3/26/10 SuAsCo Municipal Stormwater Workshop:

Stormwater Management Bylaw

Presentation Overview: Low Impact Development Why a Bylaw is needed Summary of Sterling Bylaw Community Benefits

Low Impact DevelopmentPrinciples, Techniques, and Implementation

MASSACHUSETTS LOW IMPACT DEVELOPMENT TOOLKIT

Slide show prepared by:

In coordination with:

Typical pre-development conditions:

Runoff = 10% Infiltration = 50%

WHY DO WE NEED LOW IMPACT DEVELOPMENT?

Typical post-development conditions:

Runoff = 55% Infiltration = 15%

WHY DO WE NEED LOW IMPACT DEVELOPMENT?

Social and ecological impacts of too much asphalt

WHY DO WE NEED LOW IMPACT DEVELOPMENT?

High cost and low effectiveness of conventional “pipe and pond” strategies

WHY DO WE NEED LOW IMPACT DEVELOPMENT?

LID PRINCIPLES

1. Use existing natural systems as the integrating framework for site

planning• Land use planning and watershed planning

• Identify environmentally sensitive resources: wetlands, mature trees, slopes, drainageways, permeable soils, waterway buffers

• Assess existing hydrology

• Define a development envelope

LID PRINCIPLES

2. Focus on prevention• Minimize clearing and

grading

• Cluster buildings and reduce building footprints

• Reduce road widths, use shared driveways, reduce parking area

• Align roads to minimize impact

• Use green rooftops

• Use permeable paving

• Create subwatersheds and “micromanage” runoff in a treatment train of small structures

• Flatten slopes, lengthen flow paths, maximize sheet flow

• Maintain natural flow paths, use open drainage

• Use LID techniques to manage frequent, low-intensity storms

LID PRINCIPLES

3. Treat stormwater close to the source

• Open drainage systems and filter strips

• Disconnect roof runoff

• Rain gardens

• Street sweeping

• Public education

• Reduce construction disturbance

• Minimize lawn area

LID PRINCIPLES

4. Emphasize simple, nonstructural, low-tech, low-cost methods

For more information, visit:

www.mapc.org/lid home of the

•Fact sheets•Brochures•Local codes checklist•Frequently asked questions•Internet links and resources

MASSACHUSETTS LOW IMPACT DEVELOPMENT TOOLKIT

Need for Stormwater Bylaw:

Land clearing & home building results in greater stormwater runoff and more pollution sources.

Harms streams, lakes, water supplies (impacts are clearly seen in many cities and suburban towns).

Stormwater Permits enable improved stormwater treatment practices + better site design.

Win-win with fewer water problems, lower costs to construct, and less expensive for Town to maintain.

Helps Town to address state and federal stormwater management requirements.

Purposes of Stormwater Bylaw:

• Protect the health of the waters in Town.

• Keep post-development same as pre-development to reduce flooding, pollution, property damage, and harm to aquatic life.

• Ensure that treatment practices function correctly and pose no threat to public safety.

• Set procedures for stormwater management plans, and inspection of stormwater treatment practices.

Conservation Commission administers bylaw enacted by Sterling MA : Adopts regulations after a

public hearing. Reviews applications for

stormwater permit. May approve, disapprove,

approve with conditions, withdraw w/o prejudice.

Regulations can encourage low impact design.

Bylaw enables stormwater permits for:

All new development that alters stormwater runoff.

Reuse of developed parcels (improve stormwater runoff).

“Hotspots” with greater pollution concerns.

(Not retroactive, did not address approved projects or existing problems prior to May 2009)

Stormwater permits not required for: Disturbing less than 10,000 sq.

ft. of land or less than 25% of a contiguous property

Farming activities. Timber harvests under

approved cutting plan. Repair or replacement of an

existing septic system. Building a house on a Town

accepted road (ANR lot).

Single-family dwellings do not require permits for: Installing utilities (water, gas,

electric, telephone). Repair or replacement of an

existing roof. Maintenance of gardens,

lawns and landscaping. Construction of a fence, wall,

deck, patio, shed, swimming pool, tennis court or basketball court.

Stormwater Bylaw Enforcement

The Sterling Conservation Commission or its agent shall enforce Bylaw, and may pursue all civil and criminal remedies for Bylaw violations.

Enforcement will be further defined under regulations adopted by Commission.

Development of Stormwater Bylaw:

Model bylaw based on extensive research of local bylaws and best management practices.

Bylaw Committee adjusted the model bylaw to address conditions and needs in Sterling.

Meetings with Town boards and residents to discuss and improve draft bylaw, 2008 & 2009.

Stormwater Bylaw enacted at May 2009 Annual Town Meeting

Runoff problems harm Town waters –stormwater management has many benefits:

Protect water supplies Control flooding and

avoid property damage Ensure recreation uses

of stream and lakes Less Town costs for

water treatment and drainage maintenance

Protect aquatic life

Sterling Bylaw Components Stormwater Management Bylaw Stormwater Bylaw Regulations

Key Sections of Stormwater Bylaw1. Purpose2. Definitions3. Authority4. Administration

5. Applicability

6. Procedures7. Enforcement8. Severability

4.0 Administration

Conservation Commission administers bylaw Commission establishes Stormwater Regulations References MassDEP Stormwater Manual Describes “Actions and Appeals” of Commission References a “Stormwater Credit System”

5.0 Applicability Defines Applicable Projects Establishes Exemptions Differentiates “Redevelopment” from

“New Development”

Low Impact DesignEncourages “Better Site Design” and non-structural

techniques to reduce treatment for stormwater quality and quantity. Disconnection of rooftop runoff Disconnection of non-rooftop runoff Stream buffers Grass channels Environmentally sensitive development

Photo Copyright 1999, Center for Watershed Protection

Horsley Witten Group

Conservation

Open Drainage

Rain Gardens

Rain Barrel

Reduced Imperviousness

Porous Pavement

Creating a Hydrologically Functional Lot

Creating a Hydrologically Functional Lot