This year's record droughts in California and Brazil are just the latest reminder of the growing water crisis. Today, 25 percent of the world's largest cities are experiencing over-stressed water supplies. Almost 1 billion people face water shortages, and in 15 years, the global demand for reliable water sources will likely exceed supply by 40 percent.
Reversing this trend will require looking beyond traditional solutions—and building alliances with unlikely partners.
In the past, cities have responded to water shortages by investing in gray infrastructure like reservoirs, dams and wastewater treatment plants. When demand continues to outstrip supply, cities may look to transfer water from distant reservoirs. In fact, the largest 100 cities in the world currently move 3.2 million cubic meters of water every day more than 5,700 kilometers to overcome local water shortages or pollution. These solutions are not only costly, but also have negative consequences for nature.
What if there was a better way? A cost-effective solution that's good for businesses, good for local communities and good for wildlife?
The answer lies in protecting water at its source—the rivers, forests and other natural systems that provide cities with their water. Keeping these systems healthy can reduce sediment and nutrient pollutants in our water sources. These solutions can be cheaper and more efficient than treating water after it has already been polluted.
A new report, the Urban Water Blueprint, shows just how promising these solutions can be. Drawing on three years of in-depth analysis, The Nature Conservancy, in partnership with the C40 Cities Climate Leadership Group and the International Water Association, found that conservation strategies can measurably improve the quality of water sources serving more than 700 million people living in the 100 largest cities.
One of the most promising solutions, the report found, is improving agricultural practices. When many people think of conservation, they think of protecting pristine pieces of land. But for water quality, the biggest opportunity for cities is in improving practices on working lands such as farms and ranches.
Today, 172 million people in the 100 largest cities get their water from watersheds covered by more than 50 percent cropland. These watersheds experience higher levels of sediment and nutrient runoff, which degrade water quality.
Yet simple practices like planting cover crops to hold soil in place in between harvests to restoring stream banks and wetlands that trap loose sediment and absorb nutrients can improve source water quality and reduce water treatment costs. The report found that applying these practices to some 6.4 million hectares could materially improve water quality for 600 million city dwellers.
Companies that rely on agriculture for their products can be important allies in influencing these changes along their supply chains. Some companies are already taking a lead in this area:
Take MillerCoors, for example, and its efforts to reduce water stress in the Silver Creek watershed in central Idaho. The creek is a premier trout stream and surrounded by barley growers under contract with MillerCoors. In recent years, the company created new wetland areas to trap sediment, replanted stream banks that had been degraded by grazing, and created a “Showcase Barley Farm” to develop and share best practices that can provide important conservation benefits without impacting farm productivity. This year, the company implemented new irrigation techniques designed to both save water and save farmers money.
And just this week, General Mills announced that it will expand its commitment to responsible product sourcing by implementing a water policy. The company has pledged to factor water risk considerations into business decisions, including where to locate new facilities. The policy builds on several years of work with The Nature Conservancy to assess every watershed that the company uses around the world. We are now working together to develop conservation plans for those watersheds at risk of being over-taxed.
From rivers that supply freshwater used for manufacturing, to groundwater aquifers that irrigate the crops a company sources, businesses rely on water. It's encouraging to see companies like MillerCoors and General Mills viewing these natural systems as assets in need of protection and investment.
As population growth, urbanization and climate change put ever greater stress on urban water supplies, nature is our largest untapped solution for keeping cities' water clean and flowing. Solving the challenge will require looking beyond city limits, to the businesses and farmers that play a vital role in protecting the water sources on which they and the communities in which they work rely.