(A) It is the objective of these requirements to control soil erosion and sedimentation caused by development activities, including clearing, grading, stripping, excavating and filling of land, in and around the city. Measures taken to control soil erosion and off-site sediment runoff should be adequate to assure that sediment is not transported from the site by a storm event of ten-year frequency or less. The following principles shall apply to all development activities within and around the city and to the preparation of the submissions required herein.
(B) Illinois Procedures and Standards for Urban Soil Erosion and Sedimentation Control (prepared by the Northeastern Illinois Erosion and Sedimentation Control Steering Committee, in cooperation with area Soil and Water Conservation Districts and the U.S. Soil Conservation Service, and known as the Green Book) are designed to provide protection against sediment leaving the site during a ten-year storm.
(C) Development should be related to the topography and soils of the site so as to create the least potential for erosion. Areas of steep slopes where high cuts and fills may be required should be avoided wherever possible, and natural contours should be followed as closely as possible.
(D) Natural vegetation should be retained and protected wherever possible. Areas immediately adjacent to natural watercourses, lakes, ponds and wetlands should be left undisturbed wherever possible. Temporary crossings of watercourses, when permitted, must include appropriate stabilization measures. Floodplain and wetland protection will be included in site development plans, a minimum 25-foot buffer strip shall be preserved along waterbodies and wetlands.
(E) Special precautions should be taken to prevent damages resultant from any necessary development activity within or adjacent to any stream, lake, pond or wetland. Preventative measures should reflect the sensitivity of these areas to erosion and sedimentation.
(F) The smallest practical area of land should be exposed for the shortest practical time during development.
(G) Sediment basins or traps, filter barriers, diversions and any other appropriate sediment or runoff control measures shall be installed prior to site clearing and grading and maintained to remove sediment from run-off waters from land undergoing development.
(H) The selection of erosion and sedimentation control measures should be based on assessment of the probable frequency of climatic and other events likely to contribute to erosion, and on evaluation of the risks, costs and benefits involved.
(I) In the design of erosion control facilities and practices, aesthetics and the requirements of continuing maintenance should be considered.
(J) Provision should be made to accommodate the increased run-off caused by changed soil and surface conditions during and after development. Drainageways should be designed so that their final gradients and the resultant velocities and rates of discharge will not create additional erosion on-site or downstream.
(K) Permanent vegetation and structures should be installed and functional as soon as practical during development.
(L) Those areas being converted from agricultural purposes to other land uses should be vegetated with an appropriate protective cover prior to development.
(M) All waste generated as a result of site development activity should be properly disposed of and should be prevented from being carried off the site by either wind or water.
(N) All construction sites should provide measures to prevent sediment from being tracked onto public or private roadways.
(Ord. 3319, passed 2-22-2005)