Karns Meadow Stormwater Treatment Wetland DESIGN

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Karns Meadow Stormwater Treatment Wetland
Planning, Design Funding
Brian Remlinger, Project Manager Dr. Paul Hook,
Wetland and Watershed Scientist Eric August, PE,
Water Resources Engineer
think habitat!
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Other Partners

• Volunteer, Administrative and Financial Support
  From
• 1 for the Tetons (local businesses)
• Jackson Hole Trout Unlimited
• Ducks Unlimited
• Jackson Hole One Fly
• WY Game Fish Department

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Primary Goals
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Project Need

• Sediment from urban stormwater runoff impairs
  aquatic life and cold water fisheries in Flat
  Creek.
• Loss of riparian and wetland habitat
• Local stewardship of creek
• Snake River fine-spotted cutthroat trout
• Water quality regulatory framework

Snow Storage
Snow King Tube Outlet
Snow King Ave.
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Existing Management Practices

• Address Road Traction Sand
• On-site stormwater retention regulations (e.g.
  new development)
• 20 sediment retention vaults (installation and
  maintenance)
• Improved road traction sanding methods
• Expanded street sweeping operations (including a
  new street sweeper)

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Existing Management Practices

• Others
• No Dump plaques
• Public education
• 1.2 miles of fisheries enhancements in Flat Creek
• Flat Creek streambank restoration
• Pervious brick walkways

BEFORE
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Stormwater Basin
475 acres or 27 of Town
42 miles of road
National Forest 17 sq.mi.
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Land Acquisition
2004 Town acquires Karns Property 1.6 million
Tracts 3 4 JH Land Trust holds Conservation
Easement
Affordable Housing
Grassy Park
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Feasibility
Topographic Survey

• 2005
• Feasibility Study (25,000)
• Stormwater Runoff Analysis
• Site Characteristics
• Water Rights
• Concept Design
• Uncertainties
• Rough Cost Estimates

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Hydrologic Sediment Load Survey
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Vegetation Survey
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Wetland Delineation
Wetlands Under Army Corps Jurisdiction
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2007 Stakeholder Memorandum of Understanding
The purpose was to clarify and summarize the
stakeholders goals, concerns and roles with an
emphasis on identifying areas of
shared/compatible goals and areas of potential
divergence or tradeoffs.
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2008 Preliminary Design
General Layout
Flat Creek
Rodeo Grounds Snow Storage
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Stormwater Inputs Base Flow
Sediment Load Estimate Snow King/Rodeo Grounds
100 cy/yr Kelly Tube/Cache Crk 100-400 cy/yr
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Connecting Infrastructure
(Adjustable)
Kelly Tube Outlet
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Open channels will feature a natural design
Native Upland Grasses
Native Wetland Grasses
Flowing Water
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Sediment Basins
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Sediment Basin Typical Cross-Section
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Treatment Wetland Concept

• Adequate storage for all winter and early-spring
  snowmelt and 2-year rainfall event.
• 24-hour retention time for average rainfall
  event.
• In 2008, gt90 of snowmelt runoff volume was lt6
  acre-feet/day
• In 2008, runoff from Snow King/Rodeo Grounds
  rarely exceeded 0.5 acre-feet/day.

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Habitat Enhancement Concepts
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Habitat Enhancement Examples
Existing Depression - Groundwater at Surface
Urban Greenway Project Fort Collins, CO
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Operation Maintenance Concepts

• Best Management Practice designed to work with
  minimal water management
• Seasonal Adjustments of water control structures
  will be necessary
• Annual Maintenance will include sediment basin
  clean out, weed monitoring and control, mosquito
  control and general system inspection

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Information Education

• Open House
• Signage
• Construction
• Permanent
• Newspaper
• Construction Notices
• Educational series
• Non-governmental Organization Outreach
• County Fair Booth
• Wetland Tours

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Project Phases
Year 1 Final Engineering, Design and Planning
90,000 Year 2 Construction
800,000 Year 3 Revegetation
350,000 Year 4 Initial Operation, Install
Signs, and Monitoring 110,000 TOTAL
ESTIMATED COST 1.3 million
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Funding Sources
CWA - 319 Funds 770,000 Teton Conservation
District 200,000 Local Non-profit
Organizations 100,000 Town of Jackson 230,000
Currently pursuing Federal Economic Stimulus
funding
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2008 319 Funds Proposal (Wyoming DEQ)

• Budget for 100-200 hours for preparation and
  presentation
• Get Letter of Support requests out early
• Review DEQ sample proposal and successful
  proposals
• Dont underestimate the Budget Justification
  tables
• Colleague review
• Participate in the DEQ Pre-Submittal Review
• 319 Review Panel Presentation

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Brian Remlinger [phone] brian_at_intermountai
naquatics.com
improving your world