Erosion & Sediment Control
In addition to the model ordinance, this section includes several other materials that may be useful either in drafting an ordinance or as support material:
Erosion and Sediment Control Ordinance from Minneapolis, MN: This ordinance provides few technical guidelines, using the reference to a technical document. It is an example of a very strict ordinance in terms of the sites that are required to submit erosion and control plans.
Clearing and Grading Ordinance from Olympia, WA: In many communities, clearing and grading is dealt with separately from erosion and sediment control. This ordinance provides an example.
Erosion and Sediment Control Inspection Checklist from the Lower Platte South Natural Resources District: This is a good example of a tool that can help contractors or government inspectors effectively maintain erosion and sediment control measures.
Small site design guideline from the Indiana Department of Natural Resources: For sites that are not regulated by the ordinance, guidance material such as this may help to reduce erosion and sedimentation.
Pre-Construction Meeting Notice from Montgomery County, MD: Materials like this notice help support the ordinance language, and ensure that erosion and sediment control measures are properly installed.
Introduction to Erosion and Sediment Control
By most accounts, the most dangerous period of development is the initial construction phase when land is cleared of vegetation and graded to create a proper surface for construction. The removal of natural vegetation and topsoil renders the exposed area particularly susceptible to erosion, causing transformation of existing drainage areas and disturbance of sensitive areas. Erosion control is the process of minimizing the amount of soil that runs off during the construction process, and sediment control is the process of retaining eroded soil on site, preventing damage to watercourses and infrastructure.
The model ordinance in this section borrows language from the model erosion and sediment control ordinance for Westchester County, New York, and also incorporates some additional features that may help prevent erosion and sedimentation and protect natural resources more fully. For example, the model ordinance emphasizes the use of techniques to limit clearing and grading, and requires that contractors be certified to maintain and inspect erosion and sediment control practices.
The model ordinance will need to be adapted in order to be broadly applied for several reasons. For example, some of the requirements may not be politically feasible or technically appropriate in all communities. In addition, the ordinance does not strongly correlate with the process by which building permits are granted, because the process may vary between communities.
Where you see this symbol, you'll need to make a decision or get more information in order to apply this ordinance to your community.
The size of construction sites and specific design criteria within communities will dictate variations in any erosion and sediment control ordinance. However, there are a few elements that can help make an ordinance more effective, regardless of the more specific requirements:
Reference to a specific technical manual.
Clear enforcement measures to ensure maintenance of erosion and sediment control measures.
Flexibility to allow a process to change the plan in response to field conditions.
Authority for inspectors from the muncipality to inspect construction sites at regular intervals, and particularly at points where the plan may need to be changed.
Incorporation of measures to protect natural resources such as wetlands and forests.
A specific plan approval process, with guidelines on plan submission.
Erosion and sediment control is widely accepted as a necessary practice, but there are certain caveats to making even the most well-crafted ordinance effective. First, communities need to have the staff and resources to enforce erosion and sediment control regulations, or the authority to inspect sites becomes useless. In addition, the technical manual referred to in the ordinance needs to provide useful guidance on selecting erosion and sediment control measures, and in particular should not include measures that are ineffective. Finally, education of contractors, engineers, and designers regarding the importance and effective use of erosion and sediment controls is imperative to implementing effective erosion and sediment control.