Hill Creek 303(d) list validation


Hill Creek is a 1.8 mile long cool-water stream that empties into Big Silver Lake. It was placed on the 303(d) list due to excessive sediment entering the system from both point and non-point sources. Discharge from the point source ceased about four years ago. In addition, considerable watershed improvement work (buffers, BMP’s, etc.) has been conducted over the last decade to reduce sediment reaching the stream.


Ted Johnson will conduct the following field work to determine if Hill Creek could be removed from the 303(d) list of impaired waters. 1. Monthly baseflow TSS samples collected during the ice-free period (April 1st – October 31st) for 2 years. 2. Runoff event TSS samples collected, during ice-free periods, as they occur (maximum of 5 sampling events per annum). 3. Instantaneous flow at time of grab sampling. 4. Habitat assessment done annually. 5. Streambank erosion assessment conducted once in the two year project. 6. Normal sampling parameters (transparency, DO, pH) Not in recommended guidance but will be conducted.


This level of effort should be sufficient to determine if the sediment impairment still exists or has improved to the extent that the stream can be delisted following the two year assessment.

QA Measures

Run Project Summary Report

TMDL/303d Projects
Identify Impaired Waters