An erosion and sediment control plan shall be a part of the construction plans for all developments in flood or erosion prone areas of Atmore's jurisdiction. Such plan shall accompany any application for subdivision, PUD or zoning approval, building permit, excavation, or other construction activity whenever the proposed activity is to be undertaken on a tract comprising more than five acres, if more than five contiguous acres is to be uncovered.

Whenever the area to be disturbed comprises more than one acre, four (4) copies of the plan shall be filed with the Zoning Administrator at the time of application for a Land Use Certificate and Building Permit. A copy of the plans shall also be on file at the job site. If the Zoning Administrator and/or the City Engineer determines, either upon review of such plan or on inspection of the job site, that a significant risk of off-site sedimentation or erosion exists, he will require that a revised plan be prepared. Pending the preparation of the revised plan, the work shall be either suspended or continued under conditions outlined by the Building Inspector or the City Engineer. The applicant shall be responsible for all fees and costs incurred during the review process.

Erosion and sediment control plans shall contain architectural and engineering drawings, maps, assumptions, calculations, and narrative statements as needed to describe accurately the proposed development of the site and the measures planned to meet the Basic Control Objectives. Plan content may vary to meet the needs of the specific site conditions, but must show, at a minimum, the best management practices (BMP's) which will be used to control site erosion during and after construction.

10.31

Some BMPs include:

Mulching

Sodding

Holding tanks

Sedimentation control basins

Clean up practices

Detention basins

Porous pavements

Infiltration systems

Channel storage

Recreational area storage

Diversion structure

Ponds

Aeration of soils

Minimize disturbed land area

Minimize the duration of exposure of natural elements

Retain natural vegetation

Persons engaged in land disturbing activities shall take all reasonable measures to protect all public and private property, including roadways, from damage by such activities.

The best control objectives which should be considered in developing and implementing an erosion and sediment control plan are to:

10.51

Identify Critical Areas. On-site areas which are subject to severe erosion, and off-site areas which are especially vulnerable to damage from erosion and/or sedimentation, are to be identified and receive special attention.

10.52

Limit Exposed Areas. All land disturbing activities should be planned and conducted to minimize the size of the area to be exposed at any one time.

10.53

Limit Time of Exposure. All land disturbing activities should be planned and conducted to limit exposure to the shortest feasible time.

10.54

Control Surface Water. Surface water runoff originating upgrade of exposed areas should be controlled to reduce erosion and sediment loss during exposure.

10.55

Control Sedimentation. All land disturbing activities should be planned and conducted so as to minimize off-site sediment damage.

10.56

Manage Stormwater Runoff. When the increase in the peak rates and velocity of stormwater runoff resulting from land disturbing receiving ditch or stream channel, plans are to include measures to control both the velocity and rate of increase so as to minimize accelerated erosion and increased sediment deposition in the ditch or stream channel.

10.61

Mandatory Standards. No land disturbing activity to these provisions and guidelines shall be undertaken except in accordance with the following requirements:

10.611

No land disturbing activity shall be permitted in proximity to a lake, natural watercourse, or adjacent property where applicable unless a buffer zone is provided along the boundary of sufficient width to confine visible siltation and/or prevent erosion, provided that the land disturbing activity is not in connection with the construction of facilities to be located on, over, or under a lake, natural watercourse, or adjacent property.

10.612

The angle for graded slopes and fills shall be no greater than the angle which can be retained by vegetative cover or other adequate erosion control devices or structures. In any event, slopes left exposed will, within 30 working days of completion of final grading, be planted or otherwise provided with ground cover, devices, or structures sufficient to restrain erosion.

10.613

Whenever land disturbing activity is undertaken on a tract comprising more than one acre, if more than one contiguous acre is uncovered, a ground cover sufficient to restrain erosion must be planted or otherwise provided within 30 working days on that portion of the tract upon which further active construction is not being undertaken, provided, that this activity shall not apply to cleared land forming the basin of a reservoir later to be inundated.

10.62

Design and Performance Standards. Erosion and sediment control measures, structures, and devices shall be so planned, designed, and constructed as to provide control from the calculated peak rates of runoff from a ten-year frequency storm. Runoff rates may be calculated using the procedure in the USDA, Natural Resources Conservation Services "National Engineering Field Manual for Conservation Practices," or other acceptable calculation procedures. Runoff computations shall be based on rainfall data published by the National Weather Service for the area.

10.71

Permanent Downstream Protection of Stream Banks and Channels. Provision shall be made for the permanent protection of off-site stream banks and channels from the erosive effects of increased velocity and volume of stormwater runoff resulting certain land disturbing activities.

10.711

A combination of storage and controlled release of stormwater runoff may be required for highway construction; commercial, industrial, educational, and institutional developments of one acre or more; and, for single-family developments of ten acres or more.

10.712

Detention, storage and controlled release will not be required in those instances where the person planning to conduct the activity can demonstrate that the stormwater release will not cause an increase in accelerated erosion or sedimentation of the receiving ditch, stream channel, or other drainage facility, taking into consideration any anticipated development of the watershed in question.

10.72

Borrow and Waste Areas. When the person conducting the land disturbing activity is also the person conducting the borrow or waste disposal activity, areas from which borrow is obtained shall be considered as part of the land disturbing activity where the borrow material is being used or from which the waste material originated. When the person conducting the land disturbing activity is not the person obtaining the borrow and/or disposing of the waste, these areas shall be considered a separate land disturbing activity.

10.73

Access and Haul Roads. Temporary access and haul roads, other than public roads, constructed or used in connection with any land disturbing activity shall be considered a part of such activity.

10.74

Operations in Lakes and Natural Watercourses. Land disturbing activity in connection with construction in, on, over, or under a lake or natural watercourse shall be planned and conducted in such a manner as to minimize the extent and duration of disturbance of the stream channel. The relocation of a stream, where relocation is an essential part of the proposed activity, shall be planned and executed so as to minimize changes in the stream flow characteristics, except when justification for significant alteration to flow characteristic is provided.

The person engaged in or conducting the land disturbing activity shall be responsible for maintaining all temporary and permanent erosion and sediment control measures and facilities during the development of a site. The responsibility for maintaining all permanent erosion and sediment control measures and facilities, after site development is completed, shall lie with the landowner.

Persons engaged in planning, designing, installing and maintaining sediment control measures may use generally accepted references on the subject following standard engineering and/or agricultural practices. All plans will be subject to review by the Erosion and Sediment Control Specialist, the Building Inspector and the City Engineer.

Whenever the Building Inspector and/or the City Engineer determines the significant sedimentation is occurring as a result of a land disturbing activity, despite application and maintenance of protective practices, the person conducting the land disturbing activity or the person responsible for maintenance will be required to take additional protective action.