CFE agenda 091117 - Laserfiche WebLink

Browse Search

Matching photographs taken 18 months apart during the most serious period of recent drought show a significant decrease in Lake Powell. Water II'' �esouir °ceem The Colorado River system supplies water to over 30 million people in the Southwest including Los Angeles, Phoenix, Las Vegas, and Denver. Reservoirs in the system, including the giant lakes Mead and Powell, were nearly full in 1999, with almost four times the annual flow of the river stored. By 2007, the system had lost approximately half of that storage after enduring -' the worst drought in 100 years of record f keeping.29 Runoff was reduced due to low winter precipitation, and warm, dry, and windy spring seasons that substantially reduced snowpack. Numerous studies over the last 30 years have indicated that the river is likely to experience reductions in runoff due to climate change. In addition, diversions from the river to meet the needs of cities and agriculture are approaching its average flow. Under current conditions, even without climate change, large year -to -year fluctuations in reservoir storage are possible. 112 If reductions in flow projected to accompany global climate change occur, water managers will be challenged to satisfy all existing demands, let alone the increasing demands of a rapidly growing population.16'.'9s Efforts are underway to address these challenges. In 2005, the Department of Interior's Bureau of Reclamation began a process to formalize operating rules for lakes Mead and Powell during times of low flows and to apportion limited water among the states.' 96 Change in Water Volume of Lakes Mead and Powell 1935 1940 1145 1 10 119135! 1,9W 190 1970 1976 IM) 1985 1990 °I!' 5 2(K 2t)(M wOoRyN L)SI... rR171 The filling of Lake Mead (green) was initiated in 1935, and that of Lake Powell (blue) in 1963. In 1999, the lakes were nearly full, but by 2007, the lakes had lost nearly half of their storage water after the worst drought in 100 years. 51