Santa Clarita BMP Infiltration Facility and Green Streets LID Guidance Manual

Santa Clarita, CA


PACE designed a regional infiltration Best Management Practice (BMP) facility and developed a Green Streets Low-Impact Development (LID) Application Guideline for the City of Santa Clarita. Several potential regional infiltration BMP sites were identified within the Upper Santa Clara River Watershed Management Group (USCRWMG) Enhanced Watershed Management Plan (EWMP), but a more in-depth analysis was required to determine the viability and infiltration effectiveness of each location. BMP infiltration facilities help reach short-term goals for structural BMP capacity, while a mixture of BMP and LID implementation assists with the City’s long-term infiltration volume goals.


In order to help the City reach their short-term infiltration goals, PACE performed an investigation of potential sites for the infiltration BMP facility, which included site evaluations for suitability and infiltration optimization, development of optimum layouts, and construction cost estimates. Factors such as infiltration rates, proximity of the groundwater table, existing utility conflicts, 85th percentile watershed runoff volume, and feasibility of tapping into the storm drain system heavily influenced the investigation process. A rigorous alternatives analysis carefully evaluated the merits of each site. PACE prepared final engineering design and construction drawings to support implementation at the location selected by the City.


For long-term infiltration goals, PACE developed a Green Streets LID Design Guideline Manual to assist with selection and design of LIDs for stormwater flow and pollution mitigation. Implementing more Green Streets LIDs will help maximize infiltration volumes and properly manage / treat pollutants resulting from stormwater and non-stormwater runoff within the City’s boundaries to meet the requirements of the Los Angeles County National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Permit. Relative cost comparisons, maintenance requirements, and performance data are presented for each LID application to give designers a better understanding of what is needed to implement these LID practices throughout the City.


Key Features:

  • Conceptual design of underground BMP facility
  • Treatment of stormwater and non-stormwater runoff
  • Meets NPDES MS4 permit requirements
  • LID/BMP facility study and design
  • Development of hydrologic and hydraulic characterization
  • Environmental impact assessment
  • LID application guidance
  • Funded by the Safe, Clean Water (SCW) Program

City of Santa Clarita

Stormwater Management / Flood Control, Stormwater Quality