Home Controls Economic Water Quality Ordinances Pictures Contact Site Map

 
Home

Home
Controls
Economic
Water Quality
Ordinances
Pictures
Contact
Site Map

 
Useful Links!

 

 

Low Impact Development Strategies and Tools
for NPDES Phase II Communities

WELCOME
This site has been developed through a Cooperative Assistance Agreement under the U.S. EPA Office of Water 104b(3) program in order to assist stormwater Phase II communities integrate low impact development (LID) strategies into their compliance programs. LID is a rapidly growing approach to stormwater management that offers the opportunity for Phase II communities to develop a comprehensive natural resource and water quality protection program. 

Stormwater Phase II Rule

Low Impact Development

How Can LID Be Used To Build More Effective Stormwater Programs?

 

Project Focus Areas

 

 

Stormwater Phase II Rule
In December 1999, the United States Environmental Protection Agency promulgated the Stormwater Phase II Rule (http://www.epa.gov/npdes/regulations/phase2.pdf) expanding the National Pollutant Discharge Elimination (NPDES) stormwater program. The Phase II Rule extends coverage of the NPDES stormwater program to operators of small MS4s, defined as MS4s located in urbanized areas that serve populations of less than 100,000. The Rule requires Phase II communities to develop stormwater management programs that: 
  1. Reduce the discharge of pollutants to the maximum extent practicable (MEP);

  2. Protect water quality; and

  3. Satisfy the appropriate water quality requirements of the Clean Water Act.

In the Rule, EPA also established six minimum control measures that Phase II communities are required to implement: 

  1. Public education and outreach;

  2. Public participation / involvement;

  3. Illicit discharge connection and elimination;

  4. Construction site runoff control;

  5. Post-construction runoff control; and

  6. Pollution prevention / good housekeeping.

In addition to adopting the six minimum control measures, communities will also need to identify and select and a stormwater control strategy and BMPs that satisfy the maximum extent practicable standard.

 

 

 

Low Impact Development
LID is an innovative stormwater management approach with a basic principle that is modeled after nature: manage rainfall at the source using uniformly distributed decentralized micro-scale controls. LID's goal is to mimic a site's predevelopment hydrology by using design techniques that infiltrate, filter, store, evaporate, and detain runoff close to its source. Techniques are based on the premise that stormwater management should not be seen as stormwater disposal. Instead of conveying and managing / treating stormwater in large end-of-pipe facilities located at the bottom of drainage areas, LID addresses stormwater through small landscape features located at the lot level.  

LID controls can be incorporated into almost every section of urban and suburban environments including open space, rooftops, streetscapes, parking lots, sidewalks, and medians. This versatile approach can be applied equally well to new development, urban retrofits, and redevelopment / revitalization projects. LID provides numerous benefits and advantages over conventional stormwater management approaches.  The major benefits of LID include being a more environmentally and economically sustainable way to address the adverse impacts of urbanization. By managing runoff close to its source though intelligent site design, LID can enhance the local environment, protect public health, and improve community livability.

 

 

 

How Can LID Be Used To Build More Effective Municipal Stormwater Programs?
LID controls are well-suited for use by Phase II communities. LID reduces stormwater volumes and peak stormwater runoff rates as well as provides stormwater pollutant removal. Therefore, it is an ideal approach to provide post-construction runoff control as required by the six minimum controls and pollutant removals to the maximum extent practicable standard. LID offers the opportunity to address the full range of watershed protection criteria not fully managed by end-of-pipe stormwater controls.  

LID also simultaneously addresses community issues of aesthetics and land use. The numerous vegetated LID techniques instituted throughout a community increase green space and improves the aesthetics of urban and suburban areas. This facet of LID allows it to be integrated into the community planning process. Overall land use dedicated to stormwater management is decreased with LID as the size of large stormwater catchment basins is reduced or eliminated and replaced with micro-scale management practices.

LID can be used to satisfy five of the six minimum requirements of the Phase II rule. 

  1. Public education and outreach

  2. Public participation / involvement

  3. Illicit discharge connection and elimination

  4. Construction site runoff control

  5. Post-construction runoff control

  6. Pollution prevention / good housekeeping


1.   Public education and outreach – LID BMPs can serve as educational tools, facilitate awareness of the environment, and encourage stewardship. For instance, municipalities and community organizations have used rain barrel distribution and installation programs as a forum for public awareness about the effects and impacts of residential stormwater. The use of vegetated BMPs can also bring public awareness to the effects of urbanization on hydrology and the natural water balance. LID is a visible stormwater control system as opposed to conventional controls, which often are underground infrastructure components. 

2.   Public participation / involvement – LID BMPs are integrated into the community and offer aesthetic and social benefit. LID is flexible. The differing aesthetic appeals and stormwater management efficiencies of LID BMPs allow communities to evaluate competing options for balancing community aesthetics with necessary stormwater controls. For instance, a community has the ability to choose between BMPs that provide the necessary stormwater management and provide the aesthetic values which they seek. These characteristics encourage the public to participate in the design and upkeep of their communities.  

3.   Illicit discharge connection and elimination – LID will not contribute to satisfying this requirement. 

4.   Construction site runoff control – Applying LID controls and incorporating LID methods translates into smaller scale and incremental construction disturbances. Developing with LID reduces stormwater generation and sediment loss.  

5.   Post-construction runoff control – The foundation of LID is attempting to replicate pre-development hydrology in a developed environment. One of the primary benefits of LID is the ability to limit the volume and peak flow rates of stormwater discharges by utilizing the processes of infiltration, detention, interception, and evapotranspiration. The processes employed by LID provide effective runoff control and have been used to meet hydrologic regulatory requirements.  

6.   Pollution prevention / good housekeeping – LID is an effective pollution prevention strategy because it incorporates measures, such as street sweeping, that limit the creation or transport of pollutants. Vegetated LID controls generally do not require the use of fertilizers, pesticides, or herbicides limiting chemical and nutrient pollution. The use of native plants adjusted to local climatic conditions allows LID BMPs to naturally provide stormwater management with limited plant management and maintenance.

Disclaimer

 


 

 

Copyright © 2000-2005 Low Impact Development Center, Inc. -- All Rights Reserved