Caltrans District 7 - Water Quality Volume Project

Water Quality Value calculation
Prime Contractor: 
Period of Performance: 
July, 2009 to January, 2010
Project Description: 

The purpose of this project was to identify all watersheds and determine the Water Quality Volume (WQV) for freeway and non-freeway corridors Right-of-Way in Caltrans District 7, located in Southern California. The work included examination of Caltrans maintenance yards and rest areas situated in Los Angeles and Ventura Counties within the jurisdiction of the Los Angeles Regional Water Quality Control Board’s (LARWQCB’s). Per the Stipulation and Order Regarding the Corridor Stormwater Management Studies, as-built specifications of the impervious area were used that existed before and after December 1994. After being defined by respective watersheds, the as-built drawings were examined using a scalable image viewer, and dimensions were taken for various impervious roadway sections. Any increases in impervious areas that were added since 1994 were determined along these highway corridors and treated WQV’s were calculated from these dimensions using a spreadsheet model.

ADH Responsibilities: 

ADH was responsible for the compilation of areas and WQV’s from approximately 84 miles of highway, including sections of California Highways 2, 27, 66, 90, 107, 187, 213 in Los Angeles County and Highway 232 in Ventura County.

As-Built Drawing

As-built Specification