MODULE-4 Land Use Planning

Conventional Regulatory Techniques

Wetland Ordinances/Regulations

It is a well-documented fact that wetlands are a critical component in the protection of both surface and groundwater quality. Wetlands absorb and contain flood waters and have been shown to remove significant quantities of pollutants through a combination of physical, chemical and biological processes. Clearly, the first step in protecting water quality is to protect the wetlands themselves, both by enforcing applicable state regulations to their fullest extent and, where authorized by statute, by adopting local ordinances and regulations to protect wetlands and wetland functions. Following are some techniques for protecting wetlands that can be incorporated into regulations.

  • Natural Vegetated Buffers
  • Surface Water Discharges
  • Erosion and Sedimentation Control
  • Restrictions on Pesticides and Fertilizers

Natural Vegetated Buffers

Natural vegetated buffers have tremendous value in protecting wetlands and surface waters from a variety of impacts. Buffer strips aid in reducing direct stormwater runoff discharge to surface waters, stabilize shoreline areas and provide wildlife habitat and corridors. Buffer strip widths may vary depending on the resource in question. For example, Queen Anne's County, Maryland, requires a 300 foot buffer around tidal wetlands and waters, 50% of which must be forested. If not currently wooded, trees must be planted. The non-wooded portion is maintained as natural ground cover.

Surface Water Discharges

Land development frequently results in increased discharges of surface run-off to wetlands and watercourses which may cause downstream flooding, severe alterations to wetlands hydrology, and degradation of water quality. To prevent this, direct discharge of surface run-off from roads and other paved areas to wetlands and watercourses can be prohibited by local ordinances. Developers can be encouraged to minimize the extent of paving within buffer zones and to use permeable paving materials where possible. Surface run-off should be recharged on site, using a combination of vegetated swales, detention basins and similar techniques (see also drainage requirements under Subdivision Regulations, above).

Erosion and Sedimentation Control

The discharge of sediments to wetlands and waterways often has severe consequences, ranging from direct sedimentation of wetland flora and fauna to reduction in water clarity. Therefore conservative erosion and sedimentation controls for construction activities should be enacted. Different types of erosion controls will clearly be required for different slopes, soil conditions and construction activities. Subsequent revegetation requirements can also be specified, to insure long-term site stability.

Restrictions on Pesticides and Fertilizers

Fertilized lawns often contribute substantial levels of nutrients, pesticides and herbicides to surface waters directly, via surface water runoff, and indirectly, via leaching to groundwater. Therefore, it is recommended that the extent and the location of lawn areas proposed within the buffer zones to water resources and the use of alternative landscaping be well-managed.

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