Calculation of Sediment Loads, HY 2003 through 2005, Sonoma Creek Watershed, California. Appendix D to Sediment Source Analysis

The Sonoma Ecology Center (SECSonoma Ecology Center is a not-for-profit organization located in the Sonoma Valley. http://sonomaecologycenter.org) measured suspended sediment concentration (SSC in milligrams per liter [mg/L]) and stream flow (Q in cubic feet per second [cfs]) during wet storms in the Sonoma Creek watershed. This study was performed in Hydrologic Years (HY) 2003 through 2005 with the objective of calculating stream sediment loads as part of the sediment source analysis (SSA) for the Sonoma Creek sediment TMDL (total maximum daily load). Additionally, data from HY 2006, which included the highest stream flows on record for Sonoma Creek, are appended for comparison and analysis.

In the study, SECSonoma Ecology Center is a not-for-profit organization located in the Sonoma Valley. http://sonomaecologycenter.org uses SSC data collected in HY 2003 through 2005 to estimate annual loading of sediment in Sonoma Creek and its tributaries in tons SSC per year (tons/yr). We also break down the loads into yields according to acreage of the Sonoma Creek basin and tributary basins. In addition, we give some examples of the effects of rainfall intensity and annual rainfall totals on stream flow (Q.)