueCarryingAmountandEstimatedFairValuesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e6aa8-687c-7346-ab46-70d7eb1b61fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e6aa8-687c-7832-bb87-927d3302c276" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e6aa8-687c-7346-ab46-70d7eb1b61fe" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e6aa8-687c-7832-bb87-927d3302c276" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6aa8-687c-73a5-b522-e51b84c59da4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e6aa8-687c-7832-bb87-927d3302c276" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6aa8-687c-73a5-b522-e51b84c59da4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-73a5-b522-e51b84c59da4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6aa8-687c-73a5-b522-e51b84c59da4" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-73a5-b522-e51b84c59da4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-7867-ab6d-379e5b070bcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e6aa8-687c-73a5-b522-e51b84c59da4" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-7867-ab6d-379e5b070bcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019e6aa8-687c-7b6b-9371-f190613d366d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e6aa8-687c-7867-ab6d-379e5b070bcc" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019e6aa8-687c-7b6b-9371-f190613d366d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_019e6aa8-687c-7172-970b-e9d96dcf0655" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e6aa8-687c-7832-bb87-927d3302c276" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_019e6aa8-687c-7172-970b-e9d96dcf0655" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e6aa8-687c-7172-970b-e9d96dcf0655_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019e6aa8-687c-7172-970b-e9d96dcf0655" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e6aa8-687c-7172-970b-e9d96dcf0655_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019e6aa8-687c-78cb-8316-f08cda993dd0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019e6aa8-687c-7172-970b-e9d96dcf0655" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019e6aa8-687c-78cb-8316-f08cda993dd0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e6aa8-687c-77b3-9906-ac411fbdf9d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019e6aa8-687c-78cb-8316-f08cda993dd0" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e6aa8-687c-77b3-9906-ac411fbdf9d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_019e6aa8-687c-7626-8ddc-db6e1cce4008" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e6aa8-687c-77b3-9906-ac411fbdf9d7" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_019e6aa8-687c-7626-8ddc-db6e1cce4008" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019e6aa8-687c-7909-8f5e-67650d3fa24f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e6aa8-687c-77b3-9906-ac411fbdf9d7" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019e6aa8-687c-7909-8f5e-67650d3fa24f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019e6aa8-687c-73ea-a782-91ecce73db10" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e6aa8-687c-7346-ab46-70d7eb1b61fe" xlink:to="loc_us-gaap_LongTermDebtFairValue_019e6aa8-687c-73ea-a782-91ecce73db10" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/SharebasedCompensationShareBasedCompensationEmployeesandNonemployeesDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#SharebasedCompensationShareBasedCompensationEmployeesandNonemployeesDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/SharebasedCompensationShareBasedCompensationEmployeesandNonemployeesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e6aa8-687c-7745-93a4-e79dc07b5096" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e6aa8-687c-7f7c-ba28-29245f7fff89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e6aa8-687c-7745-93a4-e79dc07b5096" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e6aa8-687c-7f7c-ba28-29245f7fff89" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e6aa8-687c-7538-a112-d1211c0cd3b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e6aa8-687c-7f7c-ba28-29245f7fff89" xlink:to="loc_us-gaap_AwardTypeAxis_019e6aa8-687c-7538-a112-d1211c0cd3b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-687c-7538-a112-d1211c0cd3b3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e6aa8-687c-7538-a112-d1211c0cd3b3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-687c-7538-a112-d1211c0cd3b3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-687c-703d-9cf1-237e1d5dad8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e6aa8-687c-7538-a112-d1211c0cd3b3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-687c-703d-9cf1-237e1d5dad8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019e6aa8-687c-7380-a4bc-739c8e68e1e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-687c-703d-9cf1-237e1d5dad8b" xlink:to="loc_us-gaap_RestrictedStockMember_019e6aa8-687c-7380-a4bc-739c8e68e1e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019e6aa8-687c-746f-b185-80ccc9aabf86" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e6aa8-687c-703d-9cf1-237e1d5dad8b" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019e6aa8-687c-746f-b185-80ccc9aabf86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusAxis_019e6aa8-687c-71ba-984e-3b5dbf0fa56d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GranteeStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e6aa8-687c-7f7c-ba28-29245f7fff89" xlink:to="loc_us-gaap_GranteeStatusAxis_019e6aa8-687c-71ba-984e-3b5dbf0fa56d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_019e6aa8-687c-71ba-984e-3b5dbf0fa56d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GranteeStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GranteeStatusAxis_019e6aa8-687c-71ba-984e-3b5dbf0fa56d" xlink:to="loc_us-gaap_GranteeStatusDomain_019e6aa8-687c-71ba-984e-3b5dbf0fa56d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_019e6aa8-687c-7c9c-8c21-d40a7c3d1704" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GranteeStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GranteeStatusAxis_019e6aa8-687c-71ba-984e-3b5dbf0fa56d" xlink:to="loc_us-gaap_GranteeStatusDomain_019e6aa8-687c-7c9c-8c21-d40a7c3d1704" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedPaymentArrangementEmployeeMember_019e6aa8-687c-793a-9580-f203cc0267dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedPaymentArrangementEmployeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_019e6aa8-687c-7c9c-8c21-d40a7c3d1704" xlink:to="loc_us-gaap_ShareBasedPaymentArrangementEmployeeMember_019e6aa8-687c-793a-9580-f203cc0267dd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedPaymentArrangementNonemployeeMember_019e6aa8-687c-7dfb-8c4b-18b707834a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedPaymentArrangementNonemployeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_019e6aa8-687c-7c9c-8c21-d40a7c3d1704" xlink:to="loc_us-gaap_ShareBasedPaymentArrangementNonemployeeMember_019e6aa8-687c-7dfb-8c4b-18b707834a4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e6aa8-687c-7c73-8b56-408920cedeb9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e6aa8-687c-7745-93a4-e79dc07b5096" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e6aa8-687c-7c73-8b56-408920cedeb9" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/TransactionsWithRelatedPartiesDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#TransactionsWithRelatedPartiesDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/TransactionsWithRelatedPartiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019e6aa8-687c-7563-97ea-f6adefec2df2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019e6aa8-687c-72c5-bedd-ce82d8e8b7e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019e6aa8-687c-7563-97ea-f6adefec2df2" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019e6aa8-687c-72c5-bedd-ce82d8e8b7e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e6aa8-687c-7e1e-b34e-fcda0010178a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019e6aa8-687c-72c5-bedd-ce82d8e8b7e7" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e6aa8-687c-7e1e-b34e-fcda0010178a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019e6aa8-687c-7e1e-b34e-fcda0010178a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e6aa8-687c-7e1e-b34e-fcda0010178a" xlink:to="loc_us-gaap_RelatedPartyDomain_019e6aa8-687c-7e1e-b34e-fcda0010178a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019e6aa8-687c-7c1c-9666-2903017c09b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019e6aa8-687c-7e1e-b34e-fcda0010178a" xlink:to="loc_us-gaap_RelatedPartyDomain_019e6aa8-687c-7c1c-9666-2903017c09b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AffiliatedEntityMember_019e6aa8-687c-7e4c-a77a-a579dd777a93" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AffiliatedEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019e6aa8-687c-7c1c-9666-2903017c09b8" xlink:to="loc_srt_AffiliatedEntityMember_019e6aa8-687c-7e4c-a77a-a579dd777a93" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_019e6aa8-687c-70fe-9788-cf2fab980701" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019e6aa8-687c-72c5-bedd-ce82d8e8b7e7" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_019e6aa8-687c-70fe-9788-cf2fab980701" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019e6aa8-687c-70fe-9788-cf2fab980701_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019e6aa8-687c-70fe-9788-cf2fab980701" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019e6aa8-687c-70fe-9788-cf2fab980701_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_019e6aa8-687c-7eb4-8b04-9d7224707aaa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_019e6aa8-687c-70fe-9788-cf2fab980701" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_019e6aa8-687c-7eb4-8b04-9d7224707aaa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_MedicalBenefitsPoolPlanMember_019e6aa8-687c-7593-947e-a5e05fb2fb65" xlink:href="gwrs-20260630.xsd#gwrs_MedicalBenefitsPoolPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_019e6aa8-687c-7eb4-8b04-9d7224707aaa" xlink:to="loc_gwrs_MedicalBenefitsPoolPlanMember_019e6aa8-687c-7593-947e-a5e05fb2fb65" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_019e6aa8-687c-7d03-83cd-646e317236d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019e6aa8-687c-72c5-bedd-ce82d8e8b7e7" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_019e6aa8-687c-7d03-83cd-646e317236d0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-687c-7d03-83cd-646e317236d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_019e6aa8-687c-7d03-83cd-646e317236d0" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-687c-7d03-83cd-646e317236d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-687c-707f-9807-1ae484c811ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_019e6aa8-687c-7d03-83cd-646e317236d0" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-687c-707f-9807-1ae484c811ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PublicOfferingMember_019e6aa8-687c-79ce-9b39-604af093039a" xlink:href="gwrs-20260630.xsd#gwrs_PublicOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_019e6aa8-687c-707f-9807-1ae484c811ec" xlink:to="loc_gwrs_PublicOfferingMember_019e6aa8-687c-79ce-9b39-604af093039a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_019e6aa8-687c-7170-803c-39b1628cd21d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019e6aa8-687c-7563-97ea-f6adefec2df2" xlink:to="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_019e6aa8-687c-7170-803c-39b1628cd21d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019e6aa8-687c-789a-bcb6-30ef945a0fe4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019e6aa8-687c-7563-97ea-f6adefec2df2" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019e6aa8-687c-789a-bcb6-30ef945a0fe4" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/CommitmentsandContingenciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_019e6aa8-687c-7b7b-b4fd-5c0c33660593" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_us-gaap_LossContingenciesTable_019e6aa8-687c-7b7b-b4fd-5c0c33660593" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-687c-73ae-bad8-1976ace3171f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e6aa8-687c-7b7b-b4fd-5c0c33660593" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-687c-73ae-bad8-1976ace3171f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-73ae-bad8-1976ace3171f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-687c-73ae-bad8-1976ace3171f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-73ae-bad8-1976ace3171f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-7253-a2c6-497112e5a8af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-687c-73ae-bad8-1976ace3171f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-7253-a2c6-497112e5a8af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_FarmersWaterCompanyMember_019e6aa8-687c-7f13-860b-817811d6e58d" xlink:href="gwrs-20260630.xsd#gwrs_FarmersWaterCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-7253-a2c6-497112e5a8af" xlink:to="loc_gwrs_FarmersWaterCompanyMember_019e6aa8-687c-7f13-860b-817811d6e58d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_RedRockUtilitiesMember_019e6aa8-687c-75b2-b946-5260b29d78c7" xlink:href="gwrs-20260630.xsd#gwrs_RedRockUtilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-7253-a2c6-497112e5a8af" xlink:to="loc_gwrs_RedRockUtilitiesMember_019e6aa8-687c-75b2-b946-5260b29d78c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_UtilityAxis_019e6aa8-687c-7941-9877-71b61bac229c" xlink:href="gwrs-20260630.xsd#gwrs_UtilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e6aa8-687c-7b7b-b4fd-5c0c33660593" xlink:to="loc_gwrs_UtilityAxis_019e6aa8-687c-7941-9877-71b61bac229c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_UtilityDomain_019e6aa8-687c-7941-9877-71b61bac229c_default" xlink:href="gwrs-20260630.xsd#gwrs_UtilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_gwrs_UtilityAxis_019e6aa8-687c-7941-9877-71b61bac229c" xlink:to="loc_gwrs_UtilityDomain_019e6aa8-687c-7941-9877-71b61bac229c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_UtilityDomain_019e6aa8-687c-722b-923d-6bed45818259" xlink:href="gwrs-20260630.xsd#gwrs_UtilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_gwrs_UtilityAxis_019e6aa8-687c-7941-9877-71b61bac229c" xlink:to="loc_gwrs_UtilityDomain_019e6aa8-687c-722b-923d-6bed45818259" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_RedRockUtilitiesMember_019e6aa8-687c-78b0-8d3c-e4ff363d077e" xlink:href="gwrs-20260630.xsd#gwrs_RedRockUtilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_gwrs_UtilityDomain_019e6aa8-687c-722b-923d-6bed45818259" xlink:to="loc_gwrs_RedRockUtilitiesMember_019e6aa8-687c-78b0-8d3c-e4ff363d077e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GrowthPremiumPayableForEachNewMeterInstalled_019e6aa8-687c-753e-96a6-58e8ba67f7fc" xlink:href="gwrs-20260630.xsd#gwrs_GrowthPremiumPayableForEachNewMeterInstalled"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_GrowthPremiumPayableForEachNewMeterInstalled_019e6aa8-687c-753e-96a6-58e8ba67f7fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_MaximumPayoutOfGrowthPremiumReceivable_019e6aa8-687c-7dcc-b66e-625960edcb84" xlink:href="gwrs-20260630.xsd#gwrs_MaximumPayoutOfGrowthPremiumReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_MaximumPayoutOfGrowthPremiumReceivable_019e6aa8-687c-7dcc-b66e-625960edcb84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GrowthPremiumObligationPeriodAfterEstablishmentOfNewAccount_019e6aa8-687c-70d5-83f9-285453c213ad" xlink:href="gwrs-20260630.xsd#gwrs_GrowthPremiumObligationPeriodAfterEstablishmentOfNewAccount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_GrowthPremiumObligationPeriodAfterEstablishmentOfNewAccount_019e6aa8-687c-70d5-83f9-285453c213ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GrowthPremiumObligationPeriodAfterClosingDate_019e6aa8-687c-7e4c-a59c-953e9050c3bc" xlink:href="gwrs-20260630.xsd#gwrs_GrowthPremiumObligationPeriodAfterClosingDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_GrowthPremiumObligationPeriodAfterClosingDate_019e6aa8-687c-7e4c-a59c-953e9050c3bc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_BusinessCombinationGrowthPremiumLiability_019fee1d-c038-7fbb-b448-f95d16ad62a5" xlink:href="gwrs-20260630.xsd#gwrs_BusinessCombinationGrowthPremiumLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_BusinessCombinationGrowthPremiumLiability_019fee1d-c038-7fbb-b448-f95d16ad62a5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GrowthPremiumObligationPeriodFromAcquisitionDate_019e6aa8-687c-7f22-9713-0527bae256e8" xlink:href="gwrs-20260630.xsd#gwrs_GrowthPremiumObligationPeriodFromAcquisitionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_GrowthPremiumObligationPeriodFromAcquisitionDate_019e6aa8-687c-7f22-9713-0527bae256e8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_NumberOfMetersInstalled_019e6aa8-687c-7ea7-8e18-123bdb75a917" xlink:href="gwrs-20260630.xsd#gwrs_NumberOfMetersInstalled"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_NumberOfMetersInstalled_019e6aa8-687c-7ea7-8e18-123bdb75a917" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_NumberOfAccountsEstablished_019e6aa8-687c-7389-b9a6-e6fab8aa48fd" xlink:href="gwrs-20260630.xsd#gwrs_NumberOfAccountsEstablished"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_NumberOfAccountsEstablished_019e6aa8-687c-7389-b9a6-e6fab8aa48fd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ICFAFeeLiability_019fee23-1aea-7d98-92e4-4c5706f2b80e" xlink:href="gwrs-20260630.xsd#gwrs_ICFAFeeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e6aa8-687c-729c-a5aa-ad7ff486982d" xlink:to="loc_gwrs_ICFAFeeLiability_019fee23-1aea-7d98-92e4-4c5706f2b80e" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/BusinessSegmentInformationSignificantExpenseDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#BusinessSegmentInformationSignificantExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/BusinessSegmentInformationSignificantExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019e6aa8-687c-73ba-8c97-639fb911d5b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e6aa8-687c-7ef6-bb3d-261e06c9f547" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e6aa8-687c-73ba-8c97-639fb911d5b4" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e6aa8-687c-7ef6-bb3d-261e06c9f547" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019e6aa8-687c-7c6a-a35d-2f01dc14e1f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e6aa8-687c-7ef6-bb3d-261e06c9f547" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019e6aa8-687c-7c6a-a35d-2f01dc14e1f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e6aa8-687c-7c6a-a35d-2f01dc14e1f9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e6aa8-687c-7c6a-a35d-2f01dc14e1f9" xlink:to="loc_us-gaap_SegmentDomain_019e6aa8-687c-7c6a-a35d-2f01dc14e1f9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e6aa8-687c-7d7f-8c8a-2cd1e14004f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e6aa8-687c-7c6a-a35d-2f01dc14e1f9" xlink:to="loc_us-gaap_SegmentDomain_019e6aa8-687c-7d7f-8c8a-2cd1e14004f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ReportableSegmentMember_019e6aa8-687c-77c8-aa63-b5073bb822b9" xlink:href="gwrs-20260630.xsd#gwrs_ReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019e6aa8-687c-7d7f-8c8a-2cd1e14004f1" xlink:to="loc_gwrs_ReportableSegmentMember_019e6aa8-687c-77c8-aa63-b5073bb822b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e6aa8-687c-74ba-95e5-4670cc0ba06e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e6aa8-687c-73ba-8c97-639fb911d5b4" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e6aa8-687c-74ba-95e5-4670cc0ba06e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e6aa8-687c-73ba-8c97-639fb911d5b4" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_UtilitiesOperatingExpensePersonnelCosts_019e6aa8-687c-7b5a-8850-27b1d0a4ef91" xlink:href="gwrs-20260630.xsd#gwrs_UtilitiesOperatingExpensePersonnelCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:to="loc_gwrs_UtilitiesOperatingExpensePersonnelCosts_019e6aa8-687c-7b5a-8850-27b1d0a4ef91" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_UtilitiesOperatingExpenseUtilitiesChemicalsAndRepairs_019e6aa8-687c-7b18-8a5d-2fcc35b45548" xlink:href="gwrs-20260630.xsd#gwrs_UtilitiesOperatingExpenseUtilitiesChemicalsAndRepairs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:to="loc_gwrs_UtilitiesOperatingExpenseUtilitiesChemicalsAndRepairs_019e6aa8-687c-7b18-8a5d-2fcc35b45548" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_UtilitiesOperatingExpenseOtherOperationsAndMaintenance_019e6aa8-687c-7e37-a349-d97594c04312" xlink:href="gwrs-20260630.xsd#gwrs_UtilitiesOperatingExpenseOtherOperationsAndMaintenance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:to="loc_gwrs_UtilitiesOperatingExpenseOtherOperationsAndMaintenance_019e6aa8-687c-7e37-a349-d97594c04312" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_019e6aa8-687c-76e4-a407-b913bbfcedf7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:to="loc_us-gaap_LaborAndRelatedExpense_019e6aa8-687c-76e4-a407-b913bbfcedf7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_019e6aa8-687c-72fa-82da-2cb8e476257d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfessionalFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:to="loc_us-gaap_ProfessionalFees_019e6aa8-687c-72fa-82da-2cb8e476257d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherGeneralAndAdministrativeExpense_019e6aa8-687c-7e31-b690-c8d044080f85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:to="loc_us-gaap_OtherGeneralAndAdministrativeExpense_019e6aa8-687c-7e31-b690-c8d044080f85" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAmortizationAndAccretionNet_019e6aa8-687c-7ca8-9957-993f5f131192" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationAmortizationAndAccretionNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e6aa8-687c-7598-8758-51d2084d7540" xlink:to="loc_us-gaap_DepreciationAmortizationAndAccretionNet_019e6aa8-687c-7ca8-9957-993f5f131192" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherExpensesAbstract_019e6aa8-687c-7da3-aa11-edf482162f4b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e6aa8-687c-73ba-8c97-639fb911d5b4" xlink:to="loc_us-gaap_OtherExpensesAbstract_019e6aa8-687c-7da3-aa11-edf482162f4b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GrowthPremiums_019e6aa8-687c-78fd-a80b-576942343111" xlink:href="gwrs-20260630.xsd#gwrs_GrowthPremiums"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherExpensesAbstract_019e6aa8-687c-7da3-aa11-edf482162f4b" xlink:to="loc_gwrs_GrowthPremiums_019e6aa8-687c-78fd-a80b-576942343111" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019e6aa8-687c-7745-91f7-571798e5a521" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherExpensesAbstract_019e6aa8-687c-7da3-aa11-edf482162f4b" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019e6aa8-687c-7745-91f7-571798e5a521" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019e6aa8-687c-7a90-b4d2-c637520454ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherExpensesAbstract_019e6aa8-687c-7da3-aa11-edf482162f4b" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019e6aa8-687c-7a90-b4d2-c637520454ee" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6aa8-687c-79b5-81a0-5d9a425b5a37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e6aa8-687c-73ba-8c97-639fb911d5b4" xlink:to="loc_us-gaap_NetIncomeLoss_019e6aa8-687c-79b5-81a0-5d9a425b5a37" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gwresources.com/role/OtherNetDetails" xlink:type="simple" xlink:href="gwrs-20260630.xsd#OtherNetDetails"/>
  <link:definitionLink xlink:role="http://www.gwresources.com/role/OtherNetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-687c-74da-8cc1-1361a8dbd910" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-687c-74da-8cc1-1361a8dbd910" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-687c-73bc-92db-6273e754bf76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e6aa8-687c-74da-8cc1-1361a8dbd910" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-687c-73bc-92db-6273e754bf76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-73bc-92db-6273e754bf76_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-687c-73bc-92db-6273e754bf76" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-73bc-92db-6273e754bf76_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-7e79-9c1b-63ae56973e72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e6aa8-687c-73bc-92db-6273e754bf76" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-7e79-9c1b-63ae56973e72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_ValenciaWaterCompanyMember_019e6aa8-687c-718f-a2ad-a710eb5b15e8" xlink:href="gwrs-20260630.xsd#gwrs_ValenciaWaterCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e6aa8-687c-7e79-9c1b-63ae56973e72" xlink:to="loc_gwrs_ValenciaWaterCompanyMember_019e6aa8-687c-718f-a2ad-a710eb5b15e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GrowthPremiums_019e6aa8-687c-7312-ba55-8c1ea84b31c0" xlink:href="gwrs-20260630.xsd#gwrs_GrowthPremiums"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_gwrs_GrowthPremiums_019e6aa8-687c-7312-ba55-8c1ea84b31c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions_019e6aa8-687c-7f26-8e7a-ef272bd2449f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions_019e6aa8-687c-7f26-8e7a-ef272bd2449f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_OtherIncomeLossDisclosureNonoperating_019e6aa8-687c-76d3-865e-aacc524b015e" xlink:href="gwrs-20260630.xsd#gwrs_OtherIncomeLossDisclosureNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_gwrs_OtherIncomeLossDisclosureNonoperating_019e6aa8-687c-76d3-865e-aacc524b015e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019e6aa8-687c-7b8e-a59c-8047da761675" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019e6aa8-687c-7b8e-a59c-8047da761675" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_GrowthPremiumReceivableForEachNewWaterMeterInstalled_019e6aa8-687c-7645-a6a4-55bb18682d3c" xlink:href="gwrs-20260630.xsd#gwrs_GrowthPremiumReceivableForEachNewWaterMeterInstalled"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_gwrs_GrowthPremiumReceivableForEachNewWaterMeterInstalled_019e6aa8-687c-7645-a6a4-55bb18682d3c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_PeriodForMaximumPayoutOfGrowthPremiumReceivable_019e6aa8-687c-73fa-b63f-3def574143ff" xlink:href="gwrs-20260630.xsd#gwrs_PeriodForMaximumPayoutOfGrowthPremiumReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_gwrs_PeriodForMaximumPayoutOfGrowthPremiumReceivable_019e6aa8-687c-73fa-b63f-3def574143ff" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_MaximumPayoutOfGrowthPremiumReceivable_019e6aa8-687c-7779-965a-2c6224839ed8" xlink:href="gwrs-20260630.xsd#gwrs_MaximumPayoutOfGrowthPremiumReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_gwrs_MaximumPayoutOfGrowthPremiumReceivable_019e6aa8-687c-7779-965a-2c6224839ed8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_gwrs_AccumulatedGrowthPremiumsReceived_019e6aa8-687c-79fe-8ce6-1e34403d16eb" xlink:href="gwrs-20260630.xsd#gwrs_AccumulatedGrowthPremiumsReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e6aa8-687c-719f-951b-74fc774026fa" xlink:to="loc_gwrs_AccumulatedGrowthPremiumsReceived_019e6aa8-687c-79fe-8ce6-1e34403d16eb" xlink:type="arc" order="7"/>
  </link:definitionLink>
</link:linkbase>
