11 September 2015 | Volume 1 | Issue 23
WHOSE WATER IS IT ANYWAY?
As the intense drought in California continues, great
strides in water conservation have been made, with the
402 reporting urban suppliers in California saving nearly
75 billion gallons of water in July 2015 compared to the
consumption in July 2013.1
CALIFORNIA WATER SUPPLY SYSTEM2
While that is an impressive accomplishment, there are
significant challenges ahead. There is simply not enough
water to meet all current demands needed by the water
suppliers. As as result, water suppliers are sifting and
shifting through their portfolio of water sources.
California has a complex water delivery system including
river, lakes, canal, desalination, groundwater and
recycled water systems. As supplies from one source
dwindle, water suppliers are shifting demand to other
sources.
The condition is particularly dire in southern California,
which relies on imported water for a significant portion
of the water needed to sustain the region’s communities. For example, the Metropolitan Water District
of Southern California (MWD)—the largest wholesale water agency in the United States, providing water
to 19 million people through 26 member public agencies3—delivers an average of 5,200 acre-feet (1.7
billion gallons) of water each day
to its customers. Historically,
MWD COLORADO RIVER DELIVERIES (2013-2015)
approximately 50% is supplied
from the Colorado River, 20%
from local supplies and 30%
from the State Water Project—
the agency responsible for
transferring water from northern
California to the south.
For 2015, MWD originally
requested 1,911,500 acre-feet
of supply from the State Water
Project. In March however, as a
result of the drought conditions
affecting the entire state, MWD
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(along with all other State Water Project customers) was allocated only 20% of their original request. For
MWD, the result was a total allocation of 382,300 acre-feet for 2015.4
With that reduction, MWD began to rely on other sources of water, including local sources (such as
recycled water, desalination, and groundwater) and its allocation of Colorado River water. Data compiled
from the United States Bureau of Reclamation shows that Colorado River water deliveries to MWD have
actually increased by 120,735 acre-feet to date in 2015 over that delivered in 2013.5 The Colorado River
is an already over-subscribed ecosystem and the ramifications to its overuse extend far beyond the
boundaries of California.
UP THE RIVER
Maximizing the use of Colorado River water certainly offers additional water security to the District’s
members. But as other entities rely on the river’s water as well, the additional demand on the Colorado
River could prove to have immediate consequences for Arizona and Nevada—particularly in these very
dry years.
Through the 1922 Colorado River Compact, and later the 1944 Mexican Water Treaty, the seven basin
states and Mexico apportioned 16.5 million acre-feet of the Colorado River’s flow amongst themselves. In
the years leading up to the 1922 Compact, the average flow in the river was roughly 18 million acre-feet.6
Contrasting that relative abundance—over the period of 1996-2012 (the latest year for which official
data has been released), the flow in the river averaged 13.5 million acre-feet. This decrease in volume,
coupled with population growth, increased agricultural irrigation activity and an overall drying of the
basin environment, has made the competition for water fierce.
In the late 1960s, Arizona lobbied for and acquired funds to build the Central Arizona Project (CAP)
canal system in an effort to drive the development of agriculture in Arizona and—in the face of the real
likelihood of growth exceeding water supply—allow the metropolitan areas of Arizona access to the
state’s Colorado River water. To broker that deal, Arizona ceded their water right seniority to California7,
meaning any reductions in allocation as a result of declines in water availability from the Colorado River
would impact Arizona first.
Nevada, which also has a junior
LAKE MEAD WATER STORAGE
water right to the Colorado River,
faces similar consequences in dry
times.
This junior status is
inconsequential in wet years.
However, in 2007, with continuing
drought, the seven basin states
adopted an operating philosophy
that would trigger curtailments
of water deliveries based on
shortage conditions. These
shortage conditions, which exist
when the Secretary of the Bureau
of Reclamation determines that
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insufficient mainstream
water is available to satisfy 2015 COLORADO RIVER DELIVERIES AS A PERCENTAGE OF 2013 DELIVERIES
7.5 million acre-feet of
annual consumptive use in
the Lower Division states,
Arizona, Nevada and
California, are based on the
projected elevation of Lake
Mead on the first of January
of each year.8
Of note is that in all of
the shortage conditions,
California continues to
receive 4.4 million acrefeet of Colorado River
water. On the other hand,
Nevada and Arizona each
receive reduced deliveries (Nevada’s portion is reduced by at least 7,000 acre-feet; Arizona’s allocation is
reduced by at least 160,000 acre-feet). The first tier of these shortage conditions and subsequently the
first tier of reduced water deliveries begin at an elevation of 1075 feet—an elevation that we are already
dangerously close to.
What makes this more interesting is that California is increasing its withdrawals from the Colorado
River—even though it will be Arizona and Nevada that suffer when the elevation of Lake Mead hits the
trigger point. In the case of Arizona, whose water use is dramatically below that of 2013, having your
neighbor use more of the available water and drive you into a shortage condition must be a bitter pill to
swallow.
ARE WE THERE YET?
The question then is how close are we, really,
to a shortage condition? While in 2015, the
elevation at Lake Mead crossed the technical
threshold of the first shortage tier, the plan
of operations actually uses the projection of
the elevation on the first of January based on
the BOR’s projections from its Colorado River
Simulation System (CRSS). These projections
are updated at least twice annually (January
and August) based on prevailing conditions
at the time.
In August 2015, the BOR released its most
recent projections and currently there is no
probability of a shortage condition occurring
in 2016. Beginning in 2017, however, the
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©2015 FATHOM Water Management, Inc. Intellectual Property. All Rights Reserved.
probability of a shortage condition increases and continues to increase to as much as 65% in 2019.9
So what does all this mean? For water utilities in California, the continued drought will mean that there
will be continued pressure to reduce demand—particularly in the agricultural, commercial and industrial
environments. While California is immune to reductions in Colorado River water availability until Lake
Mead reaches the 1000 ft elevation mark, it’s clear from BOR’s projections that there is significant
uncertainty in all water resources, and reliance on supply is a risky endeavor.
For Arizona and Nevada, the expectation must be to brace for a reduced availability of surface water.
While much has been done in these states to reduce demand, the pressures of returning growth in the
housing market, the certainty of a shortage condition and continuing volatility in the natural water supply
systems mean that a full-force adoption of demand-side management is critical.
BECOMING PART OF THE SOLUTION
Meeting the reality of today’s water situation requires a change in the way we do business. Demandside management tools like the FATHOM MDM and FATHOM U2You platforms allow for the continued
education of customers and provides the tools for industrial and commercial users to begin to perform
high level inter-company and intra-jurisdictional evaluations of water use. Encouraging all users to
become more adept at understanding their water use will provide the basis for sustainability in the
Southwest.
REFERENCES
http://www.waterboards.ca.gov/waterrights/water_issues/programs/drought/docs/fs082715_july_btn.pdf
1
http://www.lao.ca.gov/reports/2015/budget/water-bond/water-bond-021115.aspx
2
http://www.mwdh2o.com/WhoWeAre/Mission/Pages/default.aspx
3
http://www.water.ca.gov/swpao/docs/notices/15-03.pdf
4
http://www.usbr.gov/lc/region/g4000/levels_archive.html
5
Average measured flow at Lees Ferry, 1906-1922.
6
http://www.azwater.gov/AzDWR/IT/documents/Layperson’s_Guide_to_Arizona_Water.pdf
7
Record of Decision, Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake
8
Powell and Lake Mead, December 2007.
http://www.usbr.gov/lc/region/g4000/crss-5year.pdf
9
For more information, please visit www.gwfathom.com or call 1.855.FATHOM1 (1.855.328.4661).
©2015 FATHOM Water Management, Inc. Intellectual Property. All Rights Reserved.