<SEC-DOCUMENT>0001214659-19-004114.txt : 20190607
<SEC-HEADER>0001214659-19-004114.hdr.sgml : 20190607
<ACCEPTANCE-DATETIME>20190607163657
ACCESSION NUMBER:		0001214659-19-004114
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190606
FILED AS OF DATE:		20190607
DATE AS OF CHANGE:		20190607

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Dean Shannon C
		CENTRAL INDEX KEY:			0001629475

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13883
		FILM NUMBER:		19886156

	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-45185.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-06-06</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001629475</rptOwnerCik>
            <rptOwnerName>Dean Shannon C</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, Corp Comm &amp; Comm Affairs</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-06-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>86</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>50.54</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11225.23</value>
                    <footnoteId id="F2"/>
                </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 #435.</footnote>
        <footnote id="F2">Includes 27.693 shares acquired through the Employee Stock Participation Program for March 2019 through May 2019.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michelle Mortensen on behalf of Shannon Dean</signatureName>
        <signatureDate>2019-06-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
