2015-009 Council Ordinances - Laserfiche WebLink

Home Search

grading, filling, and excavating. CONSTRUCTION ACTIVITY includes the disturbance of less than one acre of total land area that is a part of a larger common plan of development or sale if the larger common plan will ultimately disturb one acre or more. CRITICAL DURATION FLOOD EVENT. The 100 -year precipitation or snow melt event with a duration resulting in the maximum 100 year return period water surface elevation. The CRITICAL DURATION FLOOD EVENT is generally either the 100 -year, 24 hour rainfall event as found in NOAA Atlas 14 or the ten-day snow melt event assumed to be 7.2 inches of runoff occurring on frozen ground (CN=100); however, other durations (e.g., 6 -hour) may result in the maximum 100 year return period water surface elevation. DETENTION BASIN. Any natural or man-made depression that stores stormwater runoff temporarily. DEVELOPMENT. Any land -disturbing activity resulting in creation or reconstruction of impervious surface including, but not limited to, municipal road construction. Normal farming practices part of an ongoing farming operation shall not be considered DEVELOPMENT. DRAINAGE SYSTEM. A system of open channel, pipe or tile, to drain property, including laterals, improvements, and improvements of outlets, which may or may not be a public system under the jurisdiction of a watershed district under Minnesota Statues Chapters 103B, 103D, or 103E. ..... EMERGENCY OVERFLOW (EOF). A primary overflow to pass flows above the design capacity around the principal outlet safely downstream without causing flooding. EROSION AND SEDIMENT CONTROL PLAN. A plan of BMPs or equivalent measures designed to control runoff and erosion and to retain or control sediment on land during the period of land disturbance in accordance with the standards set forth in this chapter. EROSION PREVENTION. Measures employed to prevent erosion including, but not limited to, soil stabilization practices, limited grading, mulch, temporary or permanent cover, and construction phasing. EXCAVATION. The displacement or removal of soil, sediment or other material. FILTRATION. A stormwater quality BMP that uses either natural media such as soil or vegetation or manufactured media to trap pollutants such as nutrients and particles in surface water. FINAL STABILIZATION. All soil disturbing activities at the site have been completed and all soils have to be stabilized by a uniform perennial vegetative cover with a density of 70% over the entire pervious surface area, or other equivalent means necessary to prevent soil failure under erosive conditions. DRAFT ORD 09-15 CHAPTER 1011STORMWATER & ESC ORDINANCE.DOCX 5/29