Lime Creek Watershed
Lime Creek is a 27,039 acre sub-watershed of the Cedar River in western Buchanan County with its outflow in northwest Benton County approximately 25 miles from Cedar Rapids. The lower one-half of the 16 mile stream was on the final 2004 Iowa list of Section 303(d) Impaired Waters. The cause/stressor was identified as biological, potentially flow alteration, habitat modification, nutrients and/or siltation.
A TMDL has not been completed for Lime Creek; however, a completed TMDL for the Cedar River includes a goal of 35% reduction of nitrate to 9.5 mg/L due to the classification as a drinking water supply resource for the people of Cedar Rapids. Recognizing Lime Creek as a contributor of nitrate to the Cedar River, the Lime Creek watershed council adopted a goal of reducing both nitrate and phosphorus by 35%.
To achieve the nutrient reduction goals and to promote broad participation and increased implementation of nonpoint source management strategies in Lime Creek the watershed council developed a performance-based incentive approach. The primary components of the incentive program were the cornstalk nitrate test (CNT), Iowa Phosphorus Index (IPI) and Soil Conditioning Index (SCI). The program also included a short list of best management practice incentives such as grassed waterways, spring nitrogen application and soil testing. The council also investigated the use of denitrifying bioreactors as an alternative nitrate reduction strategy.
Click Lime Creek project summary for a two-page PDF on the Lime Creek Watershed project.