Biofiltration In Storm Water Management - Terrain

Terrain

Volume 07 | No. 2 Summer/Fall 2007

The Newsletter of the New York Chapter American Society of Landscape Architects

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President’s Message

Green Standards for Parking Lots, continued

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Biofiltration In Storm Water Management

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Dirtworks, PC wins 2007 Honor Award

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"BAD BOY" OF THE PLANT WORLD GETTING A NEW REPUTATION

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New Firm Profile:: r2P Studio

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Open Studio

GREEN STANDARDS FOR PARKING LOTS BEGIN PUBLIC REVIEW New Rules Would Use Plantings to Reduce Pollution, Conform to Mayor Bloomberg’s PlaNYC “June 18 – City Planning Director Amanda M. Burden today announced the beginning of public review on new regulations for commercial and community facility parking lots that impose new regulations for landscaping, perimeter screening of the lots as well as requirements for canopy trees in planting islands within the lots. In keeping with the Bloomberg administration’s PlaNYC sustainability goals, the proposal will promote the greening of new parking lots and those which are enlarged, and put New York at the forefront of innovative self-sustainable planting methods. The plantings that the plan calls for would be designed to act as a natural water filter and absorb storm water runoff. Vehicular circulation within the lots would be improved by new maneuverability standards. 'Instead of imposing heat-trapping oceans of asphalt, these proposed parking lot standards will beautify our streets, cool the air, and absorb pollutants and storm water runoff, said Director Burden, 'And they will make these parking areas throughout the five boroughs more pleasant. This small change can contribute immeasurably to the environment and our quality of life." The requirements would apply to new or enlarged open parking lots of at least 18 spaces or 6,000 square feet serving retail and office buildings and institutions such as hospitals and schools. Parking garages, roof parking, gas stations and residential parking lots would be exempt from the requirements. The proposed amendment to the zoning would prescribe perimeter screening comprised of evergreen shrubbery and trees at the edges of parking lots to screen them from the streets. Evergreen bushes no more than 3 feet tall as well as ornamental trees every 25 feet would provide an attractive buffer. In addition, street trees at the curbs would also be required around the lots. Continued on page 4.

Biofiltration In Storm Water Management By Peter A. Gisolfi, ASLA, AIA, and Ronen Wilk, RLA

Communities across the nation are focusing on the need for more stringent management of storm water runoff. Many older water treatment systems and techniques are inadequate for handling the increased volume of runoff being created by the development of sites and buildings. More roofing and paved areas are being added to portions of sites that are already impervious to rain, increasing the amount of storm water that is being prevented from infiltrating readily into the ground. This runoff, along with polluted water from parking lots, is often being discharged into outdated municipal drainage systems, and ends up in streams, rivers, lakes, and oceans. Storm water systems are becoming essential elements in site design today. Regulatory agencies, building owners, architects, and developers recognize the need for new storm water management systems, and many are turning to LEED (Leadership in Energy and Environmental Design) criteria as benchmarks of sustainable site development. LEED site engineering guidelines include: •The storm water system should hold, infiltrate, and filter as much water as possible on-site. •Water should be cleaned before it is infiltrated or released off-site. •Where appropriate, water captured on-site should be used for irrigation. •Shade should be maximized over heat absorbent materials — such as asphalt — to reduce the “heat island” effect. The basic premise of approval procedures related to storm water management is that a developed site should perform within the drainage basin in the same manner as the natural site. That is, a significant portion of the water should infiltrate into the soil, and the water that enters the ground water aquifer should be filtered during and by the infiltration process. The first goal is to retain the same amount of water that would have been retained by the site’s natural condition. Test borings may indicate if a layer of clay or rock is close to the surface and causes an unusual amount of runoff from the natural site. Local engineering departments, however, often decline to accept this possibility as they review system designs. Rather, they imagine that the “natural” site absorbs storm water easily. The fundamental strategy for detention is to slow the release of storm water in surface ponds or underground chambers, then allow it to be released — at a rate less than or equal to the release rate in the site’s natural condition — into the municipal system or a natural stream. Generally, the retention system is designed also to promote infiltration into the ground water system. A recently developed technique is to filter storm water that runs off from paved surfaces and roofs through grasses and other plant material on its way to a retention system. Some wetlands plants actually have the ability to absorb pollutants. This “biofiltration process” filters the runoff naturally before it is retained, so the water is clean when it is eventually released into the drainage basin. It is especially important to clean the polluted runoff from blacktop parking lots. Asphalt is oil-based, and its surface is fouled continually by automobile emissions. In warm weather, asphalt is also hot and unpleasant. (Concrete paving reflects more heat and contributes less to the heat island effect, but concrete is costlier, and harder to repair.) 4

Remediation techniques which can help turn a blacktop parking lot from a detriment into a woodland include: •Planting trees in the lot. •Making the tree pits into biofiltration devices. •Storing filtered water in and under the lot. •Designing the system to have retention and filtration capacity that releases filtered water into the municipal drainage system only when there is overflow during major storm events. Said in the simplest way, a parking lot can function almost as a natural system — and drivers get to park in the shade!

Darien Library Water Quality Basin In the system for the parking lot of the new public library in Darien, Connecticut, which we designed, water collects in islands planted with trees and grasses. Biofiltration cleans the runoff before it is recharged into the aquifer. Infiltration is relatively prompt on this site, as the soil is coarse and sandy. Should heavy rain fill the tree islands to capacity before it can drain into the aquifer, the water overflows into an underground retention system, and to a terraced and planted biofiltration basin area. At the landscaped front of the library, storm water collects in a bio-swale and recharges underground before it is released into the municipal system. Only after the biofiltration and underground system are filled to capacity will the water flow through underground piping into the Town’s drainage system. Our system for the Darien Public Library provides for the biofiltration, cleaning and recharging of water on-site, and promotes the sustainability of the system through ease of maintenance. Equally important, it minimizes the release of storm water off-site, a condition that could create flooding and pollution in adjacent and downstream properties. The release of water off-site will be less than it was before the site was developed even though impervious surfaces have increased significantly. Another storm water management design employing biofiltration is our system for the John Burroughs School, an independent school in St. Louis. School officials had initially secured local approvals for a conventional stormwater management system. When we introduced them to the concept of biofiltration, they embraced this as an environmental and educational opportunity. The new biofiltration system we designed will be an instructional tool for the school’s 600 students, who will be involved in plant selection and installation, and will learn about important environmental and sustainability issues. Continued on the next page.

Biofiltration In Storm Water Management, continued The design features a tiered biofiltration system, using three sequential planted basins. (*B) Storm water flows from one area into the next, and then into the campus’s existing pond which serves as part of the detention system. Any overflow from the pond runs into the municipal drainage system. Infiltration of storm water into the aquifer is particularly slow on this site, as the soil is largely clay, yet runoff from the school’s parking lot only reaches the pond in a major rain event. This runoff will contain much less pollution and sediment after it has been filtered through the biofiltration basin.

NYC Department of City Planning

Drainage systems, biofiltration systems, and retention systems are not designed in a vacuum. They are parts of existing, if imperfect, ecosystems. When site development is complete, the ecosystems should not be damaged. If the combined techniques of storm water collection, filtration, and retention are used effectively, entire hydrologic systems, including surface water and ground water, can be protected, and even improved.

Long-time Parks Advocate M.M. Graff Dies at Age 97 By Eugene Patron

Rogers, President of the Foundation for Landscape Studies, and founding president of the Central Park Conservancy from 1980 until 1996. “I learned a lot from her. Her books on trees and rocks in Central Park were my best instruction.”

Brooklyn, NY – Mildred Millar Graff, who wrote about and championed New York City Parks from the 1960s through the 1980s, died at her home in Brooklyn in early July at the age of 97 . “Dickey” as her family and friends called her, combined a can-do spirit and handson advocacy to help protect and care for the natural environment and beautiful architecture of New York’s great parks and green spaces. As one of the founding members of the Friends of Prospect Park in the mid 1960s, Graff organized a campaign to care for some of the Parks most notable, but neglected, trees such as the Camperdown Elm. A self-trained tree expert, Graff soon went on to address tree care in Central Park: rolling up her sleeves to work with arborists in the Park. In the 1980s when she became too ill to get out and visit her beloved Parks, Graff, never a wallflower, fired off letters to park administrators and elected officials with her thoughts on oversight for the City’s parks. “When I remember Dickey Graff it’s not just her passion for parks I think of, but the particular time when her passion flourished,” said Adrian Benepe, Commissioner of the New York City Department of Parks & Recreation. “Dickey committed herself to helping New York’s parks back when there weren’t the many easily accessible opportunities that exist today for people to get involved at their local parks. The best tribute New Yorkers can give her is to become active participants in

According to the Greensward Foundation, Graff was born in St. David's, Pennsylvania, near Philadelphia, but grew up from the age of three in Forest Hills, Queens. After 30 years of marriage and living on Long Island, in 1964 she moved alone to Brooklyn Heights.

Mildred Millar Graff the lives of their parks through the many volunteer organizations that support parks.” “Dickey was just the kind of smart and tough friend New York’s Parks needed back when Parks didn’t receive the kind of support from the City they do today,” said Tupper Thomas, President of the Prospect Park Alliance and Prospect Park Administrator. “She went around Prospect Park like a cross between a triage nurse and town crier, identifying the sick trees and raising the alarm.”

Among the books and publications she wrote, co-authored and illustrated are Tree Trails in Prospect Park (1968), Tree Trails in Central Park (1970), Rock Trails in Central Park (1976), The Making of Prospect Park: Notes for a Projected Historical Study (1982), Central Park -Prospect Park: A New Perspective (1985) and Bridges of Central Park (1990). She also wrote articles for The New York Times, Popular Gardening and other publications. For more information on Prospect Park events, programs and membership, call the Park Hotline at (718) 965-8999 or visit www.prospectpark.org. Dial 311 for all Parks & Recreation information

“Dickey didn’t coat her opinions in sugar, but she knew what she was talking about,” said Elizabeth Barlow 5