Bridgeport Lake

Valencia, CA


A 15-acre manmade lake was developed 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 as 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 to manage runoff and maintain water quality, filtering out pollutants prior to lake discharge. Through a unique combination of natural and engineered processes, Bridgeport Lake successfully combines 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 NPDES permit and associated SWPPP for the Bridgeport development. Additionally, by incorporating stormwater conveyance and treatment, large storm drain pipes were eliminated from the development and stormwater is treated prior to discharging to the adjacent Santa Clara River. The lake has a retention capacity (first flush) of 3.75 AF, all of which is routed through a water quality filter system. The lake’s sophisticated water quality treatment system includes biofilters ad aeration to maintain existing water in the lake and any runoff that flows directly into the lake.


Water Quality (Lake):

  • 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 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 lake):

  • Water Quality Filter: collect initial runoff and retain it long enough for the majority of pollutants to be removed.
  • Wetland Planter Areas: filter out waste from runoff via various physical, chemical and biological processes, utilizing wetland plants.


Retention and Discharge from Lake:

  • 70% of urban runoff pollutants are contained within the first 1/3 to 1/2-of-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 (AF); the lake actually provides retention for 0.25 feet over its entire surface area, or 3.75 AF, 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

Newhall Land & Farming Co.


CASQA - Water Quality Awards (Stormwater) & California State Water Control Board

Lake Systems / Water Features / Pools, Lakes / Streams