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siltation. If construction activities disturb land or
<br />entail the grading of an area that is five (5) acres or
<br />greater, a land disturbance permit shall be obtained
<br />from the Missouri Department of Natural Resources
<br />(see 29.81.1, paragraph 3 of ttris Chapter).
<br />
<br />a. Temporary Erosion/Siltation Control Measures:
<br />
<br />Temporary erosion and sediment control measures
<br />are intended to retain siltation within the develop-
<br />ment site, particularly if construction is not com-
<br />pleted within a single construction season. Tem-
<br />porary erosion and siltafion control measures shall
<br />be maintained until long-term erosion/siltation
<br />control measures are fully established, including
<br />such t/me that vegetative cover is established at a
<br />sufficient densi ,ty to provide erosion control on the
<br />site. Temporary erosion/siltafion control measures
<br />shall include, but are not necessarily limited to the
<br />following:
<br />
<br />(i)
<br />
<br />Graded areas shall be stabilized immediately
<br />upon grading and maintained to prevent or
<br />minimize erosion until permanent stabiliza-
<br />tion measures are in place. Permissible
<br />erosion control techniques include contour
<br />furrowing or other surface roughening tech-
<br />niques, mulching, sodding, or other tech-
<br />niques approved by the Director of Public
<br />Works.
<br />
<br />(2)
<br />
<br />Sedimentation shall be retained on the site by
<br />filtering runoff. Where grading exceeds
<br />twenty thousand (20,000) square feet in area,
<br />the erosion/siltation control plans shall pro-
<br />vide for sediment or debris basins, silt traps
<br />or filters, staked straw bails and/or geotextile
<br />fabric, or other measures to remove sediment
<br />from nmoffwaters, as approved by the Direc-
<br />tor of Public Works.
<br />
<br />(3)
<br />
<br />Slope shall be designed to keep the slope
<br />length and gradient to a minimum to mini-
<br />mize storm water runoff velocities over' grad-
<br />ed areas.
<br />
<br />(4) Measures shall be taken to accommodate
<br /> increased runoff during grading by utilizing
<br />
<br />Land Development Standards
<br />
<br />diversion berms, ditches, and/or sediment
<br />basins designed in accordance with the stan-
<br />dards established by the Director of Public
<br />Works.
<br />
<br />(5)
<br />
<br />Land and improvements, adjoining the con-
<br />stmction site, shall be provided protection
<br />from any increase in surface water, siltation
<br />deposits, or any other consequences of ero-
<br />sion. Where it is necessary for the protection
<br />of such property, to enter upon such property,
<br />consent must be obtained from the property
<br />owner. The developer, at his/her own ex-
<br />pense, shall shore up and protect any and all
<br />buildings, walls, fences, or other property, that
<br />are ex-posed to any potential damage as a
<br />result of grading the site. The developer shall
<br />be responsible for all damage to public or
<br />private propen'y resulting from his/her failure
<br />to properly protect adjoining properties.
<br />
<br />(6)
<br />
<br />Runoff water from e.,dsting developed areas
<br />(e.g., parking lots, paved sites, buildings and
<br />similar imper,,ious surfaces) above the area to
<br />be graded shall be intercepted by sufficiently
<br />anchored straw bails and/or geotextile fabric
<br />until such time such ranoff can be directed to
<br />diversions, detention basins, concrete gutters,
<br />underground outlet systems or other perma-
<br />nent storm drainage control measures.
<br />
<br />b. Long-term Erosion/Siltation Control:
<br />
<br />The site plan and erosion control, storm drainage
<br />control, and landscape plans shall be designed to
<br />minimize erosion potential upon completion of the
<br />development and thereafter. In support of this
<br />requirement, the following design standards and
<br />guidelines shall apply.
<br />
<br />(1) The finished grading shall provide for sedi-
<br /> ment basins, diversion benns, permanent
<br /> bank stabilization, or other erosion control
<br /> techniques approved by the Director of Public
<br /> Works, whenever necessary to avoid damage
<br /> to adjoining properties, street, sidewalks,
<br /> storm drainage ways and storm sewers.
<br />
<br />chapt29.fin 5-l 0 A~ approved by the Plan Commission on October 22, 1997
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