Company lists · Data refreshed September 2026

Top 25 Hydro engineering and consulting firms based in Houston, United States

Name: Hydro engineering and consulting firms based in Houston, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 182 companies tracked

RevenueBase identified 182 hydro engineering and consulting firms headquartered in Houston, United States as of September 2026 and tracks 10,145 professional contacts across them, including 5,323 with verified work emails. Across the United States, Houston is the largest hub for this category.

This list covers hydro engineering and consulting firms headquartered in Houston, 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 28, 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 28, 2026 86% judged on-target in blind review

182Companies

10,145Contacts tracked

5,323Verified emails

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The 25 largest hydro engineering and consulting firms based in Houston, United States

Ranked by team size

Top 25 of 182 hydro engineering and consulting firms based in Houston, United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to hydro engineering and consulting 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	LJA	Indirect evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	1,001-5,000	1,932 contacts →
	Indirect evidence “Employee-Owned.” Source: RevenueBase Database · checked Sep 28, 2026
2	Walter P Moore	Indirect evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	1,001-5,000	1,298 contacts →
	Indirect evidence “Welcome to Walter P Moore!” Source: RevenueBase Database · checked Sep 28, 2026
3	Bge, INC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	1,001-5,000	1,112 contacts →
	Indirect evidence “Ranked No.” Source: RevenueBase Database · checked Sep 28, 2026
4	Quiddity	Strong evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	501-1,000	683 contacts →
	Strong evidence “Quiddity is an award-winning, full-service civil engineering, planning, surveying, and consulting firm providing innovative solutions for public infrastructure and private…” Source: RevenueBase Database · checked Sep 28, 2026
5	Lockwood, Andrews & Newnam, Inc. LAN	Strong evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	201-500	461 contacts →
	Strong evidence “Lockwood, Andrews & Newnam, Inc.(LAN) is a full-service consulting firm offering planning, engineering and program management services.” Source: RevenueBase Database · checked Sep 28, 2026
6	Tolunay-Wong Engineers, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	201-500	260 contacts →
	Partial evidence “Founded in 1993, Tolunay-Wong Engineers, Inc.(TWE) is ranked as one of the Top 10 largest civil engineering firms in Houston.” Source: RevenueBase Database · checked Sep 28, 2026
7	GSI Environmental INC	Strong evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	201-500	259 contacts →
	Strong evidence “GSI Environmental, Inc.(GSI), is an environmental engineering and science consulting firm committed to measuring, analyzing, and solving complex environmental problems around the…” Source: RevenueBase Database · checked Sep 28, 2026
8	Ehra Engineering	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	201-500	247 contacts →
	Partial evidence “EHRA Engineering is a civil engineering, surveying, low impact developing, land planning, construction phase services, traffic, emergency management and landscape architecture…” Source: RevenueBase Database · checked Sep 28, 2026
9	HVJ Associates	Indirect evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	199 contacts →
	Indirect evidence “Completing public infrastructure projects comes with tremendous pressure to serve the public while completing each project on-time and on-budget.” Source: RevenueBase Database · checked Sep 28, 2026
10	IDS Engineering Group	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	182 contacts →
	Partial evidence “Founded in 1970, IDS Engineering Group is a Houston-based civil engineering and surveying firm with over five decades of experience delivering infrastructure solutions for public…” Source: RevenueBase Database · checked Sep 28, 2026
11	Zentech Incorporated	Strong evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	181 contacts →
	Strong evidence “Zentech, Inc, an engineering consulting and software development company, headquartered in Houston, TX, is comprised of experienced professionals specializing in providing…” Source: RevenueBase Database · checked Sep 28, 2026
12	Shah Smith & Associates, INC	Strong evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	134 contacts →
	Strong evidence “Shah Smith & Associates, Inc.(SSA) is a 120+ employee Mechanical, Electrical, and Plumbing (MEP) consulting engineering firm with offices in Houston, Austin & Dallas.” Source: RevenueBase Database · checked Sep 28, 2026
13	Dec, NOW GFT	Indirect evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	1,001-5,000	128 contacts →
	Indirect evidence “Gannett Fleming is a privately held AEC firm partnering closely with our clients on some of the toughest challenges facing our communities today-and into the future.” Source: RevenueBase Database · checked Sep 28, 2026
14	RG Miller Dccm	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	111 contacts →
	Partial evidence “RG Miller \| DCCM is a Houston-based civil engineering firm providing a wide range of infrastructure services to both public and private sector clients in Texas.” Source: RevenueBase Database · checked Sep 28, 2026
15	S&b Infrastructure, LTD	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	97 contacts →
	Partial evidence “S&B Infrastructure, Ltd.(S & BI) has been in existence since 1994 as part of S&B Holdings, Ltd,(one of the largest privately-owned engineering firms in the State of Texas).” Source: RevenueBase Database · checked Sep 28, 2026
16	Nearterm Corporation	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	80 contacts →
	Partial evidence “Based in Houston, Texas, Nearterm Corporation is one of the nation’s leading executive search, interim staffing and consulting firms with two distinct market focuses in Healthcare…” Source: RevenueBase Database · checked Sep 28, 2026
17	Omega Engineers, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	79 contacts →
	Partial evidence “Founded in 1984, OMEGA is an engineering and construction management firm specializing in infrastructure, civil engineering, highway engineering, transportation planning, railway…” Source: RevenueBase Database · checked Sep 28, 2026
18	A&s Engineers, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	79 contacts →
	Partial evidence “The objective of A&S is to provide municipal engineering services, with focus on water districts, municipalities, and land development.” Source: RevenueBase Database · checked Sep 28, 2026
19	Civitas Engineering Group, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	65 contacts →
	Partial evidence “Civitas Engineering Group Inc.” Source: RevenueBase Database · checked Sep 28, 2026
20	Idcus INC	Strong evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	64 contacts →
	Strong evidence “Infrastructure Consulting & Engineering, LLC (formerly IDCUS Inc.), is a leading Texas-based professional services, civil engineering, and consulting firm specializing in public…” Source: RevenueBase Database · checked Sep 28, 2026
21	Pinnacle Engineering	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	62 contacts →
	Partial evidence “Since 1993, Pinnacle has remained focused on providing practical and complete engineering services to the offshore oil and gas industry.” Source: RevenueBase Database · checked Sep 28, 2026
22	Odyssey Engineering Group, LLC	Strong evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	11-50	59 contacts →
	Strong evidence “Odyssey Engineering Group is a Houston based civil engineering consulting firm.” Source: RevenueBase Database · checked Sep 28, 2026
23	Dally Associates	Indirect evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	11-50	57 contacts →
	Indirect evidence “Founded in 1993, Dally + Associates, Inc.” Source: RevenueBase Database · checked Sep 28, 2026
24	Decon LLC	Strong evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	11-50	55 contacts →
	Strong evidence “MBE \| SBE \| DBE \| HUB \| HHF, TBPE Firm No 16156 DECON LLC,founded by Fulvio Jaramillo, a consulting engineering firm committed to technical excellence, DECON’s services help…” Source: RevenueBase Database · checked Sep 28, 2026
25	JDM Group Company, LLC	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	51-200	51 contacts →
	Partial evidence “Since 2008… JDM Group Company has been providing consulting and construction services for both public and private sector clients in a cost effective, timely, and innovative manner.” Source: RevenueBase Database · checked Sep 28, 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: hydro engineering and consulting 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 hydro engineering and consulting firms.
Partial evidence: Its own public description names part of hydro engineering and consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name hydro engineering and consulting 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 182 hydro engineering and consulting firms based in Houston, United States

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Hydro engineering and consulting firms based in Houston, United States at a glance

As of Sep 28, 2026

52.5%Verified-email coverage

55.7Average contacts per company

11-50Median size (employees)

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

Email recency for this list is measured across the whole United States list rather than for Houston, so it is reported there. Company counts and contact totals on this page are exact for Houston, over 182 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 hydro engineering and consulting 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 Houston, United States whose own description of what they do matches “hydro engineering and consulting 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 hydro engineering and consulting 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 hydro engineering and consulting firms, and records with no verified work email. Companies headquartered outside Houston 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, 5,323 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 28, 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.

Hydro engineering and consulting firms by metro in the United States

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 hydro engineering and consulting 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 hydro engineering and consulting firms are there based in Houston, United States?

RevenueBase identified 182 hydro engineering and consulting firms headquartered in Houston, 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?

LJA, headquartered in Houston, tops this list with the largest team on record.

Which city in the United States has the most hydro engineering and consulting firms?

Houston leads the United States with 182 headquartered companies, followed by New York (99) and Austin (68).

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 5,323 verified decision-maker contacts tracked across these 182 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 28, 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.