|
Launched in 1996, Greenstreets is a large-scale, citywide greening and urban beautification program created by the New York City Department of Parks & Recreation (DPR). Using principles of smart growth, the Greenstreets program converts paved roadways into green oases of trees, shrubs and groundcover. This program has turned 172 acres of impervious grey into pervious green space. DPR has created approximately 2,400 Greenstreets citywide. The program is hugely popular, with at least 50 requests coming in each year from community members, elected officials and business improvement districts. DPR works closely with DOT Highway Design & Construction to ensure Greenstreet designs meet standards for vehicular patterns and traffic flow. DPR is exploring with DOT how best to use Greenstreets to calm traffic. By reclaiming unused roadbed for roadside gardens the citizens and communities of New York gain safer pedestrian corridors, more attractive and inviting communities and the environmental benefits of green infrastructure.  An average-sized Greenstreet of 1,500 square feet captures approximately 1,894 gallons of stormwater per year. NYC Park & Rec recently received funding to study the effectiveness of its stormwater capture designs. This street garden at Macombs Ave. and Featherbed Lane in the Bronx features Picea pungens ‘Glauca’ (Colorado blue spruce), Zelkova japonica (Japanese zelkova), ‘Knockout’ rose, Miscanthus sinensis ‘Gracillimus’ (maiden grass), Rudbeckia fulgida ‘Goldsturm’ black-eyed Susan, Hemerocallis ‘Stella d’Oro’ daylily and Narcissus ‘King Alfred’ daffodils (not visible in picture). Design: Barbara Barnes, DPR. Photo: Jessica Reback, DPR PlaNYC 2030Earth Day, April 22, 2007 is an important date in the history of New York City. On that day Mayor Bloomberg unveiled PlaNYC 2030, an ambitious and practical plan to make the sprawling city more sustainable. As part of his plan, DPR has undertaken the creation of 80 new Greenstreets each year, commencing in fall 2007. PlaNYC 2030 includes a funding commitment of $15 million for the construction of new Greenstreets from 2007 through 2017, which should increase the number of new Greenstreets dramatically. The Greenstreets sites not only beautify the urban landscape, but also clean the air, cool the city, provide habitat for wildlife and capture stormwater for irrigation. An average-sized Greenstreet of 1,500 square feet can capture approximately 1,894 gallons of stormwater per year. NYC’s Greenstreets capture a total of approximately 9,460,000 gallons of stormwater annually. This water used to go down sewer outlets but is now infiltrated instead into the ground and stored on-site. DPR landscape architects employ gently sloping sidewalks, trench drains, curb cuts, bioswales, deep excavation, and crushed bluestone storage reservoirs to accomplish this goal. DPR has recently received funding to study the effectiveness of its stormwater capture designs. In conjunction with scientists from Drexel University and the New York City Soil and Water Conservation District, DPR is conducting a monitoring study of Greenstreets that actively capture stormwater to confirm these sites are effectively intercepting runoff, capturing and storing stormwater for plant use. The study will focus on understanding rainwater interception, surface hydrology, soil moisture dynamics, and percolation and groundwater dynamics.  The Greenstreets project at 1st Avenue & 20th Street in Manhattan offers Lagerstroemia indica ‘Natchez’ crepe myrtle), Chamaecyparis ‘Gold Mop’ false cypress), Juniperus ‘Bar Harbor’ juniper), Caryopteris clandonensis (blue mist shrub), Spiraea x bumalda ‘Goldflame’ spirea, Carex glauca (blue sedge), Nepeta x fassenii ‘Walker’s Low’ catmint, Begonia x semperflorens-cultorum (wax begonia). The hardscape edging is soldiered granite block. Landscape design: Jeff Keiter. Photo: Eleanor Gantt, DPR. Pint-Sized ParksMedians and traffic triangles in the roadway constitute the most typical Greenstreets. Other opportunities are sidewalks are wide enough to allow for curbside plantings or where a two-way street meets a one-way street and forms a roadbed peninsula that can be planted to highlight the traffic change for oncoming vehicles.  This Greenstreets project at the Grand Army Plaza in Brooklyn (Soldiers and Sailors Arch in background) has a landscape of Achillea millefolium ‘Terra Cotta’ yarrow), Echinops ritro ‘Veitch’s blue globe thistle and Physocarpus opulifolius ‘Summer Wine’ common ninebark. Landscape Design: Jeff Keiter, DPR. Hardscape Design: Ryan Russo, Randy Wade and Vanessa Rauschenberger, DOT. Photo: Laura Mazza, DPR ImplementationGreenstreets are constructed through Central Forestry and Horticulture’s citywide requirements contracts. Proposed sites are surveyed and designed by landscape architects in this division. Designs are then reviewed and approved by NYCDOT’s highway design and construction team. The DOT provides the construction permits following approval of designs. Sites are maintained by the contractor for the first two-years following construction. After that, sites are maintained by the horticultural staff of each borough. PlaNYC provides $14.5 million in funding for an additional 60 maintenance staff to ensure the survival of these horticultural sites. Million TreesPlaNYC initiatives include MillionTreesNYC, a citywide, public-private program with the ambitious goal of planting and caring for one million new trees across the city’s five boroughs over the next decade. Greenstreets is using large-canopy trees wherever possible. Central Forestry & Horticulture has identified five neighborhoods with a combined low canopy cover and high asthma rates as most in need of new trees. OwnershipBecause the majority of Greenstreets are located in the roadbed on NYCDOT property the Greenstreets program is a partnership between DPR and DOT and governed by a memorandum of understanding which dictates DPR as fully responsible for the sites while they are Greenstreets. DOT may reclaim use of these lands at any time. Lessons LearnedPlanting in the roadbed poses challenges. Greenstreets face drought, pollution, road salt, dog waste, litter, foot traffic and vandalism. DPR landscape architects have developed a strong base palette of plants able to withstand harsh urban conditions. Species are selected for their drought, salt and pollution tolerance, low maintenance needs and ability to spread and suppress weeds. The designs must balance goals of aesthetics, species diversity, canopy cover, and stormwater capture with the requirements of roadway geometry. Designers carefully select plants with appropriate mature heights, widths, and habits and arrange them so as not obstruct driver visibility or compromise pedestrian safety.
See related story: “New York DOT Releases First Street Design Manual for NYC” https://landscapearchitect.com/research/article/12267 |
