Citywide Storm Drainage Master Plan
City of Elk Grove, California

West Yost assisted the City by preparing a comprehensive storm drainage master plan (SDMP) to address population growth and protect residents from flooding. 

West Yost developed planning criteria for evaluating facilities; performed hydrologic modeling to determine existing and buildout flood flows; prepared floodplain mapping; identified deficiencies in existing major drainage facilities; evaluated alternatives to eliminate existing deficiencies; identified facilities required for future development; and developed cost estimates for a Capital Improvement Plan ($155 million).

The City covers approximately 27,000 acres in Sacramento County and is served by a drainage system that includes 400 miles of underground pipelines, 60 miles of creeks or channels, 100 miles of underground trunk pipelines, four pump stations, and 18 detention basins. Results of the draft SDMP were presented to the public and development community at key points during the process.

West Yost also developed a customized GIS database to help the City manage its drainage facilities. The database was developed using the geo-database format included 11 facility classes (pipelines, detention basins, etc.) and 15 to 30 attributes (size, length, condition, etc.) for each class. The database was populated with the available information for the existing system and a methodology was developed for smoothly transferring new facilities into the database from a spreadsheet template.

West Yost has continued to assist the City with their master plan process by participating in the Expert Advisory Committee, which consists of local residents, development community representatives, and industry experts in hydrology, geomorphology, low impact development, and water quality. The committee is exploring opportunities to incorporate non-traditional drainage approaches into the master plan.