​MAIN CREEK PHASE 1 RESTORATION EFFORTS DECREASE TEMPERATURE AND POLLUTANT LOADING IN WALLSBURG WATERSHED

​Phase 1 restoration efforts in the Wallsburg Watershed have not only led to a decrease in both phosphorous and E. coli, but now Main Creek supports its cold water fishery designated use due to lowered water temperature.  Read the full account of before, during and after restoration in UTAH SUCCESS STORY: MAIN CREEK prepared by Sandy Wingert with the Utah Division of Water Quality.

WATER TEMPERATURES REDUCED

Main Creek was placed on the 2010 303(d) List for failing to protect its infrequent recreational and cold water fishery uses due to elevated levels of E. coli and water temperature.  Temperature in Main Creek exceeded the 20º C water quality standard set to protect for cold water fisheries 18% of the time between 2004-2008. Following the Phase 1 work the stream now meets its cold water fishery designated use to due to lowered instream temperature and will be removed from Utah’s 303(d) in 2016.

AVERAGE ANNUAL E. COLI CONCENTRATION

E. coli concentration in Main Creek often exceeded the water quality standard of 206 MPN/100 ml protective for infrequent recreation.​

24% REDUCTION IN E. COLI CONCENTRATION AFTER PHASE 1 RESTORATION

When comparing data before and after Phase 1 work, there is a 24% reduction in E. coli concentrations, though levels still exceed the WQS of 206 MPN/100ml for infrequent contact recreational use.

TOTAL PHOSPHORUS CONCENTRATIONS

Though Main Creek comprises only 8% of the inflow into Deer Creek Reservoir, it contributes 17% of the Total Phosphorus (TP) load.

​DOWNWARD TREND IN TP CONCENTRATION

​Trend analysis of TP concentration shows a general decrease over time however concentrations are still above the TMDL target of 0.03 mg/L. Stable concentrations point to natural sources of pollution. There is a positive correlation between flow and concentration indicating that erosion and transport of TP during high flows is a dominant process in the watershed. TP loading has decreased by 63% after Phase 1 restoration. 

FUNDING

​One of the biggest successes of this project was the support that was provided by various agencies. The overall cost of the Main Creek Restoration Project was $1,281,199