Water is essential to life. It is also fundamental to economic well-being—with a nexus to food, energy, industrial production, and a host of goods and services. Yet throw a dart on the map, and we see communities that face water challenges. Yes, we made enormous strides to address water-related public health and pollution challenges in the United States over the past century. But a host of new challenges to water quality require us to think of water management in new ways.
When the Clean Water Act was voted into law in 1972, approximately 85 percent of water quality impairments were from “point sources” of pollution, including wastewater and industrial effluent, with only 15 percent composed of runoff from city streets, suburban lawns, and farm fields. More than 40 years later (and after massive investments in structural and highly engineered pipes, pumps and treatment facilities), the pollution distribution today is exactly the opposite, with 85 percent of current water impairments associated with non-point source urban stormwater and agricultural runoff.
It couldn’t happen at a worse time for already-stretched taxpayers– or for a federal government that is already more than $18 trillion in debt.
Our waterways and coastal areas are increasingly under threat from worsening pollution caused by stormwater runoff. Urban stormwater runoff is recognized as the only major growing source of water pollution in many parts of the United States.
Traditional approaches to water supply and pollution challenges – costly construction of major public works projects such as water treatment facilities, pipes and tunnels to channel stormwater out of cities, underground storage tanks, or concrete bulkheads – have come to be known as “grey infrastructure.” In many places, they are being eclipsed by a revolutionary new approach that is cheaper, more resilient and is likely to provide a far greater economic benefit over time.
Known as “green infrastructure,” this emerging approach relies upon nature-based systems and processes, including bioretention, development of coastal wetlands, and preservation and enhancement of forested headwaters, and shows great promise for addressing the water challenges of the 21st century. These practices offer us innovative options to protect and enhance ecosystems, increase resiliency for urban areas and provide water treatment at a lower cost – and with a greater long-term economic benefit.
Bio-retention involves the construction of shallow basins that are used to slow down and treat stormwater runoff through an array of physical, chemical and biological processes. The slowed, newly clean water is then allowed to seep into the soil or can be directed into nearby waterways.
Wetlands, whether occurring naturally or constructed, are increasingly recognized for their value as water treatment systems that use vegetation, soil saturation and microbial processes to improve water quality. Besides cleaning the water, wetlands produce the added benefit of creating or restoring valuable wildlife habitat.
Forests are the world’s most effective land cover or maintenance of water quality, providing a kind of natural “sponge” that collects and filters rainwater before gradually releasing it into rivers and streams. Forest cover has been directly linked to reducing costs of purifying drinking water: the more forest there is in the watershed of the source water, the lower the treatment costs downstream.
These green infrastructure approaches have received some regulatory recognition in regional and watershed-based permitting and integrated planning at all levels of government.
Beyond that, however, Congress and the Environmental Protection Agency need to include these nature-based approaches in the federal and state selection processes for both the Clean Water and Safe Drinking Water regulatory programs. They also need to further examine new market-based approaches, such as water quality trading and public-private partnerships, that offer the potential to expand green infrastructure investment.
Green infrastructure offers more than an effective set of tools to improve water quality – it presents a nature-based lifeline to hard-pressed taxpayers for whom the more expensive traditional methods are in many cases no longer affordable.
Scarlett is global managing director for public policy at the Nature Conservancy and an adviser to the Conservation Leadership Council. More information at: http://www.leadingwithconservation.org/wp-content/uploads/2015/12/horinko.pdf