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                                                                 Exhibit 10.12.3

                      SUPPLEMENTAL PARTICIPATION AGREEMENT

         A Participation Agreement made and entered into this 30th day of
December, 2003, between The Unionville Water Company (hereinafter referred to as
the `Participating Employer'), Connecticut Water Company (hereinafter referred
to as the "Employer") and Riggs Bank NA. (hereinafter referred to as the
"Trustees").

         WHEREAS, the Participating Employer desires to reward its employees for
faithful service, to establish a bond between employer and employee, to provide
an incentive for efficient and conscientious work, to provide a fund for
retirement, disability, or death, and to retain high-calibre fellow employees;
and

         WHEREAS, there exists a 40 1(k) Profit Sharing Plan entered into on the
30th day of December, 2003 namely the SAVINGS PLAN OF THE CONNECTICUT WATER
COMPANY, called the "Plan," between the Employer and the Trustees (a copy being
attached hereto as Exhibit "A" and made a part hereof by reference); and

         WHEREAS, the Plan provides that any other Participating Employer may,
with the consent of the Employer, adopt the Plan and participate therein by a
properly executed document evidencing said intent of said Participating
Employer;

         NOW, THEREFORE, the Participating Employer hereby becomes a party to
the Plan, effective the 1st day of January, 2004, and the Employer and the
Trustees hereby consent to such adoption a participation upon the following
terms:

         (1)      Wherever a right or obligation is imposed upon the Employer by
         the terms of the Plan, the same shall extend to the Participating
         Employer as the "Employer" under the Plan and shall be separate and
         distinct from that imposed upon the Employer. It is the intention of
         the parties that the Participating Employer shall be a party to the
         Plan and treated in all respects as the Employer thereunder, with its
         employees to be considered as the Employees or Participants, as the
         case may be, thereunder. However, the participation of the
         Participating Employer in the Plan shall in no way diminish, augment,
         modify, or in any way affect the rights and duties of the Employer, its
         Employees, or Participants, under the Plan.

         (2)      The Trustees hereby agree to receive and allocate
         contributions made to the Plan by the Employer and by the Participating
         Employer, as well as to do and perform all acts that are necessary to
         keep records and accounts of all funds held for Participants who are
         Employees of the respective employers.

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                                                                 Exhibit 10.12.3


         (3)      The execution of this Agreement by this Participating Employer
         shall be construed as the adoption of the Plan in every respect as if
         said Plan had this date been executed between the Participating
         Employer and the Trustees, except as otherwise expressly provided
         herein or in any amendment that may subsequently be adopted hereto.

         (4)      All actions required by the Plan and Trust to be taken by the
         Employer shall be effective with respect to the Participating Employer
         if taken by the Employer and pursuant to the Plan, the Participating
         Employer hereby irrevocably designates the Employer as its agent for
         such purposes.

         IN WITNESS WHEREOF, the Participating Employer, the Employer and the
Trustees have caused this Supplemental Participation Agreement to be executed in
their respective names on the day and date first above written.

                                    The Unionville Water Company

                                    By:  /s/  Maureen P. Westbrook