Low Impact Development
They took all the trees and put them in a tree museum and they charged all the people a dollar and a half just to see 'em. Don't it always seem to go that you don't know what you've got till it's gone? They've paved paradise and put up a parking lot.”
Joni Mitchell
TABLE OF CONTENTS
• Development and Storm Water Runoff
• Storm Water Pollutants
• Low Impact Development (LID)
• Goals
• Benefits
• Common Practices
Development and Storm Water Runoff40% evaporation
25% deep infiltration
25% shallow infiltration
10% runoff
38% evaporation
21% deep infiltration
21% shallow infiltration
20% runoff
35% evaporation
15% deep infiltration
20% shallow infiltration
30% runoff
30% evaporation
5% deep infiltration
10% shallow infiltration
55% runoff
Natural Groundcover 10 - 20% Cover
35 – 50 %l Cover 75 - 100% Cover
Storm Water Pollutants• Not treated – Flows directly to nearest
stream• Picks up pollutants
– Sediment– Pathogens– Nutrients– Toxic contaminants– Debris/litter
©iStockphoto.com
Low Impact Development (LID)A storm water management approach that uses green space, native landscaping, and other techniques to reduce the volume of and improve the quality of storm water runoff.
Goals of LID• Mimic predevelopment hydrology• Reduce storm water runoff and pollution
– Store– Treat– Infiltrate
EPA
Common LID Practices
• Rain gardens and bioretention• Rooftop gardens• Vegetated swales, buffers, and strips• Rain barrels and cisterns• Permeable pavers• Permeable pavement• Impervious surface reduction
Common LID Practices
• Vegetated swales, buffers, and strips
Courtesy Eric FisherImage by the Environmental Protection Agency
LID Commercial Design
Image by the Environmental Protection Agency
Image by the Environmental Protection Agency
TABLE OF CONTENTS
• Development and Storm Water Runoff
• Storm Water Pollutants
• Low Impact Development (LID)
• Goals
• Benefits
• Common Practices
Resources
Bioretention.com: An online reference for designers. (n.d). Retrieved Dec. 15,2009 from http://www.bioretention.com/
Department of Environmental Resources of Prince George’s County, Maryland. (1999). Low-Impact Development Design Strategies –An Integrated Design Approach. Retrieved December 15, 2009, from http://www.lowimpactdevelopment.org/pubs/LID_National_Manual.pdf
Environmental Protection Agency. (n.d). Stormwater management best practices. Retrieved December 15, 2009, from http://www.epa.gov/greeningepa/stormwater/best_practices.htm#permeablepavers
Low Impact Development Center, Inc. (n.d.). Urban design tools. Retrieved December 15, 2009, from http://www.lid-stormwater.net/index.html
Top Related