Truckee, California
This project is situated within three watersheds: the Trout Creek, the Donner Creek; and the Truckee River. The only flowing water body within the project site is perennial Trout Creek. The water quality certification included all watershed modeling, erosion control, storm and surface water quality monitoring and the development of a Chemical Management Action Plan (CHAMP) report. The Basin Plan requires that site-specific design plans provide for on-site retention and infiltration so that no substantial increase in surface runoff volume occurs as compared to pre-project runoff volumes.
Golf course design criteria included drainage designs to direct flow paths away from Trout Creek and the positioning of greens surfaces to minimize underdrain flooding. Other design features included rock-lined stormwater conveyance ditches, grass-lined contour ditches, and infiltration ditches that would intercept and retain stormwater runoff from impervious surfaces for the 20-year, 1-hour storm. In addition to various erosion control measures, detention ponds were designed to attenuate peak flows from the 100-year storm to pre-project levels. The design of the golf course was developed to meet the environmental constraints of the area; limit the chemicals and fertilizers to be used and their means of application; and to provide protection of surface water quality in the area. 7Q10 recommended a baseline surface water monitoring program to establish water quality objectives. 7Q10 ran rainfall and runoff simulations and performed watershed analysis. Watershed runoff calculations used in the selection of BMPs were modeled using the USDA-Soil Conservation Service, “Urban Hydrology for Small Watersheds (TR 55)” computer program. Potential flows to sub-basins in the pre- and post-project conditions were determined and drainage flow paths in each sub-basin were examined to determine areas of potential high erosion.