We will modify the zoning resolution to include design guidelines for off-street parking lots for commercial and community facilities
Much of the urban landscape is impervious, including buildings, roads, and parking lots: this means water cannot trickle back into the ground, but instead flows off the hard surfaces into our sewers, putting additional strain on our infrastructure. As described above, there are strategies for reducing this runoff, such as tree plantings, other landscaping projects, porous pavement technology, and underground water storage. (See renderings: Greening Standards for Parking Lots)

The addition of trees and landscaping to parking lots offer a feasible and cost-effective means for the private sector to work with the City in curbing storm water runoff and potentially decreasing CSO events. Increased landscaping, along with storm water detention and retention, could slow down the rate at which water enters the sewer system; that will enable New York's combined sewer system to treat a higher percentage of storm water. Vegetated and gravel buffer strips along the edge of landscaped areas or surrounding detention infrastructure can also help filter pollutants from water.

The City will modify the zoning resolution to require perimeter landscaping of commercial and community facility parking lots over 6,000 square feet as well as street tree planting on the adjacent sidewalks. Parking lots over 12,000 square feet would also be required to provide a specified number of canopy trees in planting islands within each lot. The intention of this proposal is to reduce the eyesore of large asphalt expanses while more effectively managing storm water runoff and helping to cool the air.

In addition to the zoning modification, the City will analyze the costs and benefits of integrating additional BMP's into parking lots. From these findings, we will create appropriate policy to improve storm water capture and storage for parking lots as part of the New York City Interagency BMP Plan.

Progress (as of 4/22/08):
The City Council approved a green parking lot zoning amendment that applies design regulations for landscaping, perimeter screening of the lots as well as requirements for canopy trees in planting islands within commercial and community facility parking lots. In March, the CPC passed a street tree zoning amendment that requires tree planting for all new developments and major enlargements citywide, and is expected to result in approximately 10,000 new street trees per year. Also in March, the CPC passed a front yard zoning resolution that prevents excessive paving of front yards by encouraging landscaping and planting of yards throughout the city. City Council is expected to vote on these zoning amendments in spring 2008.

Parking Lots Zoning Resolution, NYC Department of City Planning