Tetra Tech Awarded $33 Million USACE Contract for Hurricane Protection in New Orleans

Tetra Tech, Inc. (NASDAQ: TTEK) announced today that it has been awarded a $33.3 million contract to build a hurricane risk reduction floodwall and five floodgates in New Orleans, Louisiana. Tetra Tech will provide civil construction services to support the U.S. Army Corps of Engineers (USACE) Hurricane Protection Office. The 18-month firm-fixed price contract includes demolition, floodwall construction, and earthwork along the lakefront levee reach from the 17^th Street Canal to Topaz Street.

"We are committed to providing the 100-year level of risk reduction for the greater New Orleans area in 2011,” said Col. Robert Sinkler, Commander of the Hurricane Protection Office.

"New Orleans’ soft soil conditions are exacerbated during wet weather events, making this a uniquely challenging project,” said Dan Batrack, Tetra Tech’s Chairman and CEO. "Tetra Tech is proud to partner with USACE to help protect the Gulf Coast, home to more than 2 million people and many of the United States’ most economically vital ports and waterways.”

About Tetra Tech (www.tetratech.com)

Tetra Tech is a leading provider of consulting, engineering, program management, construction, and technical services addressing the resource management and infrastructure markets. The Company supports government and commercial clients by providing innovative solutions focused on water, the environment, and energy. With more than 10,000 employees worldwide, Tetra Tech’s capabilities span the entire project life cycle.

Any statements made in this release that are not based on historical fact are forward-looking statements. Any forward-looking statements made in this release represent management’s best judgment as to what may occur in the future. However, Tetra Tech’s actual outcome and results are not guaranteed and are subject to certain risks, uncertainties and assumptions ("Future Factors"), and may differ materially from what is expressed. For a description of Future Factors that could cause actual results to differ materially from such forward-looking statements, see the discussion under the section "Risk Factors" included in the Company’s Form 10-K and 10-Q filings with the Securities and Exchange Commission.