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  <xsd:element id="swx_NumberOfTypesOfServicesProvidedToCustomers" name="NumberOfTypesOfServicesProvidedToCustomers" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherComprehensiveIncomeDefinedBenefitPlansRegulatoryAdjustmentNetOfTax" name="OtherComprehensiveIncomeDefinedBenefitPlansRegulatoryAdjustmentNetOfTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentFromDiscontinuedOperationNetOfTaxPortionAttributableToParent" name="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentFromDiscontinuedOperationNetOfTaxPortionAttributableToParent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherComprehensiveIncomeLossFromDiscontinuedOperationNetOfTax" name="OtherComprehensiveIncomeLossFromDiscontinuedOperationNetOfTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherComprehensiveIncomeLossFromDiscontinuedOperationNetOfTaxPortionAttributableToNoncontrollingInterest" name="OtherComprehensiveIncomeLossFromDiscontinuedOperationNetOfTaxPortionAttributableToNoncontrollingInterest" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTaxOther" name="OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTaxOther" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_OtherConstructionMember" name="OtherConstructionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherCurrentLiabilitiesExcessCostOfServiceRatesAmountToBeRefunded" name="OtherCurrentLiabilitiesExcessCostOfServiceRatesAmountToBeRefunded" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="swx_OtherCurrentLiabilitiesPolicyTextBlock" name="OtherCurrentLiabilitiesPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_OtherDeferredCreditsAndOtherLongtermLiabilitiesMember" name="OtherDeferredCreditsAndOtherLongtermLiabilitiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherIncomeExpensePolicyTextBlock" name="OtherIncomeExpensePolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherPropertyAndInvestments" name="OtherPropertyAndInvestments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="swx_OtherPropertyAndInvestmentsPolicyTextBlock" name="OtherPropertyAndInvestmentsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_OtherRevenue" name="OtherRevenue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="swx_PaidAndReceivedFromCounterpartiesForSettlementsOfMaturedSwapsTableTextBlock" name="PaidAndReceivedFromCounterpartiesForSettlementsOfMaturedSwapsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_PaymentsForDerivativeInstrumentOperatingActivities" name="PaymentsForDerivativeInstrumentOperatingActivities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="swx_PercentageOfEligibleParticipantsAcceptedPensionPayoutOffer" name="PercentageOfEligibleParticipantsAcceptedPensionPayoutOffer" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_PrepaidAndOtherCurrentAssetsPolicyPolicyTextBlock" name="PrepaidAndOtherCurrentAssetsPolicyPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_PreviousOwnersMember" name="PreviousOwnersMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_PreviousTaxEffectsFromTCJAReclassifiedToRetainedEarningsFromAOCI" name="PreviousTaxEffectsFromTCJAReclassifiedToRetainedEarningsFromAOCI" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="swx_ProceedsFromDividendsReceivedInvestingActivities" name="ProceedsFromDividendsReceivedInvestingActivities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="swx_ProceedsFromMiscellaneousInvestingActivities" name="ProceedsFromMiscellaneousInvestingActivities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="swx_ProceedsFromRepaymentsOfLinesOfCreditAndCommercialPaper" name="ProceedsFromRepaymentsOfLinesOfCreditAndCommercialPaper" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="swx_PropertyPlantEquipmentAndIntangibleAssetsGross" name="PropertyPlantEquipmentAndIntangibleAssetsGross" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="swx_RegulatoryAssetsOrLiabilitiesOffsettingAmountsInFinancialPositionTableTextBlock" name="RegulatoryAssetsOrLiabilitiesOffsettingAmountsInFinancialPositionTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_RegulatoryDeferralAccountingTreatmentMember" name="RegulatoryDeferralAccountingTreatmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_ReplacementGasConstructionMember" name="ReplacementGasConstructionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_ResidentialMember" name="ResidentialMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_RevenueEarnedOnContractsInProgressInExcessOfBillings" name="RevenueEarnedOnContractsInProgressInExcessOfBillings" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="swx_RevenueRecognitionNumberOfContractsWithOriginalDurationMoreThanOneYear" name="RevenueRecognitionNumberOfContractsWithOriginalDurationMoreThanOneYear" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_RevenueRecognizedThatIncludedInAmountsBilledInExcessOfRevenueEarnedOnContracts" name="RevenueRecognizedThatIncludedInAmountsBilledInExcessOfRevenueEarnedOnContracts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_RevolvingCreditFacilityAndCommercialPaperMember" name="RevolvingCreditFacilityAndCommercialPaperMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_ScheduleOfConstructionServicesContractsReceivableTableTextBlock" name="ScheduleOfConstructionServicesContractsReceivableTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_ScheduleOfInformationAboutReceivablesRevenueEarnedOnContractsInProgressInExcessOfBillingsAndAmountsBilledInExcessOfRevenueEarnedOnContractsTableTextBlock" name="ScheduleOfInformationAboutReceivablesRevenueEarnedOnContractsInProgressInExcessOfBillingsAndAmountsBilledInExcessOfRevenueEarnedOnContractsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_ScheduleOfRelatedTaxEffectsAllocatedToComponentsOfOtherComprehensiveIncomeLossTableTextBlock" name="ScheduleOfRelatedTaxEffectsAllocatedToComponentsOfOtherComprehensiveIncomeLossTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_ScheduleOfStockholdersEquityLineItems" name="ScheduleOfStockholdersEquityLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_ScheduleOfStockholdersEquityTable" name="ScheduleOfStockholdersEquityTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_SecuredRevolvingCreditFacilityTermLoanMember" name="SecuredRevolvingCreditFacilityTermLoanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_SignificantAccountingPoliciesLineItems" name="SignificantAccountingPoliciesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_SignificantAccountingPoliciesTable" name="SignificantAccountingPoliciesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_SmallCommercialMember" name="SmallCommercialMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_SouthwestGasCorporationMember" name="SouthwestGasCorporationMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_SouthwestGasCreditFacilityMember" name="SouthwestGasCreditFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="swx_StockholdersEquityAttributableToParentBeforeTax" name="StockholdersEquityAttributableToParentBeforeTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="swx_StockholdersEquityAttributableToParentTax" name="StockholdersEquityAttributableToParentTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="swx_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestBeforeTax" name="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestBeforeTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="swx_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestOther" name="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestOther" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="swx_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestTax" name="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="swx_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect" name="TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_TaxReformSavingsRevenueAdjustmentsMember" name="TaxReformSavingsRevenueAdjustmentsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_TransportationMember" name="TransportationMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_UnitPricedContractsMember" name="UnitPricedContractsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_VariableRateBondsTaxExemptSeriesADueTwoThousandAndTwentyEightMember" name="VariableRateBondsTaxExemptSeriesADueTwoThousandAndTwentyEightMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_VariableRateBondsTwoThousandAndEightSeriesADueTwoThousandAndThirtyEightMember" name="VariableRateBondsTwoThousandAndEightSeriesADueTwoThousandAndThirtyEightMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_VariableRateBondsTwoThousandAndNineSeriesADueTwoThousandAndThirtyNineMember" name="VariableRateBondsTwoThousandAndNineSeriesADueTwoThousandAndThirtyNineMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="swx_VariableRateBondsTwoThousandAndThreeSeriesADueTwoThousandAndThirtyEightMember" name="VariableRateBondsTwoThousandAndThreeSeriesADueTwoThousandAndThirtyEightMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>
