Company lists · Data refreshed September 2026

Top 25 Water resources engineering firms based in the United States

RevenueBase identified 2,861 water resources engineering firms headquartered in the United States as of September 2026 and tracks 260,253 professional contacts across them, including 118,285 with verified work emails. Houston is the largest hub.

This list covers water resources engineering firms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 19, 2026 86% judged on-target in blind review
2,861Companies
260,253Contacts tracked
118,285Verified emails
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The 25 largest water resources engineering firms based in the United States

Ranked by team size
Top 25 of 2,861 water resources engineering firms based in the United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to water resources engineering firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceDallas, TX, United StatesHQ checked Sep 19, 202610001+63,914 contacts →

Indirect evidence

“AECOM is the global infrastructure leader, committed to delivering a better world.”

Source: RevenueBase Database · checked Sep 19, 2026
2Strong evidencePasadena, CA, United StatesHQ checked Sep 19, 202610001+12,999 contacts →

Strong evidence

“Tetra Tech is the leader in water, environment and sustainable infrastructure, providing high-end technical and engineering services for projects worldwide.”

Source: RevenueBase Database · checked Sep 19, 2026
3Indirect evidenceNew York, NY, United StatesHQ checked Sep 19, 202610001+9,318 contacts →

Indirect evidence

“What if you could shape built and natural environments – and the future of those that use them?”

Source: RevenueBase Database · checked Sep 19, 2026
4Indirect evidenceEnglewood, CO, United StatesHQ checked Sep 19, 202610001+8,088 contacts →

Indirect evidence

“CH2M is now Jacobs.”

Source: RevenueBase Database · checked Sep 19, 2026
5Partial evidenceBoston, MA, United StatesHQ checked Sep 19, 20265,001-10,0007,527 contacts →

Partial evidence

“CDM Smith is shaping what’s next, now, with world class solutions in water, environment, transportation and energy to public and private clients worldwide.”

Source: RevenueBase Database · checked Sep 19, 2026
6Partial evidenceOlathe, KS, United StatesHQ checked Sep 19, 20265,001-10,0006,113 contacts →

Partial evidence

“Terracon is a 100 percent employee-owned consulting engineering firm providing quality services to clients.”

Source: RevenueBase Database · checked Sep 19, 2026
7Partial evidencePittsburgh, PA, United StatesHQ checked Sep 19, 20265,001-10,0004,362 contacts →

Partial evidence

“Michael Baker International is a leading provider of engineering, consulting, and technology services spanning four Verticals: Infrastructure, Places and Facilities, Federal and…”

Source: RevenueBase Database · checked Sep 19, 2026
8Indirect evidenceNew York, NY, United StatesHQ checked Sep 19, 20261,001-5,0003,556 contacts →

Indirect evidence

“STV offers professional services for the infrastructure that powers our lives.”

Source: RevenueBase Database · checked Sep 19, 2026
9Indirect evidenceWalnut Creek, CA, United StatesHQ checked Sep 19, 20261,001-5,0002,473 contacts →

Indirect evidence

“Headquartered in Walnut Creek, Calif, Brown and Caldwell is an employee-owned firm with 2,100+ professionals serving clients locally and globally from 52 locations.”

Source: RevenueBase Database · checked Sep 19, 2026
10Partial evidenceBoca Raton, FL, United StatesHQ checked Sep 19, 20261,001-5,0002,393 contacts →

Partial evidence

“Geosyntec is a consulting and engineering firm that works with private and public sector clients to address new ventures and complex problems involving our environment, natural…”

Source: RevenueBase Database · checked Sep 19, 2026
11Partial evidenceBaton Rouge, LA, United StatesHQ checked Sep 19, 2026n/a2,232 contacts →

Partial evidence

“Providence is an employee-owned engineering and environmental consulting firm.”

Source: RevenueBase Database · checked Sep 19, 2026
12Partial evidenceChantilly, VA, United StatesHQ checked Sep 19, 20261,001-5,0002,210 contacts →

Partial evidence

“ECS Group of Companies is a Chantilly, VA-based consulting engineering firm.”

Source: RevenueBase Database · checked Sep 19, 2026
13Partial evidenceSparks, NC, United StatesHQ checked Sep 19, 20261,001-5,0002,207 contacts →

Partial evidence

“KCI is a 100-percent employee-owned engineering, consulting and construction firm serving clients throughout the United States and beyond.”

Source: RevenueBase Database · checked Sep 19, 2026
14Indirect evidenceMoon Township, PA, United StatesHQ checked Sep 19, 20261,001-5,0002,145 contacts →

Indirect evidence

“Civil & Environmental Consultants, Inc.(CEC) provides comprehensive market-oriented consulting services that advance the strategic business objectives of its clients.”

Source: RevenueBase Database · checked Sep 19, 2026
15Partial evidenceLincoln, NE, United StatesHQ checked Sep 19, 20261,001-5,0002,108 contacts →

Partial evidence

“Olsson is an engineering firm made up of people who craft expert solutions and designs that improve communities.”

Source: RevenueBase Database · checked Sep 19, 2026
16Indirect evidenceNew York, NY, United StatesHQ checked Sep 19, 20261,001-5,0002,100 contacts →

Indirect evidence

“As Hazen marks 75 years, we celebrate a legacy of absolute commitment to our clients while delivering the best technical work available anywhere.”

Source: RevenueBase Database · checked Sep 19, 2026
17Partial evidenceRock Island, IL, United StatesHQ checked Sep 19, 20261,001-5,0001,985 contacts →

Partial evidence

“Leaders in Engineering and Innovation.”

Source: RevenueBase Database · checked Sep 19, 2026
18Indirect evidenceHouston, TX, United StatesHQ checked Sep 19, 20261,001-5,0001,932 contacts →

Indirect evidence

“Employee-Owned.”

Source: RevenueBase Database · checked Sep 19, 2026
19Partial evidenceWalnut Creek, CA, United StatesHQ checked Sep 19, 20261,001-5,0001,718 contacts →

Partial evidence

“For more than 90 years, Carollo Engineers has been dedicated exclusively to water and wastewater solutions.”

Source: RevenueBase Database · checked Sep 19, 2026
20Partial evidenceAlbany, NY, United StatesHQ checked Sep 19, 20261,001-5,0001,639 contacts →

Partial evidence

“CHA Consulting, Inc.(CHA) is an innovative, full-service engineering, design, consulting, and program/construction management firm providing a wide range of technology-enhanced…”

Source: RevenueBase Database · checked Sep 19, 2026
21Indirect evidencePhoenix, AZ, United StatesHQ checked Sep 19, 20261,001-5,0001,629 contacts →

Indirect evidence

“Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.”

Source: RevenueBase Database · checked Sep 19, 2026
22Indirect evidenceWoburn, MA, United StatesHQ checked Sep 19, 20261,001-5,0001,604 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 19, 2026
23Strong evidenceNorth Little Rock, AR, United StatesHQ checked Sep 19, 20261,001-5,0001,499 contacts →

Strong evidence

“Founded in 1919, Garver is an employee-owned engineering, planning, and environmental services firm focused on aviation, transportation, buildings, federal, water and wastewater…”

Source: RevenueBase Database · checked Sep 19, 2026
24Partial evidenceFort Worth, TX, United StatesHQ checked Sep 19, 20261,001-5,0001,496 contacts →

Partial evidence

“Freese and Nichols is a professional planning, consulting and engineering firm serving clients across the United States.”

Source: RevenueBase Database · checked Sep 19, 2026
25Partial evidenceKent, OH, United StatesHQ checked Sep 19, 20261,001-5,0001,395 contacts →

Partial evidence

“Davey Resource Group, Inc.(DRG) provides innovative consulting and field services that support utility infrastructure and environmental stewardship.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 2,861 water resources engineering firms based in the United States

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Water resources engineering firms based in the United States at a glance

As of Sep 19, 2026
45.5%Verified-email coverage
91.0Average contacts per company
11-50Median size (employees)
2.3%Largest-city concentration · Houston
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
1,270
11-50
983
51-200
394
201-500
103
501-1,000
38
1,001-5,000
53
5,001-10,000
7
10001+
10

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 2,861 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among water resources engineering firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “water resources engineering firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names water resources engineering firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among water resources engineering firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 118,285 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 19, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names water resources engineering firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many water resources engineering firms are there based in the United States?

RevenueBase identified 2,861 water resources engineering firms headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

AECOM, headquartered in Dallas, tops this list with the largest team on record.

Which city has the most water resources engineering firms?

Houston leads with 65 headquartered companies, followed by Tampa (34) and Austin (32).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 118,285 verified decision-maker contacts tracked across these 2,861 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.