The Colorado River Compact

Transcription

1 The Colorado River Compact 1922

2 Colorado River Watershed 1450 miles long Covers 246,000 mi 2 over parts of 7 U.S. states and Mexico Supplies water to 30 million people.

3 The Colorado River Begins High Up in the Colorado Rocky Mountains

4 Headwaters of the Colorado River in Rocky Mountain NP

5 Colorado River at Canyonlands NP, Utah

6 Colorado River Compact The Colorado River is a small river with a big impact. It currently supplies water to over 30 million people. It provides water to most of the agricultural fields used for winter crops in North America.

7 Water Storage and Electricity Its dams supplies electricity for 3-6 million The reservoirs store years worth of water

8 Colorado River Compact In 1922, the 7 states of the watershed got together to divvy up the water of the Colorado River. They agreed to a split of 15 million acre-feet per year based on recorded flows of the river (which happened to be based on good rain/snow years). Unfortunately today, that is more water allocated than typically flows in the river.

9 Upper Basin, 7.5 million acre ft/year Colorado 51.75% 3.86 m acre ft/year Utah 23.00% 1.71 m acre ft/year Wyoming 14.00% 1.04 m acre ft/year New Mexico 11.25% 0.84 m acre ft/year

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11 Irrigation in the Upper Basin

12 Lower Basin, 7.5 million acre ft/year California 58.70% 4.40 m acre ft/year Arizona 37.30% 2.80 m acre ft/year Nevada 4.00% 0.30 m acre ft/year

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14 What the Heck is An Acre-Foot? 325,853.4 gallons per year Is roughly the amount of water a typical U.S. household uses in a year. To visualize it is about one-football field covered in a foot of water.

15 The First Dam: Glen Canyon Completed in 1966 amid much public opposition. 710 feet high. Created Lake Powell.

16 Lake Powell Over 100 miles long

17 Glen Canyon Full of beautiful canyons and ancient artifacts. All now underwater.

18 Hoover Dam and Lake Mead 724 feet high Water diversions for Las Vegas happens here. Lake Mead is 112 miles long. Completed 1936 Can hold 28.5 million acre-feet of water.

19 There Were Proposals for Two More Dams on the Colorado River in the Grand Canyon These two would have been located between Hoover Dam and Glen Canyon Dam within Grand Canyon National Park.

20 Bridge Canyon Dam Would have been located on the edge of the Hualapai Indian Reservation and Grand Canyon NP

21 Bridge Canyon Dam Those buildings are old survey dwellings for the dam planning. Artist rendition of what it would have looked like

22 Proposed Marble Canyon Dam

23 Marble Canyon Dam Located between Page and Grand Canyon near Lee s Ferry Tailings from test cores to check the stability of the bed rock for a dam.

24 Echo Park Dam Site Dinosaur National Monument on Green River, CO First major dam controversy after Hetch Hetchy in the 1950 s that brought the Sierra Club back into the national spotlight. Group managed to stop dam from being built in another National Park.

25 David Brower Sierra Club First Executive Director of the Sierra Club He spent his life fighting the establishment of dams in Grand Canyon NP and Dinosaur NM. He also fought for the Wilderness Act of 1964 Helped with the establishment of Redwoods, North Cascades, Point Reyes, and other national parks.

26 Howard Zahniser Director of the Wilderness Society Author of Wilderness Act of 1964 Fought with David Brower to bring attention to plans to build the Echo Park Dam at Dinosaur National Monument. Their work changed public opinion that prevented the dam from being built.

27 Parker Dam Parker Dam creates Lake Havasu This is also where the CAP Canal leaves on its journey to Phoenix and Tucson.

28 What is the water used for? 85% of diverted water goes to agriculture. It is mostly used for water intensive crops like cotton and alfalfa (for cattle feed). Despite the enormous cost of the dams/canals and feed production, it only supports about 13% of the nations livestock supply. Despite growing rapidly, only 15% of the water goes to support Phoenix, Las Vegas, and Los Angeles.

29 Effects of Dams on the Colorado River Increased water temperature Reduced sand and silt in the water Erosion of sand bars and banks of riparian vegetation Interruption of fish and animal migration routes Loss of endangered species habitat and increased competition with non-native species Invasive species such as tamarisk, zebra mussels, bass and pikeminnows Increased evaporation and salt deposition Drowning of cultural sites

30 Endangered Fish Species in the River Humpback Chub Razorback sucker Boney tailed chub Gila trout

31 Replicating Flood Events Ecosystems of the Colorado River were based on flood events. With dams, there are no more seasonal floods. Twice, Glen Canyon Dam has released a large amount of water to try and replicate those floods and restore the sand bars. But, with increasing droughts lowering the reservoirs, that opportunity is becoming less available.

32 Central Arizona Project 361 mile canal delivering water to the Phoenix Basin and Tucson. It is the most expensive aqueduct ever built at $3.6B It carries virtually all of Arizona s allotment of water from the Colorado River.

33 Colorado River Canal The Colorado River Canal that feeds Los Angeles also leaves from Parker Dam.

34 Imperial Dam Just north of Yuma, it generates electricity and diverts water into the All-American Canal

35 All-American Canal It crosses the Algodones Dunes on its way to the Imperial Valley for irrigation.

36 Imperial Valley, CA Located below sea level, it grows the vast majority of America s winter crops.

37 Los Angeles Aqueduct and the Drying of Owens Lake In 1905, work began on the L.A. aqueduct to supply water from the Eastern Sierras to L.A. Water was diverted from the Owens River. With the Owens river unable to feed the endoheric Owens Lake, the lake dried up completely by 1913.

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39 Los Angeles Aquaduct 233 miles, mostly through unlined (and thus leaky) conduits to Los Angeles. Accounts for about 36% of L.A. s water needs.

40 The Now Dry Owens Lake When Owens Lake dried up alkaline toxic salt deposits and sediments would blow around in the wind, causing respiratory disease and cancer to nearby residents and contaminating farmers fields.

41 Lawsuits and Mitigation A series of lawsuits, culminating in a court ruling in 2008 requires the city of Los Angeles to return some water back to the lake. They are required to keep down toxic dust and restore a portion of the ecosystem.

42 Mitigation at Owens Lake They spray a fine layer on water onto the lake sediments to keep them wet, so they are less likely to blow around as toxic dust. Nonetheless, Owens Lake remains the #1 source of dust pollution in the U.S.

43 Owens Lake Not as before, but better than it was Some portions of the former lakebed have been restored to a functioning ecosystem.

44 The Salton Sea

45 Formation of the Salton Sea In 1904, the Colorado River flooded and overflowed its levees. It cut a new path across the desert into the Salton Sink, a low area below sea level. It flowed uncontrollably for 3 years.

46 The water drained through a formerly dry wash called New River

47 The Salton Sea is California s Largest Lake

48 Salton Sea Boom Times Not long afterwards, lake front communities, marinas, and fishing vessels popped up all around the Salton Sea

49 The Lake Levels Quickly Dropped Without the rivers to feed it, the lake level quickly began to drop and the water became much more salty. Many of those resort villages now found themselves a long ways from shore. Today, the Salton Sea is saltier than the ocean and not many fish can survive in it.

50 Salton Sea Fish Die Off When conditions get too salty and eutrophication occurs, there are massive fish die offs

51 New River Today, the New River is an agricultural and sewage run off stream into the Salton Sea

52 Salton Sea Today The New River s flow is composed of agricultural and chemical runoff from irrigation in the U.S. (18%) and Mexico (51%) and sewage from the City of Mexicali (29%)

53 Salton Sea Today By the time the New River crosses the U.S./Mexico border near Calexico, CA, the channel contains a stew of about 100 contaminants: Volatile organic compounds, heavy metals (including U, As, and Hg), and pesticides (including DDT) and PCBs. The waterway also holds the pathogens that cause tuberculosis, encephalitis, cholera, hepatitis, typhoid, and fecal coliform bacteria.

54 Back to the Colorado River

55 Laguna Diversion Dam For lower Yuma Valley agriculture

56 The Last of the Water Mexico diverts the last of the Colorado River s waters to the Mexicali Valley for agriculture.

57 The Colorado River no longer flows to the ocean!

58 The Colorado Delta The Colorado River once fed into the Sea of Cortez creating an enormous estuary and wetland that was home to thousands of shorebirds. It s brackish waters were nurseries for millions of fish that fed fishing villages all up and down the coast of the sea.

59 The Clams There were unique clams so abundant that they build huge mounds with their shells. Those clams are gone, the wetlands are gone, the birds are gone, and so are the fishermen.

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61 The Flow of the Colorado River Before After