Agenda - Planning Commission - 05/03/2018

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BMP Summary Sheet MS4 Name: City of Ramsey Permit Condition: IX. Appendix C. Part A and/or Part B. Unique BMP Identification Number: IX. A. and/or IX. B. *BMP Title: Discharges to Waters with Prohibited or Restricted Discharges Assessment *BMP Description: City of Ramsey Practices for discharges to ORVW waters • This BMP includes establishment of a baseline of information— determine what processes are in place and what has already been accomplished that will help meet the permit conditions • This BMP includes preparation of a written inventory of all stormwater discharges to the prohibited or restricted water(s) from within the jurisdictional boundaries of the MS4; compile necessary detail about the stormwater discharges to assess the impacts and alternatives • Prepare a map that includes all the delineated sub-watershed(s) covering the MS4 that discharge to the ORVW, including the identified discharge points and routes to the ORVW waters that the MS4 discharge may impact. • Evaluate past and future changes in the watersheds, projected out at least through the year 2020. • Determine if a new or expanded discharge has or would occur and the magnitude of the potential changes. • Evaluate alternatives to the discharge. • Propose methods of eliminating the discharge. Activity Implementation Plan As an MS4 located within a watershed that discharges to ORVW waters, City of Ramsey will submit an assessment and other documentation required in Appendix C of permit MNR040000 of which the following are major components: 1. The City of Ramsey topography generally slopes from northwest to southeast. The eastern boundary is the Rum River and the southern boundary is the Mississippi River. Both Rivers are designated ORVW' s. Many of the developments in the City, especially along the rivers, were in place prior to designation of the rivers as ORVW's. Development has continued since the designation and the level of storm water treatment has increased with time. Development is anticipated to continue in the future. 2. The City has prepared a stormwater model for the entire city based on the existing storm sewer system. The model has identified areas that are landlocked and do not discharge to the rivers, excluding these areas all runoff reaches either the Rum River or the Mississippi River. 3. The City has prepared a map showing when plats were approved for determination of where discharges have occurred since the ORVW was designated. It appears that new or expanded discharges have occurred since the ORVW was designated. The City has prepared a stormwater model for the entire city that will be used in conjunction with the plat date map to evaluate changes to the discharges. 4. The City adopted an updated Surface Water Management Plan in 2008. The plan calls for all new developments to incorporate infiltration practices and to limit discharge rates to 75% of the existing runoff rates. The city will evaluate Low Impact Development, infiltration and volume reduction strategies and will adopt ordinances requiring the practices that are best suited for the unique conditions in Ramsey. *Timeline/Implementation Schedule: Ramsey Minnesota SWPPP -56- May 2006 February 2009