Water Storage and Water Quality for CD 59 and Beaver Creek

The proposed project will be in conjunction with an improvement project to the 103E county ditch branch 309 and branch C of Renville County Ditch 59 (CD 59) system. The proposed project will construct three water and sediment control basins (WASCOB) and three ponds to provide temporary and permanent water storage for the CD 59 system, which flows directly into Beaver Creek. The construction and installation of the conservation practices will provide temporary and permanent water storage and reduce peak flows that allow sediment (TSS), nitrogen (N) and phosphorus (P) to directly enter impaired CD 59 and Beaver Creek. The 2017 Hawk Creek Watershed Restorations and Protection Strategies (WRAPS) report listed CD 59 as impaired for dissolved oxygen (DO) and had inconclusive data for sediment. The WRAPS report also set reduction goals for N, TSS, and P. CD59 has been prioritized as a Tier 1 (High Priority) impaired stream in the Hawk Creek-Middle Minnesota Comprehensive Watershed Management Plan (HCMM). The project falls within the Beaver Creek watershed (HUC 070200411), which is listed as a priority watershed in the HCMM. The HCMM set goals to address the Beaver Creek Watershed and the impaired CD 59 for altered hydrology and soil erosion and sediment loss that this project will address. These water quality practices will create 187.49 acre-feet (ac-ft) of water storage and achieve an estimated reduction of 1,845.9 pounds per year (lbs/yr) of N, 189.46 lbs/yr of P, and 14.85 tons per year (T/yr) of TSS.