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The Growing Battle Over Water


The Growing Battle Over Water

Even in regions where desalinization has the potential to add water and strict management practices are underway, water is such a vital commodity that water rights of communities, cities, and even states are often contested in court. Such legal battles sometimes stem from old agreements about the distribution of rivers and groundwater between municipalities that were drawn up before substantial growth occurred. With population growth requiring water for drinking, domestic use, agriculture, and industry, the value of water has increased substantially and old agreements are often extremely prohibitive to growth. Some of the most bitter water disputes occur in the western US, where, as we have seen, southern California relies heavily on water derived via aqueducts from the Colorado River to the east and the Owens Valley in the Sierra Nevada Mountains to the north.

California Aqueducts

Owens Valley

The City of Los Angeles has had brutal showdowns with farmers and environmentalists in the Owens Valley from where it derives about half of its water. The city built the first of two aqueducts from the valley between 1908 and 1913 and the second in 1970. These aqueducts substantially lowered water levels in Mono and Owens Lake and the Owens River and took a terrible toll on farming in the Owens Valley. The impact was so negative that farmers used dynamite to breach the aqueduct and temporarily return the flow to the Owens River. After the second aqueduct was built, a series of litigation began between municipalities in the Owens Valley and ultimately the Sierra Club. The net result has been rulings in favor of the Owens Valley, and some increases in water levels in bodies such as Mono Lake, but ultimately southern California continues to withdraw water at a faster rate than it is being replenished, so the conflict is by no means over.

The Colorado River Compact

To the east of Los Angeles, water rights for the Colorado River were defined by the Colorado River Compact of 1922, which divided states bordering the river into upper basin states (in the mountains) and lower basin states (in the plains). The compact also appropriated the annual amount of water each group of states could withdraw from the river with the upper basin states receiving the same amount as the lower basin states. The compact was modified when the Hoover Dam was constructed, at which time the lower basin states (Arizona, California, Nevada) were allocated annual withdrawal amounts. These amounts have led to fierce litigation between Arizona and California, which changed the appropriations in Arizona’s favor. For a long time, only California has completely utilized its quota each year and its surplus was guaranteed by the Secretary of the Interior until 2016. By that time, surging development in Arizona and southern Nevada will require diversion of their quotas from the Colorado and the surplus will no longer be available to California. At some stage, also, upper basin states Colorado and New Mexico may challenge the 1922 Compact to obtain increased quotas of water to fuel growth in these states. At the same time, environmental considerations were not a factor of the original compact. For example, the allocations were not based on estimates of the impact of long-term withdrawal on hydrology and ecosystems. These factors will also likely become significant issues in the future.

Forty million people from Wyoming to Mexico receive water from the Colorado River so the river is vital to communities small and large in the west. Since the compact was developed, the lower basin states have developed considerably and now use a lot more water than they did in 1922. Cities such as Phoenix and Las Vegas have experienced some of the most rapid growth in the country.

Two major reservoirs exist in the lower Colorado River basin, Lake Mead and Lake Powell, bounded by the Hoover Dam and the Glenn Canyon Dam, respectively. These reservoirs were designed for water management but both have been drying up recently. The situation is dire in both reservoirs as the images below show. Let’s start with Lake Powell. This reservoir provides water and electricity generated through turbines in the Glen Canyon Dam to millions of people. The level in Lake Powell is lower than it has ever been. As of May 2022 the level was at 3525 feet with the normal level being 3700 feet. If the level drops below 3490 feet, it is uncertain how much water can be delivered to the lower basin states from the reservoir. In addition, the dam would not be able to generate electricity, potentially cutting off power to millions.

Lake Mead’s issues may be even more pressing as the lake provides 90 percent of nearby Las Vegas’s water. The largest reservoir in the country has a level of 1049 feet in May 2022 which is 170 feet below the maximum capacity. The level is so low that sunken boats are resurfacing and an intake valve (for pumping to Las Vegas and other communities) has been exposed. Las Vegas is now taking water from the lower intake valves which were installed to retrieve water at lower lake levels. The lake is forecasted to drop another 12 feet by fall 2022. With the Lake Mead level so low, Las Vegas is planning for a future when such low water supply is the new normal. This situation where no water is flowing out of Lake Mead is known as “dead pool”. Fortunately a third intake valve and pumping station for Las Vegas’s water has been installed below the dead pool level so the city will still receive water, but the city is already imposing severe water restrictions including banning grass in yards and strictly limiting watering of grass on golf courses. The city also recycles a lot of its water. These and other measures have been successful in reducing the demand for water: over the last twenty years the population has grown by 49% but water use has shrunk by 26%. Regardless, the future looks bleak as the decades long drought in the area is forecasted to continue.

The situation is dire for both Lake Mead and Lake Powell, so the upper basin states have agreed to release more water to the lower basin states and this should help the immediate situation. But at some stage, upper basin states Colorado and New Mexico may challenge the 1922 Compact to obtain increased quotas of water to fuel growth in these states as well as provide the water farmers and ranchers desperately need. The compact was developed at a very wet time in the west and now the upper basin states can’t afford to give 50% of the water to the lower basin states.



Lake Mead water level then and now

Exposed boat ramp at Lake Powell 2021


Check Your Understanding

The following animation shows how Lake Powell has dried up since 1999.

Video: Earth 103: Water Level in Lake Powell (00:42) This video is not narrated.