The San Rafael Creek and the Arroyo Seco channel are located just south of San Rafael Ave in Pasadena, CA. A new proposed infiltration basin will intercept some wet weather flows from the San Rafael Creek which conveys runoff primarily from Los Angeles and Pasadena to the Arroyo Seco Channel. All dry weather flows will be directed to a natural stream constructed above the San Rafael Creek concrete channel. The San Pascual Park site is located further downstream along the Arroyo Seco channel where wet and dry weather runoff will be directed from Pasadena, and South Pasadena areas north of Arroyo Park and San Pascual Stables. The San Pascual site is bounded by the Arroyo Seco channel to the south and San Pascual Ave to the north and the proposed treatment wetlands will reutilize and expand the capacity of an existing dike and existing irrigation system.
The project has the potential to provide significant water quality benefits for multiple jurisdictions due to the significant drainage area size, location of the adjacent creek and channel, and available development space. The project will capture and treat 100% of the dry-weather flows.
The major mechanisms by which the project will achieve the primary objectives are diversion, runoff/pollutant capture, filtration, recharge, and release. The treatment wetland systems will provide natural filtration and capture. The San Pascual wetland will reuse the treated water for park irrigation. Native, natural landscaping will improve aesthetics of the spaces and provide habitat for wildlife and recreational use.
The treated stormwater is to be conveyed through a 15 cfs pump station. As a subconsultant to Craft Water, Inc, Myriad Engineering provided the design for the pump station including piping, valving, wet well layout, valve vault layout and design, and design layout for a transition structure from force main to gravity flow. We performed the hydraulic analysis for the pipe and pump sizing. We prepared the technical specifications using Master Format. We prepared the engineers’ construction estimate based on manufacturer costs and recent bids.
Scope of Services
- Project management
- Hydraulic analysis (piping and pumps)
- Pump station design
- Technical specification preparation
- Engineers’ construction estimates