Model On-site Storm Water Management Code
Municipal landscape codes supplement zoning ordinances and building codes all of which are used to build a community.
Zoning of land divides up the community into different land use intensities, uses and character and provide guidelines for use of the zoned lot. Most cities are zoned to ensure economic value, orderliness and to reduce conflict between diverse use of land. Building codes are used to help design structures. These codes followed by architects and engineers ensure that construction meet specific structural requirements for framing, electrical, plumbing, glazing and roofing. Building codes directly influence public safety. Landscape codes are written by communities to ensure proper site planning. Especially, site planning in regard to land clearing; tree protection; landscape planting; parking lot design; grading; and drainage. Storm water management, drainage and control of urban nonpoint pollutants are concerns being addressed in community landscape codes across the country today.
This document provides information that can be used to craft community landscape codes containing on-site storm water management regulations. The design standards contained within this document are designed to confront the problem of urban runoff and notpoint pollution generated on private properties. Information is also provided concerning as common landscape design standards generally found in most community landscape codes. The purpose of this information is to assist those that draft or amend community landscape codes to find ways of inserting storm water best management practices into their site design regulations. Standards and design methodology is provided in this document will ensure that urban sites will properly landscaped. This information can be helpful to communities in addressing on-site storm water management and community landscape design as a tool to manage urban run off. Specially run off that may contain non-point pollutants emanating form urban development, urban gardens that especially from parking lots. There are specific sources (point sources) of pollution in urban areas but these can be found and treated. It is not so easy to find or treat are non-point sources of pollution. These pollutants come from cars, pets, garden chemicals, improperly disposed of waste and highly mobile and movable sources that are hard to find or track down. The most common non-point pollutants include sediments, solid waste, and nutrients such as nitrogen, potassium and phosphorous. Chemicals such as pesticides, herbicides, heavy metals, oils and grease also are present in urban areas. These pollutants get carried about by urban run off and eventually end up in coastal waters of Louisiana or fresh water supplies used by people.
The document explains how to manage storm water on urban building sites where permeable areas are limited, large amounts of land are covered with buildings, paving and parking lots. Urban land tends to increase run off, especially run off that carries sediments, chemical compounds, bacteria and viruses that are harmful to animals and mankind alike in high concentrations. These pollutants float around in storm water and settle into the environment. Often these urban pollutants will find their way into fresh water supplies, underground aquifers and coastal waters that serve up Louisiana seafood that carries some of the pollutants right back to mankind.
Storm water best management practices are being utilized in urban landscapes on small to medium sized building lots to intercept this flow of pollutants. On-site management design allows the site to capture a proscribed percentage of sediments, pollutants and solid waste where they originate. Once captured, they can be cleaned up, destroyed or legally disposed. This document discusses some of the technical aspects of designing these on-site storm water facilities. Through out this document we reference on-site storm water management and this is to mean decentralized storm water management. This is different from centralized storm water management that looks a drainage from a town wide or regional perspective. Decentralized storm water drainage is normally designed by landscape architects or civil engineers and constructed by well trained landscape contractors who can grade, drain and plant an urban site.
In addition, this document will illustrate how BMPs can be inserted within a community landscape code to ensure that building lots are designed using practical storm water practices and planting methods to capture, infiltrate and reduce the amount of run off, sedimentation and downstream pollutant movement from each building site. The text that follows provides essential information explaining how a community landscape code can be used to encourage the development community to utilize BMP’s to manage storm water where it falls. Design details, drawings and specifications are included for both landscaping and construction of storm water best management practices that together are effective and inexpensive. Examples and technical details are provided to allow each community to calibrate design standards in their community landscape code in a way that will work best for their community.
Finally, information about landscape design principles associated with screening, buffering, shading, parking, tree canopy establishment and rebuilding natural areas within the city to better manage storm water.
Click Here for Model Landscape Code for Louisiana Towns and Cities
Click Here for Appendix A
