CUSIP No. 942749 10 2                  13G                          Page 1 of 15


                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 ---------------

                                  SCHEDULE 13G
                                 (Rule 13d-102)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
          TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED
                                PURSUANT TO 13d-2
                               (Amendment No. 21)*


                         WATTS WATER TECHNOLOGIES, INC.
                         ------------------------------
                                (Name of Issuer)

                 Class A Common Stock, par value $.10 per share
                 ----------------------------------------------
                         (Title of Class of Securities)

                                   942749 10 2
                                   -----------
                                 (CUSIP Number)

                                December 31, 2006
                                -----------------
             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

        |_| Rule 13d-1(b)
        |_| Rule 13d-1(c)
        |X| Rule 13d-1(d)

--------------------------------------------------------------------------------

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act.


CUSIP No. 942749 10 2                  13G                          Page 2 of 15


________________________________________________________________________________
1.    NAME OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

      Timothy P. Horne

________________________________________________________________________________
2.    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [_]

________________________________________________________________________________
3.    SEC USE ONLY



________________________________________________________________________________
4.    CITIZENSHIP OR PLACE OF ORGANIZATION

      United States

________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           7,229,962
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          None
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         3,572,826
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            2,421,680
________________________________________________________________________________
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      7,229,962

________________________________________________________________________________
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

      18.8%

________________________________________________________________________________
12.   TYPE OF REPORTING PERSON*

      IN



CUSIP No. 942749 10 2                  13G                          Page 3 of 15


________________________________________________________________________________
1.    NAME OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

      George B. Horne

________________________________________________________________________________
2.    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [_]

________________________________________________________________________________
3.    SEC USE ONLY



________________________________________________________________________________
4.    CITIZENSHIP OR PLACE OF ORGANIZATION

      United States

________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           None
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          None
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         None
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            None
________________________________________________________________________________
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      None

________________________________________________________________________________
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

      0%

________________________________________________________________________________
12.   TYPE OF REPORTING PERSON*

      IN



CUSIP No. 942749 10 2                  13G                          Page 4 of 15


                            STATEMENT ON SCHEDULE 13G

Item 1(a).  Name of Issuer.

                  Watts Water Technologies, Inc.

Item 1(b).  Address of Issuer's Principal Executive Offices.

                  815 Chestnut Street
                  North Andover, MA  01845

Item 2(a).  Names of Persons Filing.

                  Timothy P. Horne
                  George B. Horne

Item 2(b).  Address of Principal Business Office or, if None, Residence.

                  c/o Watts Water Technologies, Inc.
                  815 Chestnut Street
                  North Andover, MA  01845

Item 2(c).  Citizenship.

                  United States

Item 2(d).  Title of Class of Securities.

                  Class A Common Stock, par value $.10 per share



CUSIP No. 942749 10 2                  13G                          Page 5 of 15


Item 2(e).  CUSIP Number.

               942749 10 2


Item 3. If This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or
(c), Check Whether the Person Filing is a:

(a) |_| Broker or dealer registered under Section 15 of the Exchange Act.

(b) |_| Bank as defined in Section 3(a)(6) of the Exchange Act.

(c) |_| Insurance company as defined in Section 3(a)(19) of the Exchange Act.

(d) |_| Investment company registered under Section 8 of the Investment
        Company Act.

(e) |_| An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

(f) |_| An employee benefit plan or endowment fund in accordance with Rule
        13d-1(b)(1)(ii)(F);

(g) |_| A parent holding company or control person in accordance with Rule
        13d- 1(b)(1)(ii)(G);

(h) |_| A savings association as defined in Section 3(b) of the Federal
        Deposit Insurance Act;

(i) |_| A church plan that is excluded from the definition of an investment
        company under Section 3(c)(14) of the Investment Company Act;

(j) |_| Group, in accordance with Rule 13d-1(b)(1)(ii)(J).


        Not Applicable.



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Item 4.  Ownership.

            Timothy P. Horne

        (a) Amount Beneficially Owned:

           Timothy P. Horne (for purposes of this particular Item 4, "Mr.
           Horne") is deemed the beneficial owner of 7,229,962 shares of Class A
           Common Stock of the Issuer. As noted below, a substantial portion of
           Mr. Horne's beneficial ownership of Class A Common Stock is derived
           from beneficial ownership of Class B Common Stock, par value $.10 per
           share, of the Issuer, which is convertible into Class A Common Stock
           on a share-for-share basis.

           Includes (i) 1,601,220 shares of Class B Common Stock and 1,112
           shares of Class A Common Stock held by Mr. Horne, (ii) 1,210,840
           shares of Class B Common Stock held by a revocable trust for the
           benefit of Daniel W. Horne, Mr. Horne's brother, for which Mr. Horne
           serves as sole trustee, (iii) 1,210,840 shares of Class B Common
           Stock held by a revocable trust for the benefit of Deborah Horne, Mr.
           Horne's sister, for which Mr. Horne serves as sole trustee, which
           trust is revocable with the consent of the trustee, (iv) 1,085,840
           shares of Class B Common Stock held by a revocable trust for the
           benefit of Peter W. Horne, Mr. Horne's brother, for which Peter W.
           Horne serves as sole trustee, (v) 1,924,600 shares of Class B Common
           Stock held for the benefit of the estate of George B. Horne, Mr.
           Horne's late father, under a revocable trust for which Mr. Horne
           serves as sole trustee, (vi) 22,600 and 20,200 shares of Class B
           Common Stock held for the benefit of Tiffany Rae Horne (Mr. Horne's
           daughter) and Tara V. Horne (Mr. Horne's daughter), respectively,
           under irrevocable trusts for which Mr. Horne serves as trustee, (vii)
           147,740 shares of Class B Common Stock held by a revocable trust for
           the benefit of Tiffany Rae Horne, for which Walter J. Flowers, a
           partner in the law firm of Flowers and Manning, LLP, serves as
           trustee, (viii) 3,094 shares of Class A Common Stock issuable upon
           the exercise of stock options within 60 days after December 31, 2006,
           and (ix) 1,876 shares of Class A Common Stock issued to Mr. Horne as
           a restricted stock award under the Watts Water Technologies, Inc.
           2004 Stock Incentive Plan, which remain subject to certain
           restrictions on the transfer and disposition of such shares. All of
           the shares of Class B Common Stock noted in clauses (i) through (vii)
           (7,223,880 shares of Class B Common Stock in the aggregate) are
           subject to The Amended and Restated George B. Horne Voting Trust
           Agreement - 1997 ("1997 Voting Trust") for which Mr. Horne serves as
           trustee. (See Exhibit 2 for a description of the 1997 Voting Trust).



CUSIP No. 942749 10 2                  13G                          Page 7 of 15


        (b) Percent of Class:

               18.8% equity percentage
               69.3% voting percentage

               The equity percentage was determined in accordance with Rule
        13d-3 under the Securities Exchange Act of 1934, as amended. Due to the
        fact that each share of Class A Common Stock is entitled to one vote on
        all matters submitted to stockholders and each share of Class B Common
        Stock is entitled to ten votes on all matters, equity percentage is not
        equivalent to voting percentage.

        (c) Number of shares as to which such person has:

            (i)   sole power to vote or to direct the vote

                  7,229,962

            (ii)  shared power to vote or to direct the vote

                  None

            (iii) sole power to dispose or to direct the disposition of

                  3,572,826

            (iv)  shared power to dispose or to direct the disposition of

                  2,421,680



CUSIP No. 942749 10 2                  13G                          Page 8 of 15


Item 4.  Ownership.

            George B. Horne

        (a) Amount Beneficially Owned:

            During 2006, George B. Horne passed away. As a result of his death,
            he has ceased to be the beneficial owner of shares of Watts Water
            Technologies, Inc.

        (b) Percent of Class:

               0%

        (c) Number of shares to which such person has:

            (i)   sole power to vote or to direct the vote

                  None

            (ii)  shared power to vote or to direct the vote

                  None

            (iii) sole power to dispose or to direct the disposition of

                  None

            (iv)  shared power to dispose or to direct the disposition of

                  None


CUSIP No. 942749 10 2                  13G                          Page 9 of 15


Item 5.  Ownership of Five Percent or Less of a Class.

            George B. Horne

            If this statement is being filed to report the fact that as of the
            date hereof the reporting person has ceased to be the beneficial
            owner of more than five percent of the class of securities, check
            the following |X|.

Item 6.  Ownership of More than Five Percent on Behalf of Another Person.

            Timothy P. Horne

            The estate of George B. Horne has the right to receive and the power
            to direct the receipt of dividends from, or the proceeds from the
            sale of, 1,924,600 shares of Class B Common Stock held for the
            benefit of the estate of George B. Horne under a revocable trust for
            which Timothy P. Horne serves as sole trustee.

            Daniel W. Horne has the right to receive and the power to direct the
            receipt of dividends from, or the proceeds from the sale of,
            1,210,840 shares of Class B Common Stock held for the benefit of
            Daniel W. Horne under a revocable trust for which Timothy P. Horne
            serves as sole trustee.

            Deborah Horne has (subject to obtaining the consent of the trustee
            as described below) the right to receive and the power to direct the
            receipt of dividends from, or the proceeds from the sale of,
            1,210,840 shares of Class B Common Stock held for the benefit of
            Deborah Horne under a trust for which Timothy P. Horne serves as
            sole trustee, which trust is revocable with the consent of the
            trustee.

            Peter W. Horne has the right to receive and the power to direct the
            receipt of dividends from, or the proceeds from the sale of,
            1,085,840 shares of Class B Common Stock held for the benefit of
            Peter W. Horne under a revocable trust for which Peter W. Horne
            serves as sole trustee and which shares are subject to the 1997
            Voting Trust.



CUSIP No. 942749 10 2                  13G                         Page 10 of 15


Item 7. Identification and Classification of the Subsidiary which Acquired the
        Security Being Reported on by the Parent Holding Company or Control
        Person.

            Not Applicable


Item 8.  Identification and Classification of members of the Group.

            Not Applicable


Item 9.  Notice of Dissolution of Group.

            As a result of the death of George B. Horne during 2006, the group
            consisting of Timothy P. Horne and George B. Horne has dissolved.
            All further filings with respect to the securities reported on in
            this Schedule 13G will be filed, if required, by Timothy P. Horne
            individually.


Item 10.  Certification.

            Not Applicable



CUSIP No. 942749 10 2                  13G                         Page 11 of 15


                                   SIGNATURES

        After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Dated:  February 5, 2007


/s/ Timothy P. Horne
-------------------------------------------------
TIMOTHY P. HORNE




CUSIP No. 942749 10 2                  13G                         Page 12 of 15


                                INDEX OF EXHIBITS


1.    Amended and Restated Stock Restriction Agreement

2.    The Amended and Restated George B. Horne Voting Trust Agreement - 1997



CUSIP No. 942749 10 2                  13G                         Page 13 of 15


                                    EXHIBIT 1


      All Class B Common Stock shares beneficially owned by Timothy P. Horne are
held individually by or in trust for the benefit of Timothy P. Horne, the estate
of George B. Horne, Daniel W. Horne, Deborah Horne, Tara V. Horne, Tiffany R.
Horne and Peter W. Horne, and any voting trust certificates representing such
shares, are subject to an Amended and Restated Stock Restriction Agreement (the
"Agreement"). Upon any proposed voluntary transfer or transfer by operation of
law of Class B Common Stock or voting trust certificates representing such
shares by any of the above stockholders, or upon the death of such a stockholder
holding such shares or voting trust certificates, the other parties to the
Agreement (other than George B. Horne) have a pro rata right of first refusal to
purchase such shares (including a second opportunity to elect to purchase any
shares not purchased under the first right of refusal).

      The purchase price per share is the 15-day average trading price of the
Issuer's Class A Common Stock while publicly traded, except in the case of
certain involuntary transfers, in which case the purchase price is book value.

      This summary is qualified in its entirety by reference to the text of the
Agreement which is incorporated herein by reference to Exhibit 2 to the Issuer's
Current Report on Form 8-K dated October 31, 1991, and to the text of Amendment
No. 1 to the Agreement which is incorporated herein by reference to Exhibit
10.21 to the Issuer's Annual Report on Form 10-K dated September 16, 1997.



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                                    EXHIBIT 2

      The 1,601,220 shares of Class B Common Stock held by Timothy P. Horne,
individually, 1,210,840 shares of Class B Common Stock held by a trust for the
benefit of Daniel W. Horne, 1,210,840 shares of Class B Common Stock held by a
trust for the benefit of Deborah Horne, 1,924,600 shares of Class B Common Stock
held by a trust for the benefit of the estate of George B. Horne, 1,085,840
shares of Class B Common Stock held by a trust for the benefit of Peter W.
Horne, 22,600 and 20,200 shares of Class B Common Stock held for the benefit of
Tiffany Rae Horne and Tara V. Horne, respectively, under irrevocable trusts for
which Mr. Horne serves as trustee, and 147,740 shares of Class B Common Stock
held by a trust for the benefit of Tiffany Rae Horne (7,223,880 shares of Class
B Common Stock in the aggregate) are subject to the terms of The George B. Horne
Voting Trust Agreement-1997 (the "1997 Voting Trust"). Under the terms of the
1997 Voting Trust, the trustee (currently Timothy P. Horne) has sole power to
vote all shares subject to the 1997 Voting Trust.

      Under the terms of the 1997 Voting Trust, in the event Timothy P. Horne
ceases to serve as trustee of the 1997 Voting Trust, then Daniel J. Murphy, III,
a director of the Issuer, and Walter J. Flowers, a partner in the law firm of
Flowers and Manning, LLP (each, a "Successor Trustee" and collectively, the
"Successor Trustees"), shall thereupon become co-trustees of the 1997 Voting
Trust if such individuals are willing and able to succeed. At any time, Timothy
P. Horne, if then living and not subject to incapacity, may designate up to two
additional persons, one to be designated as the primary designee (the "Primary
Designee") and the other as the secondary designee ("Secondary Designee"), to
serve in the stead of any Successor Trustee who shall be unable or unwilling to
serve as a trustee of the 1997 Voting Trust. Such designations are revocable by
Timothy P. Horne at any time prior to the time at which such designees become a
trustee. If any of the Successor Trustees is unable or unwilling or shall
otherwise fail to serve as a trustee of the 1997 Voting Trust, or after becoming
a co-trustee shall cease to serve as such for any reason, then a third person
shall become a co-trustee with the remaining two trustees, in accordance with
the following line of succession: first, any individual designated as the
Primary Designee, next, any individual designated as the Secondary Designee, and
then, an individual appointed by the holders of a majority in interest of the
voting trust certificates then outstanding. In the event that the Successor
Trustees shall not concur on matters not specifically contemplated by the terms
of the 1997 Voting Trust, the vote of a majority of the Successor Trustees shall
be determinative. No trustee or Successor Trustee shall possess the
Determination Power unless it is specifically conferred upon such trustee
pursuant to the provisions of the 1997 Voting Trust.

      The 1997 Voting Trust expires on August 26, 2021, subject to extension on
or after August 26, 2019 by stockholders (including the trustee of any trust
stockholder, whether or not such trust is then in existence) who deposited
shares of Class B Common Stock in the 1997 Voting Trust and are then living or,
in the case of shares in the 1997 Voting Trust the original depositor of which
(or the trustee of the original depositor of which) is not then living, the
holders of voting trust certificates representing such shares. The 1997 Voting
Trust may be amended by vote of the holders of a majority of the voting trust
certificates then outstanding and by the number of trustees authorized to take
action at the relevant time. Shares may not be removed from the 1997 Voting
Trust during its term without the consent of the trustees.



CUSIP No. 942749 10 2                  13G                         Page 15 of 15


      This summary is qualified in its entirety by reference to the 1997 Voting
Trust which is incorporated herein by reference to Exhibit 9.2 of the Issuer's
Annual Report on Form 10-K dated September 28, 1999 filed with the Securities
and Exchange Commission.