2019 ACEC Idaho Engineering Excellence Award Winning Projects

McMillen Jacobs and Associates Logo
Print Image

The American Council of Engineering Companies (ACEC) of Idaho announced the winners of the Idaho Engineering Excellence Awards (EEA) Competition this week. Each year ACEC of Idaho, representing the consulting engineers of Idaho, sponsors the EEA CompetitionIt is open to all engineering or surveying firms, whether or not they are members of ACEC of Idaho. The competition gives public recognition to those engineering achievements that demonstrate a high degree of merit and ingenuity, and that provide a major contribution to technical, economic, and social advancement.

ACEC of Idaho held a luncheon on April 8, 2019 to recognize these outstanding projects and studies and to highlight the contributions the engineering industry makes to growth and progress in our society. McMillen Jacobs Associates received three ACEC Idaho Engineering Excellence Awards:

  • 1st Place Environmental – Esther Simplot Park Design-Build Project
  • 1st Place Water Resources – Swan Lake Reservoir Expansion Project
  • 2nd Place Energy – Allison Creek Hydroelectric Project

A team of McMillen engineers, designers, and clients attended the award luncheon to accept the great honor. The projects highlighted were examples of great challenges, problem solving, and engineering solutions that culminated into an excellent project.

A brief description of the three Award Winning projects can be found below.


Esther Simplot Park Design-Build Project

The Boise River Greenbelt serves as a linkage between several parks or “precious jewels” in the Treasure Valley of Idaho. These parks honor some of Boise’s finest civic leaders and remarkable women who were committed to their community. This river front park project turned an undeveloped 55-acre parcel into another important recreational gem for the community of Boise, encompassing 17 acres of ponds and 8.9 acres of riparian natural areas. Due to its proximity to the Boise River, several complex environmental, habitat, and recreational issues needed consideration throughout the design, excavation, and construction.

Environmental: Low Impact Development and coordination with environmental agencies factored into the design, providing an ecosystem-based approach that allows the development to function as part of the natural environment. Examples include flood protection, irrigation, and the collection and treatment of stormwater runoff from both the park and surrounding neighborhoods.

Habitat: The design promotes fish and wildlife habitat both in-stream and in the riparian zone, including protection and improvement of warm water pond habitat.

Recreation: Many of Boise’s recreational activities revolve around the City’s rivers and ponds. Improvements include accessible pathways, trail surfacing, and relocation of the greenbelt to provide improved site access. The collaborative result and thoughtful design solutions at Esther Simplot Park will enhance recreational opportunities and provide for the community and environment for years to come.

Swan Lake Hydroelectric Project

A Complex Problem – The Swan Lake Hydro Facility is a 25 MW hydroelectric facility that includes a 174 ft tall concrete arch dam with a previously ungated ogee spillway. The purpose of this project was to enhance an existing dam in a way that would offset diesel generation for SEAPA for years to come, in an economically stable and environmentally sustainable manner. Challenges involved the uniqueness of the flashboard system and the remote location of the facility, which was accessible only by boat, plane, or helicopter.

Innovative Engineering Solution – The Swan Lake Reservoir Expansion Project involved the design and construction of a 23 ft wide vertical operating lift gate, a 30 ft tall concrete pier, and a 78 ft long emergency flashboard gate system at the spillway to raise the reservoir 15 ft. Extensive modeling and testing to determine the best option to overcome cost and displace the most diesel generation helped determine the nominal 15 ft raise option. Demolition and construction materials were delivered via barge or float plane. Existing facility equipment required mechanical and electrical upgrades to accommodate improvements. A collaborative engineering effort led to excellent results for the client. Overall, the modifications allow for more storage of spillway flows, resulting in a longer generation period, thereby reducing dependence on diesel generation.

Allison Creek Hydroelectric Design-Build Project

Located near the Trans-Alaska Pipeline System in Alaska, this hydro project presented challenges due to its remote location, rough terrain, and extremely cold weather.  It consists of a concrete gravity dam, a conventional intake, 7,000 feet of buried/surface penstock, a diversion structure, a powerhouse capable of producing 6.7 MW of electricity per hour for CVEA’s customers at peak production. This new hydroelectric plant brings CVEA’s renewable energy portfolio from 50% to 64% and reduces its dependence on diesel generation plants by 750,000 gallons of diesel. This project will reduce annual fuel generation costs by $2.4 million and eliminate 12,000 tons of carbon dioxide annually.

McMillen Jacobs presented insightful suggestions to provide cost savings and operation/maintenance improvements. Examples include a change to the penstock concept design resulting in two sizes of penstock separating the low-pressure from the high-pressure zone, the addition of a 765’x16’ tunnel to avoid running the penstock over the top of the ridge, and burying the penstock which provided freeze protection, longer operation in the colder months, protection from avalanches, and reduced impact to wildlife. The cost savings and advantages were unprecedented considering the difficulty of construction and the remote nature of the project sight. Overall, the project was delivered nearly 20% under the budget with a total savings exceeding $10M.


Congrats to all the engineers, clients, and team members that worked hard to find innovative engineering solutions and make these great projects a reality!

(Pictured in photo from left to right: Randy Presleigh, Bobbi Preite, Jake Woodbury, Eric Wolfe, David Johnston, Kelly Burrows, Greg Allington, John Tensen, Joe Carson, Vincent Autier)