Modjeska Park Stormwater Construction

Modjeska Park Underground Stormwater Detention & Infiltration System – City of Anaheim

The Modjeska Park Underground Stormwater Detention & Infiltration System Project utilizes the footprint of an existing 37,000 sq. ft. parking lot to capture and infiltrate approximately 182-acre feet of dry weather urban runoff and first flush stormwater into the City of Anaheim’s groundwater each year. This is water that would otherwise flow untreated to the Bolsa Chica Channel and eventually to the Pacific Ocean.

Ghirardelli Associates provided the City of Anaheim with construction management, contract administration, structures and civil inspections for the Modjeska Park Underground Detention and Infiltration System Project from project award to completion.

Key features included:

  • Excavation of 48,600CY native material
  • Export of 17,000CY of the native material
  • Construct CIP drop structure to intercept existing 48” RCP
  • Construct 6 Acre-ft (2.0 MGal) reinforced precast high strength concrete detention gallery, including a pretreatment settling chamber & comprising 456 individual pieces
  • Divert flow through a mash trash capture vault with stainless steel capture screens
  • Backfill & compact 31,600CY of material
  • Install decorative interlocking pervious pavers for parking lot surface
  • Restore park landscape

The system allows water that flows into the Watershed to instead percolate into the groundwater, removing pollutants. Signage will educate over 4,000 monthly park visitors about methods to reduce stormwater pollution.