Following the Natural Resources Conservation Service (NRCS) Watershed planning process, the Kewaunee County Land and Water Conservation Department (LWCD) and Wisconsin Department of Natural Resources (WDNR) created a 9-key element plan for the Ahnapee River Watershed, located in northeast Kewaunee County encompassing portions of Lincoln, Ahnapee, Casco, and Pierce Townships. Silver Creek (HUC code 040301020203), Ahnapee River (HUC code 040301020204) and Rio Creek (HUC code 040301020202) sub-watersheds were selected 9-key element plans fall under the Environmental Protection Agency (EPA) Nonpoint Source (Section 319) Program and help to determine the contributing causes and sources of nonpoint sources of pollution, while creating partnerships with all stakeholders to address water quality problems The Ahnapee River watershed covers 136 square miles in northeastern Kewaunee County and southern Door County. Approximately 55,890 acres (65%) of the watershed lie within the boundaries of Kewaunee County, including 41.2 miles of streams, creeks, and rivers. Silver Creek is the largest tributary to the Ahnapee River. Three Mile Creek is a small intermittent stream that drains from Krohns Lake to Lake Michigan and is the only creek in the watershed classified as a Class II Trout Water. The Ahnapee River watershed also contains several of Kewaunee County’s largest lakes. According to the WDNR, the watershed overall generally has good water quality, but the Ahnapee River was placed on the impaired waters list for Total Phosphorus (TP) in 2014. In 2016, the WDNR reassessed the Ahnapee River, but continued to document phosphorus impairments (WDNR Watershed Ahnapee River, 2018). Silver Creek, which outlets into Lake Michigan, has fair to poor water quality and Rio Creek has very poor water quality. Both creeks experience impacts from farmland erosion and other nonpoint sources throughout the watershed. In 2018, Silver Creek was added to the impaired water listing for TP impairments and Rio Creek has not yet been designated (WDNR Watershed Ahnapee River, 2018). The Ahnapee River watershed is dominated by agriculture and is ranked high for nonpoint sources affecting streams and groundwater. The Northeast Lakeshore TMDL is in the initial development phase and is the first TMDL located in Kewaunee County. WDNR began surface water testing in 2016 and along with WAV volunteers continue to collect adequate water quality and flow data to be used to calculate nutrient loading in the Ahnapee River Watershed. Testing in Rio Creek began in May of 2018. WDNR estimates the entire TMDL process to be completed in 2022. Once complete, this 9-key element plan will be modified to reflect additional water quality results and (when complete) Northeast Lakeshore TMDL findings for sources of pollutant loads and necessary load reductions to meet water quality standards in each HUC-12 subwatershed. Surface water and groundwater are often inter-connected in karst geology in the watershed. Roughly 70% of the County’s citizens rely on the Eastern Dolomite aquifer for their drinking water; however, in this “karst” geology, surface water and groundwater can be directly connected. Fracture traces, sinkholes, and other direct conduits commonly found in karst settings can provide surface water and any associated nutrients or pathogens direct pathways to groundwater.

Ahnapee River Watershed 9Key Plan