GEF

Unit 1  |  Why Water Matters 32 Preserving natural infrastructure contributes to the sustainability of water systems. Another component of sustainable water systems is the valu- ation of natural infrastructure such as wetlands, barrier islands , forests, and healthy soil. In this approach, people value the ecosystem services and other benefits of these natural features in providing clean water. Examples of this approach are demonstrating that natural systems can pro- vide sustainable water, often at lower cost than building new infrastructure. In 1996, New York City was faced with the prospect of con- structing a water treatment plant at a cost of $6 billion - $8 billion after its water supply was found to be in violation of Environmental Protection Agency (EPA) water quality stan- dards. Instead, the city chose to invest about $1.5 billion in ecosystem restoration in the Catskill Mountains, the source of its water. In this case, valuing the purifying service of intact ecosystems proved more effective and cheaper than building water treatment infrastructure. A further facet of water sustainability is the discipline of managing water as a social resource. Traditionally, water man- agement has been carried out in a top-down manner, in which NATURAL INFRASTRUCTURE Natural features such as forests, wetlands, and barrier islands that provide the same benefits as manmade water infrastructure. BARRIER ISLANDS Long, narrow islands close to the mainland, which protect land areas and cities from flooding and provide a range of ecological services. ECOSYSTEM SERVICES Services such as crop pollina- tion and flood control which are provided by natural ecosystems.