<?xml version="1.0" encoding="US-ASCII"?>
<!-- This schema was created by staff of the U.S. Securities and Exchange Commission. -->
<!-- Data and content created by government employees within the scope of their employment -->
<!-- are not subject to domestic copyright protection. 17 U.S.C. 105. -->
<xs:schema
xmlns:xs="http://www.w3.org/2001/XMLSchema"
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:sbs-sbsef-fex="http://xbrl.sec.gov/sbs-sbsef-fex/2024"
targetNamespace="http://xbrl.sec.gov/sbs-sbsef-fex/2024"
elementFormDefault="qualified"
xsi:schemaLocation="http://www.xbrl.org/2006/ref http://www.xbrl.org/2006/ref-2006-02-27.xsd">
<xs:import schemaLocation="sbs-sbsef-com-2024.xsd" namespace="http://xbrl.sec.gov/sbs-sbsef-com/2024"/>
<xs:annotation>
<xs:appinfo>
<link:linkbase id="lnk">
<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/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
<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: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:roleRef roleURI="http://xbrl.sec.gov/sbsef/role/ExhI" xlink:type="simple" xlink:href="sbs-2024.xsd#ExhI"/>
<link:roleRef roleURI="http://xbrl.sec.gov/sbsef/role/FileInformation" xlink:type="simple" xlink:href="sbs-2024.xsd#FileInformation"/>
<link:roleRef roleURI="http://xbrl.sec.gov/sbsef/role/AffiliatesOnly" xlink:type="simple" xlink:href="sbs-2024.xsd#AffiliatesOnly"/>
<link:presentationLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/sbsef/role/ExhI">
<link:loc xlink:type="locator" xlink:href="sbs-2024.xsd#sbs_SbsefFinancialPositionLineItems" xlink:label="SbsefFinancialPositionLineItems"/>
<link:loc xlink:type="locator" xlink:href="sbs-2024.xsd#sbs_SbsefFinancialResourcesOneYearCostCoverageNarrativeTextBlock" xlink:label="SbsefFinancialResourcesOneYearCostCoverageNarrativeTextBlock"/>
<link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SbsefFinancialPositionLineItems" xlink:to="SbsefFinancialResourcesOneYearCostCoverageNarrativeTextBlock" order="1.0" priority="10"/>
<link:loc xlink:type="locator" xlink:href="sbs-2024.xsd#sbs_SbsefFinancialResourcesIncludeLiquidAssetsCoveringSixMonthsCostsFlag" xlink:label="SbsefFinancialResourcesIncludeLiquidAssetsCoveringSixMonthsCostsFlag"/>
<link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SbsefFinancialPositionLineItems" xlink:to="SbsefFinancialResourcesIncludeLiquidAssetsCoveringSixMonthsCostsFlag" order="2.0" priority="10"/>
<link:loc xlink:type="locator" xlink:href="sbs-2024.xsd#sbs_SbsefRepresentationsRegardingSourcesEstimatesFutureResourcesTextBlock" xlink:label="SbsefRepresentationsRegardingSourcesEstimatesFutureResourcesTextBlock"/>
<link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SbsefFinancialPositionLineItems" xlink:to="SbsefRepresentationsRegardingSourcesEstimatesFutureResourcesTextBlock" order="3.0" priority="10"/>
</link:presentationLink>
<link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/sbsef/role/ExhI">
<link:loc xlink:type="locator" xlink:href="sbs-2024.xsd#sbs_SbsefFinancialPositionLineItems" xlink:label="SbsefFinancialPositionLineItems"/>
<link:loc xlink:type="locator" xlink:href="sbs-2024.xsd#sbs_SbsefFinancialResourcesOneYearCostCoverageNarrativeTextBlock" xlink:label="SbsefFinancialResourcesOneYearCostCoverageNarrativeTextBlock"/>
<link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SbsefFinancialPositionLineItems" xlink:to="SbsefFinancialResourcesOneYearCostCoverageNarrativeTextBlock" order="1.0" priority="10"/>
<link:loc xlink:type="locator" xlink:href="sbs-2024.xsd#sbs_SbsefFinancialResourcesIncludeLiquidAssetsCoveringSixMonthsCostsFlag" xlink:label="SbsefFinancialResourcesIncludeLiquidAssetsCoveringSixMonthsCostsFlag"/>
<link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SbsefFinancialPositionLineItems" xlink:to="SbsefFinancialResourcesIncludeLiquidAssetsCoveringSixMonthsCostsFlag" order="2.0" priority="10"/>
<link:loc xlink:type="locator" xlink:href="sbs-2024.xsd#sbs_SbsefRepresentationsRegardingSourcesEstimatesFutureResourcesTextBlock" xlink:label="SbsefRepresentationsRegardingSourcesEstimatesFutureResourcesTextBlock"/>
<link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SbsefFinancialPositionLineItems" xlink:to="SbsefRepresentationsRegardingSourcesEstimatesFutureResourcesTextBlock" order="3.0" priority="10"/>
</link:definitionLink>
</link:linkbase>
</xs:appinfo>
</xs:annotation>
</xs:schema>
