Water Quality Treatment Program

Mill Creek Wetlands

IMEG developed construction documents (Plans & Specifications) and provided construction observation for the construction of the Mill Creek Wetlands . This project is providing water quality treatment consistent with the National Pollutant Discharge Elimination System (NPDES) General Permit for Storm Water Discharges Associated with Construction and Land Disturbance Activities Order No. 2010-0014-DWQ (NPDES No. CAS000002) for storm water runoff emanating from the New Model Colonies Development. The project is also intended to allow for future treatment of storm water for a portion of the Chino Preserve Development Area.


The total area of treatment is 1,500 acres. Low-flow discharges and storm water runoff from the catchment area will be discharge into the Cucamonga Creek Storm Channel via local storm drain systems, the storm water runoff will then be captured via diversions structures at the point of entry of the Cucamonga Creek into the Prado Basin (Mill Creek). Diverted flows are directed through basins for sedimentation and trash removal and the routed through additional basins for retention and water quality treatment. This project is the first of its kind to allow for regional treatment of storm water runoff via conveyance through water of the US to a local facility.


The project includes storm drain design, hydraulic modeling, basin flow routing analysis, and HECRAS modeling of the Cucamonga Creek Channel.




Ontario, CA



1,500 Acres