State of the World 2004 Boosting Water Productivity Sandra Postel and Amy Vickers
Boosting Water Productivity Overview: 1. A New Mindset for Managing Water 2. Water-Rich, Water-Poor 3. Water, Crops, and Diets 4. Cities and Homes 5. Industrial Water Use and Material Goods Consumption 6. Policy Priorities
Freshwater Ecosystems Rivers, lakes, wetlands, and underground aquifers They store, move, and cleanse water as it cycles between sea, air, and land Healthy ecosystems need - Minimum quality and quantity of water - Natural flow pattern
World Water Use Agriculture (70%) Industry (22%) Towns and Municipalities (8%) Source: World Bank, World Development Indicators, 2001
Human Influences on Freshwater Ecosystems Water tables are falling from overpumping of groundwater Many streams and rivers run dry for portions of the year Large inland lakes are shrinking Worlds freshwater wetlands have diminished in area by half
Current Water Use Patterns Are Unsustainable Impacts accelerate with increases in population and consumption Large-scale water development projects (i.e., dams, reservoirs, diversion projects) have social and ecological costs: - Ecosystems destroyed - Fisheries decimated - Aquatic species imperiled - People displaced from their homes
1. A New Mindset for Managing Water Freshwater is a life support system for ecosystems Must allocate sufficient water throughout the year to protect valuable ecosystem functions Can use remaining water to satisfy human demands efficiently, equitably, and productively
Water Productivity of Selected Countries Source: FAO, USGS, OECD India China Russian Federation United States Brazil Australia Germany Egypt GDP per cubic meter of water use (2000 dollars) Water Productivity: Value of economic goods and services per cubic meter of water extracted from the natural environment
2. Water-Rich, Water-Poor Water-poor areas have higher demands because crop production requires more irrigation in drier climates Uneven distribution of water on a global scale - 6 countries (Brazil, Russia, Canada, Indonesia, China, and Colombia) account for half of Earths freshwater supply
Estimated Annual Water Withdrawals Per Capita, Selected Countries (2000) Cubic Meters Per Person Per Year Ethiopia Brazil Russian Federation India Egypt United States Source: FAO, USGS
Affluence and Poverty Influence of power, politics, and money can override natural abundance or scarcity of water Phoenix, Arizona: Desert climate, but imports water from Colorado River Ethiopia: 84% of the Niles flow originates within its territory, but faces famine due to drought
1 out of 5 people in developing world (1.1 billion people) face risk of disease and death due to lack of access to safe drinking water Populations Lacking Access to Safe Drinking Water and Sanitation (2000) Africa 36%40% Latin America & Caribbean 13%22% Asia 19%53% No Safe Drinking Water No Adequate Sanitation Region Source: World Health Organization
Meeting Basic Needs Urgent task: to provide all people with minimum amount of clean water needed for good health and sanitation More than enough water to accommodate everyones basic needs but political will and financial commitment lacking When private corporations manage water systems, cost-recovery can take priority over meeting basic needs
3. Water, Crops, and Diets Must raise productivity of agricultural water use to meet growing food needs as water stress deepens and spreads Three Challenges: Delivering and applying water to crops more efficiently Increasing yields per liter of water consumed Shifting diets to satisfy nutritional needs with less water
Water, Crops, and Diets Surface water irrigation efficiency is typically poor (can be as low as 25-40%) Losses due to leaks, seepage, evaporation
Improving Irrigation Efficiency Micro-irrigation methods - drip and micro-sprinklers reduce volume of water applied to fields by 30-70% and increase crop yields by 20-90% - using high-yielding and early- maturing crop varieties - deficit irrigation: only watering plants during critical growth stages Changes in cropping patterns and growing methods
Improving Irrigation Efficiency Affordable technologies for small plots - ex.: treadle pumps: human powered devices that give access to shallow groundwater - using ponds, check dams, and other structures to irrigate crops during dry season, recharge groundwater Collecting and storing rainfall
Dietary Choices Liters of Water potatoesbeanswheatricepoultrybeef Water consumed to supply 10g of protein Water consumed to supply 500 calories rice beef Based on California crop yields and water productivity. Source: Renault and Wallender (2000)
Dietary Choices Average U.S. diet, high in meat content, requires twice as much water as an equally nutritious vegetarian diet Cutting consumption of animal products in half would reduce: - nations dietary requirements of water by 37% - incidence of heart disease - cruelty to animals - pollution of streams from industrial animal feedlots
4. Cities and Homes Waste is a major urban water management problem In many cities, water losses are 15% - 40%, some higher Unaccounted-for Water (UFW): volume of water withdrawn from nature but that never reaches an end-user, due to - Leaky pipes and mains - Theft - Meter inaccuracies
Problems with Urban Water Losses Surrounding regions experience water stress: withdrawals outstripping available supplies When surplus water is extracted This lost water, if recovered, could help cities facing scarcity meet their water needs More energy required to pump, treat, and distribute excess water - Rivers run dry - Habitats wither - Wildlife disappears
Household Water Use, Selected Cities and Countries Liters Per Capita Per Day Source: Thompson et al. (2001), National Water Demand Management Centre, Environment Agency, U.K. (2003), Gombos (2003), Water Services Association of Australia (2001), Mayer et al. (1999)
Household Water Use Tips to reduce indoor household water consumption by almost 50%: Choose water-efficient appliances (clothes washers, dishwashers) Install water-efficient fixtures (toilets, showerheads, faucets)
Household Water Use Large domestic water demand for irrigation of lawns, landscapes, and golf courses - 30 billion liters of water a day in the U.S. 45 million kg of fertilizers and chemicals used per year Excess fertilizers and chemicals run off into streams, seep into groundwater - contaminating drinking water - polluting lakes and ponds
Household Water Use To reduce outdoor water consumption… Use more efficient sprinklers and irrigation systems Choose natural landscaping and native plants - drought-adaptive grasses, groundcovers, wildflowers and plants that thrive naturally in local climate
5. Industrial Water Use and Material Goods Consumption Major water-using industries: Thermal electric power Iron and steel Pulp and paper Chemicals Petroleum Machinery manufacture Water is used for cooling, washing, processing, heating In developing countries, pollutant loads rising along with industrial water demand
Industrial Water Use and Material Goods Consumption Incentives for increasing efficiency of water use in industrial facilities: Cost savings Need to comply with permit requirements Advances in technologies that allow process water to be reused and recycled Availability of low-cost reclaimed nonpotable water
How Individuals Can Reduce Their Impacts on Freshwater 1.Purchase fewer material goods 2.Eat a nutritious, less meat- intensive diet 3.Select native plants and grasses for landscapes, rely on natural rainfall
How Individuals Can Reduce Their Impacts on Freshwater 4.Install water-efficient appliances and fixtures 5.Support local land use ordinances that protect wetlands, aquifers, and watersheds 6.Serve on local water management boards to monitor and enforce water protection strategies
6. Policy Priorities: Government Action 1.Protect public trust in water 2.Institute or strengthen groundwater regulations to promote sustainable use 3.Implement tiered water pricing to encourage conservation: unit price of water increases along with consumption
Policy Priorities: Government Action 4.Restrict water use during seasonal lows 5.Encourage water trading between willing sellers and buyers to reallocate available supply
About the Authors Boosting Water Productivity by Sandra Postel and Amy Vickers Sandra Postel is co-author of Rivers for Life: Managing Water for People and Nature (Island Press, 2003), and director of the Global Water Policy Project in Amherst, MA. More at Amy Vickers, author of the award-winning Handbook of Water Use and Conservation: Homes, Businesses, Landscapes, Industries, Farms (WaterPlow Press) is an engineer and water conservation specialist based in Amherst, MA. More at
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