Tetra Tech Designs Innovative Irrigation System in Lakewood, California

As part of the Los Cerritos Watershed Management Plan, the City of Lakewood, California, selected Tetra Tech to provide preliminary engineering, design services, and construction support services for the stormwater and runoff capture project in Bolivar Park.

Bolivar Park currently uses potable water for all irrigation needs. The City is implementing a smart regional stormwater best management practice that results in water quality improvements in the Los Cerritos channel, enables stormwater infiltration, and provides an alternate water supply for the park’s irrigation needs.

Tetra Tech’s design consists of an air-inflated, rubber dam diversion system to redirect all urban and stormwater runoff from the Los Cerritos channel through a pre-treatment system that removes trash, debris, and sediment. A pump station and drainage pipeline will convey the water into a 2.9-million–gallon, multi-chambered storage and infiltration facility beneath the park. The collected stormwater will be treated and used to irrigate the landscaped areas in Bolivar Park, satisfying 100 percent of the park’s 9.5-million-gallons-per-year irrigation needs.

The project team from Tetra Tech has been a delight to work with. They have been on time, delivered on their promises, they have done everything we have asked them to do. I’d have to say that Tetra Tech is one of the best consultants that I’ve worked with in recent memory.

Lisa Rapp, Public Works Director, City of Lakewood, California

To improve the stormwater capture system’s performance, Tetra Tech applied smart water technology by using real-time controls. The sensors installed in the underground storage facility and infiltration chamber will monitor and measure water levels and are connected to National Weather Service data through a secure, cloud-based system to assess the likelihood of upcoming precipitation. If rain is anticipated, the technology will evaluate whether the stormwater capture system has the capacity to perform during the upcoming storm to avoid flooding. If the system does not have adequate storage capacity, it will evaluate other options such as reducing the diversion rate, increasing irrigation use, evaluating the infiltration rates for groundwater recharge, or discharging filtered stormwater back into the channel.

Tetra Tech conducted water quality model simulations to assess the performance potential for the project during the preliminary engineering stage of design. Tetra Tech determined that the use of active control systems for the diversion system, pump station, and storage facility would boost the water quality pollutant capture performance of the facility by up to 50 percent, because the system can automatically adjust the diversion and activate the pump station in real-time to respond to various storm conditions. The primary goal of this project in Bolivar Park is to improve the water quality in the Los Cerritos channel by removing pollutants, such as metals and bacteria, which would normally be discharged into the ocean.

Highlights

Tetra Tech and the project team have been awarded the following accolades:

• 2016 Environmental Business Journal Award for Innovative Technology
• City of Lakewood 2016 External Service Provider of the Year