WATTS WATER TECHNOLOGIES, INC. SUPPLEMENTAL EMPLOYEES RETIREMENT PLAN As Amended and Restated Effective May 4, 2004

Exhibit 10.18

WATTS WATER TECHNOLOGIES, INC.

SUPPLEMENTAL EMPLOYEES RETIREMENT PLAN

As Amended and Restated
Effective May 4, 2004

TABLE OF CONTENTS

ARTICLE I

NAME, PURPOSE AND EFFECTIVE DATE

1.01    NAME AND PURPOSE

• The supplemental retirement plan set forth herein as the "Watts Water Technologies, Inc. Supplemental Employees Retirement Plan" (the "Plan"). The Plan is established, and shall be maintained, solely for the purpose of providing supplemental retirement benefits which cannot be provided under the Watts Water Technologies, Inc. Pension Plan (the "Qualified Plan") for certain Participants. The Plan is unfunded and maintained primarily for purpose of providing deferred compensation for Participants who are part of a select group of management or highly compensated employees."

1.02    EFFECTIVE DATE

• This restated Plan shall be effective May 4, 2004 (the "Effective Date"). This Plan shall apply to Participants who retire or terminate their employment with the Employer after the Effective Date. The Plan was originally effective on January 1, 1989 (the "Original Effective Date"). Participants who retire or terminate their employment with the Employer on or after the Original Effective Date but prior to the Effective Date of this Plan shall have their benefits determined based on the Plan provisions in effect on the date they retire or otherwise terminate their employment with the Employer.

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ARTICLE II

DEFINITIONS

Whenever used in this Plan, unless the context clearly indicates otherwise, the following terms shall have the following meanings:

2.01

"Code" means the Internal Revenue Code of 1986.

2.02

"Compensation" means the total compensation payable to an eligible Employee by the Employer and reportable to the Federal Government for income tax purposes on Form W-2, or any form prescribed by the Internal Revenue Service to take its place.

• Compensation also includes: (i) amounts contributed by the Employee at the election of the Employee pursuant to a salary deferral arrangement under Section 401(k), (ii) amounts contributed or deferred at the election of the Employee and which are not includible in gross income of the Employee by reason of Section 125 of the Code, (iii) amounts deferred at the election of the Employee pursuant to a salary deferral agreement under the Watts Water Technologies, Inc. Management Stock Purchase Plan (formerly called the Watts Industries, Inc. Management Stock Purchase Plan), and (iv) amounts deferred at the election of the Employee pursuant to a salary deferral agreement under the Watts Water Technologies, Inc. Non-Qualified Deferred Compensation Plan (formerly called the Watts Industries, Inc. Non-Qualified Deferred Compensation Plan).

  For any Employee listed in Tier 1, Tier 1-A or Tier 1-T of Appendix A, there shall be no limit on such Employee's Compensation. For any Employee listed in Tier 2 of Appendix A, in no event shall such Employee's Compensation exceed $383,450 for the Plan Year beginning January 1, 2004. For any eligible Employee not listed in Tier 1, Tier 1-A, Tier 1-T or Tier 2 of Appendix A, in no event shall such Employee's Compensation exceed $306,760 for the Plan Year beginning January 1, 2004. For each subsequent Plan Year, the $383,450 and $306,760 limitations shall be adjusted at the same time and in the same proportion as the adjustment to the maximum benefit limitation under Internal Revenue Code Section 415(d) which is applicable to the Qualified Plan. In all other respects, the limitations on annual Compensation under this Section shall be applied in the same manner in determining Final Average Compensation as the limitation under Internal Revenue Code Section 401(a)(17) is to be applied under the Qualified Plan.

2.03

"Employer " means Watts Water Technologies, Inc. (formerly known as Watts Industries, Inc.) or any successor thereto and any other entity now or hereafter affiliated with Watts Water Technologies, Inc. which participates in the Qualified Plan.

2.04

"Final Average Compensation" means, unless otherwise modified in the Appendices, the average of the Participant's Compensation for the sixty (60) consecutive months during the last one hundred and twenty (120) months of his service prior to his termination of employment for which he received the highest total Compensation. If a Participant has not completed at least sixty (60) months of Service with the Employer, his Final Average Compensation shall be the average of his Compensation during his period of Service with the Employer.

2.05

"Participant" means an Employee who meets the eligibility requirements for this Plan in the manner set forth in Article 3.

2.06

"Plan Administrator" means Watts Water Technologies, Inc., or its duly authorized representative.

2.07

"Social Security Benefit" means the primary insurance benefit payable annually to an Employee at Normal Retirement Age under Title II of the Social Security Act as in effect on the date he terminates his employment or on his Normal Retirement Age, if earlier, computed without regard to any reduction or loss of benefits which may result due to other income, delay in making

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• application or any other reason; provided, however, that in the case of a Participant who terminates his employment prior to his attainment of Normal Retirement Age, his Social Security benefit shall be computed in accordance with the following provisions:

  (a)

  If the Participant has satisfied the eligibility requirements for an Early Retirement Benefit under Section 4.02 prior to his termination, his Social Security Benefit will be based on the assumption that he received no further Compensation from his termination date until he attained his Normal Retirement Age.
  
  

  (b)

  If the Participant has not satisfied the requirements for an Early Retirement Benefit prior to his termination, his Social Security Benefit will be based on the assumption that he remained in the service of the Employer until he reached his Normal Retirement Age and that he continued to receive the same rate of Compensation from the Employer as in effect on his termination date until his Normal Retirement Age.

• The income used for purposes of computing a Participant's Social Security Benefit will be the portion of his Compensation which is treated as wages for the purposes of the Social Security Act. The Participant's income earned prior to his first full year of employment as a Participant will be estimated by applying a 6% salary scale projected backwards from his first full year of employment with the Employer.

2.08

"Sponsoring Employer" means Watts Water Technologies, Inc. (formerly known as Watts Industries, Inc.).

2.09    CERTAIN DEFINITIONS UNDER QUALIFIED PLAN APPLY

• The following terms shall have the same meaning at any relevant time as that contained in the Qualified Plan. Any amendment under the Qualified Plan to the meaning of a term listed hereunder shall also apply under this Plan to the same extent and in the same manner as under the Qualified Plan.

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ARTICLE III

ELIGIBILITY

3.01    PARTICIPATION

• Prior to January 1, 1994, the Board of Directors, designated the Employees who were eligible to participate in the Plan under Section 4.01(a). These Employees are listed in Tier 2 of Appendix A, attached hereto.

  On and after January 1, 1994, any Employee not designated in Tier 1, Tier 1-A, Tier 1-T or Tier 2 of Appendix A whose Compensation under the Qualified Plan is limited under Internal Revenue Code Section 401(a) (17), or who entered into a salary deferral agreement under the Watts Water Technologies, Inc. Management Stock Purchase Plan or, effective September 1, 2003, the Watts Water Technologies, Inc. Non-Qualified Deferred Compensation Plan, is eligible to participate in this Plan.

  Effective January 1, 1998, the Board of Directors shall designate the Employees who are eligible to participate in the Plan under Appendix B. These Employees are listed in Tier 1 of Appendix A.

  Effective January 1, 2003, the Board of Directors shall designate the Employees who are eligible to participate in the Plan under Appendix C. These Employees are listed in Tier 1-A of Appendix A.

  Effective May 4, 2004, the Board of Directors shall designate the Employees who are eligible to participant in the Plan under Appendix D. These Employees are listed in Tier 1-T of Appendix A.

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ARTICLE IV

RETIREMENT BENEFITS

4.01    AMOUNT OF NORMAL OR DEFERRED RETIREMENT BENEFIT

• Subject to the provisions of Section 4.04, the amount of the annual Normal Retirement Benefit or Deferred Retirement Benefit (as defined in this Section 4.01) payable in the Normal Form of Payment to a Participant who retires under this Plan on or after his Normal Retirement Date shall be the excess, if any, of (a) or (b), whichever is applicable, over (c):

  (a)

  For eligible Participants listed in Tier 2 of Appendix A, forty-five percent (45%) of his Final Average Compensation less fifty percent (50%) of his Social Security Benefit, multiplied by a fraction (not to exceed one), the numerator of which is his years (and fractions thereof) of Benefit Service and the denominator of which is twenty-five (25).
  
  

  (b)

  For eligible Participants not listed in Tier 1, Tier 1-A, Tier 1-T or Tier 2 of Appendix A, the annual benefit payable in the form of a straight life annuity determined under the relevant normal or deferred retirement benefit provisions of the Qualified Plan, but based on Final Average Compensation as defined in this Plan and ignoring any limitations under Internal Revenue Code Section 415.
  
  

  (c)

  The annual benefit is payable in the form of a straight life annuity under the Qualified Plan.

• Notwithstanding the above, the amount of annual Normal Retirement Benefit or Deferred Retirement Benefit for eligible Participants listed in Tier 2 of Appendix A attached hereto shall in no event be less than the amount determined as if the eligible Participant was not listed in Tier 1, Tier 1-A, Tier 1-T or Tier 2 of Appendix A and eligible for the Normal Retirement Benefit or Deferred Retirement Benefit described in Section 4.01(b) of the Plan.

4.02    AMOUNT OF EARLY RETIREMENT BENEFIT

• Subject to the provisions of Section 4.04, the amount of the annual Early Retirement Benefit (as defined in this Section 4.02) of a Participant who elects to retire on or after his Early Retirement Date shall be a benefit computed in accordance with (a) or (b) below, as elected by the Participant in accordance with the requirements of Section 6.03:

  (a)

  A benefit commencing on his Normal Retirement Date in an amount equal to his Accrued Normal Retirement Benefit as defined and determined in accordance with Section 4.03.
  
  

  (b)

  A reduced benefit commencing on his Early Retirement Date or the first day of any month thereafter but prior to his Normal Retirement Date, as elected by the Participant, which benefit shall be computed as the excess of (i) over (ii) where:
  
  

  (i)

  is equal to the benefit determined in Section 4.01(a) or 4.01(b) above, as applicable, reduced in amount in the same manner as the reduction made to the amount of benefit payable under the Qualified Plan prior to his Normal Retirement Date, and
  
  

  (ii)

  is equal to the benefit determined under Section 4.01(c) reduced in the same manner as the reduction made to the amount of benefit payable under the Qualified Plan prior to his Normal Retirement Date.

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4.03    ACCRUED NORMAL RETIREMENT BENEFIT

• For an eligible Participant whose benefit is determined in accordance with Sections 4.01(a) and (c), such Participant's Accrued Normal Retirement Benefit at any time prior to his Normal Retirement Date, shall be determined as the amount of Normal Retirement Benefit that the Participant would have received under subsection (a) of Section 4.01 if he had remained in the employ of the Employer to his Normal Retirement Date, but based on his Final Average Compensation and Social Security Benefit as of the date such Accrued Normal Retirement Benefit is being determined. Such amount shall then be multiplied by a fraction in which the numerator is the number of years (and fractions thereof) of Benefit Service that the Participant has completed, and the denominator is the number of years (and fractions thereof) of Benefit Service that the Participant would have completed if he had remained in the employ of the Employer to his Normal Retirement Date, and such amount shall then be reduced by the amount determined under subsection (c) of Section 4.01; provided, however, that in the case of a Participant who has completed twenty-five (25) years of Benefit Service and has satisfied the conditions for an Early Retirement Benefit, the fractional reduction of this Section 4.03 shall not apply in determining his Accrued Normal Retirement Benefit.

  For an eligible Participant whose benefit is determined in accordance with Sections 4.01(b) and (c), such Participant's Accrued Normal Retirement Benefit at any time prior to his Normal Retirement Date shall be determined as the excess of the benefit determined in accordance with Section 4.01(b) over the benefit determined in accordance with Section 4.01(c).

4.04    SPECIAL RETIREMENT BENEFIT

• Notwithstanding any other provision to the contrary, eligible Participants listed in Tier 1 of Appendix A shall be entitled to receive the Special Retirement Benefit as set forth in Appendix B, which is hereby incorporated and made a part of this Plan, in lieu of the benefit otherwise provide under this Article IV. Eligible Participants listed in Tier 1-A of Appendix A shall be entitled to receive the Special Retirement Benefit as set forth in Appendix C, which is hereby incorporated and made a part of this Plan, in lieu of the benefit otherwise provided under this Article IV. Eligible Participants listed in Tier 1-T of Appendix A shall be entitled to receive the Special Retirement Benefit as set forth in Appendix D, which is hereby incorporated and made a part of this Plan.

4.05    ADJUSTMENT OF THE QUALIFIED PLAN OFFSET FOR CERTAIN PARTICIPANTS

• Notwithstanding the foregoing provisions of this Article IV, in the event the annual benefit payable under the Qualified Plan in the form of a straight life annuity exceeds the maximum benefit limitation of Internal Revenue Code Section 415 and the Participant elects to receive a Spouse Joint and Survivor Annuity form of payment under the Qualified Plan, the Qualified Plan offset described in Section 4.01(c)(ii) shall be equal to the straight life annuity Actuarial Equivalent of the benefit actually elected by the Participant under the Qualified Plan.

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ARTICLE V

VESTING

5.01    VESTING

• Subject to Section 5.03, a Participant's Accrued Normal Retirement Benefit shall be fully vested upon the date which is the earlier of (i) his completion of six (6) years of Service, (ii) his Early Retirement Date, or (iii) his attainment of Normal Retirement Age, provided he is actively employed by the Employer on such date. A Participant whose employment with the Employer ceases prior to his satisfaction of one of the full vesting conditions of this Section 5.01 shall not be entitled to any benefit under this Plan.

5.02    AMOUNT OF VESTED ACCRUED BENEFIT

• The amount of the Accrued Normal Retirement Benefit of a Participant shall be determined under Section 4.03. In the event that the payment of a Participant's vested Accrued Normal Retirement Benefit commences prior to his Normal Retirement Date in