EXHIBIT 99.1 Exhibit 99.1 NEWS RELEASE January 29, 2025 Tetra Tech Reports Strong First Quarter Results ·   Record Revenue $1.42 billion, up 16% Y/Y ·   Record Net Revenue $1.20 billion, up 18% Y/Y ·   Operating Income $23 million; adjusted operating income $138 million, up 24% Y/Y ·   Record Backlog $5.44 billion, up 15% Y/Y ·   Raised high-end and reaffirmed midpoint of FY25 EPS guidance Pasadena, California . Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services in water, environment and sustainable infrastructure, today announced results for the first quarter ended December 29, 2024. First Quarter Highlights · Revenue increased 16% Y/Y to $1.42 billion · Net Revenue 1 increased 18% Y/Y to $1.20 billion · Operating Income $23 million; adjusted Operating Income increased 24% Y/Y to $138 million · EPS $0.00; adjusted EPS 1 increased 25% Y/Y to $0.35 · Backlog increased 15% Y/Y to $5.44 billion · Industry-leading DSO of 55.9 days Recent Key Wins · $498 million five-year multiple award contracts to deliver architect-engineering services and civil works support for USACE in Los Angeles and Japan Districts · $249 million five-year multiple award contract for planning and engineering services for USACE Mobile District · $100 million five-year multiple award contract for the Office of Land and Emergency Management for research and analysis of emerging advanced environmental technologies · $66 million five-year single award contract to provide disaster and emergency response services in the U.S. Midwest · $46 million multiple award architect-engineering contract for flood and emergency response for USACE 1 Non-GAAP financial measures which the Company believes provide valuable perspectives on its business results. Refer to tables at the end of the release and Regulation G Information for reconciliations to the comparable GAAP metrics. Chairman and CEO Comments Dan Batrack, Chairman and CEO, commented, “Tetra Tech began fiscal 2025 with a strong first quarter, which included all-time record high quarterly revenue and backlog, and record high first quarter adjusted operating income and EPS. We continued to see significant demand for our differentiated services in water, environment, and sustainable infrastructure across our global operations. In the first quarter, we added over $1 billion of new contract capacity, which included contracts for essential water supply, flood control structures and inland navigation. With our record backlog and momentum, we are well positioned to respond to our U.S. and international clients’ priorities.” Quarterly Dividend and Share Repurchase Program On January 27, 2025, Tetra Tech’s Board of Directors approved the Company’s 43 rd consecutive quarterly dividend at an amount of $0.058 per share, a 12% increase year-over-year, payable on February 26, 2025, to stockholders of record as of February 12, 2025. In the first quarter, Tetra Tech repurchased $25 million of common stock. Additionally, as of December 29, 2024, the Company had $323 million remaining under its $400 million share repurchase program. Business Outlook The following statements are based on current expectations. These statements are forward-looking, and the actual results could differ materially. These statements do not include the potential impact of transactions that may be completed or developments that become evident after the date of this release. The Business Outlook section should be read in conjunction with the information on forward-looking statements at the end of this release. At the direction of the new U.S. Administration, Tetra Tech has paused some of its U.S. federal government work, particularly with USAID, while assisting our clients with their review of multiple programs across the various government agencies we support. Tetra Tech has updated its guidance for fiscal year 2025 based on its current outlook, which includes the potential impact of the ongoing U.S. federal government review process. For fiscal 2025, Tetra Tech expects the full year guidance for net revenue 2 to range from $4.365 billion to $4.765 billion and adjusted EPS 3 to range from $1.37 to $1.52. For the second quarter in fiscal 2025, Tetra Tech expects net revenue to range from $1.0 billion to $1.1 billion and EPS to range from $0.30 to $0.33. Webcast Investors will have the opportunity to access a live audio-visual webcast and supplemental financial information concerning the first quarter of fiscal 2025 results through a link posted on the Company’s website at tetratech.com on January 30, 2025, at 8:00 a.m. (PT). 2 Reconciliation of the net revenue guidance to the most directly comparable GAAP measure is not available without unreasonable efforts because the Company cannot predict the magnitude and timing of all the components, including subcontractor costs, required to provide such reconciliation with sufficient precision. 3 The only adjustment in our guidance for EPS is to exclude the legal settlement costs of $0.35 in the first quarter of fiscal 2025. Reconciliation of GAAP and Non-GAAP Items In thousands (except EPS data) Three Months Ended December 29, 2024 December 31, 2023 Revenue $ 1,420,561 $ 1,228,267 Subcontractor costs (223,231 ) (213,098 ) Net revenue $ 1,197,330 $ 1,015,169 Operating Income $ 22,526 $ 111,081 Legal contingency costs 115,000 - Contingent consideration - (37 ) Adjusted Operating Income $ 137,526 $ 111,044 EPS $ 0.00 $ 0.28 Legal contingency costs 0.35 - Adjusted EPS $ 0.35 $ 0.28 About Tetra Tech Tetra Tech is the leader in water, environment and sustainable infrastructure, providing high-end consulting and engineering services for projects worldwide. With 30,000 employees working together, Tetra Tech provides clear solutions to complex problems by Leading with Science ® to address the entire water cycle, protect and restore the environment, design sustainable and resilient infrastructure, and support the clean energy transition. For more information about Tetra Tech, please visit tetratech.com or follow us on LinkedIn and Facebook . CONTACTS: Jim Wu, Investor Relations Charlie MacPherson, Media & Public Relations (626) 470-2844 Forward-Looking Statements This release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. The use of words such as "anticipate," "expect," "could," "may," "intend," "plan" and "believe," among others, generally identify forward-looking statements. These forward-looking statements are based on current expectations and beliefs of Tetra Tech’s management and currently available operating, financial, economic and other information, and are subject to a number of risks and uncertainties. Readers are cautioned that these forward-looking statements are only predictions and may differ materially from actual future events or results. A variety of factors, many of which are beyond our control, could cause actual future results or events to differ materially from those projected in the forward-looking statements in this release, including but not limited to: continuing worldwide political and economic uncertainties; the U.S. Administration’s potential changes to fiscal policies; the cyclicality in demand for our overall services; the fluctuation in demand for oil and gas, and mining services; risks related to international operations; concentration of revenues from U.S. government agencies and potential funding disruptions by these agencies; dependence on winning or renewing U.S. government contracts; the delay or unavailability of public funding on U.S. government contracts; the U.S. government’s right to modify, delay, curtail or terminate contracts at its convenience; compliance with government procurement laws and regulations; the impact of global pandemics; credit risks associated with certain clients in certain geographic areas or industries; acquisition strategy and integration risks; goodwill or other intangible asset impairment; the failure to comply with worldwide anti-bribery laws; the failure to comply with domestic and international export laws; the failure to properly manage projects; the loss of key personnel or the inability to attract and retain qualified personnel; the ability of our employees to obtain government granted eligibility; the use of estimates and assumptions in the preparation of financial statements; the ability to maintain adequate workforce utilization; the use of the percentage-of-completion method of accounting; the inability to accurately estimate and control contract costs; the failure to adequately recover on our claims for additional contract costs; the failure to win or renew contracts with private and public sector clients; growth strategy management; backlog cancellation and adjustments; risks relating to cyber security breaches; the failure of partners to perform on joint projects; the failure of subcontractors to satisfy their obligations; requirements to pay liquidated damages based on contract performance; the adoption of new legal requirements; changes in resource management, environmental or infrastructure industry laws, regulations or programs; changes in bank and capital markets and the access to capital; credit agreement covenants; industry competition; liability related to legal proceedings, investigations, and disputes; the availability of third-party insurance coverage; the ability to obtain adequate bonding; employee, agent, or partner misconduct; employee risks related to international travel; safety programs; conflict of interest issues; liabilities relating to reports and opinions; liabilities relating to environmental laws and regulations; force majeure events; protection of intellectual property rights; stock price volatility; the ability to impede a business combination based on Delaware law and charter documents; and other risks and uncertainties as may be described in Tetra Tech’s periodic filings with the Securities and Exchange Commission, including those described in the “Risk Factors” section of Tetra Tech’s Annual Report on Form 10-K for the fiscal year ended September 29, 2024. Readers should not place undue reliance on forward-looking statements since such information speaks only as of the date of this release. Tetra Tech does not intend to update forward-looking statements and expressly disclaims any obligation to do so. Non-GAAP Financial Measures To supplement the financial results presented in accordance with generally accepted accounting principles in the United States (“GAAP”), we present certain non-GAAP financial measures within the meaning of Regulation G under the Securities Exchange Act of 1934, as amended. We provide these non-GAAP financial measures because we believe they provide a valuable perspective on our financial results. However, non-GAAP measures have limitations as analytical tools and should not be considered in isolation and are not in accordance with, or a substitute for, GAAP measures. In addition, other companies may define non-GAAP measures differently which limits the ability of investors to compare non-GAAP measures of Tetra Tech to those used by our peer companies. A reconciliation of these non-GAAP financial measures to the most directly comparable GAAP financial measures is set forth above in this release. Tetra Tech, Inc Consolidated Balance Sheets (unaudited - in thousands, except par value) As of December 29, September 29, 2024 2024 Assets Current assets: Cash and cash equivalents 248,104 232,689 Accounts receivable, net 1,117,666 1,051,461 Contract assets 122,310 129,678 Prepaid expenses and other current assets 143,768 113,555 Total current assets 1,631,848 1,527,383 Property and equipment, net 67,102 73,065 Right-of-use assets, operating leases 172,080 177,950 Goodwill 1,968,684 2,046,569 Intangible assets, net 142,097 160,585 Deferred tax assets 96,916 105,529 Other non-current assets 100,457 101,595 Total assets 4,179,184 4,192,676 Liabilities and Equity Current liabilities: Accounts payable 238,157 197,440 Accrued compensation 222,549 332,096 Contract liabilities 359,957 351,738 Short-term lease liabilities, operating leases 61,184 63,419 Current contingent earn-out liabilities 24,153 26,934 Other current liabilities 361,345 247,900 Total current liabilities 1,267,345 1,219,527 Deferred tax liabilities 24,902 30,162 Long-term debt 888,450 812,634 Long-term lease liabilities, operating leases 134,759 140,095 Non-current contingent earn-out liabilities 22,007 21,812 Other non-current liabilities 149,702 138,033 Equity: Preferred stock - authorized, 2,000 shares of $0.01 par value; no shares issued and outstanding at December 29, 2024 and September 29, 2024 - - Common stock - authorized, 750,000 shares of $0.01 par value; issued and outstanding, 268,028 and 267,717 shares at December 29, 2024 and September 29, 2024, respectively 2,680 2,677 Additional paid-in capital 21,153 35,900 Accumulated other comprehensive loss (187,754 ) (78,875 ) Retained earnings 1,855,818 1,870,620 Tetra Tech stockholders' equity 1,691,897 1,830,322 Noncontrolling interests 122 91 Total stockholders' equity 1,692,019 1,830,413 Total liabilities and stockholders' equity 4,179,184 4,192,676 Tetra Tech, Inc. Consolidated Statements of Income (unaudited - in thousands, except per share data) Three Months Ended December 29, December 31, 2024 2023 Revenue $ 1,420,561 $ 1,228,267 Subcontractor costs (223,231 ) (213,098 ) Other costs of revenue (975,853 ) (824,671 ) Gross profit 221,477 190,498 Selling, general and administrative expenses (83,951 ) (79,417 ) Legal contingency costs (115,000 ) - Income from operations 22,526 111,081 Interest expense, net (7,218 ) (9,577 ) Income before income tax expense 15,308 101,504 Income tax expense (14,530 ) (26,524 ) Net income 778 74,980 Net income attributable to noncontrolling interests (31 ) (8 ) Net income attributable to Tetra Tech $ 747 $ 74,972 Earnings per share attributable to Tetra Tech: Basic $ 0.00 $ 0.28 Diluted $ 0.00 $ 0.28 Weighted-average common shares outstanding: Basic 267,854 266,585 Diluted 271,886 268,690 Tetra Tech, Inc. Consolidated Statements of Cash Flows (unaudited - in thousands) Three Months Ended December 29, December 31, 2024 2023 Cash flows from operating activities: Net income $ 778 $ 74,980 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 16,063 19,484 Amortization of stock-based awards 8,142 7,641 Deferred income taxes 767 (1,624 ) Other non-cash items 775 123 Changes in operating assets and liabilities, net of effects of business acquisitions: Accounts receivable and contract assets (91,725 ) (22,288 ) Prepaid expenses and other assets (26,186 ) (28,615 ) Accounts payable 44,194 33,790 Accrued compensation (101,641 ) (80,069 ) Contract liabilities 27,527 41,862 Income taxes receivable/payable (1,538 ) (15,941 ) Cash settled contingent earn-out liability (2,720 ) - Other liabilities 138,627 (20,097 ) Net cash provided by operating activities 13,063 9,246 Cash flows from investing activities: Capital expenditures (3,433 ) (3,434 ) Net cash used in investing activities (3,433 ) (3,434 ) Cash flows from financing activities: Proceeds from borrowings 90,000 125,000 Repayments on long-term debt (15,000 ) (60,000 ) Repurchases of common stock (25,000 ) - Shares repurchased for tax withholdings on share-based awards (13,307 ) (12,670 ) Payments of contingent earn-out liabilities (145 ) (18,862 ) Stock options exercised 114 335 Dividends paid (15,549 ) (13,873 ) Principal payments on finance leases (1,719 ) (1,539 ) Net cash provided by financing activities 19,394 18,391 Effect of exchange rate changes on cash and cash equivalents (13,609 ) 5,655 Net increase in cash and cash equivalents 15,415 29,858 Cash and cash equivalents at beginning of period 232,689 168,831 Cash and cash equivalents at end of period $ 248,104 $ 198,689 Supplemental information: Cash paid during the period for: Interest $ 4,295 $ 6,369 Income taxes, net of refunds received of $1.7 million and $0.9 million $ 14,489 $ 43,297 Tetra Tech, Inc. Regulation G Information December 29, 2024 Reconciliation of Revenue to Revenue, Net of Subcontractor Costs ("Net Revenue") (in millions) 2024 2025 2022 2023 1st Qtr 2nd Qtr 6 mos 3rd Qtr 9 Mos 4th Qtr Total 1st Qtr Consolidated Revenue 3,504.0 4,522.6 1,228.3 1,251.6 2,479.9 1,344.3 3,824.2 1,374.5 5,198.7 1,420.6 Subcontractor Costs (668.5 ) (771.5 ) (213.1 ) (199.0 ) (412.1 ) (234.7 ) (646.8 ) (230.0 ) (876.8 ) (223.3 ) Net Revenue 2,835.5 3,751.1 1,015.2 1,052.6 2,067.8 1,109.6 3,177.4 1,144.5 4,321.9 1,197.3 GSG Segment Revenue 1,820.9 2,158.9 575.0 597.1 1,172.2 640.6 1,812.7 670.6 2,483.4 751.8 Subcontractor Costs (484.4 ) (523.4 ) (132.3 ) (130.6 ) (263.0 ) (152.3 ) (415.3 ) (158.1 ) (573.4 ) (150.6 ) Net Revenue 1,336.5 1,635.5 442.7 466.5 909.2 488.3 1,397.4 512.5 1,910.0 601.2 CIG Segment Revenue 1,738.4 2,424.6 669.1 671.2 1,340.3 723.6 2,063.9 722.9 2,786.7 688.2 Subcontractor Costs (239.3 ) (309.0 ) (96.6 ) (85.1 ) (181.7 ) (102.2 ) (283.9 ) (90.9 ) (374.8 ) (92.1 ) Net Revenue 1,499.1 2,115.6 572.5 586.1 1,158.6 621.4 1,780.0 632.0 2,411.9 596.1 Reconciliation of Net Income Attributable to Tetra Tech to Adjusted EBITDA (in thousands) 2024 2025 2022 2023 1st Qtr 2nd Qtr 6 mos 3rd Qtr 9 Mos 4th Qtr Total 1st Qtr Net Income Attributable to Tetra Tech 263,125 273,420 74,972 76,446 151,418 85,810 237,228 96,154 333,382 747 Income Tax Expense 85,602 127,526 26,523 31,341 57,864 32,894 90,757 39,266 130,023 14,530 Interest Expense 1 11,584 46,537 9,578 9,883 19,461 9,912 29,374 7,897 37,271 7,218 Depreciation 13,859 19,980 6,951 5,637 12,588 5,713 18,301 5,421 23,722 5,402 Amortization 13,174 41,226 12,533 12,094 24,627 13,790 38,417 11,538 49,955 10,661 FX Hedge Gain (19,904 ) (89,402 ) - - - - - - - - EBITDA 367,440 419,287 130,557 135,401 265,958 148,119 414,077 160,276 574,353 38,558 Contingent Consideration - 12,255 (37 ) 14 (22 ) 500 477 2,064 2,541 - Acquisition & Integration Expenses 2 - 49,554 - - - - - 7,138 7,138 - Legal Contingency Costs - - - - - - - - - 115,000 COVID-19 Credits (6,486 ) - - - - - - - - - Adjusted EBITDA 360,954 481,096 130,520 135,415 265,936 148,619 414,554 169,478 584,032 153,558 1 Includes write-off of deferred debt origination fees of $3.8 million in fiscal 2023 2 Includes lease impairment charge of $16.4M in fiscal 2023

the item shown at left

other guidance in this release

Text is the filed exhibit, verbatim.