Via Princessa Park Infiltration BMP Feasibility Study and Design

Santa Clarita, CA

 

Regional Feasibility Study

PACE performed a site selection / feasibility analysis for a regional infiltration BMP facility in the City of Santa Clarita. Many potential regional infiltration BMP sites were identified within the Upper Santa Clara River Watershed Management Group (USCRWMG) Enhanced Watershed Management Plan (EWMP). However, a more in-depth analysis was required to determine each location’s viability and infiltration effectiveness. In order to help the City reach their short-term infiltration goals, PACE investigated the potential sites, including site evaluations for suitability, infiltration optimization, development of optimal 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 was then performed to evaluate the merits of each site carefully and PACE made recommendations to the City. The City selected the Via Princessa site.

 

Safe Clean Water Funding Pursuit & Feasibility Study

The Feasibility Study was completed in compliance with LA County’s Safe Clean Water (SCW) program guidelines to be considered for project funding. The study included summarizing the project’s objectives, including preliminary design of the project (including diversion structures, hydrodynamic separator, 30 ac-ft infiltration capacity infiltration BMP, onsite LIDs, monitoring requirements, O&M plan, and outline of the capture area). The Feasibility Study summarized the benefits of the project, which include improved water quality, water supply, community investments, and nature-based solutions. This study involved multiple engineering analyses, including geotechnical investigations, site surveys, hydrology analysis, a CEQA preliminary assessment, and coordination with LA County Flood Control District, Vector Control District, and SCRRA for conceptual approval of multiple project components. The project has officially been awarded the $20.1M in funding requested by SCW.

 

Detailed Site Design

The detailed design of the Regional Park and BMP Project is currently underway, recently crossing the 60% design mile marker. The proposed infiltration BMP facility incorporates sedimentation management through a two-stage pre-treatment process, including a sedimentation structure which will help extend the design life of the corrugated metal pipe (CMP) infiltration laterals and facilitate easier maintenance for City crews. The park site itself will incorporate a series of swales designed to convey on-site flows to the infiltration BMP, and will serve as park amenity features and educational centerpieces. PACE is also designing approximately 1,700 LF of soil cement bank lining, which will protect the proposed project from erosive forces of both the Santa Clara River and Honby Channel. The soil-cement bank lining will be buried to facilitate vegetation growth and create a seamless transition from the project site to the naturalized Santa Clara River. Through the connection of proposed park trails to existing City infrastructure and the restoration of Honby Channel, this project will make valuable community resources newly available to those living nearby, many of whom are recognized as being part of a disadvantaged community.

 

Key Features:

  • Feasibility study
  • Multi-benefit BMP facility
  • Development of hydrologic and hydraulic characterization
  • LID application guidance
  • Meets requirements of NPDES MS4
  • Dry wash park amenity conveys onsite flows
  • Design (PS&Es)
Client

City of Santa Clarita

Categories
Stormwater Management / Flood Control, Stormwater Quality