More Than a Decade of Drought on Colorado River Sculpts Impending Southwest Water Shortage
More Than a Decade of Drought on Colorado River Sculpts
Impending Southwest Water Shortage
The Colorado River serves as one of the most vital water sources in the United States, providing
water to nearly 40 million people in the West.
Numerous resources are dependent on the river, which has been under drought conditions since
2000. According to the U.S. Department of the Bureau of Reclamation, several resources that
depend on a healthy river system include hydroelectric power generation, fish and wildlife, as well
as water for municipal, industrial and agricultural use.
As drought conditions grip the western part of the country, states are reinforcing preparations
they've made years ago in the possibility of a water shortage.
Officials are taking steps to monitor current water levels and analyze future scenarios for potential
shortages. As part of its 24-month study, the Bureau of Reclamation issues a study every month
based on computer modeling of lake elevations, trying to give water managers solid data to plan for
future water reserves.
The river is divided into two districts-the upper basin and the lower basin-with Arizona, Nevada and
California making up the lower basin, while Colorado, New Mexico, Wyoming and Utah encompass
the upper basin. Take note of some basic refinements which can be added to a commercial
centrifugal or positive displacement pump. Regarding pumps that have overhung impellers, moving
to a solid shaft is a straightforward adjustment over the basic sleeved shafts. Mechanical seals can
be enhanced with the addition of silicon carbide faces, and elastomers ought to be replaced with
Viton. Finally, magnetic bearing protectors are certainly a huge step upin relationship to the lip
seals which most industrial pumps rely on to keep bearing sump oil clean.
Mexico is also allocated 1.5 million acre-feet from the river.
As part of the Colorado River Compact instituted in 1922, the two basins were each allotted 7.5
million acre-feet per year. One acre-foot is equivalent to 325,851 gallons of water according to the
Southern Nevada Water Authority (SNWA).
Lake Mead, the largest reservoir in the U.S. and supplier of nearly 90 percent of southern Nevada's
water supply, is dwindling to near-record low levels. It also holds water for California, Arizona and
Mexico. As of the end of June, the lake sat at an elevation of 1,082 feet above sea level.
"The levels of Lake Mead are solely dependent on runoff from the Colorado River," said SNWA
Spokesman Bronson Mack.
The first intake sits at elevation 1,050 feet above sea level and the second intake resides at elevation
1,000 feet. Currently the SNWA is building a third intake, which is expected to be completed in
2015, that will sit at an elevation of 860 feet to keep supplying the region with Colorado River water.
Another reservoir along the river is Lake Powell, which straddles the Utah-Arizona border.
Lake Powell, which acts as a savings account for the upper basin similarly to Lake Mead in the lower
basin, is operated in tandem with Lake Mead, with the average release of water from Powell to Mead
typically around 8.23 million acre-feet per year.
"That allows Lake Powell to, in pump alarm good, wet years, release more water to Mead and in dry
years, it also allows them to release less water to Mead," Mack said.
In the past 14 years, there have been only three years where the river flows have either been normal
or slightly above normal. The last above-average year was 2011, when inflows in Lake Powell were
130 percent of average, Mack said.
Currently, the state of Arizona is not under any water shortages and still receives its full 2.85 million
acre-feet allotment. However, by 2017, officials said there is a greater-than-50-percent probability of
a shortage, according to the aforementioned computer models.
The shortage time-frame was delayed by one year after predictions for this coming water year
(starting Oct. 1) indicated that the flow from Lake Powell to Lake Mead will be 9 million acre-feet,
due to a strong snowpack in the watershed, said Tom Buschatzke, the assistant director of the Water
Planning Division for the Arizona Department of Water Resources.
In Arizona, there are priorities in place for Colorado River users. The senior users are those in the
Yuma region, an essential agricultural area in the state. The more junior users get their water
provided to them by the Central Arizona Project (CAP), a 336-mile-long system of aqueducts, tunnels
pumping plants and pipelines.
The CAP receives about 23 percent of the states Colorado River allotment and diverts its water from
Lake Havasu, which unlike Lake Mead, doesn't see its levels fluctuate.
Buschatzke said there are water reserves throughout the state of Arizona in case a shortage takes
Established in 1996, the Arizona Water Banking Authority is a state agency that stores about 3.2
million acre-feet of excess Colorado River water in aquifers underground to be used in times of
shortage. There are also individual providers that can store water and receive long-term credits.
About. The majority of installed pumps were not initially sourced for their current function. Often, a
line in a plant is moved and the pump that once providedcooling fluid to an injection molding
machine is now asked to transfer oil from a rail car to a tank. All too often, this causes many
problems for the pump and the factory. Pumps operate where the pump curve crosses the system
curve. When you move a pump from one system to another, this means that the system curve is
different. This new system may cause the pump to operate away from its best efficiency point,
leading to shaft breakage and other component failures that are simply symptoms of a mis-matched
pump and system.5 million acre-feet of water is stored by those providers.
Storing water has allowed water officials plenty of time to prepare for a shortage situation.
Pamela Pickard, president of the CAP board, recently wrote that "CAP is likely to experience
shortage by 2017, but that shortage will primarily affect central Arizona agriculture which is already
preparing for planned reductions in their CAP supplies."
Pickard also wrote that the CAP shortages are not expected to impact Arizona cities for 10 to 15
years, due to the fact that cities have the highest priority within the CAP system.
In the short term, over the next five to 15 years or so, upper basin states are in a better position for
water supply than the lower basin due to the Law of the River, Buschatzke said.
The greater concern for those states would be the loss of power production from Lake Powell and
the Glen Canyon Dam, which forms the reservoir, since they rely more heavily on hydroelectricity
than the lower basin states, Buschatzke said.
According to a recent article from Circle of Blue, the upper basin states want to keep the surface
level of Lake Powell above 3,490 feet because below that point hydropower generation from Glen
Canyon Dam would stop.
The revenues that come from the hydropower have surcharges that can create funding for programs
such as the Endangered Species Act that help the upper basin continue to use its water, Buschatzke
Mack added that the effects of the drought on the river have been more visible in the lower basin, in
particular because of the dwindling of levels at Lake Mead.
Because the river is such a vital resource, many regulatory guidelines, federal laws, court decisions,
decrees and compacts are in place. Collectively they are known as the "Law of the River."
If a shortage were to take effect, some states could be in better shape than others.
For instance, the Colorado River Basin Project Act of 1968, which authorized the development of the
CAP, among other projects in the upper basin, states that water supply for the CAP would be
subordinate to California's apportionment.
California's reliance on the river (4.4 million acre-feet) is primarily for irrigation of several huge
agricultural areas such as the Coachella and Imperial Valleys, that are extremely important to the
food supply to the entire United States, especially during the winter months.
In the event of a shortage, Nevada and Arizona would have to curtail their usage while California
Mack said this is because the Colorado River was initially divided up based on how much agriculture
or potential agriculture each state supplied.
While short-term priorities are taking effect, the long-term picture is less clear.
In 2012, the Bureau of Reclamation, along with agencies representing the seven basin states,
completed the Colorado River Basin Study.
According to the study, "the amount of water available and changes in the demand for water
throughout the Basin over the next 50 years are highly uncertain and dependent upon a number of
factors. The potential impacts of future climate variability and climate change further contribute to