Last Tuesday the Arizona Capitol Times sponsored an event entitled Water Shortage Causes and Solutions. Arizona Department of Water Resources Director Tom Buschatzke and Central Arizona Project Director Ted Cook laid out a grim assessment of our water outlook going forward. (301) Morning Scoop: Water shortage causes and solutions - YouTube
With Lake Powell at 24 percent capacity and Lake Mead at 30 percent capacity, Butchatzke estimated Central Arizona would find itself in a Tier 2a shortage by next January. This cut happens when Lake Mead’s elevation declines to 1050 feet. Currently the lake’s elevation sits at . . . wait for it . . . 1049 feet. Hmmm . . .
Sensing a trend here?
Chart from US Bureau of Reclamation
Unless it rises by next August when the US Bureau of Reclamation (BOR) makes its shortage determination for the following year Central Arizona will be in a Tier 2a shortage and possibly even a Tier 2b shortage. A Tier 2a shortage would cut another 80,000 acre-feet from Central Arizona’s Colorado River deliveries. A Tier 2b shortage would cut another 45,000 acre-feet, but who’s counting?
Well, let’s do the math. Assuming Arizona takes at least a Tier 2a cut, when added to the voluntary cuts the Lower Basin states took in the 500+ plan last December, the CAP will have cuts totaling over half of its Colorado River allocation. With a Tier 2b cut, this would total to an amount of approximately 845,000 acre-feet from the normal delivery of 1,415,000 acre-feet according to BOR. arizona-water-settlement-agreement-12-14-07.pdf (cap-az.com) A Tier 2b cut would result in a total of almost 60 percent of CAP water that we would have to leave behind Hoover Dam!
Unless we have a Noachian flood, or a giant blizzard in July followed by massive runoff a couple of weeks later, it doesn’t look so good. Given the fact that BOR estimates lake levels to drop to 1037 feet by September, it looks likely levels would certainly hit the Tier 2b level of 1045 feet in August when BOR would make the call for next year. Lake Mead water level running well below predictions, could drop another 12 feet by fall - CNN
It could happen! (Actually, this shot was taken in December 2018)
Photo by Cactus Reports (Pinetop, Arizona)
Even if there were blizzards in July, the 22-year-long drought has dramatically curtailed runoff. According to CAP Director Ted Cook, Colorado had a snowpack 90 percent of normal winter before last. Unfortunately, this resulted in a runoff of only 30 percent of normal. This year’s snowpack roughly duplicated the previous year, but estimates so far show a runoff of only 56 percent of normal. The watersheds dry forests have led to an abnormal amount of the melting snow going straight down into the ground. In addition, warmer winters at the end of the season have led to earlier and thus, less runoff.
Speaking at the same Arizona Capitol Times event, Dave Roberts of the Salt River Project (SRP) indicated SRP wants to increase the capacity of Bartlett Lake by raising Bartlett Dam either 62 feet or 97 feet. A 97-foot increase in dam height would increase lake capacity from 178,000 acre-feet to 628,000 acre-feet. SRP has also lost one-third of its storage capacity in Horseshoe Dam due to sedimentation. SRP has a plan to recapture that lost capacity, Roberts said.
If it were just that simple!
Image by Big Local
There are no silver bullets in solving this water crisis. In addition to increasing dam size, it will take lots of smaller measures to meet the challenges we face. Desalination can play a small part, but Central Arizona may also have to talk with the Colorado River Indian Tribes among others to lease water. Oh yes, and then there’s that dreaded “C” word . . . conservation. Without fixing the holes in the leaky bucket there is just not enough available water to continue with the status quo. More on that in another blog.