Laserfiche WebLink
Updated Storm Water Management Plan (SWMP) <br />City of Ramsey, Minnesota <br />Public Waters: Those waters of the state identified as public waters or wetlands under <br />Minnesota Statutes, Section 103G.005. <br />Rational Method: A method of estimating the peak runoff from a watershed that is <br />based on the formula Q = CIA. Where: <br />Q = peak flow rate in cubic feet per second <br />C = a runoff coefficient based on the percentage of impervious surface, type of <br />vegetative cover, and soil type <br />I = rainfall intensity in inches per hour as determined from an area IDF curve <br />A = watershed area in acres <br />Reach: A hydraulic engineering term to describe a longitudinal segment of a stream or <br />river influenced by the natural or man-made obstruction. In an urban area, the segment <br />of a stream or river between two consecutive bridge crossings or between two reservoirs <br />would most typically constitute a reach. <br />Redevelopment: Any development including but not limited to rebuilding, renovation, <br />revision, remodeling, reconstruction or redesign of or at an existing development. <br />Regional Flood: A flood which is representative of large floods known to have occurred <br />generally in Minnesota and reasonably characteristics of what can be expected to occur <br />on an average frequency in the magnitude of the 100 -year recurrence interval. A regional <br />flood is synonymous with the term "base flood" used in the Flood Insurance Study. <br />Regulatory Flood Protection Elevation: A point not less than one -foot above the water <br />surface profile associated with the 100 -year flood as determined by the use of the 100 - <br />year flood profile and surrounding technical data in the Flood Insurance Study plus any <br />increase in flood heights attributable to encroachments on the floodplain. It is the <br />minimum elevation the DNR requires Cities to regulate by ordinance. <br />Retention: The permanent storage of runoff from rainfall and snowmelt events with <br />volume reduction coming from infiltration, evaporation or emergency release. <br />Riprap: A combination of large stone, cobbles and boulders used as an erosion control <br />BMP. Riprap is typically used to line channels, stabilize banks, reduce runoff velocities, <br />or filter out sediment. <br />Runoff (Storm Water): The overland and near surface flow from rainfall and snowmelt. <br />Runoff Coefficient: A measure of the rate of runoff that isstatistically generated from a <br />parcel of land that is based on the land use, percent of impervious surfacing, soil type and <br />vegetative cover. The higher the coefficient, the higher the amount of runoff anticipated <br />from the parcel. Rational method runoff coefficients range from 0.2 for meadow lands to <br />0.95 for paved surfaces. <br />Section XI <br />February 20, 2015March 6, 2015 Page 81 <br />