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Anderson Daycare October 19, 2016 be to install new pavement above existing pavement,the actual site disturbance area is limited to approximately 27,300 sq. ft. Site drainage patterns are split between west and east,roughly along the ridge line of the existing principal building. The eastern or front yard runoff is routed to the Yahara south of the site via the River Road ditch, and the western or back yard runoff trends to the south and west directly to the Yahara. The site accepts runoff only from approximately 400 sq. ft. of adjacent land lying to the north. The site is depicted on the attached project plans. Regulatory Requirements The project is classified as redevelopment. Because site disturbance is less than one acre a WDNR permit for construction site disturbance is not necessary. The following requirements of Dane County Ordinance Chapters 11 and 14 must be met: 1. Water quality treatment must retain the 20-micron particle for a 1-yr storm event. This requirement is generally considered equivalent to the 40%TSS reduction requirement on an average annual basis. 2. "Maintenance of Effort" requirements for peak discharge rates will be met passively due to the reduction in impervious areas for the redeveloped site. 3. Redevelopment of the site pavements must comply with the requirements of Chapter 11 —Shoreland, Shoreland-Wetland, and Inland-Wetland Regulations. On-site Soils On-site soils include McHenry Silt Loam, St. Charles Silt Loam, and Alluvial Land. Although the NRCS mapping shows the hydric Alluvial Land soils as encroaching within the upland shelf of the redevelopment area, we believe based on the site topography that these soils are limited to the lowland beneath the upland shelf. Likewise, based on topography, wetlands are not present within the redevelopment area. Both of the silt loam soils are classified as HSG Group B soils. No soil borings were advanced for the project. A site soils map is provided as an attachment. Post-Developed Conditions Runoff from the western watershed, which includes the bulk of the redevelopment area, will be routed via grassed swales to a biofilter which will discharge to the west. Runoff from the eastern watershed, which includes the portions of the redeveloped driveways near River Road, will be directed to the River Road ditch untreated and undetained. Shoreland Zoning In accordance with Dane County Ordinance Chapter 11.11(2)(c), replacement of existing (nonconforming) impervious surfaces with similar surfaces within the existing impervious surface area footprint is allowed with a Shoreland Zoning Permit. Delineation of a wetland boundary (and the associated 75 ft. setback) may not be possible this fall due to the impending end of the growing season and high workloads for WDNR staff and Page 2 of 6 18226000_memo 101916