Worldwatch Paper #170: Liquid Assets: The Critical Need to Safeguard Freshwater Ecosystems
July 2005
Sandra Postel
ISBN: 1-878071-76-9
78 pages
By taking advantage of the work that healthy watersheds and freshwater ecosystems perform naturally, cities and rural areas can purify drinking water, alleviate hunger, mitigate flood damages, and meet other societal goals at a fraction of the cost of conventional technological alternatives.
But because commercial markets rarely put a price on these "ecosystem services," and because governments around the world are failing to protect them, they are being lost at a rapid rate. Global warming is the wild card that could further exacerbate the impacts of human activities on the natural systems that safeguard our water supply—impacts that include falling water tables, shrinking wetlands, vanishing species, and a decrease in both the quality and quantity of available freshwater.
Contents
Summary
Introduction
Assessing the Damage—and How We Got Where We Are
Healthy Watersheds for Safe Drinking Water
Food Security With Ecosystem Security
Reducing Risks, Preserving Resilience
Bringing Water Policies Into the 21st Century
Endnotes
Index
Figure 1: The Global Hydrological Cycle
Figure 2: River Flow Into the Aral Sea, 1926–2003
Figure 3: Flow of the Colorado River Below All Major Dams and Diversions, 1904–2004
Figure 4: Missouri River Flows Before and After Regulation by Dams
Figure 5: Nitrogen Fertilizer Consumption, Selected Regions and the World, 1960–2003
Figure 6: Water Use in the Metropolitan Boston Area, 1960–2004
Figure 7: Water Consumed to Supply Protein and Calories
Table 1: Selected U.S. Cities That Have Avoided Construction of Filtration Plants Through Watershed Protection
Table 2: Caps on the Modification of Freshwater Ecosystems, Selected Examples
Sidebar 1: Life-Support Services Provided by Rivers, Wetlands, Floodplains, and Other Freshwater Ecosystems
Sidebar 2: Human Impacts on Freshwater Ecosystems and Their Services
Sidebar 3: Protecting Drinking Water Supplies and Biodiversity: The Watershed Trust Fund of Quito, Ecuador
Sidebar 4: Conserving Water to Avoid New Dam or Diversion Projects: The Success of Metropolitan Boston
Sidebar 5: Valuing Water for Food, Livelihood, and Ecosystem Security: the Hadejia and Jama’are Floodplains of Northeaster
Sidebar 6: Twelve Priorities for Updating Water Policies
