By Amy Crawford
Since 2007, urban areas have been home to more than half the global population—a proportion that is expected to rise. Growing cities are putting pressure on the lakes and rivers on which they depend for water. But the needs of nature don't have to be in conflict with human needs. By funding conservation projects upstream, cities around the world are finding that they can protect the natural environment and ensure they have clean, reliable water supplies.
The approach starts with addressing deforestation, erosion and agricultural runoff in the headwaters—just as New York City conserved the land around its upstate reservoirs so it could supply its millions of residents with clean drinking water. “The basic premise is that it’s cheaper and easier to fix the problem before it gets to the cities,” explains Andrea Erickson-Quiroz. (To see how water funds work, check out our infographic.) She leads The Nature Conservancy’s global effort to bring together governments, utilities, businesses and nonprofits, pooling money from downstream water users in water funds, which invest in upstream conservation.
In 2000, TNC helped set up the first water fund, in Quito, Ecuador, to protect and restore grasslands and forests high in the Andes, improving river flows and reducing erosion that muddies the water on which downstream city residents depend. The fund has a budget of more than $1.5 million per year, most of it covered by the city’s water company, which contributes 2 percent of its own budget. The project has the double benefit of improving water flow and quality while preserving and restoring vulnerable Andean habitat—about 100,000 acres so far.
Over the years, TNC facilitated the creation of 29 more water funds worldwide, and it has another 30 “in the pipeline,” Erickson-Quiroz says. Most are in North and South America, but she and her team are now turning their attention to other countries, including China, where at least a third of lakes and rivers are too polluted for human use—but where more environmentally sensitive agriculture has the potential to improve water quality.
Beyond the Source, a recent TNC report on water security for communities, calculates that nearly 700 cities—about one in six worldwide—could create water funds that would pay for themselves through savings in water-treatment costs.
Word is spreading among city leaders and utility managers that conservation is a smart investment. As cities realize the benefits, Erickson-Quiroz says, TNC encourages participating mayors to talk to other mayors about nature as a tool.
“That’s how you start the movement.”
MUNICIPAL WATER SYSTEMS: A rapidly growing population, frequent droughts and silt-clogged reservoirs have combined to make lines for water a somewhat regular sight around São Paulo.© Sebastiao Moreira/EPA/REDUX
SÃO PAULO, BRAZIL
In 2014, as Brazil prepared to host the World Cup, its biggest city faced a slow-moving disaster. Half of São Paulo, a megalopolis of more than 20 million residents, gets drinking water from a series of enormous reservoirs in the Atlantic Forest along Brazil’s southeastern coast. Human use has reduced the forest to 30 percent of its original size, and recent growth in development, farming and ranching has accelerated soil erosion. As silt settled at the bottom of the reservoirs, it reduced their storage capacity. When a historic drought struck in 2015, reservoirs were quickly reduced to mud. Water was rationed or even cut off. More than 10 years ago, the upstream municipality of Extrema and Brazil’s National Water Agency set up the country’s first Water Producer Program. With help from multiple agencies and TNC, it raises money from water users and pays upstream landowners an annual fee of almost $40 an acre to protect or restore riverbank forests. The Conservancy is working with 14 municipalities to expand the project, which will reduce sedimentation and treatment costs for São Paulo by restoring 35,000 acres of degraded landscapes in high-priority areas throughout the watershed.
TANA RIVER: The river provides water to almost 9 million residents in Nairobi and surrounding areas. The water fund helps upstream farmers improve their lands and reduce soil runoff. © International Center for Tropical Agriculture (CIAT)/G. SMITH
In about 25 years, the population of Kenya’s capital city doubled to nearly 4 million people, 95 percent of whom rely on water from reservoirs in the mountainous Upper Tana River watershed. As Nairobi’s needs increase, hillside agriculture along river tributaries exacerbates erosion that periodically chokes the city’s water system with silt, stopping water service for days. “It’s something they’ve dealt with [for decades], but it’s gotten worse and worse,” says Colin Apse, who directs TNC’s freshwater conservation work in Africa. The Conservancy started working with the Kenyan government, nonprofits, utilities and corporations, including Coca-Cola and East Africa Breweries, to create a water fund. It pays for equipment and training to help farmers control erosion with terraced cultivation and buffer zones along streams. Since 2015, the program has been implemented at about 15,000 farms, and in late 2016 water clarity levels approached World Health Organization standards for the first time since measurements began. Africa’s first water fund has attracted interest—including Cape Town, South Africa—prompting TNC to create an online toolbox to help other cities set up their own.
RIO GRANDE RIVER: After an intense fire caused ash and soil to foul the Rio Grande, a water fund was created to restore forests and make them more tolerant to fires.© AP Photo/Albuquerque Journal/Pat Vasquez-Cunningham
ALBUQUERQUE, NEW MEXICO
In the summer of 2011, a tree fell on a power line in the Jemez Mountains, sparking a mega-fire that would burn for six weeks, destroy more than 156,000 acres of ponderosa pine forests and impair nearby municipal water systems. The fire’s intensity was compounded by drought and decades of fire suppression, which allowed the trees to grow unnaturally close to one another while dangerous amounts of flammable debris accumulated on the forest floor. A few weeks after firefighters extinguished the blaze, storms sent a torrent of soot-black water and debris down the Rio Grande, forcing communities that depend on the river for water to shut off their intakes. In the crisis, Laura McCarthy, TNC’s associate director for New Mexico, saw an opportunity to correct a century of bad forestry and expand a pilot water fund that TNC had set up with the city of Santa Fe. Today, the Rio Grande Water Fund is using public and private cash to pay for forest thinning and prescribed burns, with a goal of treating 600,000 acres of forest along the river and its tributaries by 2035. The work will restore the forest to a more natural state—and make it more resistant to mega-fires.
EDWARDS AQUIFER: The Nature Conservancy helps identify—and broker deals to protect—land where water enters the aquifer. This area is known as the "recharge zone." © DSCZ/Getty Images
SAN ANTONIO, TEXAS
The enormous Edwards Aquifer, believed to hold several trillion gallons of water, provides drinking water to more than 2 million people in south-central Texas, including the city of San Antonio. Carved from what was the bed of an ancient shallow sea, the aquifer is a labyrinth of underground chambers that collect precipitation via a network of surface cracks and sinkholes. Water then filters through porous limestone, supplying springs, streams and lakes. Replenishing the Edwards with clean water is critical for the region, but the aquifer’s recharge zones are particularly vulnerable to polluted runoff and urban sprawl. It’s a threat that San Antonio started to address in 2000, when voters approved a sales tax increase to protect land in the recharge zone and buy conservation easements from ranchers. The Nature Conservancy plays a major role in identifying and negotiating these protections, and voters have shown their support by approving three more ballot initiatives. “There’s a very high awareness within central Texas about this resource,” says Laura Huffman, TNC’s Texas state director. “It’s one of the few places in the country where you can say the word aquifer and people know what you’re talking about.” With continued public support—and help from TNC—the initiatives have preserved more than 143,000 acres, or 20 percent of the recharge zone used for city water.
SAVANNAH RIVER: As coastal development grows near the mouth of the Savannah River, nearby cities are securing their water supplies through upstream conservation efforts. © Posnov/Getty Images
Not every water fund begins with a crisis; some are designed to prevent problems. In Georgia and South Carolina, TNC, along with other nonprofits, universities and government agencies, collaborated with five municipal water authorities to create the Savannah River Clean Water Fund to address emerging water-treatment issues. The Savannah River watershed supplies water for some 550,000 people in the region that includes Augusta and Savannah, Georgia, and Beaufort and Hilton Head Island, South Carolina. In recent years saltwater intrusion has begun to affect groundwater, making surface resources more important. Continued urbanization and growth could increase runoff and raise treatment costs. The fund, incorporated in 2014, will use about $1 million raised annually from the utilities to buy conservation easements for tracts of floodplain forest. “The basin is in good shape because it has all this natural land, and to wait for problems to appear and then address the challenge at that point would be too little, too late,” says Eric Krueger, who directs TNC’s science work in South Carolina.
Amy Crawford is a Michigan-based freelance writer who also contributes to Smithsonian, CityLab and The Boston Globe.