Company lists · Data refreshed September 2026

Top 25 Water resource management firms based in the United States

Name: Water resource management firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 22, 2026 2,184 companies tracked

RevenueBase identified 2,184 water resource management firms headquartered in the United States as of September 2026 and tracks 199,260 professional contacts across them, including 90,591 with verified work emails. Houston is the largest hub.

This list covers water resource management 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 22, 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 22, 2026 86% judged on-target in blind review

2,184Companies

199,260Contacts tracked

90,591Verified emails

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The 25 largest water resource management firms based in the United States

Ranked by team size

Top 25 of 2,184 water resource management firms based in the United States, ranked by team size, largest first. Data refreshed Sep 22, 2026. RevenueBase Smart Search rates how each company's information relates to water resource management 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	AECOM	Indirect evidence	Dallas, TX, United StatesHQ checked Sep 22, 2026	10001+	63,914 contacts →
	Indirect evidence “AECOM is the global infrastructure leader, committed to delivering a better world.” Source: RevenueBase Database · checked Sep 22, 2026
2	Tetra Tech	Partial evidence	Pasadena, CA, United StatesHQ checked Sep 22, 2026	10001+	12,999 contacts →
	Partial 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 22, 2026
3	WSP In The U.S	Indirect evidence	New York, NY, United StatesHQ checked Sep 22, 2026	10001+	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 22, 2026
4	CDM Smith	Partial evidence	Boston, MA, United StatesHQ checked Sep 22, 2026	5,001-10,000	7,527 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 22, 2026
5	Michael Baker International	Indirect evidence	Pittsburgh, PA, United StatesHQ checked Sep 22, 2026	5,001-10,000	4,362 contacts →
	Indirect 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 22, 2026
6	Brown And Caldwell	Indirect evidence	Walnut Creek, CA, United StatesHQ checked Sep 22, 2026	1,001-5,000	2,473 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 22, 2026
7	Geosyntec Consultants	Indirect evidence	Boca Raton, FL, United StatesHQ checked Sep 22, 2026	1,001-5,000	2,393 contacts →
	Indirect 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 22, 2026
8	Civil & Environmental Consultants, INC	Indirect evidence	Moon Township, PA, United StatesHQ checked Sep 22, 2026	1,001-5,000	2,145 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 22, 2026
9	Olsson	Indirect evidence	Lincoln, NE, United StatesHQ checked Sep 22, 2026	1,001-5,000	2,108 contacts →
	Indirect evidence “Olsson is an engineering firm made up of people who craft expert solutions and designs that improve communities.” Source: RevenueBase Database · checked Sep 22, 2026
10	Hazen And Sawyer	Indirect evidence	New York, NY, United StatesHQ checked Sep 22, 2026	1,001-5,000	2,100 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 22, 2026
11	LJA	Indirect evidence	Houston, TX, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,932 contacts →
	Indirect evidence “Employee-Owned.” Source: RevenueBase Database · checked Sep 22, 2026
12	Carollo Engineers	Partial evidence	Walnut Creek, CA, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,718 contacts →
	Partial evidence “For more than 90 years, Carollo Engineers has been dedicated exclusively to water and wastewater solutions.” Source: RevenueBase Database · checked Sep 22, 2026
13	Rk&k	Partial evidence	Baltimore, MD, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,641 contacts →
	Partial evidence “RK & K is a full-service planning, engineering, environmental, and construction management/inspection firm serving a wide range of clients throughout the United States.” Source: RevenueBase Database · checked Sep 22, 2026
14	GEI Consultants, INC	Indirect evidence	Woburn, MA, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,604 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 22, 2026
15	Freese And Nichols	Indirect evidence	Fort Worth, TX, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,496 contacts →
	Indirect evidence “Freese and Nichols is a professional planning, consulting and engineering firm serving clients across the United States.” Source: RevenueBase Database · checked Sep 22, 2026
16	Volkert, INC	Indirect evidence	Mobile, AL, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,199 contacts →
	Indirect evidence “Volkert’s history began in 1925 when it was founded in New Orleans as Doullut & Erwin to provide waterfront and heavy construction services, as well as airport design services…” Source: RevenueBase Database · checked Sep 22, 2026
17	Verdantas	Indirect evidence	Tampa, FL, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,139 contacts →
	Indirect evidence “At Verdantas, we blend engineering and environmental science together with advanced technology and world-renowned labs to create solutions with the big picture in mind.” Source: RevenueBase Database · checked Sep 22, 2026
18	Apex Companies	Indirect evidence	Rockville, MD, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,137 contacts →
	Indirect evidence “Who is Apex?” Source: RevenueBase Database · checked Sep 22, 2026
19	Haley & Aldrich	Indirect evidence	Burlington, MA, United StatesHQ checked Sep 22, 2026	501-1,000	1,124 contacts →
	Indirect evidence “Haley & Aldrich is committed to solving our clients’ most meaningful challenges in the built and natural environments.” Source: RevenueBase Database · checked Sep 22, 2026
20	Barr Engineering CO	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,088 contacts →
	Indirect evidence “Barr provides engineering and environmental consulting services to clients across the Midwest, throughout the Americas, and around the world.” Source: RevenueBase Database · checked Sep 22, 2026
21	Woodard & Curran	Partial evidence	Portland, ME, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,060 contacts →
	Partial evidence “Woodard & Curran is more than just a consulting firm – we are an employee-owned integrated science, engineering, design-build, and operations company specializing in water and…” Source: RevenueBase Database · checked Sep 22, 2026
22	WSB	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 22, 2026	1,001-5,000	1,053 contacts →
	Indirect evidence “Forge ahead.” Source: RevenueBase Database · checked Sep 22, 2026
23	David Evans And Associates, INC	Partial evidence	Portland, OR, United StatesHQ checked Sep 22, 2026	501-1,000	1,031 contacts →
	Partial evidence “Since its founding in 1976 in Portland, Oregon, DEA has become a recognized leader for progressive and sustainable design and management solutions for complex transportation, land…” Source: RevenueBase Database · checked Sep 22, 2026
24	Inframark	Strong evidence	Horsham, PA, United StatesHQ checked Sep 22, 2026	1,001-5,000	973 contacts →
	Strong evidence “As an Azuria owned company, Inframark is a widely recognized leader in Water Infrastructure Operations and Infrastructure Management Services.” Source: RevenueBase Database · checked Sep 22, 2026
25	GAI Consultants, INC	Indirect evidence	Homestead, PA, United StatesHQ checked Sep 22, 2026	501-1,000	964 contacts →
	Indirect evidence “Transforming ideas into reality® since 1958, GAI Consultants is an engineering, planning, and environmental consulting firm that provides customized solutions and local expertise…” Source: RevenueBase Database · checked Sep 22, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: water resource management firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names water resource management firms.
Partial evidence: Its own public description names part of water resource management firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name water resource management firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 2,184 water resource management firms based in the United States

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Water resource management firms based in the United States at a glance

As of Sep 22, 2026

45.5%Verified-email coverage

91.2Average contacts per company

11-50Median size (employees)

2.6%Largest-city concentration · Houston

Sep 22, 2026Page data refreshed

Companies by employee count

1-10

986

11-50

740

51-200

299

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

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 2,184 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 resource management 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 resource management 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 resource management 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 resource management 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, 90,591 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 22, 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.

Water resource management firms by metro

Water resource management firms in Houston56

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 resource management 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 resource management firms are there based in the United States?

RevenueBase identified 2,184 water resource management 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 resource management firms?

Houston leads with 56 headquartered companies, followed by Austin (23) and Portland (23).

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 90,591 verified decision-maker contacts tracked across these 2,184 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 22, 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.