Ownership Submission
FORM 5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Form 3 Holdings Reported
Form 4 Transactions Reported
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

ANNUAL STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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1. Name and Address of Reporting Person *
WHALEN DANIEL A
 2. Issuer Name and Ticker or Trading Symbol
TETRA TECH INC [TTEK] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
_____ Officer (give title below) __X__ Other (specify below)
Retired Director
(Last)
(First)
(Middle)

5866 OSTRANDER ROAD		 3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year)
09/30/2006
(Street)


OAKLAND, CA 94618		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Reporting
(check applicable line)

_X_ Form Filed by One Reporting Person
___ Form Filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned at end of Issuer's Fiscal Year
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Amount (A) or (D) Price
Common Stock             374,992 I See Note (1)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned at End of Issuer's Fiscal Year
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
(A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Options - Common Stock               (3)   (4) Common Stock
24,000
  24,000
D
 

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
WHALEN DANIEL A
5866 OSTRANDER ROAD
OAKLAND, CA 94618		       Retired Director

Signatures

Jeffrey D. Cornelius, For Brown Investment Advisory & Trust Co., Under Power of Attorney Dated 1/22/99 11/01/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Shares are held in the name of the Daniel A. Whalen 2006 Grantor Retained Annuity Trust, dated May 6, 2006 [187,496 shares] and the Katharine C. Whalen Grantor Retained Annuity Trust, dated May 6, 2006 [187,496 shares].
(2) Exercise price for options issued 3/1/2003 is $13.16 per share. Exercise price for options issued 3/1/2004 is $21.41 per share. Exercise price for options issued 3/1/2005 is $16.55 per share.
(3) Options are fully vested.
(4) Options granted on 3/1/2003 expire 3/2/2013. Options granted on 3/1/2004 expire 3/2/2014. Options granted on 3/1/2005 expire 3/2/2015.

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