Donaldson Run Tributary B Stream Restoration Project Update - - PowerPoint PPT Presentation

Donaldson Run Tributary B Stream Restoration Project Update

February 23, 2011 Taylor Elementary School

‘Big picture’ concepts

Past land use and drainage decisions have

severely impacted County streams

Watershed improvements and in-stream

restoration efforts are both essential

Urban stream corridor damage must be

addressed comprehensively

Stream restoration accomplishes multiple

resource management objectives

Neighborhood partnership is essential

County/Donaldson Run Civic Association Partnership

10+ year partnership Stream restoration top neighborhood priority NCAC approved Tributary B funding in

December 2007; County Board 2008; DES providing additional funds

Extensive County/DRCA public process:

meetings, workshops, stream walks, newsletter articles, park signs, Citizen articles, and other media coverage

Tributary A Tributary C

Taylor School

Tributary B

Donaldson Run Watershed Boundary

Donaldson Run watershed

KEY PROJECT FACTS:

• Approved Neighborhood Conservation

Program Project

• 1,400 linear feet to Upton street
• 26%

impervious cover in watershed

• Natural channel design approach

Review of changes from 30% to 60% design

Reducing width of channel/floodplain to

reduce footprint and tree/valley impacts

Limiting re-location of pathway and

narrowing pathway

Reducing disturbance and tree impacts

below the footbridge

Updates from 60% design to current design level (~75%)

Step pool ‘grade control’ and ‘riffle’

structures

Analysis of hillside and storm pipe drainage

inputs

Water main survey Planting plan Invasive plant management

Step Pool ‘Grade Control’ and ‘Riffle’ Structures

Control stream

energy

Protect streambanks Provide improved

stream habitat

Hillside drainage inputs

Working with specific

property owners

Accommodating flow

inputs in project design

Storm pipe drainage inputs

Verifying

easements/pipe conditions

Incorporating needed

repairs/modifications into project design

30” Water Main – Primary Source

• f Supply to Lee Water Station

Long-exposed pipe segments in valley identified

as 30” water main and surveyed to determine location

Interim work completed to protect exposed pipe Few apparent conflicts with stream restoration

design except at stilling basin

Small borings will be excavated to confirm pipe

elevations

Stream restoration design will improve protection

Trees

No change in tree impacts from project

from 60% designs to current design

One tree removed to protect water main

(previously listed as a potential removal)

One tree has fallen (previously listed as a

removal)

Project impact: 36 trees>10” diameter, 72

trees overall

Invasive Management & Planting Plan

Goals:

To restore forest structure and

function

To support recreational use and

aesthetics

Why invasive management?

• Displace native species
• Reduce wildlife habitat
• Alter ecosystem processes

Courtesy NPS

Japanese stiltgrass (Microstegium vimineum)

Invasive Management & Planting Plan

“On a global basis...the two great destroyers of biodiversity are, first habitat destruction, and, second invasion by exotic species. — E. O. Wilson

Japanese Barberry (Berberis thunbergii)

Current Forest Conditions

Resources

Natural Resource Management Plan

http://www.arlingtonva.us/departments/parksrecreation/docu ments/file76445.pdf

Ecological community mapping

l

Modified urban landscape

Species inventory for Zachary Taylor Park “Keeping it Natural”

http://www.arlingtonva.us/departments/EnvironmentalServic es/epo/PDFfiles/Keeping%20It%20Natural.pdf

Wisteria

Kudzu

Invasive Plants

85-95% invasive species in the shrub and ground layers invasive species present on both park and private properties 27 different species

Implications

Invasive management considerable

component of the project

Project requires integrated planting and

invasive plant removal

4-6 year planting and invasive plant

maintenance schedule

Complete removal of invasive species is

likely not possible

Most successful if private citizens are

involved in invasive management

Planting Plan

Site specific All plants will be native to Zachary Taylor

Park

Planting “zones” to account for habitat

changes with elevation and distance from the stream.

Special plantings for sensitive areas Multi-year to account for invasive control

and natural forest succession

Zoned Planting - Example

Slope Floodplain

Special Areas – Stream Banks

Special Areas – Bare Slopes

Scarlet oak Quercus coccinea Arrowwood Viburnum dentatum Bluestem goldenrod Solidago caesia

Invasive Management

Pre-project

l

removal of invasive shrubs

l

• utreach to homeowners

During construction/planting

l

“Clean” equipment

l

Mulch or mats for trees/shrubs

l

Seed heavily

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Protect deer candy

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Multiple planting cycles

Invasive Management

Post-Project/Maintenance

• Protect trees and shrubs
• Focus on stream banks
• Target species
• Coordinate invasive removal

and planting

• Timing of control will depend
• n plant life cycle
• Flexible and adaptive

English Ivy (Hedera helix)

Next Steps

Continue work with property owners on

hillside drainage inputs and design work for storm pipe drainage inputs

Finalize planting plan and invasive plant

management plan

Develop construction access/staging plan Hold stakeholder advisory group meeting prior

to full design completion

Target design completion by end of summer Construction schedule still TBD

For more information contact:

Jason Papacosma / Christin Jolicoeur Arlington County Dept. of Environmental Services Environmental Management Bureau (703) 228-3613 jpapacosma@arlingtonva.us cjolicoeur@arlingtonva.us Learn more at: www.arlingtonva.us – search “Donaldson Run.”

Tributary A, June 2010