This document discusses strategies for improving water resource protection in real estate development projects. It promotes an open space design approach that requires conserving at least 60% of project sites as open space. This protects water supplies, habitat and other natural resources while also reducing infrastructure costs. The document provides model zoning regulations and guidelines to implement this approach, including conducting conservation analyses, minimizing impervious surfaces, using low impact development stormwater techniques, and incentivizing permanent land conservation.

1. Clean Water in Real Estate Development
April 2, 2014
Kurt Gaertner
Massachusetts Executive Office of Energy and Environmental Affairs
The State’s Open Space Design / Natural Resource
Protection Model Zoning & Water Resource Protection
in Suburban & Rural Areas

2. Land Use Priority Plans
competedas of January 2014:

3. 3

5. “Conventional” Planning
& Design
• Generally involves larger lots
• Style of suburban development over the past 50 years
• Clearing and grading of significant portions of a site
• Wider streets and larger cul-de-sacs
• Enclosed drainage systems for stormwater conveyance
• Large detention ponds
Conventional Development
Smart Development
Less land clearing and grading costs
Reduced infrastructure costs
Protection of regional water quality
Reduced stormwater runoff
Loss of natural land or open space
Depleted drinking water supply
Reduced quantity and quality of
water resources
Increased infrastructure costs &
maintenance

6. The Principles are intended to
guide state & local actions
Sustainable Development Principles
1. Concentrate Development and Mix Uses
2. Advance Equity
3. Make Efficient Decisions
4. Protect Land and Ecosystems
5. Use Natural Resources Wisely
6. Expand Housing Opportunities
7. Provide Transportation Choice
8. Increase Job and Business Opportunities
9. Promote Clean Energy
10. Plan Regionally

8. Problems with current practice:
• Special Permit Required – Discretionary
• Process often cumbersome, long, & expensive
• Large parcel size requirements
• Insufficient amount of land protected
• Less than ideal land conservation
• Dimensional standards inhibit use
Open Space Design
• By Right/Mandatory
• Formulaic and quick
• No minimum lot size
• [60%] of land area protected
• Strategic protection via Conservation
Analysis & Findings
• Flexible Design Standards – lot size,
frontage, setbacks, roads, etc.

9. New Model Open Space Design Bylaw/Ordinance
• Based on Natural Resource Protection Zoning
• Accompanied by subdivision regulations &
special permit regulations for density
bonuses and shared driveways
• Replaced the OSRD model in EEA’s Smart
Growth/Smart Energy Toolkit
• Addresses problems with application of Cluster,
OSRD, Conservation Subdivision zoning
• Formatted to be easily customized, though
municipal counsel should be consulted
• Interaction with other local regulations must be
considered (esp. Board of Health)
• Addresses process questions raised by the Wall
Street v. Westwood decision

10. • http://www.mass.gov/envir/smart_growth_toolkit/
• Website that is user friendly, comprehensive, and
MA focused
• Integrated materials on each smart growth
technique to promote understanding and local
passage of new zoning bylaws
• Case studies show real world implementation,
many in Massachusetts communities

11. Why did EEA develop this bylaw and why does it want communities to adopt it?
• Reduced environmental and fiscal impact
o Reduced costs to construct/maintain roads and infrastructure
o Less impervious surface and runoff
o Protection of water supplies, habitat, greenways, productive forest, agriculture, etc.
• Advances EEA objectives while providing housing and treating landowners equitably
100 acre wooded site with
field, stream, and trail before
development
Two-acre zoning;
conventional subdivision
Natural Resource Protection
Zoning (>75% preservation)
Images from “NRPZ – The Green Side of Smart Growth” by Lacy, Ritchie, & Russell

12. Yield: Allowable Residential Units
• Units calculated by dividing the net acreage by the allowed density
• Net acreage calculation accounts for site-specific development limitations
Net Acreage Calculation
To determine net acreage, subtract the following from the total (gross) site acreage:
[Half] of the acreage of land with slopes of [20%] or greater;
[The total acreage] of land subject to easements or restrictions prohibiting
development, lakes, ponds, vernal pools, 100-year floodplains as most recently
delineated by FEMA, Zone I and A around public water supplies, and all wetlands
as defined in Chapter 131, Section 40 of the General Laws and any state or local
regulations adopted there under, as delineated by an accredited wetlands specialist
and approved by the Conservation Commission; and
[Ten] percent of the remaining site acreage after the areas of A and B are removed
to account for subdivision roads and infrastructure.
Note: Does not account for wastewater disposal
Unit Count Calculation
• Divide the net acreage by the required acreage (allowed density) for a unit
• Allowed density can vary by zoning district

13. Applicability:
• Allowed by right – permitted via subdivision or site plan review
• Required in designated districts, permitted elsewhere
• Local choice as to which districts and which housing types
• Conventional subdivisions are by special permit
• Could also be applied to non-residential development
Dimensional Requirements:
Goal: Make it as easy as possible to
conserve land and natural resources by
arranging units/lots in as unconstrained a
manner as practicable

14. Open Space:
• Permanently conserves [60%] of land area
• Required % may be reduced by up to [10%] for land devoted to common water or
wastewater infrastructure; this land must be subject to a Restrictive Covenant
• Preserved open space required to be contiguous to the greatest extent practicable
• Protection under Article 97 or a permanent Chapter 184 type restriction required
o Restrictive Covenant under Chapter 184 required if CR not accepted
o CR must specify permitted and prohibited uses consistent with the zoning
• Allowable and Prohibited Uses addressed in detail
o Alternate language provided to address active and motorized recreation
o Small portion [5%] may be paved/built on consistent with open space use
• Submission requirements specify provision of a Conservation Analysis as per the
Subdivision Regulations

15. Subdivision Regulations:
Design Process: Landscape architect or other design professional must follow a prescriptive
Conservation Analysis based process:
1. Informational meeting encouraged to discuss conservation & development priorities
2. Conservation Analysis delineates Primary and Secondary Conservation Areas
• Contiguity requirement; can be waived
3. Written Conservation Findings specify areas to preserve and develop
4. Subdivision laid out within the Developable Area
5. Planning Board decision; incorporates Conservation Findings

16. Conservation Analysis
and Findings
• Identify conservation
value areas on the site
such as wetlands,
significant trees or tracts
of forest, steep slopes,
habitat, cultural resources
or buffer zones. Remove
these from the
“developable area”
• Place houses and roads in
the developable area
• Memorialize with
“conservation findings”
incorporated into the
subdivision approval

17. Open Space Plans should guide land
conservation in subdivisions

18. LID Site Design
• Conservation of
natural hydrology,
trees, and vegetation
• Minimized impervious
surfaces
• Dispersal of
stormwater runoff
• Conservation of
stream & wetland
buffers
• Ecological landscaping
#1 AVOID IMPACTS – Preserve Natural
Features
#2 REDUCE IMPACTS – Reduce
Impervious Cover
#3 MANAGE IMPACTS – Use Natural
Features & Low-Impact Techniques
to Manage Stormwater

19. Site Design Practices
• Reduce storm pipes, curbs
and gutters
• Preserve sensitive soils
• Cluster buildings and reduce
building footprints
• Reduce road widths
• Minimize grading
• Limit lot disturbance
• Reduce impervious surfaces

20. Source: R. Claytor
Source: City of Portland, OR
Source: CWP
Better Site Design on
Roadways and Driveways
• Narrower streets
• Alternative cul-de-sacs
• Shared driveways

21. Narrow Street
14 houses
$24,200 to repave
$1,700/house
Wide Street
9 houses
$40,400 to repave
$4,500/house

22. Vegetated Swales
Conveyance, Treatment, Infiltration
• Roadside swales
(“country
drainage”) for
lower density
and small-scale
projects
• For small
parking lots
• Mild side slopes
& flat longitudinal
slopes
• Provides area for
snow storage &
snowmelt
treatment
Fully Grown

23. Rain Gardens/Bioretention

24. Bioretention Schematic
Planting Soil -
Primarily Sand
Underdrain System
Vegetation on Surface
Runoff

26. LID Model Bylaw
• Provides incentive for conservation site
planning
• “Stormwater Credits” reduce the size and
number of conventional practices
• Requirement to treat stormwater
• Expands upon Massachusetts Stormwater
Policy by including all land areas (beyond
Wetland Protection Act jurisdiction)

27. Model Stormwater Bylaw
1. Purpose and Intent
2. Authority
3. Scope and Applicability
4. Definitions
5. Administration
6. Permit Procedures and Requirements
7. Performance Standards: LID Criteria
8. Enforcement
9. Surety
10. Construction Inspections
11. Certificate of Completion
12. Perpetual Inspection and Maintenance
Appendix A: Example System of LID Credits and
Incentives

28. Integrated Stormwater Management
Design Objectives
• Runoff reduction
• Groundwater recharge
• Water quality mitigation
• Channel erosion protection
• Overbank and extreme flood
protection

29. Kurt Gaertner
Kurt.Gaertner@state.ma.us
617-626-1154
Contact Information :