The Colorado River Basin and the need for Forecasting Improvement - PowerPoint PPT Presentation

The Colorado River Basin and the need for Forecasting Improvement Colby N. Pellegrino, Director - Water Resources Southern Nevada Water Authority

COLORADO RIV IVER Col olorado Riv River provid ides water to o 7 7 western states s an and th the cou ountry of of Mexico • Water to o 40 40 milli illion people le • 5.5 5.5 milli illion acr acres of of ag agricultural l lan land • 22 22 federally ly recognized trib tribes

Colorado River Overview Nevada receives 30 300, 0,000 acr acre-feet of of Col olorado Riv River water an annuall lly, ac accessed th through facili ilitie ies at t La Lake Mead. Colorado: 3.9 Col 3.9 mill llion Nevada: 300 300,000 Wyomin ing: 1 1 mill illion Ari rizona: 2.85 2.85 mill illio ion New Mexic ico: 850, 850,000 Ut Utah: 1.7 1.7 mill illio ion Calif California: 4.4 4.4 mill illion In n add addit itio ion, the the cou ountry of of Me Mexic ico o rece eceiv ives 1.5 mi milli lion on acr acre-feet of of Co Color orado o Ri River ann annuall lly.

COLORADO RIV IVER DROUGHT For the past 17 years, the Colorado River has been experiencing severe drought conditions, affecting Lake Mead’s water levels. 2000 vs. 2016 levels NASA Earth Observatory images by Joshua Stevens

COLORADO RIVER DROUGHT For the past 18 years, the Colorado River has been experiencing severe drought conditions, affecting Lake Mead’s water levels . Drought impacts: - Availability of supplies - Resource allocations - Water quality in the lake - Infrastructure operations 2000 Today 5

Drought Response The Basin States developed a framework to manage shortages, utilizing Lake Mead water elevations as triggers. Nevada/Arizona’s share of Colorado River shortages Nevada: 13,000 af af / Arizona: 320,000 af af 1,075 ft. Nevada: 17,000 af af / Arizona: 400,000 af af 1,050 ft. Nevada: 20,000 af af / Arizona: 480,000 af af 1,025 ft. Initiate reconsultation for shortage below 1,025 ft. Lake Mead

PROTECTING LAKE MEAD Proposed voluntary reductions would be tied to Lake Mead’s elevations 2007 Interim im Gu Guideli lines Co Combin ined Red eductio ions (k (kaf) ) Sh Shor ortages (k (kaf) Volu oluntary Red eductio ions (k (kaf) (20 (2007 Interim im Gu Guideli lines Sh Shor ortages + + Volu oluntary Redu eductio ions) Lake Mea La ead Elevatio El ion (ft ft) ) AZ NV AZ NV CA AZ NV CA TOTAL 1,090 0 0 192 8 0 192 8 0 200 1,085 0 0 192 8 0 192 8 0 200 1,080 0 0 192 8 0 192 8 0 200 1,075 320 13 192 8 0 512 21 0 533 1,070 320 13 192 8 0 512 21 0 533 1,065 320 13 192 8 0 512 21 0 533 1,060 320 13 192 8 0 512 21 0 533 1,055 320 13 192 8 0 512 21 0 533 1,050 400 17 192 8 0 592 25 0 617 1,045 400 17 240 10 200 640 27 200 867 1,040 400 17 240 10 250 640 27 250 917 1,035 400 17 240 10 300 640 27 300 967 1,030 400 17 240 10 350 640 27 350 1,017 < 1,025 480 20 240 10 350 720 30 350 1,100