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A presentation about clean water and development. Presented by Anne Kitchell with Horsley Witten Group during the Buzzards Bay Coalition's 2014 Decision Makers Workshop series. Learn more at www.savebuzzardsbay.org/DecisionMakers
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Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Anne Kitchell Horsley Witten Group, Inc. April 2, 2014
2014 Decision Makers
Workshops: Construction and
Clean Water
Thinking about Clean Water & Development
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
A quick trip to www.savebuzzardsbay.org
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
On today’s agenda
• The impacts of development
• Watershed decisions for decisions makers − Where to build − How to build − How to manage
“the built” • What is coming…
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
The visible impacts from existing development
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Urbanization results in increased surface runoff
BEFORE AFTER
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Watershed impacts at~10% impervious are well documented:
• Water quality issues • Impacts to biological
communities • Increased flooding • Stream erosion • Loss of recreational uses • Shellfish bed closures • Reduced recharge &
baseflow • Wetland & contiguous
forest loss • Increased % managed lawn
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
% Impervious cover is an indicator
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Impervious Cover at the Community Scale
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
8-10%
20%
30% > 65%
< 5%
As seen in the stream
% impervious
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Time (hrs)
Runo
ff (c
fs)
Post-development More runoff volume Arrives faster
Pre-development
Runoff Hydrograph
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
2 great (but dated) references
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Runoff WQ data from~3,800 storm events, 17 states
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Streams with <50 sq miles drainage upstream
0102030405060708090
100
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
% IC Upstream
% o
f R
efer
ence
C
omm
unit
y
n=125
Meet WQC
Fail WQC
12% IC Threshold
% of Reference Community compares 7 metrics- Taxa Richness, Modified HBI , Scraper/Filterer, EPT/Chironomidae, % Dominant Taxa, EPT Index, Community Loss
Bellucci, CTDEP
Linking the Bugs to IC
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Note: Data averaged from existing Massachusetts Estuaries Project Reports
Contour plots of modeled total nitrogen concentrations (mg/L) in Three Bays.
Source: MEP 2006
Pre-colonial
Present Day Future Buildout
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David Johnson and Kate Morkeski load a device that feeds fertilizer into the salt marsh on Plum Island. BOSTON GLOBE OCTOBER 18, 2012 http://www.mbl.edu/tide/data/
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Watershed Decisions • Where we build
– Land use planning – Land conservation – Buffers for protected areas
• How we build – Site Design – Construction – Stormwater/Wastewater
• How we manage what has been built – Retrofit/Redevelopment – Pollution prevention
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
How would you rate your land use planning from a water resource protection perspective?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
How valuable are your local wetlands?
Source: Buzzards Bay Coalition website
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Do you rely on minimal state protections or more stringent local bylaws?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
What are your disturbance thresholds for ESC?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
The problem with how we build
• More and more marginal sites are in play • Not enough consideration for existing site
topography • Lack of respect for native vegetation and
topsoil • Cramming as much on site as possible based
on lot lines and zoning rather than site constraints
• Over-reliance on engineered black boxes
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Conventional LID/New Urbanism
Is consideration of LID required in your local regs?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Time (hrs)
Runo
ff (c
fs)
Post-development More runoff volume Arrives faster
Pre-development
Runoff Hydrograph
Post-development with detention basins to “match the peak”
Post-development (with LID)
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
BMPs used at this site eliminated offsite runoff
Bioretention
Bioretention
Permeable Paver
Infiltration Chambers
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Take a look when its raining…
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Notable Local Porous Asphalt Applications
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Which of these best exhibits the LID spirit?
A B
C D
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Lacey & Arrowhead Lanes
Conventional vs LID?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
GI practices
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
How is stormwater managed here?
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cluster layout
Jordan Cove, CT -12 lots clustered on 6.9 acres - Designed to minimize site runoff
Low- mow areas
Bioretention cul-de-sac
grassed swales
pervious & shared driveways Rain gardens
Low Impact Development Does it really work?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Low Impact Development Does it really work?
Conventional
LID Cluster
Glen Brook Green (Jordan Cove) Research/Demo Project
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Are you settling for last year’s Big Box?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Grants Block Retrofit - Providence, RI Morris Beacon Design
Are you taking advantage of redevelopment opportunities?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Cottages on Greene, East Greenwich, RI Union Studio, Morris Beacon Design
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Which wastewater systems are you promoting?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Are PRBs in your future?
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
What’s Coming?
• Cape Cod Commission 208 Project • Draft Small MS4 Stormwater Permits for
Massachusetts: – Evaluate development codes for LID barriers – Annual tracking of impervious cover – Retrofit inventory for municipal properties – Program linked to impaired waters – Stormwater standards for entire MS4, not just within wetland
jurisdiction
• Trends in new Stormwater Manuals • Stormwater Utilities? • Local LID by-laws?
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City of Attleboro – Site Design Criteria
A. Use LID measures to the Max Extent Practicable B. Document Planning Process
1. Identify and map critical resources 2. Delineate potential building envelopes that avoid
these resource areas C. Document % Natural Open Space Retained D. Minimize Impervious Surfaces and Document % of
Site Imperviousness E. Disconnect Impervious Surfaces and Document %
of Effective Impervious Cover F. Document Use of Applicable Site Design Features
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
How can you require LID??!
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Can we have it all?
• Where to build • How to build • How to manage
what’s been built
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Us at night from space (NASA, 2012)
Horsley Witten Group, Inc. Horsley Witten Group, Inc.
Anne Kitchell Horsley Witten Group, Inc. April 2, 2014
2014 Decision Makers
Workshops: Construction and
Clean Water
Thinking about Clean Water & Development
Questions?
