Laserfiche WebLink
Catchment Profiles <br />Existing Catchment Summary <br />Acres <br />Dominant Land <br />Cover <br />Parcels <br />38.1 <br />Residential <br />68 <br />CATCHMENT DESCRIPTION <br />This catchment contains a nearly even mix of single- <br />family residential, commercial, and undeveloped land <br />uses. Stormwater generated within this catchment is <br />directed to a storm sewer network below 142nd Ave. <br />which discharges into retention pond P25216 just <br />east of Xkimo Street. The pond subsequently <br />discharges into an oxbow lake adjacent to the Rum <br />River. <br />EXISTING STORMWATER TREATMENT <br />Stormwater retention pond P25216 provides <br />pollutant treatment for the entire 38-acre catchment. <br />In addition to the pond, street cleaning is provided by <br />the City of Ramsey twice per year with mechanical <br />sweepers. Present-day stormwater pollutant loading and treatment is summarized in the table below. <br />Existing Conditions <br />, -s u i <br />Number of BMPs <br />BMP Types <br />TP (Ib/yr) <br />SS (Ib/yr) <br />olume acre-feet/ r <br />Net Treatment <br />Base Loading Treatment <br />Existing <br />Loading <br />2 <br />Stormwater Pond and Street Cleaning <br />19.0 2.9 15% 16.1 <br />6,895 1,367 20% 5,528 <br />19.3 0.0 0% 19.3 <br />PROPOSED RETROFITS OVERVIEW <br />Retention pond P25216 appears to be a natural depression which was retrofitted with an outlet control <br />device to manage flow discharge. This pond could be modified to increase storage capacity to more <br />sufficiently treat its developed drainage area. <br />Hydrodynamic devices were also proposed along the tertiary storm sewer lines on 142nd Ave and Xkimo <br />St. These devices were purposefully sited to achieve contributing drainage areas of approximately 10 <br />acres in size. This limits high peak discharges through the device that could cause sediment <br />resuspension and decreased effectiveness. <br />City of Ramsey Stormwater Retrofit Analysis <br />