collaboration and planning for successful stream management
TRANSCRIPT
Collaboration and Planning for Successful Stream ManagementDenise Cameron, Woodard & CurranJohn Livsey, Town of Lexington, MA
The Original Green Infrastructure:The Stream Channel
A Typical New England Stream History
Circa 1930
1930 - Today
Route 2
1930
TODAY
The Need
▀ Persistent flooding and complaints from public▀ Sediment buildup in streams and wetlands▀ Old and deteriorated drainage infrastructure▀ Desire to improve water quality and protect
wildlife habitats ▀ Consistently increasing stormwater
regulatory requirements
Driving Action through Planning: Development of Stream Management Plans
Conservation
Public Works
A Collaborative Approach
A Plan for Action
Town of Lexington worked with Woodard & Curran to develop a plan for both watershed restoration anddrainage enhancement.
A Phased Implementation
The plan was implementedin three phases,per major watershed:
▀ Charles River▀ Mystic River▀ Shawsheen River
It starts with data…
A multi-year,comprehensivedrainage study,including both:
▀ Desktop Assessment▀ Field Surveys
...it grows through public involvement…
▀ Began collaboration early▀ Formal and informal meetings:
Director of Conservation Watershed Stewards Capital Expenditure Committee TMMA (Town Meeting Members Association) Board of Selectmen
▀ Build support for program to getfunding at Town Meeting
…it is refined through prioritization…
Conducted a pair-wise comparisonwith the following scoring criteria
Health & Safety Flood Mitigation Coordination with other
Town Projects Environmental Benefits Social Impact Improved O&M Regulatory Compliance
…and it leads to a consensus for CIP
▀ From the three watershedstream management plans,a single, Capital ImprovementsPlan was developed
A Balanced Funding Approach
Infrastructure Project Funding
Ecological Drainage Restoration Funding
The Plan’s Foundation:Field Surveys
Structures and Crossings
Stream Reaches
Stormwater Outfalls
What We Looked For In The Field…
What we found in the field…
What we found in the field…Culverts in
good shape…
…and culverts with structural and safety
issues
What we found in the field…Trash and debris…
…hydraulic restrictions
What we found in the field…Sediment buildup…
…and straightened channels
What we found in the field…Stormwater Inputs…
…and drainagetrouble spots.
The Plan’s Recommendations: Project Identification
Categories of Recommendations
▀ Infrastructure & drainage restoration▀ Wetlands protection▀ Drainage investigation▀ Roadway and drainage system O&M▀ Long-term O&M for streams
Fact Sheets
▀ One per recommendation▀ Summarizes existing
conditions andproposed project
▀ Detailed maps
Putting the Plan into Action:Project Case Studies
Willard’s Woods Stream Restoration
Willard’s Woods Stream Restoration
Willard’s Woods Stream Restoration
▀ Rather than replacing thefailed culvert, the Townopted to daylight the stream
Willard’s Woods Stream Restoration
▀ A rock vane wasconstructed forenergy dissipationand grade control
Willard’s Woods Stream Restoration
Willard’s Woods Stream Restoration
▀ A headwall was constructed for the stream crossing under North Street
Willard’s Woods Stream Restoration
▀ Pedestrian bridge was constructed at trail crossing
Willard’s Woods Stream Restoration
▀ To save an existing tree, a stone wall was created using stones from the failed culvert
Willard’s Woods Stream Restoration
▀ The stone was alsoused to reconstructthe stone wall alongNorth Street
Willard’s Woods Stream Restoration:A Multi-disciplinary Approach
▀ Successful streamrestoration ismultidisciplinary Scientists Engineers Landscape Architects, Contractors experienced in
ecological restoration
Willard’s Woods Stream Restoration:Creating a Natural Stream…not a Ditch
▀ Construction documents were developed to allow for flexibility during construction to better mimic the irregular conditions of a natural stream.
Willard’s Woods Stream Restoration: Reference Reach Model
Willard’s Woods Stream Restoration:Which one is the New Stream?
Willard’s Crossing:
▀ Sediment buildup at the trail culvert restricts culvert flow, contributing to upstream flooding
Willard’s Crossing: Culvert Removal
Willard’s Crossing: Bridge Construction
▀ Vehicular Bridge to improve emergency access▀ Stone channel to manage flooding both upstream
and down
Willard’s Crossing: Bridge Construction
Vine Brook – Streambank Stabilization
Vine Brook – Streambank Stabilization
▀ Bank failure led to sediment buildup in Vine Brook
Vine Brook – Streambank Stabilization
Vine Brook – Streambank Stabilization
Vine Brook – Streambank Stabilization
Whipple Hill Culvert
Replacement
Pleasant Street Drainage
Improvements
Valleyfield Drainage
Assessment
Upcoming Projects
Conclusions: Keys to Success
Keys to Success
▀ Engage community, municipal departments, and environmental groups to make it one all-encompassing project
▀ Don’t separate water quantity and quality▀ Make it an active plan – not just a study sitting
on shelf▀ Don’t lose momentum!
Contacts
▀ Woodard & Curran Denise Cameron ([email protected]) Zach Henderson ([email protected])
▀ Town of Lexington John Livsey ([email protected]) David Pavlik ([email protected]) Karen Mullins ([email protected])
▀ Town of Lexington web site http://www.lexingtonma.gov/stormwater
Questions &Discussion