<?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>0001694769</rptOwnerCik>
            <rptOwnerName>Knowlton Richard</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>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, Maine Division</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

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        <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>1693</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>

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        <derivativeTransaction>
            <securityTitle>
                <value>Performance Share Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
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            <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>6193</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6193</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Share Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <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>1023</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1023</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">See explanation in remarks below</footnote>
        <footnote id="F2">All outstanding Company Performance Share Units (&quot;PSUs&quot;) granted prior to March 14, 2018 (which are no longer subject to performance-based vesting) were assumed by SJW and converted into a time-based vesting SJW restricted share unit award based on the Equity Award Ratio (as defined in the Merger Agreement) covering a number of shares of common stock of SJW based on the number of shares of Company common stock that was subject to each applicable PSU award immediately prior to the closing of the Merger.  All outstanding PSUs granted on or after March 14, 2018 were assumed by SJW and converted into a time-based vesting award covering a number of shares of common stock of SJW based on the target number of PSUs (determined in a manner consistent with the Compa,ny's past practice) that was subject to each applicable PSU award immediately prior to the closing of the Merger multiplied by the Equity Award Ratio (as defined in the Merger Agreement).</footnote>
        <footnote id="F3">SJW assumed all outstanding Company Restricted Share Units that were subject to service-based vesting (&quot;RSUs&quot;) and such RSUs were converted into SJW restricted share units based on the Equity Award Ratio (as defined in the Merger Agreement).</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 Richard Knowlton</signatureName>
        <signatureDate>2019-10-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
