Bridgeport Lake Water Quality and Stormwater Enhancement

Valencia, CA

 

PACE developed a 15-acre manmade lake to serve as the heart of the master-planned Bridgeport community in northern Los Angeles County. In addition to being the focal aesthetic feature of this high-end development, the lake system also serves as the primary drainage facility for the site and a water quality and urban storm runoff enhancement facility. Bridgeport Lake incorporates a unique system of aeration, biofilters, water quality filters, and wetland planter areas, filtering out pollutants prior to lake discharge. Through a unique combination of natural and engineered processes, the lake serves as a recreational amenity and environmental habitat with stormwater conveyance for the community, a stormwater runoff retention and treatment system, and lake water quality management system.

 

The Bridgeport Lake system fulfills the post-construction requirements of the National Pollutant Discharge Elimination System (NPDES) permit and associated Storm Water Pollution Prevention Plan (SWPPP) for the Bridgeport development. Additionally, by incorporating stormwater conveyance and treatment, large storm drain pipes were eliminated from the development. Stormwater is treated prior to discharging to the adjacent Santa Clara River. The lake has a retention capacity (first flush) of 3.75 acre-feet, which is routed through a water quality filter system. Biofilters and aeration maintain existing water in the lake and any runoff that flows directly into the lake.

 

Lake Water Quality

Biofilters serve to strip water of nutrients that would promote algae growth and aid in the creation of aerobic conditions within the lake to prevent lake eutrophication. Aeration introduces oxygen into the lake to increase dissolved oxygen levels and promotes natural convection of water to prevent stratification of the lake water column through recirculation. Wetland planter areas promote and enhance water quality through naturally occurring biological processes.

 

Urban Storm Runoff Controls

Prior to entering the lake, a water quality filter collects initial runoff and retains it long enough for the majority of pollutants to be removed. Wetland planter areas filter out waste from runoff via physical, chemical, and biological processes utilizing wetland plants.

 

Retention and Discharge

70% of urban runoff pollutants are contained within the first 1/3 to 1/2 inch of initial stormwater runoff. In order to contain this first 1/2 inch, Bridgeport Lake would need to provide a storage area of 2.9 acre-feet; the lake actually provides retention for 0.25 feet over its entire surface area, or 3.75 acre-feet, which is more than enough capacity to retain initial stormwater runoff.

 

Key Features:

  • Naturalized aquatic ecosystem
  • Submerged gravel bed biofilters
  • Fine diffused aeration
  • Wetland water quality filters
  • Urban stormwater runoff controls
  • Stormwater runoff detention
  • Manmade lake shoreline / lining
  • Lake pump station / circulation system
Client

Newhall Land & Farming Co.

Award

CASQA Award (Stormwater); California SWRCB Water Quality Award

Categories
Lake Systems / Water Features / Pools, Lakes / Streams