Collaboration and Planning for Successful Stream Management

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