City of South San Francisco - Orange Memorial Park Storm Water Capture/Treatment and Reuse/Infiltration

South San Francisco, CA

Project scope consisted of the construction of stormwater mid-stream diversion, underground piping, cistern, and infiltration gallery. Scope of work also included primary treatment for irrigation reuse, new irrigations systems and new PG&E service, located in South San Francisco, CA. $5.5 Million.

This project is part of the City of South San Francisco Capital Improvement Program. Swinerton Management and Consulting provided Construction Management services for this unique and innovative project. The scope of work included captured storm water from Colma Creek which is a concrete lined channel for treatment, infiltration and reuse. This project not only removed toxic chemical from the storm water, but it helps downstream inundation. Mercury, PCB and trash are extracted from the diverted flow which helps downstream water quality. Portion of the water is stored in an underground cistern for further treatment and reused for irrigation. The remainder is directed into a vast infiltration gallery to recharge the ground water system. Project elements include:

  • Concrete Instream Diversion Structure
  • Complex Concrete grit | Trash Chamber
  • 750 Linear Feet of 36” Diversion Pipe
  • Concrete Flow Splitter
  • Underground Cistern and Infiltration Gallery using Flow Tank
  • Water Auality Treatment Shed and Pumping Facilities


  • Mid-stream storm water capture, treatment, and recharge
  • Storm runoff from multiple upstream agencies
  • Installation of a concrete diversion structure in an existing concrete channel
  • Installation of a concrete trash and grit removal structure
  • Installation of 750 LF of 36″ HDPE diversion pipe
  • Excavation and installation of an underground cistern and infiltration gallery


City of South San Francisco


  • Lotus Water Engineering
  • Brown and Caldwell