Stormwater Division

Low Impact Development

Contact Us



Low Impact Development, or LID, is an emerging concept in site development and stormwater management. The goal of LID is for the developed site to have as little increase as possible in runoff flow rate, runoff volume and runoff-borne pollution compared to the site's condition before development. LID is not growth management; LID is developing in a way that protects our water resources above and below ground.

Bioswale
Rain Garden
Bioretention
Green Roof

Pervious Pavement

Development has impacts on the hydrologic cycle. Runoff volume is increased due to placement of impervious areas such as pavement and from compaction of soil from heavy equipment. This can lead to increased flooding in low-lying areas. Sites are usually designed so that the increased runoff volume is transported away as quickly as possible. The increased volume and efficient transport of runoff typically lead to higher flow rates. Along streams this can lead to increased flooding. Finally all developed lands can produce more runoff-borne pollutions than lands in their natural condition.

Bioretention, sometimes called rain gardens when used in residential areas, and swales, sometimes enhanced as bioswales, are some common LID stormwater management practices, but there are many other stormwater practices that can be considered to be LID when properly implemented, such as green roofs or pervious pavements. Even a drainage retention area (DRA) can be part of an LID stormwater management system. A properly designed LID stormwater management system provides a "treatment train" of best management practices where runoff is reduced and treated through a series of best management practices.

Potential benefits to residents:
   
S  increases community character
S  improves quality of life
S  increases open space
S  promotes pedestrian-friendly landscaping
   
Potential benefits to developers:
   
S  reduces land clearing and grading costs
S  reduces infrastructure costs (streets, curbs, butters, sidewalks)
S  increases lot values and community marketability
   
Potential benefits to communities:
   
S  balances growth needs with environmental protection
S  reduces infrastructure and utility maintenance costs
Potential benefits to the environment:
   
S  protects environmentally-sensitive areas
S  increases wildlife habitat by preserving trees and vegetation
S  protects water quality by reducing pollutant loads
S  reduces flooding potential
LID Planning

It's also important to remember that some LID practices are site planning practices. These include relatively simple measures like directing runoff from rooftops and other paved areas to grassy areas, rain barrels, cisterns or Bioretention Areas.

Another simple LID measure is Florida Friendly Landscaping. Other LID site planning methods are more complicated, such as designing subdivisions as cluster developments to preserve open space with natural vegetation.

Resources

- General Interest (non-technical)

Coming soon!

- Design Professionals (technical)

EPA Low Impact Development Literature Review (PDF)
Low Impact Development Design Strategies (PDF)
Low Impact Development Hydrologic Analysis (PDF)
Low Impact Development Hydrologic Analysis with appendices (PDF)
 

Map1

Map images courtesy of Pierce County, Washington and AHBL, Inc.
Map2

 
 

Marion County Administration ▪ 601 SE 25th Ave. ▪ Ocala, FL  34471 ▪ (View Phone Listing)

Read the Legal Disclaimer
Copyright © 2008
Contact Webmaster