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(A) Requirements applicable to all developments. No development shall:
(1) Result in any new or additional expense to any person other than the developer for flood protection; or
(2) Increase flood elevations or decrease flood conveyance capacity upstream or downstream of the area under the ownership or control of the developer. This requirement shall not prohibit the removal or reduction of built obstructions to flow, such as increasing culvert capacity or lowering roadway elevations.
(B) Building permits. Stormwater facilities shall be functional before building permits are issued for residential and nonresidential subdivision.
(C) Single parcel developments. Stormwater facilities shall be functional where practicable for single parcel developments before building construction begins.
(D) Overland flow paths. The development shall have an overland flow path at the downstream limit of the property that will pass the base flood flow at a stage at least one foot below the lowest adjacent foundation grade in adjacent structures without increasing damage to structures or property. If the upstream drainage area is less than 20 acres, the storm sewer pipe and inlet sized for the base flood can be constructed in lieu of providing an overland flow path. Overland flow paths internal to the site shall be considered as part of the major stormwater system and shall be designed for conveyance of the base flood (critical duration) and shall be a minimum of one cfs per tributary acre without damage to structures.
(E) Protection of buildings. All usable space in new buildings or added to existing buildings hydraulically connected to a major stormwater system, site runoff storage facility or overland flow path shall be elevated, flood proofed, or otherwise protected to at least one foot above the blocked restrictor elevation of the site runoff storage (detention) facility or the calculated high water elevation of the overland flow path, or two feet above the base flood elevation, whichever is greater.
(F) Depressional storage. The function of existing on-site depressional storage shall be preserved for both on-site and off-site tributary flows in addition to required detention. When depressional storage is removed, it must be compensated for in the site runoff storage facility at one and one-quarter to one ratio if the depression is identified as a regulatory floodplain and at a one to one ratio if the depression is not a regulatory floodplain, provided that offsite areas tributary to the existing depressional storage are routed through the site runoff storage facility. This requirement is in addition to the site runoff storage required in § 164.023. The Chief Subdivision Engineer may allow the function of depressional storage to be preserved if the applicant performs detailed pre- and post-project hydrologic and hydraulic modeling to identify the effect of the depressional storage on discharges over a range of rainfall frequencies.
(Ord. 10-164, passed 6-17-2010) Penalty, see § 164.999
(A) Stormwater facility discharges. Stormwater facilities shall be required and designed so that runoff exits the site at a point where it exited prior to the subject development and in a manner such that flows will not increase flood damage to adjacent property except when otherwise approved by the Chief Subdivision Engineer. Concentrated discharges from new developments must enter conveyance systems capable of carrying the design flow rate without increasing flood damages or maintenance costs downstream.
(B) Minor stormwater system criteria. Minor stormwater systems shall be sized to convey runoff from the tributary watershed under fully developed conditions. Storm sewers shall be sized to convey the ten-year storm in a full (non-surcharged) pipe condition unless otherwise directed by the road authority.
(C) Major stormwater system criteria. Major stormwater systems shall be sized to carry the base flood without causing additional flood damage.
(D) Existing subsurface and surface drainage systems.
(1) Stormwater systems shall properly incorporate and be compatible with existing subsurface and surface drainage systems including agricultural systems. Designs shall not cause damage to the existing drainage system(s) or the existing adjacent or tributary land including those with agricultural uses.
(2) The following principles and requirements shall be observed in the design.
(a) Off-site outfall. Existing agricultural subsurface and surface drainage systems shall be evaluated with regard to their capacity, condition and capability to properly convey low flow groundwater and two-year site runoff to a surface outlet without damage to downstream structure and land use on the adjacent properties. If the outfall drain tile and surface drainage systems prove to be inadequate, it will be necessary to modify the existing systems or construct new systems which will not conflict with the existing systems and will not impact the existing agricultural land use.
(b) On-site. Agricultural drainage systems shall be located and evaluated on-site. All existing on-site agricultural drain tile not serving a beneficial use shall be abandoned by trench removal prior to other development and recorded on record plans. If any existing drain tiles continue to upland watersheds the developer must maintain drainage service during construction until new sewers can be installed for a permanent connection.
(c) Off-site tributary. Existing drainage systems shall be evaluated with regard to existing capabilities and reasonable future expansion capacities. All existing tributary drain tiles shall be incorporated into the new conduits including observation structures located at the property limits, shall provide a free flow discharge and shall not allow surface runoff to enter the system.
(d) New roadway construction. New roadway construction shall preserve existing sub-surface systems within the right-of-way. Inspection wells shall be placed at the right-of-way (ROW) and tiles found to not be flowing between inspection wells at the end of the construction shall be replaced.
(E) Design runoff rate. Design runoff rates for minor stormwater systems may be calculated using the Rational Method.
(F) Design rainfall. Any design runoff rate calculation method for conveyance shall use data from Illinois State Water Survey Updated Bulletin 70 (March 2019) Northeast Sectional Code.
(G) Stormwater system easements. For projects involving subdivision, major and minor stormwater systems shall be located within easements or rights- of-way explicitly providing for public access for maintenance of the facilities. For all other projects requiring a permit, easements (minimum ten feet wide) are required for public access for maintenance of stormwater facilities only for new construction or modifications involving components of a drainage system that conveys runoff from off-site properties. For commercial and/or industrial property, the stormwater system does not have to be located within an easement or public right-of-ways unless the system serves multiple properties or is constructed on an adjacent property. Instead, the owner or owner’s representative shall provide a signed agreement to the county authorizing it to enter the facility to maintain the stormwater system if the owner fails to correct any deficiencies brought to the owner’s attention by the governmental entity.
(H) Flow and ponding depths. Maximum flow depths for new transverse stream crossings shall not exceed six inches at the crown of the road during the 100-year storm condition. For flow over a new roadway or parallel to a new roadway, the product of the flow depth (in feet) and velocity (in feet per second) shall not exceed four for the 100-year storm condition. The maximum flow depth on a roadway shall not exceed six inches at the crown for flow parallel to the roadway. The maximum stormwater ponding depth during the 100-year critical storm event in any yard or parking area shall not exceed nine inches, and the maximum storage elevation shall not be maintained for more than four hours. Inlets shall have capacity to allow the inflow, based on the design pipe capacity, with no more than three inches of ponding over street inlets.
(I) Diversion of flow to another watershed. Transfers of waters between watersheds (diversions) shall be prohibited except when such transfers will not violate the provisions of § 164.021(A) and are otherwise lawful. Watersheds for purpose of regulation under this section shall be the major watershed divides as defined in the County Stormwater Management Plan.
(J) Best management practices requirement.
(1) Developments shall incorporate all best management practices as may be required pursuant to the United States Clean Water Act, 33 U.S.C. §§ 1251 et seq., as amended. Developments shall be designed to create a healthy aquatic ecology, provide for sustainability, minimize maintenance and human intervention, and treat stormwater as a multiple-use resource. The Chief Subdivision Engineer does reserve the right to require specific stormwater best management practices at a particular site if it discharges to a sensitive ecological area or if the intended use of the property produces a particularly detrimental water quality of the discharge.
(2) Listed below are examples of BMPs that meet the intent of the chapter:
(a) Minimize mass grading and disturbance of soils;
(b) Lay out streets and lots to conform to the natural topography of the site;
(c) Minimize new impervious surfaces by clustering of neighborhoods and homes, minimizing street widths and parking lots, and reducing lot sizes and building setbacks;
(d) Preserve and create natural landscaping, buffers and filter strips;
(e) Utilize permeable areas to maximize infiltration of runoff into the ground through the use of biofilters, filter strips, swales, infiltration trenches, permeable pavement and native vegetated open spaces;
(f) Direct runoff to permeable areas and/or utilize stormwater for reuse by:
1. Directing roof runoff towards permeable surfaces, drywells, French drains, vegetated swales or other BMPs instead of driveways or other non-permeable surfaces;
2. Grading impervious surfaces to direct runoff to permeable areas, utilizing level spreaders or other methods to distribute the impervious runoff onto pervious surfaces;
3. Using cisterns, retention structures or rooftops to store precipitation or runoff for reuse; and
4. Removing berms and designing pavement edges (e.g., curb cuts) in order to direct water to permeable landscaped areas.
(g) Improve water quality of stormwater leaving the site through the use of a naturalized detention basin designed to maximize the removal and transformation of runoff pollutants. Design should include:
1. Emergent vegetation in the bottoms of the wetland basins and along the periphery of wet bottom basins and side slopes vegetated in native prairie (traditional dry bottom basins are not approved BMPs);
2. Stilling basins at major detention basin inlets and maximizing the distance between major inlets and the basin outlet;
3. Installation of pre-settlement or mechanical stormwater treatment units prior to discharge of stormwater into primary detention basins; and
4. In locations where detention basin discharge to adjacent/downstream wetlands, designing detention basin outlet structures to spread and infiltrate runoff through the use of level spreader devices.
(Ord. 10-164, passed 6-17-2010; Ord. 19-238, passed 9-19-2019)
(A) Release rate.
(1) If no release rate is specified in an adopted watershed plan in accordance with § 164.003, then sufficient flood storage shall be provided so that the site will not discharge at a rate greater than 0.15 cfs/acre of development during and after a rainfall event with a 100-year frequency except for sites exempted in § 164.020(C). Unless exempted in § 164.020(C), sites shall not discharge at a rate greater than 0.04 cfs/acre of development during and after a rainfall event with a two-year frequency.
(2) This area of hydrologic disturbance on the site shall be used to calculate the required site runoff storage volume. The on-site watershed area tributary to the point of discharge shall be used to calculate the allowable release rate for the site runoff storage facility, which shall be the maximum release rate allowed considering only the on-site watershed area runoff.
(3) In the event the downstream creeks, streams, channels, conduits or other drainage facilities are inadequate to receive the release rate herein above provided and there is no adopted watershed plan available, then the allowable release rate shall be reduced to that rate permitted by the receiving downstream creeks, streams, channels, conduits or other drainage facilities; and additional detention volume shall be required to store that portion of the runoff exceeding the capacity of the receiving drainage facilities.
(B) Design methods.
(1) Event hydrograph routing methods or the modified rational method may be used to calculate design runoff volumes for site runoff facilities. The methods must be HEC-1, (SCS methodology), HEC-HMS, TR-20 or TR-55 tabular method.
(2) Event methods shall incorporate the following assumptions:
(a) Antecedent moisture condition equals two;
(b) Appropriate Huff rainfall distribution; and
(c) Twenty-four-hour duration storm with a 1% probability (100-year frequency) of occurrence in any one year as specified by data from Illinois State Water Survey Updated Bulletin 70 (March 2019) Northeast Sectional Code.
(C) Existing release rate less than allowable. For sites where the undeveloped release rate is less than the maximum release rate in division (A) above, the developed release rate and corresponding site runoff storage volume shall be based on the existing undeveloped release rate for the development.
(D) Downstream water surface elevations. All hydrologic and hydraulic computations must utilize appropriate assumptions for downstream water surface elevations, from low flow through the base flood elevation, considering the likelihood of concurrent flood events.
(E) Extended detention requirement.
(1) The requirements of this section will apply only when an existing agricultural land use is downstream of and adjacent to a site runoff storage facility outlet. The runoff from a three-quarters-inch rainfall event over the hydraulically connected impervious area of the new development shall be stored below the elevation of the primary gravity outlet (extended detention) of the site runoff storage facility. The facility may be designed to allow for evapotransporation or infiltration of this volume into a subsurface drainage system and shall not be conveyed through a direct positive connection to downstream areas.
(2) The hydraulically connected impervious area used in the calculation of required extended detention volume may be reduced by the Chief Subdivision Engineer if the soils are prepared to maximize infiltration and deep rooted grasses or other plants selected for their ability to promote infiltration or water absorption are planted in areas appropriately dedicated. The reduction in hydraulically connected impervious area used in the calculation shall be equal to the area of the development meeting the above soils/native planting requirement.
(3) Subsurface drainage systems may be designed as a component of the extended detention portion of the detention basin to assist in infiltration in accordance with the following criteria.
(a) The extended detention volume shall be discharged at a rate no greater than (no earlier than) that required to empty the calculated extended detention volume within five days of the storm event.
(b) For purposes of meeting the maximum subsurface drainage discharge requirements, flow control orifices and weirs may be used.
(c) All design extended detention volume shall be provided above the seasonal high ground water table or the invert elevation of the ground water control system.
(d) Farm field tile shall not be used as a component of the extended detention system, unless evaluated per § 164.022(D).
(F) Site runoff storage facility design requirements. Storage facilities shall be designed and constructed with the following characteristics.
(1) The site runoff storage facility shall provide one foot of freeboard above the calculated (blocked restrictor) high water elevation.
(2) The storage facilities shall be accessible and easily maintained.
(3) Storage facilities shall facilitate sedimentation and catchment of floating material. Unless specifically approved by the Chief Subdivision Engineer, concrete lined low-flow ditches shall not be used in detention basins.
(4) Storage facilities shall minimize impacts of stormwater runoff on water quality by incorporating best management practices.
(5) Storage facilities shall maximize the normal flow distance between detention inlets and outlets, to the extent possible.
(6) Storage facilities shall be designed so that the existing conditions pre-development peak runoff rate from the 100-year, critical duration rainfall will not be exceeded assuming the primary restrictor is blocked. One foot of freeboard shall be provided over the blocked restrictor water level.
(7) Storage facilities with single pipe outlets shall have a minimum inside diameter of 12 inches. Where flow control orifices are used, the minimum diameter is four-inch. If design release rates necessitate a smaller outlet, structures such as perforated risers or other self-cleaning restrictors shall be used.
(8) Basin side slopes should not be steeper than four to one (horizontal to vertical); five to one side slopes are preferred. For wet-bottom basins, side slopes not steeper than two to one may be used below the safety ledge.
(9) Wet-bottom storage facilities must include a safety shelf, minimum six feet width, two and one-half feet to three feet below the normal water line.
(10) The permanent pool volume in wet-bottom basins shall be at least equal to the two-year, 24-hour runoff volume from the tributary watershed. The minimum permanent pool depth is three feet, excluding safety shelves. If fish habitat is to be provided, over 25% of the bottom area must be at least ten feet deep.
(11) Dry bottom detention basins shall be graded with not less than 1% slope across basin floor.
(12) All detention basins shall be provided with an overflow structure capable of passing pre- development peak runoff rate capable of meeting the requirements of division (F)(6) above.
(13) All detention basins discharging at grade shall discharge a minimum of 20 feet from any property line unless an agreement allowing discharge closer to the property line is secured from the adjacent property owner or road authority. Vegetative buffers, level spreaders or other appropriate BMPs shall be utilized at the outlet structure to promote spreading and infiltration of the discharge.
(14) Riprap or other approved method of dissipating energy shall be utilized at all end sections and point discharge locations.
(15) Standards for naturalized detention basins include: flat side slopes (eight to one from two- year water level to one-half foot below normal water level), shallow zones of emergent vegetation at water’s edge, combination of natural vegetation and open water area. Uses of aerators, cascades, water falls and the like are encouraged. A planting/ maintenance shall be submitted and approved by the Chief Subdivision Engineer.
(G) Site runoff storage facility requirements within the regulatory floodplain. Storage facilities located within the regulatory floodplain shall:
(2) Store the required amount of site runoff to meet the release rate requirement under all stream flow and backwater conditions in the receiving stream up to the ten-year flood elevation; and
(3) The Chief Subdivision Engineer may approve designs which can be shown by detailed hydrologic and hydraulic analysis to provide a net watershed benefit not otherwise realized by strict application of the requirements in division (G)(1) and (G)(2) above.
(H) Site runoff storage facility requirements within the regulatory floodway. Site runoff storage facilities shall not be located within the regulatory floodway.
(I) Off-site facilities. Site runoff storage facilities may be located off-site if the following conditions are met.
(2) Adequate storage capacity in the off-site facility is dedicated to the development and placed in an appropriate easement on the off-site property.
(3) The development includes means to convey stormwater to the off-site storage facility. The conveyance system shall be placed in an appropriate easement on the off-site property.
(J) Cross-stream structures for site runoff storage facilities. Structures constructed across the channel to impound water to meet detention requirements shall be prohibited on any perennial stream unless part of a public flood control project with a net watershed benefit. Those streams appearing as blue on a USGS quadrangle map shall be assumed perennial unless better data is obtained. All cross- stream structures for the purpose of impounding water to provide detention in all cases on perennial and intermittent streams must demonstrate that they will not cause short term or long-term stream channel instability.
(Ord. 10-164, passed 6-17-2010; Ord. 19-238, passed 9-19-2019)
(A) Applicability. Regulations under this section apply only to croplands, pasturelands, farmsteads and outbuildings associated with those agricultural practices. Compliance with the requirements of this section shall be construed as compliance with the stormwater ordinance for the above land uses and no further regulation under the ordinance will apply. Any other land use, including, but not limited to, greenhouses, nurseries, container grown plants, equestrian facilities, the sale of agricultural products to the public or any other commercial activities involving the new construction of gravel or paved parking facilities or buildings, where the aggregate area of proposed impervious surfaces is 25,000 square feet or more are required to comply with all applicable sections of this chapter.
(B) Conservation planning and performance standards.
(1) To comply with this section, landowners shall practice conservation planning whose product shall be a management system, which addresses site runoff, soil erosion and sediment control, surface and subsurface drainage. Any acreage with a signed and approved NRCS Conservation Plan is exempt from the requirements of this section and the chapter.
(2) Applicable approved practices include:
(a) Vegetated grass waterways;
(b) Contour buffer strips;
(c) Critical area planting and cover crops;
(d) Terrace ridges and diversions;
(e) Contour strip cropping;
(f) Contour farming;
(g) Conservation crop rotation;
(h) Conservation tillage and crop residue management; and
(i) Other standard practices for conservation planning in accordance with the NRCS Field Office Technical Guide (current edition) or as otherwise approved by the County NRCS District Conservationist.
(3) The performance standard for conservation planning and implementation shall be a management system which will develop a set of field practices which will reduce the calculated actual soil loss to the “tolerable soil loss” (T) as calculated by the revised Universal Soil Loss Equation for the actual site conditions. Cropland tillage and resource management methods shall be consistent with the Technical Guide Notice IL-108 and shall be considered evidence of compliance with the “T” performance standard.
(C) Drainage practices, requirements and design criteria.
(1) Drainage for agricultural purposes shall be consistent with those practices identified as appropriate for good husbandry given the soil types, slopes and crops. An agricultural drainage system may consist of both subsurface drainage systems and surface drainage systems. Where active drainage districts maintain drainage systems, they shall be consulted on surface and subsurface drainage within the district boundaries.
(2) Requirements applying to subsurface and surface drainage system shall be as follows.
(a) Agricultural subsurface drainage systems. Drain tile systems shall be maintained and constructed in accordance with subsurface drainage recommendations for the appropriate soil drainage group as specified by the University of Illinois Extension Service Drainage Guide link http://urbanext.illinois.edu/lcr/drainage.cfm. Surface inlets into the subsurface drainage system shall be allowed where their use cannot be practicably avoided due to topography. They shall be installed using flow controls such as orifices and perforated risers with gravel filters and /or vegetative filters. In cases where the installation of the surface inlet is for the purpose of enhancing the drainage of farmed wetlands, the individual shall consult with the County NRCS District Conservationist.
(b) Surface drainage systems. Surface drainage systems shall be maintained and constructed in accordance with surface drainage recommendations for the appropriate soil drainage group as specified by the University of Illinois Extension Service link http://urbanext.illinois.edu/lcr//drainage.cfm . Surface drainage systems shall be built with geotechnically stable slopes and the surface when applicable shall be further stabilized utilizing the establishment of cool and warm season grass mixes as identified in Field Office Technical Guide (Illinois 108).
(c) Buffer strips. Open channels with a definable bed and banks shall use buffer strips having a minimum width of 25 feet in order to reduce the amount of erosion occurring from the conveyed flows as well as to help filter the runoff from the site into the waterway.
(d) Agricultural drainage systems. Agricultural drainage systems shall also comply with all regulations regarding wetlands as enforced by federal, state and local agencies.
(D) Sediment control for open channels.
(1) All open channel drainage systems shall maintain practices adjacent to the open outlet channel that will reduce the transportation of sediment off-site. Runoff from agricultural fields must pass through a sediment control system prior to discharge into the open channel conveyance system.
(2) Approved sediment control systems may consist of the following:
(a) Vegetated buffer shall have a minimum width of 25 feet planted with permanent grasses appropriate for soil stabilization and filtering;
(b) Grade control structures for over fall stabilization;
(c) Sediment traps adjacent to the stream channel; and
(d) Other standard practices for conservation planning in accordance with the NRCS Field Office Technical Guide (current edition) or as otherwise approved by the County NRCS District Conservationist or the Administrator.
(E) Maintenance and construction of drainage systems. Agricultural drainage systems shall be maintained so as to convey the expected flows for good drainage practices. The existing agricultural surface drainage systems shall not be enlarged unless the enlargement is consistent with all other divisions of this section. Maintenance and construction of subsurface drainage systems will not be subject to the requirements of other sections of this chapter except as they are regulated by other agencies. Maintenance projects by legally functioning drainage districts on existing agricultural drainage systems will not be subject to further permitting requirements under this chapter except as they relate to the jurisdiction of other agencies.
(Ord. 10-164, passed 6-17-2010)
(A) Applicability. In a conservation-designed subdivision as defined in the County Subdivision Ordinance, as codified in Chapter 154, a density bonus is granted for each acre (or fractional acre) of land utilized for stormwater infiltration. See § 154.268 of the subdivision regulations.
(B) Infiltration credit.
(1) To obtain the maximum infiltration credit, infiltration BMPs shall be designed, installed and maintained to infiltrate runoff to the maximum extent practicable in accordance with one of the following goals:
(a) Infiltrate sufficient runoff volume so that the post-development infiltration volume shall be at least 90% of the pre-development infiltration volume, based on an average annual rainfall for the region; or
(b) Infiltrate at least 25% of the post-development runoff volume from the two-year, 24-hour design storm with a Type II distribution. Separate curve numbers for pervious and impervious surfaces shall be used to calculate runoff volumes and not composite curve numbers.
(2) Natural conditions such as soil types and slopes will affect the ability of a site to meet these infiltration goals. Projects that are shown to meet these goals will be granted full (100%) credit (i.e., one acre of credit for one acre of land dedicated to stormwater infiltration). Projects that exceed these goals or partially meet these goals will be given credit according to the following table:
Goal #1 90% Average Volume % Calculated | Goal #2 25% 2-Year Volume
% Calculated | % Credit |
Goal #1 90% Average Volume % Calculated | Goal #2 25% 2-Year Volume
% Calculated | % Credit |
> 92.5% | > 26.0% | 110% |
90.0% to 92.5% | 25.0% to 26.0% | 100% |
85.5% to 89.9% | 23.8% to 24.9% | 95% |
81.0% to 85.4% | 22.5% to 23.7% | 90% |
76.5% to 80.9% | 21.3% to 22.4% | 85% |
72.0% to 76.4% | 20.0% to 21.2% | 80% |
67.5% to 71.9% | 18.8% to 19.9% | 75% |
63.0% to 67.4% | 17.5% to 18.7% | 70% |
58.5% to 62.9% | 16.3% to 17.4% | 65% |
54.0% to 58.4% | 15.0% to 16.2% | 60% |
50.0% to 53.9% | 14.0% to 14.9% | 55% |
< 50% | < 14.% | 0% |
(C) Pretreatment required. Before infiltrating runoff, pretreatment shall be required for parking lot and/or commercial area runoff that will enter an infiltration system. The pretreatment shall be designed to protect the infiltration system from clogging prior to scheduled maintenance and to protect groundwater quality. Pretreatment options may include, but are not limited to, oil/grease separation, sedimentation, biofiltration, filtration, swales or filter strips. To minimize potential groundwater impacts, it is desirable to infiltrate the cleanest runoff. To achieve this, a design may propose greater infiltration of runoff from low pollutant sources such as roofs, and less from higher pollutant source areas such as parking lots and commercial areas.
(D) Infiltration. Infiltration from areas requiring pretreatment and regional devices (facilities with a drainage area of five acres or greater) for infiltration from residential development shall not be installed within 400 feet of a community water system well or within 100 feet of a private well.
(Ord. 10-164, passed 6-17-2010)
SEDIMENT AND EROSION CONTROL
(A) Applicability. No person shall commence or perform any clearing, grading, stripping, excavating or filling of land without having first obtained a site development permit from the Development Review Division of the County Land Use Department. Requirements for a site development permit are found in §§ 164.080 through 164.085 of this chapter.
(B) Site planning. Sediment and erosion control planning shall be part of the initial site planning process. In planning the development of the site, the applicant shall consider the susceptibility of existing soils to erosion and topographic features such as steep slopes and stream corridors which must be protected to reduce the amount of sediment and erosion which occurs. Where appropriate, existing vegetation shall be protected from disturbance during construction by fencing or other means.
(C) Planning process. In the planning process, the applicant shall also address the following.
(1) For projects that involve phased construction, existing land cover for those areas not under current development shall be addressed. If existing land cover does not consist of an appropriate ground cover then these phases shall be planted temporarily to reduce erosion from idle land.
(2) In planning the sediment and erosion control strategy, preference shall be given to reducing erosion rather than controlling sediment. In order to accomplish this, the plan must carefully consider the construction sequence of the phases so that the amount of land area exposed to erosive forces is the minimum consistent with completing construction.
(Ord. 10-164, passed 6-17-2010)
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