Just to quickly recap some of the battleground issues facing the various and sundry water districts in Colorado. To help me get my own head around the situation.
In 1922, a group of politicians and water experts signed the Colorado River Compact, whereby the Upper Basin states — Colorado, Wyoming, Utah and New Mexico — were allocated 7.5 million acre-feet of water from the Colorado River, annually, and were required to release, downstream, an equal amount of water to the Lower Basin states — California, Arizona and Nevada. A 50/50 split. 7.5 million acre-feet, to each side.
The measurement of the Colorado River flow is made at Lee’s Ferry, just downstream from Lake Powell.
I understand that Arizona politicians were not happy with that state’s allotment of 2.8 million acre-feet, and didn’t actually sign the Compact until 1944. Apparently, Arizona’s leadership thought California was taking too much of the Colorado River water. The dispute was settled by the US Supreme Court in 1963.
Meanwhile, the Upper Basin states have never used their full allotment of 7.5 million acre-feet. My research suggests that the maximum amount of Colorado River water used by Colorado, Utah, Wyoming and New Mexico was 4.9 million acre-feet. The average is more like 4.5 million.
What the Upper states don’t use, ends up in Lake Powell, at least temporarily. But in order for the water to be “counted” towards the Lower Basin allocation, it must be released from Lake Powell, from whence it flows into poor old Lake Mead. California, Arizona and Nevada — in the midst of drought conditions — have been draining Lake Mead faster than it can be filled by natural water flows from Lake Powell.
So we’re basically dealing with ‘unnatural’ water flows.
The water elevation at Powell has sunk nearly 100 feet since 2000, largely due to emergency releases of water aimed at keeping Lake Mead from sinking to an elevation of 1,075 feet, the point at which the federal government must declare a water shortage under a 2007 agreement. Such a declaration would require mandatory water delivery cuts to the Lower Basin states, and would trigger widespread water rationing…
…And would likely touch off an ugly dispute between the Upper and Lower Basins.
We shared a graph yesterday in Part Two, showing the theoretical flows in the Colorado River, at Lee’s Ferry, over the past 1,300 years — based on the information contained in tree rings.
If the Upper Basin states were to suffer a lengthy drought like the one that took place between the years 1125 and 1175 — marked in yellow, in the above graph — we would be unable to deliver 7.5 million acre-feet per year without massive changes to everyone’s water use in the Upper Basin.
And that would, presumably, include changes to everyone’s water use along the Front Range, because Denver and Colorado Springs and eastern half of Colorado have been pumping water out of the Colorado River and its tributaries, and sending it over the Continental Divide, for agricultural, municipal and industrial uses.
If we can’t deliver our Colorado River allotment to Lee’s Ferry, the Lower Basin states can (theoretically) declare a “compact call,” triggering negotiations that might subject the Upper Basin states to water rationing. That theoretical prospect, long considered remote, is now looming — and has aggravated the historic rift between Colorado’s well-forested-mostly-agricultural Western Slope, where most of the water resides, and the urban-lawns-and-concrete Front Range, where most of the people reside.
The lower Lake Powell gets, the higher the probability that a “compact call” going to happen, at some point in the (possibly near) future. According to Douglas Kenney, director of the Western Water Policy Program at University of Colorado Law School, “A compact call would be devastating in the Upper Basin. It would be total chaos.”
Total chaos, because 96 years after the signing of the Colorado River Compact, we still have no hard and fast legal mechanism to govern a compact call. There’s no clear trigger for the process — unlike the elevation triggers at Lake Mead — and there is no clear process that follows declaration of a compact call, nor any rules about who would be asked to cut their water use.
Or who will be forced, by their state government, to cut their water use.
Colorado went through a difficult drought in 2002-2003, following several years of abundant rainfall and snow pack. This past year has been another difficult season in southwestern Colorado, with much of the San Juan River basin seeing record low precipitation. Here’s how the drought situation looked this past summer, with the darkest reds indicating “exceptional drought.”
During this recent drought situation, the Denver-based Colorado Water Conservation Board made a rather unusual move. Based on a 1980 “stream flow” water right, CWCB made a “call” on the San Juan River upstream of Pagosa Springs. This “call” meant that no one with water rights dating from later than 1980 could pull even a drop of water from that stretch of the San Juan. The river was running pretty low in August, when the “call” was made.
But everyone with water rights dating from earlier than 1980 could still draw their full allotment.
CWCB did not justify their “call” on the river, but we might assume they were trying to protect the aquatic life in the river?
Or maybe not? Maybe they had a different agenda?
The main problem with the CWCB call is that the water users along that stretch of the San Juan, with rights pre-dating 1980, had enough allocated rights to completely drain the river. And in fact, immediately following the CWCB “call” the water level in the San Juan dropped even lower than before the call was made. So the “call” had exactly the opposite effect from what the CWCB “stream flow” rights were supposed to produce, when they were awarded by the water court in 1980.
The assumption, by some local water experts, is that the CWCB “call” caused historic water users become anxious about the immediate future, and to pump even more water, as a safety measure.
Which brings us back, perhaps, to the 1922 Colorado River Compact. Many of the water rights along the Colorado River and its tributaries pre-date 1922. Almost all of those water rights are held by agricultural users. Meanwhile, the water rights held by municipalities in Colorado are often post-1922.
If the Lower Basin states actually made a “call,” would it ultimately cause less water to flow into Lake Mead?