Urban Water Quality Issues - Green Design & Development

http://www.bae.ncsu.edu/topic/lid/ Dwane Jones [email_address] 919.249.5959

Introduction: What is “Green Design & Development?” Green Design & Development

http://www.bae.ncsu.edu/topic/lid/ Working Definition Green Building and Development is environmental responsiveness. It is integrating water quality, and air quality concepts with building technology. Green Design & Development

Source: USGBC Daylighting Solar Panels Green Roof Bike Paths Biodiesel/Other Fuels Bicycles Water Harvesting Multi-Use Recycling Efficient Lighting Natural Air Flow +

Green Planning Green Design & Development

Conventional land development involves removal of all vegetation, compacting the soil and putting in large areas of hard (impervious) surfaces like roads, parking lots and roofs . The compacted soil and impervious surfaces prevent stormwater from soaking into the ground (called infiltration). This results in a tremendous increase in surface runoff. By traveling much faster, stormwater runoff overwhelms streams causing flooding, damaging public and private property and destroying habitat for fish and wildlife. http://www.bae.ncsu.edu/topic/lid/

Further, conventional practices collect and convey stormwater runoff through storm drains and pipes to a centralized, manmade stormwater facility to manage stormwater flow and remove pollutants. This typically requires extensive use of pipes and sometimes large, costly, stormwater best management practices .

Natural areas Smaller lawns Better pedestrian access Wildlife Habitat Open Space Wooded Lots Modern Trend: Homebuyers

Forsyth County July 2006- 331,859 April 2000- 306,044 + 25,815 (most recent census) Growth Trends: North Carolina

Design, construct, & maintain each development site to protect , or restore , the natural hydrology (the scientific study of the properties, distribution, and effects of water on the earth's surface) of the site so that the overall integrity of the watershed is protected. This is done by creating a “hydrologically” functional landscape. http://www.bae.ncsu.edu/topic/lid/

-Minimize land clearing - Amended Soils -Minimize use of impervious surfaces -Infiltration -Natural hydrology -Removal of most or all vegetation -Soil Compaction -Use of large amounts of impervious surfaces -Costly infrastructure -Altered hydrology

LID PRACTICE / DEVICE Peak Flow Control Volume Reduction Water Quality Improvement Water Conservation Bio-retention Cell • • • Cistern • • ~~> • <~~ • Curbless Parking Lot Islands • • • Downspout Disconnection • • • Grassed Swale • • • Green Roof • • Infiltration Trench • • • Narrow Road Design • • • Permeable Pavers/Pavement • • • Rain Barrel • • • Rain Garden • • • Sand Filter • • Tree Box Filter • • Tree Planting • •

LID Subdivision Low Impact Development

Mix land uses. Compact building design. Diverse housing opportunities. Walkable neighborhoods. Distinctive, attractive communities. Preserve open space, farmland, natural beauty, and critical environmental areas.

7. Reinvest in and strengthen existing communities and achieve more balanced regional development. 8. Provide a variety of transportation options. 9. Make development fair, predictable, and cost-effective. 10. Encourage stakeholder participation.

-Perspectives (Designer, Developer, Governing Authority) -*Local Ordinances & Site Plan Review Process (often antiquated) *The developer may request a variance, but often these can be time-consuming. -Local Opposition from Governing Body

-Minimize risks -Satisfy client -Utilize accepted practices -Gain respect from governing authority -Minimize financial risk -Maximize Profit -Minimize Time (permitting etc.) -Maximize value -Minimize surprises -Satisfy clients/customers Designer Developer

-Minimize risks -Minimize short-range and long-range government expenses -Enforce environmental regulations -Performance of Practices Local Government -Protection of Landowners

Green Construction (Land) Green Design & Development

Using narrower, shorter streets and ROW Smaller lots and setbacks, narrow frontages Reducing the amount of residential lawns Spreading stormwater runoff over pervious areas Using open channels instead of curbs/gutters Site Design

-Identify Buildable & Non-buildable areas* -Annual Rainfall Data* -Topography* -Soils* -Zoning/Public Input* -Floodplain/Floodway* -Land Uses/Adjacent Land Uses*

-Access/Egress -Easements -Costs -Lot Orientation -Infrastructure Technologies/Techniques* -Aesthetics

-Topography -Potential Hydric Soils -Streams/Water Bodies www.terraserver.com -Help determine placement of streets, lots, buildings etc. -US Army Corps of Engineers & DWQ

- Consider sheetflow -Shallow depressions (during rainy seasons)

http://www.bae.ncsu.edu/topic/lid/ -US Army Corps of Engineers & DWQ -Note: Each acre of coastal wetland contributes from $800 to $9,000 to the local economy through flood protection and recreation such as bird watching, fishing, and boating (Kirby, 1993)

Design Practices: -Minimize construction in wetlands by building compact developments -Plan roads and utilities to cross at the narrowest point in the system -Use permeable pavement for access roads, trails, and overflow parking -Preserve contiguous riparian buffers along wetlands and wildlife habitat -Create wetlands that mimic natural hydrological processes Source: Green Growth Guidelines

www.bae.ncsu.edu/stormwater Soil Survey -Infiltration

-Federal Emergency Management Agency (FEMA) -National Flood Insurance Program (NFIP)

-Moderate Temperatures -Wind Buffers -Reduce stormwater volumes -Minimize Erosion Note: Research shows that nearly 60% of suburban residents actively engage in wildlife watching…the majority is willing to pay a premium for homes in these settings (Adams, 1994)

Design Practices: -Keep the width & length of stream crossings at a minimum -Use existing crossings when possible -Use bottomless culverts beneath road crossings for fish passage -Preserve contiguous buffers -Use LID integrated management practices -Use natural streambank stabilization practices -Avoid or minimize alteration to natural stream flow Source: Green Growth Guidelines

Design Practices: -Avoid or minimize the placement of infrastructure in the buffer zones -Avoid or minimize multiple crossings -Use native vegetated buffers, when possible Source: Green Growth Guidelines

-Wildlife Resources Commission -Non-profits

-National Register of Historic Places

Design Practices: -Base design on average daily traffic -Provide safe and efficient access for emergency vehicles -Use minimum design requirements (LID) -On-street parking lanes should serve as traffic lanes -Urban Streets with parking on both sides (rec: 32’) -Neighborhood street with parking on one side (rec: 24’) -Local street width (rec: 18’) -Cost savings, pedestrian safety, and reduction in impervious cover Source: Green Growth Guidelines

The amount of impervious surface created by cul-de-sacs can be reduced by creating a pervious island in the center

Source: The News Magazine of the Federated Conservationists of Westchester County, http://www.fcwc.org/WEArchive/010203/roofs.htm

Photos courtesy of Whitney Kurz

Green Building (Home/Structure) Green Design & Development

Integrating Green Design with Low Impact Development & Conservation Design Green Design & Development

Capturing roof runoff Disconnecting pavement and roof drainage Infiltration Practices/Planting trees Rehabilitating soils Reconfiguring driveways, parking lots, and streets Comprehensive Design

Use of permeable pavements Routing runoff through swales to slow velocity, remove pollutants, & infiltrate Restoring “daylighting” historic streams to enhance naturalized open channels Comprehensive Design

http://www.bae.ncsu.edu/topic/lid/ Filtering system designed for evapotranspiration & infiltration Useful for parking lot runoff Economical for small sites Useful for removing: -Suspended solids, hydrocarbons, certain metals, and nutrients

Bioretention Treatment, Retention, Infiltration, Landscaping Excavation filled with engineered soil mix Herbaceous perennials, shrubs, trees Ponded water infiltrates within 72 hours Overflow outlet and optional underdrain Source: CWP Source: Massachusetts LID Toolkit

Bioretention Applications Parking lot islands Median strips Residential lots Office parks Source: Larry Gavin Source: LID Center Source: City of Portland, OR Source: Massachusetts LID Toolkit

Bioretention Area Small parking lots Source: Massachusetts LID Toolkit

Stormwater Planters Runoff Reduction, Treatment, Attenuation “ Bioretention in a Box” Vegetative uptake of stormwater pollutants Pretreatment for suspended solids Aesthetically pleasing Reduction of peak discharge rate Source: City of Portland, OR Source: City of Portland, OR Source: Massachusetts LID Toolkit

http://www.bae.ncsu.edu/topic/lid/

Water quantity benefits Indirect water quality benefits Infiltration

Permeable Paving Applications Parking stalls Overflow parking Driveways Walkways and plazas

www.bae.ncsu.edu/stormwater Increased insulation Decreased heat island effect Decreased stormwater volumes and rates Decreased long-term replacement costs Increased property value Downsizing HVAC

www.bae.ncsu.edu/stormwater Conventional Small-scale Controls street width treescape runoff

Vegetated Swales Conveyance, Treatment, Infiltration Roadside swales (country drainage) for lower density and small-scale projects; For small parking lots; Mild side slopes and flat longitudinal slopes; Provides area for snow storage & snowmelt treatment Source: Massachusetts Smart Growth Toolkit

Vegetated Filter Strips Pretreatment and Attenuation Mild vegetated slopes Adjacent to small parking lots and roadways Another opportunity for snow storage Source: City of Portland, OR Source: City of Portland, OR Source: Massachusetts Smart Growth Toolkit

Narrow roads; “Country drainage.” Shared driveways; Houses sited with natural terrain; Vegetation retained.

Short driveways and shallow front yard setbacks allow for rear yard retained vegetation. Downspouts discharge to natural terrain for recharge.

www.bae.ncsu.edu/stormwater Green Design

www.bae.ncsu.edu/stormwater Green Design -Biofilter/bioretention -Green Roof -Rainwater Collection -Porous Paving: Gravel Pave -Waterless Urinals -Low-flow fixtures -Superinsulation (R21 walls & R30 roof) -High Performance Glazing on Windows - On Demand Water Heating -Daylighting -Duct System made of fabric -Over 75% of construction/demolition waste was salvaged or recycled - Recycled material used in walls, floors, and windows -Local material use

www.bae.ncsu.edu/stormwater Bioretention Permeable Pavement Cistern Greenroof LID (Commercial) Disconnected

www.bae.ncsu.edu/stormwater Residential + LID Site Create a Hydrologically Functional Lot

www.bae.ncsu.edu/stormwater + Conservation Open Drainage Rain Gardens Amended Soils Rain Barrel Residential LID Site Permeable Pavement Create a Hydrologically Functional Lot

www.bae.ncsu.edu/stormwater Aerial Photo Courtesy of Y. Lyda LID (Institutional)

www.bae.ncsu.edu/stormwater level spreader rain gardens cistern/rain barrel vegetated buffer permeable pavement bioretention Aerial Photo Courtesy of Y. Lyda LID (Institutional)

Green Design Exercise Primary Conservation Areas (1) Wetlands (2) Waterbodies (3) Floodplains (4) Steep Slopes Secondary Conservation Areas Mature Woodlands (4) Wildlife Habitats Buffers around wetlands & waterbodies Prime Farmland (5) Historic/cultural areas

Green Design Case Study Griffin Acres

The process begins with determining how many lots could be developed under conventional zoning; this is the base yield of the property. From that point, the plan development process follows four basic steps: Source: Massachusetts Smart Growth Toolkit

Identify Conservation Value Areas on the site such as wetlands, significant trees or tracts of forest, habitat, cultural resources or buffer zones. Remove these from the “developable area”. 1. Source: Massachusetts Smart Growth Toolkit

Place houses in the remaining area in a way that would maximize residents enjoyment of these areas by providing access to open space and preserving views. 2. Source: Massachusetts Smart Growth Toolkit

Align roads and trails on the site to provide pedestrian and vehicle access. 3. Source: Massachusetts Smart Growth Toolkit

4. Draw lot lines around the homes. Source: Massachusetts Smart Growth Toolkit

1. Meet with local officials to review current development ordinances (often, officials look favorably upon pre-development meetings). 2. Identify ways to work together to minimize development impacts. 3. Focus on LID (developer should have a general knowledge of practices he/she plans to implement).

4. Plan to make site visits with local officials/staff. 5. Since site design information comes from different sources, data should be synthesized into a single map.

Create a Green Design & Development Committee to review plans Planners Engineers Architects Landscape Architects Biologists, Ecologists, and Hydrogeologists Others Also create incentive-based programs

Puget Sound Water Quality Action Team - http:// www.wa.gov/puget_sound The Low Impact Development Center - http:// www.lowimpactdevelopment.org Stormwater Research Center - http:// www.stormwatercenter.net U.S. Environmental Protection Agency - http:// www.epa.gov/owow/nps/urban.html UW Center for Urban Water Resources - http:// depts.washington.edu/cuwrm / http://www.bae.ncsu.edu/topic/lid/

Urban Water Quality Issues - Green Design & Development

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