Why Natural Conservation Methods Matter for the Future of Urban Water Supplies

Pitt River watershed in northeastern California. (Photo: SImon Fraser University/flickr).

The liquid that comes cascading out of the faucet each time you step up to the sink to brush your teeth, wash your hands or refill your self-cleaning, basil-growing aquarium has to come from somewhere, you know. And unless the municipal water supply in your city or town has been compromised or you are hyper-aware of personal water usage due to drought, there’s a good chance you might not know where that somewhere is.

Released earlier today by the Nature Conservancy in collaboration with the International Water Association and the C40 Cities Climate Leadership Group, the Urban Water Blueprint is an exhaustive, solution-oriented report of 108 pages that explores five key natural water conservation methods — forest protection, reforestation and improved farming practices being just three of them — that can improve the health of local watersheds (that somewhere) and enable clean, reliable water to continue to flow freely to increasingly crowded cities.

In addition to the report itself, Urban Water Blueprint includes a fascinating interactive website that details the state of 2,000 water-supplying ecosystems and the 530 cities across the globe, home to more than 1 billion people, that draw from them. The water situation — including specific risks such as agricultural runoff and erosion and the management solutions that should be employed to remedy them in conjunction with traditional infrastructure — in a handful of major cities ranging from Los Angeles to New York, London to Beijing are explored in further detail.

In drought-stricken Los Angeles, for example, conservation practices aided by strong municipal water management, have allowed supply to keep up with rapidly growing demand. However, as detailed in the report, because the city’s water supply travels such a long distance (over an average of 71 kilometers), the city’s far-flung watersheds would greatly benefit from natural conservation practices such as the prevention of farm field nutrient runoff.

The situation in London is quite different, and quite dire. Unlike in surface water-supplied L.A., nearly half of London’s water supply comes from groundwater sources. (London, somewhat surprisingly, receives less annual rainfall than Dallas). Considering the age of the British capital city, a sizable amount of London’s natural watersheds have been developed, turning the focus away from natural conservation methods to the repair of antiquated infrastructure.

According to the report, the 100 largest cities in the world comprise only a small chunk — 1 percent — of the planet’s total land area. The watersheds that supply these cities, however, make up 12 percent of the planet's total land area — a swath of forest, rivers, lakes and streams that’s roughly the size of Russia.

“This analysis answers for the first time, the fundamental questions of what investments can be taken to incorporate nature in the delivery of clean water and the quantitative value of these actions for water managers,” explains Giulio Boccaletti, global managing director for water for the Nature Conservancy. “Cities that invest in watershed conservation can no longer be the rare exception; rather such investments need to become a regular part of the toolbox for water managers. For this to happen, people living in cities need to understand where their water comes from so that city and water managers can support measures that will often be implemented outside of metropolitan areas.”

Head on over to the Urban Water Blueprint website to learn more about the health of the water in your city — and the watershed that supplies your city — along with the natural conversation methods that will help keep it clean and abundant well into the future.

Nature Conservancy graphic on watersheds