Low Impact Development Better Streets for Water Quality

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Low Impact Development -- Better Streets for
Water Quality

• Sustainability Collaborative
• August 4, 2004
• Chris Eaton, AICP,
• Angelo Eaton Associates

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Presentation Overview

• Green Streets, Green Roofs, Green Parks
• why, what, how
• Low Impact Development - State of the Art in the
  Pacific Northwest
• Buildings/roofs
• Parks
• Parking Lots
• Streets
• Samples of built projects, standards and
  guidelines
• Resources

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Why work to solve issues?

• Environmental Benefits
• Infiltrate storm water close to source mirrors
  the natural system
• Reduces runoff
• Reduces detention requirements
• Improves groundwater recharge
• Current water quality treatment may not
  adequately address pollution issues such as
  temperature
• Pending water quality rules (TMDLs) may increase
  standards

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Why work to solve issues?

• Improve Quality of Life
• Additional street trees
• Provides more livable streets
• Public has more awareness of water quality
• Salmon are happier with cooler water

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Why is Low Impact Development Important?
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What is Low Impact Development?

• Low Impact Development (LID) seeks to reduce
  impacts of built environment
• Emulate natural hydrology
• Recharge ground water
• Zero runoff
• Maximize Infiltration
• Minimize Impervious Surface
• Treat runoff at the source
• Handle first ½ rainfall with infiltration
  measures
• Smaller parking areas and streets/driveway areas

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How to achieve LID for water quality

• Pervious driveways and sidewalks
• Pervious pavement overflow parking
• Collect roof runoff
• Rain Garden (bio-retention)
• Swales and strips (bio-filtration)
• Hot Spot water quality treatment

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Alternative Storm Water Management in Oregon and
Washington

• Low Impact Development related to water quality
  and storm water
• Buildings/roofs
• Parks
• Parking Lots
• Streets
• Tualatin Basin Alternative Storm Water Manual
• Samples of built projects

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Samples of new designs - Roofs

• Buckman Terrace, Portland, OR

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Samples of new designs - Roofs

• Convention Center, Scupper and Rain Garden,
  Portland, OR

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Samples of OLD designs - Roofs

• Marble Scupper Trajan Forum, Roma, Italy (early
  2nd century A.D.)

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Samples of new designs - Parks

• Ralph Stanley Park, CascadeStation, Portland, OR

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Samples of new designs Parking Lots

• Water Quality Swale, Parking Lot C, Tualatin
  Commons, Tualatin, OR

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Samples of new designs - Parking Lots

• Pervious Pavers on overflow parking area,
  Tualatin Police Building, Tualatin, OR

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Samples of new designs - Streets

• SEA Streets, NW 2nd Ave (between 117th and 120th)
  Greenwood Neighborhood, Seattle, WA

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Samples of new designs - Streets

• Eagle Landing, Clackamas, Oregon, 2004

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Why are streets important?

• Typical urban street standards assume a piped
  infrastructure with raised curbs
• Current Storm water standards require new
  streets/development to meet water quality and
  detention standards.
• In Tualatin Basin, these standards generally
  based on Clean Water Services

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Why are streets important?

• There are new prototypes being developed (or
  reinvented) for use for both streets and
  parking areas

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Water Quality Model Street Standards

• Goal work with local government staff to
  develop street/stormwater design criteria that
  would be approved through the land division
  process.

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Tualatin Valley Water Quality Endowment Fund
Project

• Tualatin Basin Alternative Storm water Manual
• Follow-up to Audubon project Stormwater Pavement
  Impacts Reduction (SPIR) project
• 10 Tualatin Basin local governments
• Clean Water Services
• Getting Green Street concepts through the
  permit process

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Alternative Storm Water Manual

• This will make it possible for new development or
  new road projects to incorporate green street
  features without needing a variance or special
  process.

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Alternative Storm Water Manual

• Approach
• Meet or exceed the minimum standards for
• Road right of-way widths
• Stormwater systems
• Detention,
• Water quality and
• Pollution reduction requirements.
• Swale design follows design parameters
  illustrated and described in this manual.
• Swale vegetation shall be consistent with CWS
  standards.
• Determine pre and post development stormwater
  runoff quantities.
• Analyze the down-stream capacity.
• Provide detention that meets or exceeds the level
  required. Size the facilities accordingly.
• Plant additional street trees of certain type

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Alternative Storm Water Manual

• If infiltration is proposed, provide facility
  sizing information including soil percolation
  rates.
• Public Streets - City or County road design
  standards for pavement width and ROW width will
  apply. Curbless streets or alternatives curbs as
  illustrated in this manual are acceptable and
  shall not require a road variance.
• Narrower pavement widths are encouraged, but
  would be an exception to those standards and will
  require a special variance.
• Private green streets are acceptable if they
  meet the criteria and standards outlined in this
  manual.
• Street Classification - The Green Street approach
  is best suited to Local Streets, although could
  also be applied to collector and arterial
  streets.
• Maintenance responsibility for Green Street
  stormwater facilities must be established.

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Alternative Storm Water Manual

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Alternative Storm Water Manual

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Alternative Storm Water Manual

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Alternative Storm Water Manual

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Implementation Issues

• Maintenance is an unknown for local governments
• Cost and equipment
• Public education
• Engineering studies on long term projects are
  underway, but not final
• Physical limitations (slope and soil constraints)
• DEQ Underground Injection Control (UIC) Program
• UIC program does NOT apply to all swales
• Rule authorized approach is not burdensome
• Amount of land in right-of-way
• Developer perception is that approval of new
  approaches may be difficult

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Built Projects, Standards and Guidelines

• Important to show local officials, professionals,
  and investors built examples
• Understand that some LID looks different
• Public education

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Infiltration Planter
Storm water Manual, Portland Bureau of
Environmental Services, Portland, Oregon, 2002
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Downspout
Storm water Manual, Portland Bureau of
Environmental Services, Portland, Oregon, 2002
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Curbless Parking Lot
Clean Water Services Water Quality Laboratory,
Hillsboro, Oregon, 2001
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Curbless Parking Lot Swale
Clean Water Services Water Quality Laboratory,
Hillsboro, Oregon 2001
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Swale
Clean Water Services Water Quality Laboratory,
Hillsboro, Oregon, 2001
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Porous Pavement
Tualatin Police Training Facility, Tualatin,
Oregon, 2001
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Downspout
Storm water Manual, Portland Bureau of
Environmental Services, Portland, Oregon, 2002
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Parking Lot Island Wheel-Stop Weepholes
Portland Community College Annex, Portland,
Oregon, 2001
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Wheel-Stop Weephole
Portland Community College Annex, Portland,
Oregon, 2001
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Parking Lot Island Swale Pedestrian Connection
OMSI, Portland, Oregon, 2001
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Weep hole Needing Maintenance
Reed College, Portland, Oregon, 2001
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Local Street with Swales
Metro, Green Streets Manual, 2001
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Local Treewell
Metro, Green Streets Manual, 2001
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Urban Treewell
Metro, Green Streets Manual, 2001
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Resources

• Metro Greenstreets, Innovative Solutions for
  Stormwater Stream Crossing, Metro Handbooks,
  June 2002, www.metro-region.org
• SEA Streets, City of Seattle Conservation and
  Environment website, June 2002,
  www.seattle.gov/util/seastreets
• City of Portland, Bureau of Environmental
  Services, http//www.cleanrivers-pdx.org/tech_reso
  urces/2002_swmm.htm
• Oregon Department of Environmental Quality (DEQ),
  http//www.deq.state.or.us/wq/
• City of Vancouver, BC http//www.city.vancouver.b
  c.ca/engsvcs/streets/greenstreets/

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James Taylor Chair in Landscape and Livable
Environments, Patrick Condon