Low Impact Development

Presentation at the Sustainable/Resilient Coastal Communities Workshop September 10, 2008 Monmouth University, NJ Andrew Willner Visiting Scholar Monmouth University Urban Coast Institute, Baykeeper Emeritus, NY/NJ Baykeeper Andrew J. Willner, Inc.

USEPA Memorandum from Assistant Administrator to Regional Administrators

“ Green infrastructure can be both a cost-effective and an environmentally preferable approach to reduce stormwater and other excess flows entering combined or separate sewer systems, in combination with, or in lieu of, centralized hard infrastructure solutions…”

- Benjamin Grumbles (March 5, 2007)

Green Infrastructure Statement of Intent

(Signed on 4/19/07 by USEPA, National Association of Clean Water Agencies, Natural Resources Defense Council, Low Impact Development Center, Association of State and Interstate Water Pollution Control Administrators)

“ …to formalize a collaborative effort…to promote the benefits of using green infrastructure in protecting drinking water supplies and public health, mitigating overflows from combined and separate sewers and reducing stormwater pollution, and to encourage the use of green infrastructure by cities and wastewater treatment plants as a prominent component of their CSO, SSO, and MS4 programs…”

Stormwater in New Jersey

The New Jersey Department of Environmental Protection (DEP ) is responsible for administering the state’s stormwater management program. New Jersey had developed a comprehensive stormwater management program and has some of the most stringent stormwater regulations in the country.

The DEP administers the state’s National Pollution Discharge Elimination System (NPDES) program and requires that all construction sites disturbing more then one acre, many industrial sites, and all Municipal Separate Storm Sewer Systems (MS4’s) obtain permit coverage. Permitted MS4’s are also required to establish Stormwater Management Programs (SWMP).

All projects must be designed so that the peak post-development runoff rate from the 2, 10, and 100 year storm event do not exceed 50, 75, and 80 percent of the predevelopment peak runoff rates. The DEP requires that stormwater treatment best management practices (BMPs) be designed to remove 80% of the total suspended solids (TSS) load on an annual basis. In certain watersheds the state may also require BMPs to remove nutrients and/or hydrocarbons. The state requires that water quality BMPs be designed to treat the flow from a water quality storm of 1.25 inches of rain in 2 hours. The state has compiled a list of acceptable BMPs and assigned a removal credit to each of them. Proprietary BMPs may not be used on new developments until they have been through a formal state review process.

As an incentive for developers to use environmentally conscious site design, the state offers removal credits for various environmental design components. For more detailed information on New Jersey’s stormwater management program please visit their website. Be advised that there may be additional permitting requirements at the county and municipal level.

What Engineers are telling municipalities they have to do to comply with Stormwater regulations Rapid Collection, Conveyance, & Disposal of Runoff

Inadequately Managed Storm water and CSO’s Threaten Water Quality

Infiltration of stormwater on an undisturbed landscape is around 50%, while stormwater runoff is around 10%. When a landscape is hardened by impervious surfaces such as roads, roofs, and parking lots, approximately 55% of stormwater is lost to runoff and only around 15% infiltrates .

Images adapted from USEPA graphics

Pros and Cons of the Traditional Approach The Water as Waste Approach

PRO’S • Effectively removes “waste” runoff away from developed sites CON’S • Environmental costs • Public infrastructure costs

Pros and Cons of Low Impact Development

PRO’S • Replicates pre development hydrology in the post-development landscape • Reduces generation of runoff • Sustains eco hydrology • Reduces public and private infrastructure costs CON’S • LID is a new technology (limited cost & performance studies) • Involves a new approach to urban design (differs significantly from standard practice) • Requires study of site specific constraints and opportunities (complicates “mass production”)

Specific Goals of LID

• Reduce the development “footprint” • Minimize site imperviousness • Encourage onsite infiltration, storage, and evapotranspiration of rain water • Generally increase the flow path (time of concentration)

Low Impact Development (LID)

Goal: Maintain or restore the pre-development hydrologic regime of developed and developing watersheds

by design

Evolving “Pollution Prevention” Approach to Urban Water Planning

Low Impact Development Siskiyou stormwater curb extension (Portland, OR) The Willow School (Gladstone, NJ)

Green roofs Ruhr University,

BUILDING NYC

Bochum, Germany

Examples of LID projects on the Building Scale

Urban Brooks,

“clean water” diverted away from combined sewers

Examples of LID projects integrated into the Streetscape

“clean water” = roof and yard runoff, groundwater, springs

ET overflow infiltration runoff

Examples of LID Projects Integrated into Large Scale Urban Developments

runoff conveyance channel runoff infiltration on porous steps

porous walkways and conveyances

Q-How do LID technologies work, hydrologically?

A-By reducing the rate, volume, and altering the timing of runoff from developed watersheds

Runoff reductions with rain gardens

Rate of Runoff Vs. Time - 3/13/05

Control 1" 2.5" 4" Runoff reductions with green roofs 1400 1200 1000 800 Montalto et al (2007) in preparation 600 400 200 0 8 6 4 2 0 16 14 12 10 0 50 100 150

Minutes Elapsed Precipitation intensities

Control

on 03/13/05

200 1"

NYCDEP Drainage Design Storm Intensity: 15.13 cm/hr (5.95 in/hr for 6 minutes)

2.5" 250 4"

Minutes elapsed

LID technologies provide: • Ecological and habitat benefits • Flood reduction benefits • Recharge aquifers • Heat island benefits • Aesthetic benefits (associated with property values) • Human well being (associated with “Biophilic design”) • Etc…

LID Opportunities Identified

“Urban Brooks” convey rainwater harvested from street to wetland Porous pavements on sidewalks and driveways Standard roofs replaced with Green roofs

Green roofs

Image: Northwest EcoBuilding Guild OH 007 CSO Shed: Rendering depicting green roofs installed on brownstones and commercial rooftops

Rate of Runoff Vs. Time - 3/13/05

Control 4" 1400 1200 1000 800 600 400 200 0 0

Starts raining

50

Runoff from standard roof Runoff from green roof

100 150

Minutes Elapsed Stops raining

200 250

Porous pavements

Porous promenade – Hoboken, NJ OH 007 CSO Shed: Porous pavements introduced on sidewalks and driveways

Urban brooks

Urban Brooks – Zurich, Switzerland Treatment Wetland Drainage network OH 007 CSO Shed: Street runoff diverted to treatment wetland sidewalk street (crowned in center) curb metal grate curbside channel

Would you be interested in installing systems that keep rainwater out of the sewer on your property?

NO

LID Overall Public Acceptance :

YES 0% 20% 40% 60% 40% 20% 0% 60% How would you feel about gov’t programs

HOW WOULD YOU FEEL ABOUT PROGRAMS THAT

runoff reduction measures on private 100% property in your watershed?

YOUR WATERSHED?

Based on survey of opinions of random sampling of 300 owners of multifamily residential buildings in OH-007 CSO-shed. Response rate = 17%

Willingness to Pay for Green Roofs :

100% 80% 60% 40% I WOULD BE WILLING TO PAY MORE THAN A NORMAL ROOF RESURFACING TO HAVE A GREEN ROOF ON MY PROPERTY.

I WOULD BE WILLING TO HOUSE A GREEN ROOF ON MY PROPERTY IF IT COST ME NO MORE THAN WHAT AN ORDINARY ROOF COST.

I WOULD NOT BE WILLING TO HOUSE A GREEN ROOF ON MY PROPERTY NO MATTER HOW MUCH IT COST 20% 0% YES NO I WOULD BE WILLING TO PAY FOR A GREEN ROOF REGARDLESS OF COST AS LONG AS IT IS PROVEN TO REDUCE CSOS.

Based on survey of opinions of random sampling of 300 owners of multifamily residential buildings in OH-007 CSO-shed. Response rate = 17%

Policy Scenario Investigated

 Public agency responsible for reducing storm water impacts provides a public subsidy to private property owners to install LID technologies on their property  Public subsidy is equivalent to the difference in life cycle costs between the LID and conventional surface (ex: homeowner pays for conventional roof but gets a green roof)

There are lots of Public Private Partnerships Why not also for controlling storm water impacts?

• Partnership Programs of the NYC Watershed Agreement • NYC Toilet Rebate Program • NJ Solar Incentive Programs

Bayonne LID Pilot Project Planning

Preliminary Analysis The Water Studio (Columbia University) Instructors: Michael Conard, Kate Orff Students: Jay Lim, Amparo Casani, Deniz Guteri Regulator 4 Outfall 7

Area Breakdown

Surface Type

Roads Sidewalks and Car Parks Roofs Green Spaces Total

Area (acres)

37 31 75 84 227

Percent of Total Area

16% 14% 33% 37% 100%

Student Proposal #1: Downspout Disconnect Program

Student Proposal #2: Front Yard Rain Gardens

Student Proposal #3: “Green Belt” Program

Working with Newark, NJ, NY/NJ Baykeeper is Proposing to Use the Newark City Hall as a Showcase for LID Technology, Including a Green Roof, Rain Gardens as Well as Green Materials Used During its Rehabilitation as Chicago has Done Newark City Hall Chicago City Hall Green Roof

Conclusions

• • • •

Planned strategically in suburban or even a very densely developed urban watershed, LID can be a cost effective means of stormwater control under a variety of performance and cost scenarios Planned and implemented appropriately, LID can green our communities, help restore habitat, and provide green public access along our waterways.

Cost effectiveness requires a public private partnership in stormwater management To be useful incentives would need to be developed to encourage adoption of LID in a) existing development b) new development and redevelopment

Contact Information Andrew Willner Andrew J. Willner, Inc.

732 768 4848 [email protected]

m www.andrewwillner.com

Addition Credits for Slides and Photos eDesigns Dynamics and GAIA Institute