Estimating Sediment Production for the Sonoma Creek TMDL

Used In: 
Watershed Plan
Used In: 
Watershed Scorecard
Lawton, Rebecca; Collins, L.; Dawson, A
Publication Date: 
Sonoma Ecology Center
Publication Place: 
Sonoma, CA

The Sonoma Ecology Center teamed up with Watershed Sciences, Martin Trso, P.G., Talon Associates LLC, and Tessera Consulting to conduct a Sediment Source Analysis in the Sonoma, Schellville, and Carneros watersheds for the Sonoma Creek TMDL. The intent of the project was to identify sediment sources in the watershed, estimate rates of sediment supply for each source between the years 1800 and 2005, and report on results as the basis for an implementation plan to be written by the California Regional Water Quality Control Board (RWQCB).

Four approaches were taken in the analysis:
Correlation of drainage network length and field-measured sediment supply stratified by different geomorphic units to predict erosion from channels;
Evaluation of aerial photography to estimate sediment supply from landslides;
(3) Assessment using historical ecology coupled with a Revised Universal Soil Loss Equation model to predict erosion from surfaces both pre- and post-European impact;
(4) Analysis using SEDMODL on sediment contributions from roads and stream crossings.

Results were checked two ways: (1) through an independent analysis of fine sediment deposition in downstream marshes and (2) by sampling suspended sediment and turbidity in mainstem Sonoma Creek and tributaries as a basis for calculating sediment loads.

Results indicate total sediment supply to be more than twice that of background.

The TMDL implementation plan being developed by the RWQCB will be based on these values and seek reductions in the areas of greatest sediment production. The TMDL will result in an amendment to the Water Quality Control Plan for the San Francisco Bay Basin.

SEC filepath: 
W:\Publications_Presentations\Posters\Sediment-Turb/2007Oct1_SSA_Poster_Final.ppt and W:\Publications_Presentations\Posters\Sediment-Turb/pdfs/2007Oct1_SSA_Poster_Final.ppt
TMDL, sediment, fish habitat
Date Period: 
01/01/1800 - 01/01/2005
2007Oct1_SSA_Poster_Final.ppt7.87 MB
2007Oct1_SSA_Poster_Final.pdf211.84 KB

Estimating Sediment Production for the Sonoma Creek TMDL data, by Station

There are no stations with data