why low impact development?
DESCRIPTION
Why implement a Low Impact Development strategy? Because infiltrating and managing stormwater in a way that reproduces native hydrology matters. This talk was presented at a special "Forging the Link" workshop for PNW stormwater managers, Vancouver, WA, 3/9/11. Please contact the author before using.TRANSCRIPT
Introduction: Why Low Impact Development?
Robert Emanuel, Ph.D.Oregon State University
Oregon Sea Grant Extension
Where is your community in the watershed?
Puget Sound Action Team, WSU Pierce County Extension
Puget Sound Action Team, WSU Pierce County Extension
Video by Laura James, Seattle, WA
Photo: Motoya Nakamura/The Oregonian
Impacts of Conventional Approaches
Water quantity: too much too fast Water quality: the stormwater superhighway
for non-point pollutants Costs: O & M, combined sewer overflows, etc.
Water Quantity Impacts: Flooding & Erosion
Stormwater Pollutants Suspended solids/sediments Nutrients (nitrogen, phosphorus) Metals (copper*, lead, zinc, cadmium, mercury) Oil & grease* Cleaning chemicals Detergents or soaps Bacteria Pesticides* Increased temperature
*Recent studies show link between these pollutants and salmonid olfactory disorientation and pre-spawning mortality.
To better protect our watersheds
To reduce infrastructure costs
To make our communities more attractive
Low Impact Development plans, ordinances, and best management practices
Slide: Chesapeake NEMO
Slide: Chesapeake NEMO
Slide: Chesapeake NEMO
Slide: Chesapeake NEMO
Slide: Chesapeake NEMO
Slide: Chesapeake NEMO
Slide: Chesapeake NEMO
Pringle Creek Development in Salem
Kensington Estates
Total acres: 23.92
Lots: 103 (4,143 ft2 ave.)
Open space: 15 acres (63%)
Effective impervious area: ~ 0 %
Kensington Estates Cost Comparison
Conventional Low Impact
Site Prep $220,000 $150,000
Erosion Control $75,000 $25,000
Storm drainage $430,000 $ 150,000
Utilities $650,000
$625,000
Road Construction $250,000 $275,000Total $1,625,000 $1,225,000
Unit Cost $15,777 $11,893
Slide: Chesapeake NEMO
Slide: Chesapeake NEMO
New Seasons-Interstate, Portland OR
Portland Community College, Portland OR
Bay City, OR
Port Orford, OR Photo: Frank Burris, OSU
Glencoe Elementary School, Portland, OR
Photo by Tom Liptan, City of Portland Environmental Services
Photo Koch Landscape Architecture, City of Portland Environmental Services
Photo Koch Landscape Architecture, City of Portland Environmental Services
http://www.asla.org/awards/2007/07winners/517_nna.html
Gravel Wetland
Green Street Planters
SW 12th @ Montgomery (PSU)
Pringle Creek, Salem, OR
Rogue Valley Sewer Services
Shorebank Pacific, Ilwaco, WA
SeQuential Biofuels, Eugene, OR
Photo Robert Emanuel
Photo Derek Godwin
Not all pollution is the same:
1. Site Planning/Land Use2. Source Controls3. Structural BMP’s
Effectiveness
What do these strategies cost?
What strategies yield greatest benefits?
What strategies help build resilience?
