<SEC-DOCUMENT>0001214659-19-003889.txt : 20190530
<SEC-HEADER>0001214659-19-003889.hdr.sgml : 20190530
<ACCEPTANCE-DATETIME>20190530164656
ACCESSION NUMBER:		0001214659-19-003889
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190528
FILED AS OF DATE:		20190530
DATE AS OF CHANGE:		20190530

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Townsley Paul G.
		CENTRAL INDEX KEY:			0001430698

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13883
		FILM NUMBER:		19867171

	MAIL ADDRESS:	
		STREET 1:		1720 NORTH FIRST STREET
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95112

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CALIFORNIA WATER SERVICE GROUP
		CENTRAL INDEX KEY:			0001035201
		STANDARD INDUSTRIAL CLASSIFICATION:	WATER SUPPLY [4941]
		IRS NUMBER:				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>marketforms-45089.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-05-28</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001430698</rptOwnerCik>
            <rptOwnerName>Townsley Paul G.</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>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>VP, Rates &amp; Reg Matters</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-05-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>91</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>50.22</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19622.56</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the number of shares withheld by and surrendered to the Issuer to satisfy the tax withholding obligations that arose in connection with the vesting of the Restricted Stock (RSA) Award #404.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michelle Mortensen on behalf of Paul G. Townsley</signatureName>
        <signatureDate>2019-05-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
