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  <xs:element id="swx_DividendReinvestmentAndStockPurchasePlanMember" abstract="true" name="DividendReinvestmentAndStockPurchasePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="swx_CenturiSecuredRevolvingCreditFacilityMember" abstract="true" name="CenturiSecuredRevolvingCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
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  <xs:element id="swx_DebenturesNotes4.05Due2032Member" abstract="true" name="DebenturesNotes4.05Due2032Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="swx_AdjustmentsToAdditionalPaidInCapitalPromissoryNotesInAssociationWithRedeemableNoncontrollingInterest" abstract="false" name="AdjustmentsToAdditionalPaidInCapitalPromissoryNotesInAssociationWithRedeemableNoncontrollingInterest" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="swx_NumberOfPerformanceShareUnitsGranted" abstract="false" name="NumberOfPerformanceShareUnitsGranted" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
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  <xs:element id="swx_ImpairmentOfAssetsAndOtherCharges" abstract="false" name="ImpairmentOfAssetsAndOtherCharges" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="swx_AccumulatedDefinedBenefitPlansAdjustmentRegulatoryAdjustmentAttributableToParentMember" abstract="true" name="AccumulatedDefinedBenefitPlansAdjustmentRegulatoryAdjustmentAttributableToParentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="swx_AccountsReceivableForServicesTableTextBlock" abstract="false" name="AccountsReceivableForServicesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
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  <xs:element id="swx_IndustrialDevelopmentRevenueBondsMember" abstract="true" name="IndustrialDevelopmentRevenueBondsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="swx_DebenturesNotes5.45Due2028Member" abstract="true" name="DebenturesNotes5.45Due2028Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_IPOExcludingOverAllotmentOptionMember" abstract="true" name="IPOExcludingOverAllotmentOptionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_ProceedsFromRepaymentsOfLinesOfCreditAndCommercialPaper" abstract="false" name="ProceedsFromRepaymentsOfLinesOfCreditAndCommercialPaper" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="swx_CenturiGroupInc.Member" abstract="true" name="CenturiGroupInc.Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
</xs:schema>
