Why Low Impact Development?

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?