Like a bathtub collecting and then directing the water that falls within its sides, a watershed includes the physical area involved in capturing precipitation, filtering and storing water, and determining the amount of water released into stream and river systems at lower levels. Watersheds may be large or small, and smaller watersheds (sub- or micro-watersheds) join to become larger watersheds. Figure 1.1 illustrates the inverse pyramid shape of a typical Andean watershed and shows how watersheds connect catchment areas in upper elevations with different kinds of water users below. Since human survival and economic development depend on water and other natural resources located in watersheds, they are not simply geographic territories. Watersheds have economic and social aspects that are intertwined with the environment. For thousands
Figure 1.1 Typical Andean Micro-Watershed.
of years, people have manipulated watershed resources—including water, soil, vegetation, and wildlife—to spur political and socioeconomic development. Watershed management is about this strategic use of watershed resources.
Watershed management strategies are shaped by local political, socioeconomic, and cultural conditions. People and organizations representing a wide array of interests live and work in watersheds. Farmers use the land to raise crops and livestock and may rely on water for irrigation. Businesses may extract a watershed’s natural resources, such as timber or minerals, or simply help tourists enjoy the natural beauty. Hydroelectric companies rely on water flow to produce electricity. In fact, all businesses and households consume water in their daily activities. They also rely on the watershed ecosystem to absorb their waste, whether it is dumped in rivers or landfills. NGOs may have other interests, such as protecting the watershed’s biodiversity and integrity as a functioning ecosystem. For some communities, watersheds may have spiritual or cultural significance. Local governments are often responsible for managing the natural resources in their jurisdiction and must navigate these competing interests. Throughout the book, I refer to these interest groups collectively as “local stakeholders.”
Watersheds connect people through their ability to affect each other by impacting the watershed ecosystem on which they all depend. For example, watersheds link higher catchment areas, where water collects, with lower areas where people use water for various purposes. People in upper catchment areas often engage in economic activities such as agriculture, logging, and mining that pollute the soil and water and damage the vegetation maintaining the natural water cycle. This can decrease the quantity and quality of water available to communities downstream.
Without some system for reconciling the competing interests of people who depend on watershed resources, conflicts inevitably arise. All too often, these conflicts lead stakeholders to consume watershed resources (e.g., forests, soil, water, biodiversity, etc.) at an unsustainable rate, threatening the integrity of watershed ecosystems and making everyone worse off. While people living in watersheds feel the effects of watershed degradation most directly, it is construed as a global problem because it threatens an estimated two billion people worldwide (Millennium Ecosystem Assessment 2005b, 3). Damage to watershed ecosystems limits peoples’ access to food and water and exacerbates problems of poverty, disease, and climate change. During the 1990s and 2000s, transnational networks of IGOs, state development agencies, NGOs and experts promoted local IWM programs around the world as the best strategy for tackling this problem.