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Page 17 achieving volume reduction to restore or maintain the natural hydrology of the site using green infrastructure practices or other stormwater management practices. Identify any receiving waters that have construction-related water impairments or are classified as special as defined in the Construction Stormwater permit. Describe additional requirements for special and/or impaired waters. Pre-Construction Site Runoff Due to the current agricultural operation and previous bus maintenance operation, runoff currently drains to the onsite wetlands and the Mississippi River, likely containing pollutants like sediment, pesticides, fertilizers, and other nutrients. The established hayfields, open meadows, and forested hillsides serve as buffers and allow for sediment to settle out. The cultivated fields were planted with soybeans in 2024, and annual tillage/residue cover varies based on the crops planted and cultivation methods. The soils mapped onsite are primarily non-hydric and have a high-water infiltration rate (20). Table 17 outlines several factors indicating the susceptibility of the soil to erosion. The two soil map units most susceptible to sheet/rill erosion correspond to the lower floodplain and the western hillslope/bluff. Most of the site is only slightly susceptible to sheet/rill erosion. The majority of the site is susceptible to wind erosion. Table 17. Soil Factors Affecting Erosion Map Unit1 % of Project Area K Factor2 Wind Erodibility3 (0.02-0.69) (Group 1-8) 258B; Sandberg loamy sand, 1-6% slopes 16.3% 0.10 2 258E; Sandberg loamy coarse sand, 6- 30% slopes 6.3% 0.15 2 771; Elk River fine sandy loam, 0-2% rarely flooded 10.1% 0.28 3 D62A; Hubbard-Mosford complex, Mississippi River Valley, 0-3% percent slopes 10.8% 0.02 2 D67B; Hubbard loamy sand, 1-6% slopes 55.4% 0.02 2 D67C; Hubbard loamy sand, 2-12% slopes 0.9% 0.02 2 W; Water 0.3% -- -- 1 The lower floodplain corresponds to soil map unit 771 and the western hillslope/bluff corresponds to soil map unit 258E. 2 The K Factor measures susceptibility to sheet/rill erosion and ranges from 0.02 to 0.69, with the higher values indicating greater susceptibility. 3 The Wind Erodibility Group categorizes soils in cultivated areas susceptible to wind erosion. Group 1 is the most susceptible, and group 8 is the least susceptible. Construction Site Runoff Section 30-2174 of the Elk River City code regulates stormwater and urban runoff control. Approximately 200 acres will be disturbed for project development. A City-approved Stormwater Pollution Prevention Plan (SWPPP) and Permit is required (25). Similarly, the