<SEC-DOCUMENT>0001502013-25-000006.txt : 20251211
<SEC-HEADER>0001502013-25-000006.hdr.sgml : 20251211
<ACCEPTANCE-DATETIME>20251211184332
ACCESSION NUMBER:		0001502013-25-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20251210
FILED AS OF DATE:		20251211
DATE AS OF CHANGE:		20251211

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lynch James Patrick
		CENTRAL INDEX KEY:			0001502013
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13883
		FILM NUMBER:		251566117

	MAIL ADDRESS:	
		STREET 1:		1675 LAURELWOOD DRIVE
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95125

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CALIFORNIA WATER SERVICE GROUP
		CENTRAL INDEX KEY:			0001035201
		STANDARD INDUSTRIAL CLASSIFICATION:	WATER SUPPLY [4941]
		ORGANIZATION NAME:           	01 Energy & Transportation
		EIN:				770448994
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1720 N FIRST ST
		STREET 2:		C/O CALIFORNIA WATER SERVICE CO
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95112
		BUSINESS PHONE:		4083678200

	MAIL ADDRESS:	
		STREET 1:		1720 FIRST ST
		STREET 2:		C/O CALIFORNIA WATER SERVICE CO
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95112
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-12-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001035201</issuerCik>
        <issuerName>CALIFORNIA WATER SERVICE GROUP</issuerName>
        <issuerTradingSymbol>CWT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001502013</rptOwnerCik>
            <rptOwnerName>Lynch James Patrick</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1720 NORTH FIRST STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95112</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP CFO and Treasurer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-12-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>550</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>42.8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4618.9</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were purchased in multiple transactions at the price of $42.795.  The reporting person undertakes to provide full information regarding the number of shares purchased</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: /s/ Michelle R. Mortensen For: James P. Lynch</signatureName>
        <signatureDate>2025-12-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
