On August 27th, New York Attorney General Andrew M. Cuomo announced that his office will provide $1.8 million of a $7 million settlement with a number of towns in Westchester that had been illegally dumping raw sewage into the Bronx River.
“The funding will be provided to seven entities, including the Bronx River Alliance, THE POINT Community Development Corporation, the New York Botanical Garden, the New York City Parks Department, and the Westchester County Planning Department, for “green infrastructure” – natural systems, like wetlands, or engineered systems that mimic them – that capture and treat polluted stormwater before it reaches the river.”
The idea here is to use existing ecosystems to filter pollutants and protect streams and other water sources. While some pollutants require artificially engineered treatment systems powered largely by fossil fuels, many other pollutants, such as human waste and conventional, non-toxic household waste, can be filtered with natural systems powered by old-fashioned, solar-based photosynthesis.
It turns out that most pollution control equipment is not only capital-intensive, but also expensive to operate and maintain. The good thing about the use of natural systems as pollution control devices is that they tend to be cheaper to build and much cheaper to maintain. The term currently being used to describe the practical use of ecosystems to protect the environment is “ecosystem services.” A number of scholars have worked to quantify the monetary value of these services, including my colleague Geoff Heal at the Columbia University School of Business, who is the co-author of a landmark 2004 National Academy study entitled, “Valuing Ecosystem Services: Toward Better Environmental Decision Making.”
This study pointed out in 2004 some indisputable facts that we later learned the hard way during Hurricane Katrina: when we destroy natural ecosystems to develop land, we also destroy the services that those systems provide for us. In the case of New Orleans, the ability of the city to withstand the power of the hurricane was impaired by the development of wetlands and islands that once served as a natural buffer for the city. Heal and his co-authors pointed out that the economic analysis that led to paving over these areas did not factor in the economic benefits of the services provided for the city and its inhabitants by surrounding wetlands and protected ecosystems.
In New York, we can see an excellent example of the importance of ecosystem services. About 90% of the water we use in New York City comes from the Delaware-Catskill water system, about 120 miles north of the city. Over the past dozen years, the city has been able to purchase land and subsidize best management practices for the watershed, avoiding the need for extensive filtration of our upstate water supply. If, in fact, the federal EPA required us to filter this water, it would cost about $8 billion to build the facilities needed to treat the billion gallons of water New York City residents use every day. It would cost between $300-400 million each year to operate these filtration facilities. Instead, we spend about $200 million a year (pdf) to preserve ecosystems and manage our land use in ways that help keep our water supply clean naturally.
We are beginning to learn that the natural environment is more than something nice to look at or camp in, that it actually does work of economic value that can improve our quality of life. The irony is that one of the best ways to preserve the quality of our countryside is to concentrate our population in cities and towns. Redeveloping the “brownfields” of our inner cities can help preserve the “greenfields” of the exurbs.
Our policymakers are starting to learn about and take advantage of the practical value of ecological preservation and restoration. We see evidence of this every time we turn on the tap water in New York City, and, thanks to Attorney General Cuomo, we will soon see evidence of this in a cleaner Bronx River as well.