Low-Impact Development
What is LID?
Low-impact development (LID) is a term used to describe land
planning design approach to managing stormwater runoff. LID
emphasizes conservation and use of on-site natural features to
protect water quality through infiltration, filtering, storage and
detaining runoff close to its source. As land is developed,
impervious areas replace the nature that absorbed rainwater and
infiltrated most runoff into the soil to replenish groundwater basins
and streams.
In 1990, LID began in Maryland as an alternative to traditional
stormwater BMPs at new construction sites. It has since been
promoted as a method to help meet goals of the Clean Water Act
because it encourages site sustainability and smart growth in a
manner that respects and preserves the characteristics of the city's
watersheds, drainage paths, water supplies and natural
resources.
Low-impact development (LID) is a term used to describe land
planning design approach to managing stormwater runoff. LID
emphasizes conservation and use of on-site natural features to
protect water quality through infiltration, filtering, storage and
detaining runoff close to its source. As land is developed,
impervious areas replace the nature that absorbed rainwater and
infiltrated most runoff into the soil to replenish groundwater basins
and streams.
In 1990, LID began in Maryland as an alternative to traditional
stormwater BMPs at new construction sites. It has since been
promoted as a method to help meet goals of the Clean Water Act
because it encourages site sustainability and smart growth in a
manner that respects and preserves the characteristics of the city's
watersheds, drainage paths, water supplies and natural
resources.
How does LID work?
The key to effective LID is to capture urban runoff and use it on site
for infiltration, irrigation and other beneficial uses before it enters
the storm drain system of the city. This can be done around
homes, as well as in streets, alleys, parks and other open spaces
throughout a city.
The key to effective LID is to capture urban runoff and use it on site
for infiltration, irrigation and other beneficial uses before it enters
the storm drain system of the city. This can be done around
homes, as well as in streets, alleys, parks and other open spaces
throughout a city.
What are the benefits of LID practices?
Several benefits of LID are:
Several benefits of LID are:
- habitat protection
- improved management of water quantity
- reduction of runoff
- groundwater recharge through infiltration
- cost savings
- preserving natural site characteristics
- reduction of impervious surfaces
- minimizing downstream impacts
TRADITIONAL APPROACH
| LID APPROACH |
Are there guides for LID?
The County of Los Angeles is in development for their LID
Ordinance. For up to date information on the consideration of the
ordinance and to read the Final Proposed Draft, click on LA
Stormwater Program's website. The CIty of Los Angeles has a
handbook examing LID's green infrastructure and its impact on
water supply (PDF).
The San Francisco Bay Area Stormwater Management Agencies
Association has released a Design Guidance Manual that
discusses LID practices in relation to stormwater quality protection.
The CA State Water Resources Control Board has a webpage
devoted to LID information, including a great Top Ten Practices list
and a link to the California state LID Policy Review.
The U.S. Department of Housing and Urban Development created
a practices guidebook for LID, stormwater, and wastewater
treatment in residential structures.
The Environmental Protection Agency (EPA) has released a
workbook to show how stormwater costs can be lowered in cities
by the use of LID practices.
Online resources for costs of LID projects may be found at the LID
Urban Design Tools website.
Finally, Surfrider Foundation runs a wonderful workshop programs
to build Ocean Friendly Gardens to aid with permeability, retention
and water conservation.
The County of Los Angeles is in development for their LID
Ordinance. For up to date information on the consideration of the
ordinance and to read the Final Proposed Draft, click on LA
Stormwater Program's website. The CIty of Los Angeles has a
handbook examing LID's green infrastructure and its impact on
water supply (PDF).
The San Francisco Bay Area Stormwater Management Agencies
Association has released a Design Guidance Manual that
discusses LID practices in relation to stormwater quality protection.
The CA State Water Resources Control Board has a webpage
devoted to LID information, including a great Top Ten Practices list
and a link to the California state LID Policy Review.
The U.S. Department of Housing and Urban Development created
a practices guidebook for LID, stormwater, and wastewater
treatment in residential structures.
The Environmental Protection Agency (EPA) has released a
workbook to show how stormwater costs can be lowered in cities
by the use of LID practices.
Online resources for costs of LID projects may be found at the LID
Urban Design Tools website.
Finally, Surfrider Foundation runs a wonderful workshop programs
to build Ocean Friendly Gardens to aid with permeability, retention
and water conservation.
