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Lower Colorado River Basin Ecosystem Assessment Case Study. Mark Lellouch, Karen Hyun, Sylvia Tognetti Sonoran Institute Published by Island Press. Sonoran Institute decisiones comunitarias que respetan la Naturaleza y su Gente. Programa del Noroeste de México
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Lower Colorado River Basin Ecosystem AssessmentCase Study Mark Lellouch, Karen Hyun, Sylvia Tognetti Sonoran Institute Published by Island Press
Sonoran Institutedecisiones comunitarias que respetan la Naturaleza y su Gente Programa del Noroeste de México Dr. Joaquin Murrieta Saldivar Director
The Sonoran Institute promotes community decisions that respect the land and people of western North America
Human Well-being Indirect Drivers Ecosystem Services Direct Drivers MillenniumAssessment Framework • Indirect Drivers of Change • Demographic • Economic (globalization, trade, market and policy framework) • Sociopolitical (governance and institutional framework) • Science and Technology • Cultural and Religious • Human Well-being and • Poverty Reduction • Basic material for a good life • Health • Good Social Relations • Security • Freedom of choice and action • Inland Water-Ecosystem Services • Provisioning: Food Production, biodiversity • Regulating: Climate regulation, hydrological flows • Cultural: Spiritual, Recreational • Supporting: Soil formation, nutrient cycling • Direct Drivers of Change • Changes in land use • Species introduction or removal • Technology adaptation and use • External inputs (e.g., irrigation) • Resource consumption • Climate change • Natural physical and biological drivers (e.g., volcanoes)
MA Inland Water Ecosystem Services • Supporting • Soil formation: sediment retention and accumulation of organic matter • Nutrient cycling: storage, recycling, processing, and acquisition of nutrients • Pollination: support for pollinators
The Law of the River • Prior appropriation • Present Perfected Rights • 1922 - The Colorado River Compact • Upper and Lower Basin allocations of 7.5 maf each • 1928 - The Boulder Canyon Act • Hoover Dam and the All-American Canal • 1944 - Treaty with Mexico • 1.5 maf to Mexico
Historical Flows of the Colorado River Below All Major Dams and Diversions, 1905-2000
The “Unregulated” System • The Delta is currently economically justifiable. • The Delta is not “dead.” • Conservation Priorities - A Map of the Possible • La Ciénega - MODE Canal • Limitrophe and the Riparian Corridor • Andrade Mesa - All-American Canal • Río Hardy - Drainage Water in Mexico
Campo Mosqueda • 8 hectáreas de Mesquite • 1,000 árboles plantados con irrigación • La Familia Mosqueda se espera que plante entre 5-10 Has de mesquite en los próximos años
Campo Ramona 1.5 has de mesquite
Population growth in the Colorado River Basin • Only 6 million people in the Basin, but CR supplies water to 30 million • 8 of the 10 fastest growing cities are in AZ, NV and CA • Top three are in Phoenix and Las Vegas areas • An average of 175 new homes went up in the Phoenix area every day in 2005 • Enough water in AZ for at least another 60 years of growth • Issue is not lack of water but environmental and social costs of unrestricted growth
Why look at policy options in the Colorado River Basin? • Highly engineered system, physically controlled by an incredible system of dams and canals • Highly regulated system, institutionally controlled by a system of rigid protocols, rules, laws and an international treaty • Decision makers can improve management of the Colorado River by looking at trade-offs among policies
MA Findings Applied to the Lower Colorado Basin • 1. Ecosystem changes in last 50-75 years • Construction of 2 major reservoirs • Flows from Glen Canyon dam now determined by needs of water and power customers downstream rather than natural processes • Tremendous growth of cultivated and urban areas in the Lower Basin • Salt cedar becomes the dominant species along the lower mainstem • River no longer regularly flows into the Sea of Cortez • 2. Gains and losses from ecosystem change • Degradation of ecosystem services • Negative impacts on beaches and native fish and plant species in Grand Canyon • Delta reduced from 1.9 million to 150,000 acres • Salinization of soils in the Mexicali Valley • Exacerbation of poverty for certain groups • Cucapa way of life and culture threatened with extinction • 3. Ecosystem prospects for next 50 years • Depends to a large degree on growth and policy choices • Climate change may drastically reduce flows and raise sea level • Impacts on ecosystems and accompanying services can be mitigated • 4. Reversing ecosystem degradation • Restoration of riparian ecosystem in Grand Canyon and of key elements of Delta ecosystems is possible at a relatively low cost
4 Scenarios to 2050 Dry Future • 39% decrease in flows due to climate change • Limited interstate water market • Continued unrestricted urban growth • No water for ecosystems beyond existing commitments
The Market Rules • Interstate storage and delivery of conserved water (Basin States alternative) • Extension of ICS concept to Mexico • Missed opportunity to use market mechanisms to dedicate instream flows to the Delta
Powell’s Prophecy • Extension of ICS to Mexico + dedicated environmental flows • Vision for the arid West • Protection of rural landscapes • Managed urban growth • Base and pulse flows for the Delta
A Delta and Estuary Once More • Bi-national ecosystem-based management • Restoration of the Delta and estuary • Water conservation in both cities and agriculture
Muchas Gracias Joaquin Murrieta Tel. 520.290-0828 joaquin@sonoran.org www.sonoran.org