Leia este post em Português.

Serious water crises have plagued Brazil’s major cities in recent years. Severe pollution in Rio de Janeiro’s Guanabara Bay is jeopardizing sailing and other water sports at the upcoming Olympic Games. A historic drought from 2013 to 2015 in São Paulo dramatically slowed farm and factory production, threatening the national economy. Residential water rationing forced people to stockpile water in canisters, which became breeding grounds for mosquito-borne dengue and may have contributed to the recent Zika outbreak.

Some causes are familiar: inadequate enforcement of regulations, leaky water distribution systems, and population growth and urban development outstripping available water supplies.   But looking outside the cities’ boundaries, a lesser-known cause emerges: degraded natural infrastructure.

Natural infrastructure (sometimes called “green infrastructure”) refers to natural and open spaces like forests or wetlands that are strategically managed to protect downstream water supplies. If these natural areas are lost to urban sprawl, converted to farms, or are otherwise degraded, city water supplies are more likely to suffer shortages or become polluted. When managed properly, natural infrastructure directs more clean water to cities by controlling water flows, preventing sediment buildup that would otherwise choke streams and rivers, and absorbing pollutants before they flow into waterways.

While some innovative solutions have emerged to protect and restore natural infrastructure—such as Water Funds, public-private partnerships that jointly invest in natural infrastructure—these are still more the exception than the rule. Most cities in Brazil and throughout Latin America rely exclusively on “gray infrastructure” like water treatment plants and man-made reservoirs for their water supplies, even as environmental threats intensify.

How to Scale Up Natural Infrastructure?

Brazil may not yet fully embrace natural infrastructure, but two central elements could help secure more investment: a clear understanding of the business benefits and knowledge-sharing on managing natural infrastructure programs. A few new projects and tools are emerging to achieve these two goals.

Making the Business Case

Natural infrastructure can safeguard and complement traditional water infrastructure systems, for example, by avoiding water pollution that would otherwise need to pass through a conventional water treatment plant, thus reducing costs.

In some cases, the return on investment can be substantial. Like 19 other cities in Latin America, São Paulo has a Water Fund supported by The Latin America Water Funds Partnership, an association of The Nature Conservancy (TNC), FEMSA Foundation, Inter-American Development Bank (IADB) and the Global Environmental Facility (GEF), in partnership with many other partners. TNC estimates that restoring at least 14,300 hectares (35,000 acres) of degraded land in São Paulo’s supply watersheds would reduce sedimentation by 50 percent, saving $2.5 million every year and reducing water treatment costs by 15 percent over the course of 10 years.

WRI and a network of partners developed the “Green-Gray Assessment” method, an economic analysis tool that helps decision makers compare the potential values of natural infrastructure investments alongside the costs and benefits of traditional infrastructure. WRI and others have tested the assessment in places ranging from the United States to Kenya, finding that natural infrastructure oftentimes offers significant cost savings over or when complemented by gray infrastructure.

This year, WRI and FEMSA Foundation will evaluate the costs and benefits of natural infrastructure investments in São Paulo and Monterrey, Mexico, while the Natural Infrastructure in Brazil initiative—led by WRI, International Union for the Conservation of Nature, TNC, BioAtlantica Institute and the Boticario Group Foundation—will conduct case studies in São Paulo, Vitória and Rio de Janeiro.

Sharing Knowledge and Building Capacity

Implementing natural infrastructure programs requires know-how on a range of topics, from prioritizing which lands to protect and restore to identifying sustainable financing mechanisms. Traditionally, water managers and other decision-makers in Brazil have lacked information on how to carry out these practices, but here, too, tools are emerging.

The Restoration Opportunities Assessment Method (ROAM) guides stakeholders through the development of strategies to restore degraded or deforested natural areas. Experts have already applied ROAM in several regions of Latin America. Other tools such as InVEST, RIOS and ROOT can also evaluate the costs and benefits of natural infrastructure, including the potential value of ecosystem services. And in Brazil, the 10-year-old Oasis Initiative  has provided technical assistance to more than 300 landowners supporting natural area conservation, shedding light on how rural development and water stewardship can be compatible.

This year, the Natural Infrastructure in Brazil project and FEMSA Foundation will build on this knowledge by releasing guidance to help decision makers realize profitable investments in natural infrastructure. The guidance will inform strategies for the Latin American Water Funds Partnership’s 40 water funds.

Brazil’s water systems may not be secure yet. But with the right tools and collaboration, the country can start investing in natural infrastructure projects that can provide clean, sufficient water supplies in vulnerable cities for decades to come.

This post was developed by WRI, FEMSA Foundation, Inter-American Development Bank, the Boticario Group Foundation, The Nature Conservancy, the International Union for Conservation of Nature and Instituto BioAtlântica, which are joining forces to scale up natural infrastructure investments to help secure urban water supply in Latin America.