Thomas Gast & Associates Environmental Consultants

Name

Thomas Gast & Associates Environmental Consultants

Legal name

Thomas Gast & Associates Environmental Consultants

Website

https://tgaec.com

Company type

Private

Founded year

2006

Operating status

Operating

Headcount range

1–10 employees

Ownership category

akta.pro rank

Product category

Environmental Consulting Services

NAICS

Environmental Consulting Services (54162)

SIC

Services-Commercial Physical & Biological Research (8731)

akta.pro primary industry

Wetlands & Waters of the U.S. Delineation / Riparian Assessments (EUAHAHAC)

Keywords

• Environmental consulting services
• Fisheries investigations
• Instream flow studies
• Watershed restoration planning
• Hydrology and water quality

Headquarters

HQ city

Arcata

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Infrastructure, Marketing or Sales

Revenue model

1. Environmental Consulting Services: TGAEC generates revenue through fee-for-service consulting engagements on fisheries, hydrology, restoration, and environmental compliance projects. Revenue is project-based, derived from subcontracts with prime contractors on large infrastructure projects (Caltrans bridge replacements, dam removals), direct contracts with government agencies and tribal nations, and agreements with private sector clients. Projects span instream flow studies, hydroacoustic monitoring, bathymetric surveys, aquatic species relocation, biological monitoring, and watershed restoration planning.

Pricing tiers

Go-to-market motion2 records

Distribution channels1 record

Marketing channels3 records

Core offering

Thomas Gast & Associates Environmental Consultants (TGAEC) is a federally and California State registered Small Business that provides science-based environmental consulting services focused on fisheries investigations, instream flow studies, hydrology, and stream restoration. The firm delivers six core service lines — Instream Flow Studies, Fisheries Consulting, Bathymetry Studies, Watershed Restoration Planning/Implementation, Stream Flow Measurements and Water Quality Monitoring, and Construction Monitoring — to government agencies, tribal nations, construction companies, utilities, and conservation non-profits across North America's aquatic ecosystems.

Product overview

Thomas Gast & Associates Environmental Consultants (TGAEC) is a federally and California State registered Small Business specializing in environmental consulting services. The company offers a portfolio of interconnected scientific consulting services centered on fisheries investigations, aquatic ecosystems, and water resources. Core offerings include Instream Flow Studies (with IFIM implementation and hydraulic habitat modeling), Fisheries Consulting (sampling, population assessments, PIT tagging), Bathymetry Studies (sonar and ADCP-based river/reservoir mapping), Watershed Restoration Planning and Implementation (grant writing, project management, construction management), Stream Flow Measurements and Water Quality Monitoring (ADCP measurements, water quality parameters), and Construction Monitoring (hydroacoustic monitoring, aquatic species relocation, biological monitoring). These services are delivered as professional consulting engagements rather than software products, supporting permitting, impact assessment, and resource management for clients across North America's aquatic ecosystems.

Differentiator

Problem solved

Functional benefit

Products and services

• Instream Flow Studies

Quantifiable outcome

• Monitored underwater noise for impact driving of steel piles ranging from 18" to 60" diameter across multiple California bridge construction projects, stopping pile driving when regulatory thresholds were exceeded.
• +2 more outcomes

Named customers22 records

Segments5 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

18 partnerships are on record, tiered core and key.

• Alluvion Biological SciencescoreStrategic or Co-development PartnerTGAEC has an established subcontracting relationship with Alluvion Biological Sciences across numerous Caltrans and California state agency projects. Alluvion serves as the prime contractor with TGAEC providing specialized fisheries, hydroacoustic monitoring, and biological monitoring services. This partnership appears across multiple project types including bridge replacements, hydroacoustic monitoring, and biological monitoring (e.g., Dr. Fine Bridge Replacement, Elk Crossing Replacement, Pine Hill Pile Driving, Six Culverts along 101, McHenry Avenue Bridge Replacement, Hunter Creek Bridge Seismic Restoration).
• The Dutra GroupcoreStrategic or Co-development PartnerTGAEC provides hydroacoustic monitoring and biological monitoring services to The Dutra Group (a marine construction company) on waterfront construction projects including the California State University Maritime Academy Waterfront Berthing Construction and the Alameda Marina Shoreline Improvement Project. TGAEC's real-time underwater noise monitoring enables Dutra to pause construction when regulatory thresholds are exceeded.
• California Department of Water Resources (DWR)coreStrategic or Co-development PartnerTGAEC was subcontracted by DWR (via ESA) to develop the ADCP Velocities Data Portal for the Sacramento/San Joaquin Delta, a GIS-based web tool to visualize water current measurements for policymakers and land managers. This collaboration involved ESA, DWR, Dr. James Graham, and Humboldt State University.
• Yurok TribecoreStrategic or Co-development PartnerTGAEC has an ongoing relationship with the Yurok Tribe for fisheries data analysis and monitoring. Projects include the Trinity River Chinook Long Term Outmigrant Data Analysis (2017-2019) and the Trinity River Compilation and Analyses (2021), supporting the Trinity River Restoration Program.
• Pulikla Tribe of the Yurok People (PTYP)coreStrategic or Co-development PartnerPTYP partnered with TGAEC for bathymetric surveys and monitoring following the Klamath Dam Removal — the largest dam removal in U.S. history. TGAEC conducted high-resolution bathymetric surveys using integrated ADCP/GNSS technology to evaluate sediment transport dynamics along the Resighini reach of the Klamath River.
• Tolowa Dee-ni' Nation (TDN)coreStrategic or Co-development PartnerTGAEC assisted TDN in implementing a multi-year pesticide vulnerability assessment for the Smith River Estuary (Da'-me'). TGAEC provided project management, permit acquisition, sampling strategy, fisheries and benthic macroinvertebrate field sampling, and tissue sample analysis for bioaccumulation of contaminants from agricultural practices.
• CalTroutkeyStrategic or Co-development PartnerTGAEC provided pre-construction biological surveys, fisheries sampling, water quality monitoring, and aquatic species relocation for the Cochran Creek and Quail Slough Fish Passage and Habitat Enhancement Project led by CalTrout, a nonprofit focused on California trout and salmon restoration.
• Pacific Coast Fish, Wildlife and Wetlands Restoration Association (PCFWWRA)keyStrategic or Co-development PartnerTGAEC partnered with PCFWWRA to identify, assess, and prioritize restoration sites for non-natal salmonid rearing habitat in Humboldt Bay tributaries. TGAEC contributed to a successful CDFW Prop 1 grant proposal and provided technical expertise for the Non-Natal Habitat Enhancement project for ESA-listed salmonids.
• Normandeau Associates, Inc.coreStrategic or Co-development PartnerTGAEC served as a subcontractor to Normandeau on the Carmel River Habitat Suitability Curve Development project for the Monterey Peninsula Water Management District, assisting with testing the transferability of habitat data for South Central California Coast steelhead. Normandeau was also a client for the CDFW California Anadromous Fish Passage Assessment project.
• Pacific Gas and Electric Company (PG&E)coreStrategic or Co-development PartnerTGAEC provides ongoing electrofishing boat services and staff to PG&E for suppression of invasive pikeminnow populations in the Van Arsdale Reservoir (Potter Valley Hydroelectric Project). Previously conducted three-pass depletion electrofishing for trout abundance estimation on the Stanislaus River for PG&E's Spring Gap-Stanislaus Hydroelectric Project under FERC license requirements.
• GHDkeyStrategic or Co-development PartnerTGAEC worked with GHD on the Eel River Valley Groundwater Assessment (2020-2021) for Humboldt County under the Sustainable Groundwater Management Act. GHD served as the lead consultant with TGAEC providing streamflow and hydrological expertise. Also collaborated with GHD on the Jacoby Creek Water Sustainability Feasibility Study.
• Environmental Science Associates (ESA)coreStrategic or Co-development PartnerESA served as the prime contractor with TGAEC as a subcontractor on the ADCP Velocities Data Portal Development for DWR, and on the San Francisco-Oakland Bay Bridge Pier E3 and E5 Marine Foundation Dismantling Sound Exposure Study (2016) for Caltrans, where TGAEC provided boats and boat operators for fish cage deployment.
• Eel River Recovery ProjectkeyStrategic or Co-development PartnerTGAEC served as the technical consultant for the Tenmile Creek Water Conservation and Restoration Pilot Planning Project (2018-ongoing) for the Eel River Recovery Project, funded by CA Proposition 1 grant. TGAEC conducted discharge measurements, developed rating curves, and applied the U.S. EPA VELMA ecohydrology model for hydrological baseline estimation.
• Buckeye and North Coast Regional Land TrustkeyStrategic or Co-development PartnerTGAEC led both planning and implementation phases of the Felt Ranch Off-Channel Rearing Habitat Enhancement (Wood Creek Phase 3) project, including grant writing, PIT tag array installation and daily analysis, eDNA and physical fish surveys, water quality monitoring, and post-construction performance monitoring.
• Redwood Community Action Agency (RCAA)keyStrategic or Co-development PartnerTGAEC assisted RCAA in securing funding and provided services for the Lower Ryan Creek Off-Channel Habitat and Floodplain Enhancement project in Eureka, CA. Services included deploying data loggers, water quality measurements, fisheries monitoring, and habitat assessments for salmonid migration and floodplain connectivity.
• Coastal Ecosystems Institute of Northern CaliforniakeyStrategic or Co-development PartnerTGAEC served as prime contractor managing four subcontractors on the Cochran Creek Fish Passage and Channel Restoration Planning and Design project (2015-2016) in partnership with the Coastal Ecosystems Institute of Northern California and State Coastal Conservancy Prop 1 funding.
• Sutter County Resource Conservation DistrictkeyStrategic or Co-development PartnerTGAEC provided multidisciplinary restoration services for the Feather River Side Channels project (2024-ongoing), including grant writing, bathymetric surveys, fisheries and avian monitoring, wetland delineations, and performance monitoring comparing pre- and post-construction habitat conditions.
• Resource Conservation District of Tehama CountykeyStrategic or Co-development PartnerTGAEC led grant writing, technical coordination, bathymetric surveys, and fisheries monitoring (snorkel surveys, beach seining) for the Battle Creek Confluence side channel project aimed at improving habitat for Chinook salmon, steelhead, and other native aquatic species near the Sacramento River.

Scale indicators4 records

Recent moves6 records

Expansion highlights6 records

Broad incumbents

• GHD: Global engineering and environmental consulting firm engaged as lead on Humboldt County SGMA groundwater work where TGAEC provided streamflow expertise. Overlap in hydrology, groundwater, and environmental services, but operates at significantly larger scale.
• Kleinfelder: Large engineering, construction, and environmental services firm engaged with TGAEC on PG&E invasive species suppression work. Overlap in environmental monitoring and utility-sector compliance, but Kleinfelder is a broad incumbent with significantly larger capabilities.
• Environmental Science Associates (ESA): Large multi-disciplinary environmental consulting firm; serves as prime contractor to TGAEC on the ADCP Velocities Data Portal and Bay Bridge sound exposure study. Overlapping capabilities in environmental compliance, hydrology, and restoration, but broader portfolio and larger scale.

Direct peers

• Stillwater Sciences: California-based environmental consulting firm specializing in fisheries, aquatic ecology, instream flow, and watershed restoration — directly comparable service portfolio and Northern California client base. Both firms serve state agencies, tribes, and NGOs on hydroacoustic, instream flow, and habitat restoration projects.
• Northwest Hydraulic Consultants: Specialty hydrology and aquatic resources consulting firm focused on the Pacific Northwest and Western U.S. Comparable expertise in streamflow measurement, sediment transport, and instream flow analysis.
• McBain Associates: Northern California environmental and biological consulting firm specializing in fisheries, aquatic ecology, and water resources. Similar size, service portfolio, and Pacific Northwest client base to TGAEC.
• Palmer Environmental Consulting Group: Listed as both a client and a comparable firm — environmental consulting firm with fisheries, habitat assessment, and aquatic resource expertise spanning the U.S. and Canada, including the Casino Mine Dam Breach Assessment in Yukon that TGAEC supported.
• Cramer Fish Sciences: Specialty fisheries and aquatic ecology consulting firm focused on the western U.S., with deep expertise in salmonid monitoring, population assessments, and instream flow studies. Comparable service mix and California/Pacific Northwest operating footprint.
• Normandeau Associates: Environmental consulting firm where TGAEC's founder previously worked; provides fisheries, habitat assessment, and aquatic resource services including the Carmel River Habitat Suitability work TGAEC subcontracted on. Directly comparable specialty, with broader geographic reach.
• Alluvion Biological Sciences: California-based biological consulting firm and TGAEC's most frequent prime contractor on Caltrans projects; provides fisheries, biological monitoring, and construction compliance services. Directly comparable specialty and customer base.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks5 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/thomas-gast-&-associates-environmental-consultants

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Thomas Gast & Associates Environmental Consultants