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  <xs:element id="swx_DebtInstrumentMandatoryPrepaymentAsPercentageOfCashProceedsReceived" abstract="false" name="DebtInstrumentMandatoryPrepaymentAsPercentageOfCashProceedsReceived" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
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  <xs:element id="swx_SaleOfStockAmountOfCommonStockOfferedForSale" abstract="false" name="SaleOfStockAmountOfCommonStockOfferedForSale" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="swx_AccruedPurchasedGasCostsMember" abstract="true" name="AccruedPurchasedGasCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_OmnibusIncentivePlanMember" abstract="true" name="OmnibusIncentivePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_GeneralMember" abstract="true" name="GeneralMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_AdjustmentsToAdditionalPaidInCapitalContributionsFromParent" abstract="false" name="AdjustmentsToAdditionalPaidInCapitalContributionsFromParent" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="swx_PipelineAndStorageSegmentMember" abstract="true" name="PipelineAndStorageSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_DebtInstrumentCovenantRatioOfFundedDebtToTotalCapitalization" abstract="false" name="DebtInstrumentCovenantRatioOfFundedDebtToTotalCapitalization" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="swx_RestrictedStockUnitPlanAndManagementIncentivePlanMember" abstract="true" name="RestrictedStockUnitPlanAndManagementIncentivePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCustomerDeposits" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCustomerDeposits" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="swx_PrepaidAndOtherCurrentAssetsPolicyPolicyTextBlock" abstract="false" name="PrepaidAndOtherCurrentAssetsPolicyPolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="swx_DefinedBenefitPlanPensionFundingDuringPeriod" abstract="false" name="DefinedBenefitPlanPensionFundingDuringPeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="swx_UnamortizedGainOnReacquiredDebtMember" abstract="true" name="UnamortizedGainOnReacquiredDebtMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_ScheduleOfEffectiveInterestRatesOnLongTermDebtTableTextBlock" abstract="false" name="ScheduleOfEffectiveInterestRatesOnLongTermDebtTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="swx_IncomeTaxesTable" abstract="true" name="IncomeTaxesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="swx_LineOfCreditFacilityMinimumAmountOutstandingDuringPeriod" abstract="false" name="LineOfCreditFacilityMinimumAmountOutstandingDuringPeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="swx_IncomeTaxDisclosureLineItems" abstract="true" name="IncomeTaxDisclosureLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="swx_DebenturesNotesThreePointEightPercentageDueTwoThousandAndFortySixMember" abstract="true" name="DebenturesNotesThreePointEightPercentageDueTwoThousandAndFortySixMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_DebenturesNotesThreePointSevenPercentageDueTwoThousandAndTwentyEightMember" abstract="true" name="DebenturesNotesThreePointSevenPercentageDueTwoThousandAndTwentyEightMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_RegulatoryOffsetsToDeferredTaxBalancesMember" abstract="true" name="RegulatoryOffsetsToDeferredTaxBalancesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_RiggsDistlerMember" abstract="true" name="RiggsDistlerMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_DeferredRevenueMember" abstract="true" name="DeferredRevenueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_FinanceLeasePrincipalPaymentsLeasesEnteredOrModifiedDuringPeriod" abstract="false" name="FinanceLeasePrincipalPaymentsLeasesEnteredOrModifiedDuringPeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="swx_DeferredIncomeTaxExpenseBenefitComponentsDomain" abstract="true" name="DeferredIncomeTaxExpenseBenefitComponentsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_SettledInterestRateHedgesMember" abstract="true" name="SettledInterestRateHedgesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="swx_DeferredTaxAssetsLiabilitiesEmployeeBenefits" abstract="false" name="DeferredTaxAssetsLiabilitiesEmployeeBenefits" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="swx_LineOfCreditFacilityCovenantsNetLeverageRatioWithCertainMaterialAcquisitions" abstract="false" name="LineOfCreditFacilityCovenantsNetLeverageRatioWithCertainMaterialAcquisitions" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="swx_TransportationMember" abstract="true" name="TransportationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
