<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-10-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000276209</issuerCik>
        <issuerName>CONNECTICUT WATER SERVICE INC / CT</issuerName>
        <issuerTradingSymbol>CTWS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001218375</rptOwnerCik>
            <rptOwnerName>HANLEY MARY ANN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>CONNECTICUT WATER COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>93 WEST MAIN STREET</rptOwnerStreet2>
            <rptOwnerCity>CLINTON</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06413</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-10-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7622</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>70.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">See explanation in remarks below</footnote>
    </footnotes>

    <remarks>(1) On October 9, 2019, pursuant to the Second Amended and Restated Agreement and Plan of Merger (the &quot;Merger Agreement&quot;), dated as of August 5, 2018, by and among Connecticut Water Service, Inc., a Connecticut corporation (the &quot;Company&quot;), SJW Group, a Delaware corporation (&quot;SJW&quot;), and Hydro Sub, Inc., a Connecticut corporation and a wholly owned subsidiary of SJW (&quot;Merger Sub&quot;), SJW completed the previously announced acquisition of the Company through the merger of Merger Sub with and into the Company (the &quot;Merger&quot;), with the Company surviving the Merger as a wholly owned subsidiary of SJW.  The Merger became effective upon the filing of the certificate of merger with the Secretary of the State of the State of Connecticut on October 9, 2019 (the &quot;Effective Time&quot;).

Pursuant to the Merger Agreement, at the Effective Time, each issued and outstanding share of common stock, without par value, of the Company (the &quot;Common Stock&quot;), except for certain excluded shares, was canceled and converted into the right to receive an amount in cash equal to $70.00 per share of Common Stock, payable without interest.</remarks>

    <ownerSignature>
        <signatureName>/s/ Kristen A. Johnson, POA for MaryAnn Hanley</signatureName>
        <signatureDate>2019-10-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
