Building a Green Infrastructure

By Robert Pirani, Vice President for Environmental Programs, and Elias Schewel, Research Associate, RPA

When it comes to that wet stuff we all need a bit of every day, cities are turning more quickly to green and smart strategies: conserving wetlands, controlling farm runoff and installing low-flow toilets instead of building filtration plants, adding more chlorine and tapping groundwater.

Still, it's a struggle. Old-school thinking, whether it comes from the engineer, lawyer, or politician, still stymies new approaches that don't fit standard engineering, regulation, or management practices. Separate rules often govern groundwater and surface water, and stormwater and drinking water, even though they are inextricably connected below and above ground.

Identifying the ways to overcome this challenge is the charge for a workshop panel at Regional Plan Association's upcoming Regional Assembly, April 16. Visionary architect and RPA Board member James Polshek will lead a distinguished panel in a conversation about making the extraordinary, ordinary.

Traditionally designed or "gray" infrastructure treats water as a waste product, controls its natural fluctuations, and separates its management from related goals and objectives. In contrast, green infrastructure techniques--ranging from protecting headwater forests to rain gardens, and street trees in urban areas--are being implemented in cities and regions around the country. These innovative designs can save scarce land and money while providing considerable co-benefits: protecting and restoring ecosystem services, lowering vulnerability to flooding and reducing the growing costs of disasters, saving energy that might have been used to treat and transport water, and creating local jobs.

Perhaps the best known example of green infrastructure practice is New York City Department of Environmental Protection's Filtration Avoidance agreement with the US EPA to allow a combination of headwater forest, riparian area conservation, and other upstream investments to substitute for construction of a filtration plant for the City's Catskill and Delaware drinking water reservoirs, estimated to cost $6 to $10 billion dollars.

On a smaller scale, the potential of bioswales, street trees, and new building roofs are catalogued in the City's recently released Stormwater Management Plan. Implementation of such improvements could help reduce the need for additional stormwater storage facilities, like the $357 million Paedergat Basin plant in Brooklyn that opened in 2008. Planting street trees, rebuilding streets, or building green roofs will reduce the need for such new facilities in the future, while improved the quality of life for millions of New Yorkers.

One such proposal was recently put forward by RPA, Brooklyn Greenway Initiative, and WEDesign for West Street in Greenpoint, Brooklyn. A system of curb cuts that drain stormwater into continuous planting beds will eliminate 80% of combined sewer overflow events while providing greenery and public space in this redeveloping neighborhood.

This spring's record setting storms are a soggy reminder that we need to up the ante. Rising Currents, the new exhibition at MOMA, showcases Green Infrastructure thinking in dramatic and bold proposals for the Harbor. Inspired by Workshop presenter Guy Nordenson's Palisades Bay, five teams of designers have proposed dramatic interventions that re-think the hard boundaries between land and water. Instead, islands, oyster reefs, and canals are employed to manage anticipated sea-level rise and storm surges.

Our Workshop Panel will offer an expert assessment of the prospects for Building a Green Infrastructure. Commissioner David J. Burney from the New York City Department of Design and Construction, Commissioner Caswell F. Holloway from the New York City Department of Environmental Protection, Helena Durst of The Durst Organization, Jeffrey Raven from The Louis Berger Group, and Guy Nordenson of Guy Nordenson & Associates turn innovation into business-as-usual.