Willdan History Timeline

Willdan was created in 1964 by two engineers who shared a vision of solving the challenges in larger communities through engineering. That two-person crew would grow into a national team of over 1,400 professionals. Today, we are recognized not just for our vast experience in engineering, but also for our innovative energy work and trusted expertise across technical fields.

City Report

Founding mission

Willdan is founded to help plan and guide the urbanization of Dairy Valley, now the City of Cerritos in Los Angeles County, California.


William Stookey and Dan Heil form a partnership, opening their first office in a trailer in a cow field behind City Hall, to work with Dairy Valley providing building and safety, contract staff support, and civil planning and engineering services.

This mission of serving public agencies with contract engineering and planning would guide the fledgling company’s next decades.

Paramount Civic Center

45 years with Paramount

The City of Paramount contracts with Willdan for City Engineering services. This contract represents Willdan’s longest continuous client relationship, 45 years to date. In this time, Paramount transforms itself, is named the “All-American City”, and Willdan Engineering Director Bill Pagett continues to serve as City Engineer as he has for the past 32 years.

1970 - 1990
I805 under construction

Expansion: Bridge and disaster recovery

Over the next two decades, Willdan grows its civil and structural engineering, disaster recovery and districting services, and expands throughout the Southwest.

Responding to the collapse of freeway overpasses in several regional quakes, Willdan designs seismic retrofit of dozens of bridges state-wide for the California Department of Transportation.

John Knipe, Contract City Engineer at Westlake Village for 20+ years, reports on Lindero Canyon Road Bridge

City of Westlake Village

Willdan is awarded an ongoing contract to provide city engineering services to the City of Westlake Village in Ventura County, California. Willdan has overseen over 500 City projects to date, garnering awards such as Transportation Project of the Year for Lindero Canyon Road Bridge.

Aerial view of LA River Channel

LA River Flood Control

Willdan begins providing civil, structural, geotechnical engineering and management services to the Los Angeles River Flood Control project for US Army Corps of Engineers. This project is later awarded APWA’s National Project of 2002 and has saved residents in 14 communities millions of dollars in flood insurance to date.

public finance experience map

Expands into public finance consulting

Willdan acquires MuniFinancial, one of the largest public finance consulting firms in the United States, based in Temecula, California. Willdan opens an Orlando, Florida office which continues to serve public finance clients in the Southeast. Over next two decades, Willdan extends public finance consulting services to most US states.

training exercise

Emergency preparedness solutions

In response to new client needs after the attacks on September 11, 2001, Willdan develops Homeland Security services to provide emergency response, hazard planning, analysis, training, and community and enterprise resilience to meet our clients’ greatest emergency preparedness challenges.


Goes public

Willdan Group, Inc. completes initial public offerings in NASDAQ, becoming a publicly traded company under the symbol WLDN, generating an infusion of resources that would enable it to expand into new areas, raising funds for future growth.

Tom Brisbin

Brisbin becomes CEO

Tom Brisbin joins Willdan as CEO. Formerly a top executive at AECOM and TetraTech, Dr. Brisbin brings strategy for bold growth and forward-looking orientation.

Energy efficiency installs at Hilton

Adds energy solutions

Willdan adds energy efficiency to our offered solutions with the acquisition of Intergy Corp. This California-based consulting firm had assisted companies, institutions, and agencies with planning and implementing their energy efficiency, water conservation, and renewable energy strategies with proprietary software, since 2003.

Our ConEd Green Team installer

Con Edison Direct Install

Willdan wins the Consolidated Edison Small Business Direct Install Program for small and medium business energy efficiency upgrades in New York. Willdan opens a Manhattan office and goes on to win contracts with New York State Energy Research & Development Authority, New York Power Authority, and NYC Energy Efficiency Corporation in the subsequent years. Through these program services, Willdan has been helping New York State work toward its goal to reduce statewide energy usage.

Elk Grove Rain Garden

Staffing an entire department

The City of Elk Grove, California contracts with Willdan to staff entire Public Works Department. Willdan-managed projects garner multiple awards, especially for California’s most comprehensive Rain Garden and city-wide streetlight LED replacements.

PSE installers

Expands into new regions

Willdan opens offices in Chicago, Texas, New Jersey, DC, Washington state, and elsewhere. Our intrepid direct install team crisscrosses Washington state from 2015 to present, making a buzz for Puget Sound Energy's energy efficiency initiatives in towns large and small.

Willdan PM monitors air quality

Adds Performance Contracting, Building Engineering

Willdan expands into performance contracting and building energy engineering by acquiring 360 Energy Engineers and Abacus Resource Management Company. 360 is a leading engineering and energy management consulting firm based in Lawrence, Kansas. Abacus serves utility and municipal clients in the Pacific Northwest. Above: Willdan monitors an air quality control project at King County Aquatic Center, WA.

Community microgrid report

Community Microgrids

New York State Energy Research and Development Authority selects Willdan to analyze the feasibility of constructing community microgrids in eight New York communities. Willdan’s successful performance on this project leads to microgrid projects in other states.

Marshak Science Towers energy efficient install

Power Engineering

Willdan acquires Genesys Engineering, PC, a power engineering firm in NY, bringing strong expertise in large-scale university and industrial energy infrastructure, specifically cogeneration and central plant engineering. This acquisition strengthens Willdan’s capabilities in distributed energy resources.

Integral Analytics booth

Big Data Analytics

Willdan acquires data science firm Integral Analytics. As a a recognized leader in big data analytics software, IA helps utility managers evaluate and dispatch electricity resources more effectively as the electric grid transforms and incorporates distributed energy resources. This acquisition strengthens Willdan’s capabilities in grid data analytics.

Willdan - NAM

Acquires Bay Area Energy Engineering Co

Willdan acquires Newcomb Anderson McCormick (NAM), an energy engineering consultancy with 13 years of expertise in energy efficiency projects, distributed resources, and strategic energy plans and programs primarily for municipal and higher education customers, especially in the Bay Area.

Willdan-Lime Energy

Lime Energy Brings Major EE Direct Install Programs

Willdan acquires Lime Energy Co., which has designed and implemented direct install energy efficiency programs for 15 of the largest utilities in the U.S. The acquisition expands Willdan’s customer base and its geographical presence in southeastern and mid-Atlantic regions.

Willdan-The Weidt Group locations map

Energy Performance Software for New Buildings: The Weidt Group

Willdan acquires The Weidt Group, an energy consulting and software development firm that has specialized since 1977 in energy and operational performance of new and existing buildings. Our geographic footprint expands.


Energy Efficiency for Industry

Willdan acquires Onsite Energy Corporation, which has specialized in industrial energy management services in California since 1982.


Energy Analysis and Strategy

Willdan acquires Energy and Environmental Economics, Inc. (E3), developers of industry-leading analytical tools in electrical resource planning, greenhouse gas scenarios, and energy markets analysis, founded in 1989.

Today: As Willdan enters its second half century, we continue our core mission of serving communities with superior technical solutions, now with a team of over 1,400 professionals in dozens of states, along with a comprehensive suite of services and software to meet the new challenges and opportunities of our times.