Strongly worded letter today from John Entsminger of the Southern Nevada Water Authority about the failure to reach a deal on Colorado River cutbacks:
More later, I’m supposed to be paying attention to a zoom meeting, but making this as broadly publicly available as possible seemed important. Click the “view document” link to see the whole thing.
On the eve of the release of the US Bureau of Reclamation’s August Colorado River reservoir forecasts – freighted with meaning this month because of Reclamation’s ultimatum to the states about the need to cut water use – we look back at the last four decades of water-supply management to pose the central question:
How did we get into this mess? Our answer in brief:
When the Colorado’s flow was up, we used it all.
When it was down, we drained the reservoirs.
The river’s natural flows have been down for a long time.
And during the few stretches of somewhat higher flows, we did not significantly refill the reservoirs.
Colorado River water use outpacing supply. Graph by Jack Schmidt, Utah State University
Operating year to year, it is easy to get lost in the river’s annual ups and downs, and the immediate desire to get water to farm fields and cities – THIS YEAR! NOW!
But the longer view, based on the best available data, makes clear our mistakes during the past 20 years. Since the year 2000, the blue line in the graph above has spent little or no time above the red line. That is water use outpacing supply.
The result – the most recent three consecutive dry years have left us with headline-clear problems:
The graph’s nuances are worth noting.
Blue dots represent each year’s total natural water supply – the sum of the natural water yield of the entire Upper Basin and of the many springs and tributaries that flow into the Colorado River in the Grand Canyon. This natural supply, not considering the Gila, Bill Williams, or Virgin Rivers, averaged 12.8 maf/yr (million acre feet per year) in the 21st century, 23% less than the average between 1981 and 1999.
To help visualize longer-term trends and cycles, we statistically smoothed the data to create the blue line, which more clearly shows the longer-term ups and downs of the Colorado River’s flow. The smooth line makes clear the wet periods of the 1980s and 1990s, and the deep droughts of the early 2000s and of today. Importantly for our current mess – the “wets” of the 21st century were not as wet, and the “drys” were drier, than those of the late 20th century.
The red line – total basin water use and reservoir evaporation loss (not including uses and losses in the Gila, Bill Williams, Virgin, or Little Colorado watersheds) – crept up through 2000 as the Central Arizona Project finally grew into the paper water allocations of the 20th century Law of the River.
Total consumptive uses and losses, including treaty deliveries to Mexico, peaked in 2000 at ~15.8 maf and were reduced during the next 2 years. Thereafter, average basin-wide consumptive uses and losses remained ~14.2 maf/yr between 2003 and 2020, and individual years were consistently within 4% of the average of that period. Throughout the 21st century, total Upper Basin uses and losses were ~30% of the basin-wide total.
Sustained consumptive uses and losses that exceed the natural supply can only be sustained by draining the reservoirs – but only so long as there is available water in the reservoirs. Thus, it is no surprise that the 21-year average (2000-2020) rate of water consumption and losses that exceeded the natural supply by ~1.2 maf/yr led to today’s crisis.
There were a few opportunities to rebuild reservoir storage, especially in 2005, 2008, 2009, 2011, 2017, and 2019, but a decades’ long water consumption rate that exceeds natural supply is unsustainable. The reservoirs are now mostly drained.
The reservoirs’ decline. Graph by Jack Schmidt, Utah State University
The history of water storage, described in the two graphs, has gone like this:
Thus, today’s crisis – two decades of low natural supply, including some short, very dry periods, cannot sustain consumption and losses that exceed the natural supply and that have not significantly changed since 2003.
What are the policy implications of this analysis?
The present water-supply crisis is a simple mass balance problem and we sought to describe this mass balance in the simplest way – averaging for the entire watershed
How did we consider inflows?
How did we estimate consumptive uses and losses?
We assumed that the uncertainty of all values was 2 or 3 significant digits and rounded off our calculations accordingly.
Drought Monitor map showing change over the last two months. Green is good.
Rain lately every afternoon at or near my house – big noisy thunder-cracking stuff. (I’ve started tucking a raincoat into my bike bag.)
Rio Grande flowing again.
Green is good.
Janet Wilson had a helpful story yesterday in the Desert Sun about California’s negotiations over its piece of the looming Colorado River cutbacks. Its bottom line is that California – the state with the largest Colorado River allocation – is talking about kicking in 500,000 acre feet of water. Or maybe it’s really just 400,000 acre feet of water – as the Metropolitan Water District of Southern California’s Bill Hasencamp told her, paraphrased, the negotiations are fluid and numbers could change.
A reminder of what Reclamation Commissioner Camille Touton told senators just seven weeks ago:
In the Colorado River Basin more conservation and demand management are needed in addition to the actions already underway. Between 2 and 4 million acre feet of additional conservation is needed just to protect critical elevations in 2023. (emphasis added)
4 million acre feet is obviously out of reach. It always was.
But if Wilson’s numbers about California’s contributions are right – and she’s a good reporter, we have every reason to believe they’re in the ballpark – 2 million acre feet of additional conservation is beyond the grasp of a voluntary deal as well.
The arithmetic is straightforward.
The Upper Basin has said “not our problem“.
Nevada’s share of the river is so tiny that its contribution is couch cushion change, a rounding error.
That leaves, in round numbers, 1.5 million acre feet of water to come out of Arizona just to get to Touton’s bottom line number for additional conservation. That would require completely drying up the Central Arizona Project canal. (CAP is taking 1.031maf this year, and averaged ~1.4maf over the previous fives years). I’m frequently surprised by Arizona, but it seems unlikely that they’ll agree to a voluntary deal that dries up the CAP canal. If that’s where we end up, Arizona’s best alternative to a negotiated agreement will be to just make the feds do it, make them take the heat. (Worth noting that FiveThirtyEight has Arizona Democrat Mark Kelly slightly favored to hold his seat. Water politics is high stakes politics.)
Combine that with the reality that Arizona’s Native American communities, major water rights holders, have complained that they’ve been cut out of this entire process, according to a July 22 letter just surfaced.
I can imagine creative accounting that might allow everyone to grin through their teeth and count water moved down to Lake Powell from Flaming Gorge and other Upper Basin reservoirs as part of the 2 million. That’s pretty clearly not what Touton called for in June. It’s not “additional conservation”. But it might create some space for a face-saving deal.
Whether that would be enough to protect us from dead pool is another question.
The Bureau of Reclamation’s most recent “minimum probable” model runs show Lake Powell dropping below power pool – unable to generate electricity, and forced to move water through bypass tubes that Reclamation has made clear it does not trust – by October 2023.
Under that same scenario, Lake Mead drops to elevation 992 feet above sea level over the next 24 months.
(Trust me, having to type a Lake Mead elevation level without having to use a comma made me clench.)
At that point, a lack of water will make massive cuts a self-executing reality. We’ve drained our buffer. You can’t use water that doesn’t exist.
In a July 22 letter, the leaders of 14 Colorado River Basin Tribal governments complained to the U.S. Department of Interior about being left out – again – of the current negotiations around short terms Colorado River cutbacks:
Click through to see the full letter.
Duly noted
Sadly for most of you, this story is behind Politico/E&E paywall.
In drought, we pump groundwater. Albuquerque’s Rio Grande Valley, summer 2021
I dropped off the Santa Fe Overland at Albuquerque about a year ago during the drouth that prevailed over the southwest at that time. The range was as dry and hard as a table. Rivers and streams had dried up. Cattle were dying and the country seemed utterly desolate.
Imagine my astonishment and delight when I visited this thirty-acre truck garden to find trees, flowers, grasses and the entire range of vegetables growing in the most luxurious and prolific way. It was like an oasis in the desert. Everywhere stretched the rows of beautiful green, demonstrating the resurrection power of irrigation.
Drouth had no terrors here. This grower laughed at her threats and called her bluff. Even a dried up river did not taunt him, for he simply tapped the underflow near the surface and was pumping at low cost an immense stream of water.
– Albuquerque Journal, Oct. 30, 1905, quoting an unnamed author writing in the monthly magazine “The Earth” describing their visit to Blueher’s Gardens in Albuquerque’s Old Town
I thought a lot about this passage, which my book coauthor Bob Berrens found in an old Albuquerque Journal, on my Sunday bike ride through the Albuquerque reach of the Rio Grande Valley.
While the Rio Grande itself, the part between the levees, is drying, the trend Herman Blueher and the other Old Town market gardeners started in the 1890s – using wells to keep parts of the valley floor green even as the river dries – has become a dominant way of life in the Rio Grande Valley.
Between the levees, the river in 2022 has begun drying in the Albuquerque reach for the first time in four decades, as we grind through the summer of our third consecutive terrible spring runoff. By one measure I’ve been using, this is the worst three-year stretch here since the drought of the 1950s.
It’s a complicated mix right now of hydrology and management decisions. While the river channel itself, the part between the levees, dwindles, flows of water in the irrigation ditches through town are actually up a bit. This almost certainly won’t last. The Middle Rio Grande Conservancy district has burned through the last of its imported San Juan-Chama Project water, and the only water left in storage is a bucket set aside to ensure the valley’s Native American Pueblos, with their senior water rights, can continue irrigating.
But get off the river into the communities that surround it, and you’ll barely notice the drought.
After riding out onto the Alameda bridge yesterday to gape in dark fascination at the dwindling river, my mental health management ally Scot (bike rides, amiright?) and I ducked into what I think is called the Rio Grande Estates subdivision, a little cluster of homes built in the 1980s off of Rio Grande Boulevard in the far North Valley.
Last year around this time, as the river limped, a bike ride through Rio Grande Estates was an “aha” moment for me.
On the ride: lawns, green, sprinklers spraying into the street (see picture above from that fateful day).
Home with the maps: what, what? All those homes have their own shallow wells!
When Johnson Drilling put in wells in the summer of 1988, they found a good, productive aquifer layer of gravels at about 30 feet down. The entrance to the neighborhood here is about a quarter mile from the river – the part where water usually flows on the surface. The interconnections between surface and underground water is such that the gravel layer Johnson hit is basically a part of the river – the “underflow”, as our 1905 correspondent put it.
“Drouth had no terrors here.”
What Bob and I call the “Ribbons of Green” in the new book very intentionally includes this. Our ribbons extend far beyond the boundaries of “river” set by the levees, because this is all part of the river too – the tree-lined ditchbanks, the lush lawns of these valley homes. We’ve pinned the river itself between narrow levees and then manually spread its dwindling water ourselves – with diversion dams and ditches, or with our groundwater wells – across the river’s old flood plain.
If you’re irrigating off of a ditch, this year is about to get a lot tougher. If you’ve got a well – for your lawn, or your pasture, or your farm – you’ll be OK this year. How long that can continue is an open question, very locally situational.
I’m off for the next couple of days to a state legislative committee hearing where folks will be discussing a bunch of relevant questions about what we do next:
If these questions had easy answers, we’d have already finished the quiz and handed it in to the proctor. This is hard stuff.
As stakeholders negotiate the current crisis on the Colorado River, we believe the representatives of the states of the Upper Basin – our states – are making a dangerous argument.
Their premise is simple. With deep cutbacks needed, the Upper Basin states argue that their part of the watershed already routinely suffers water supply shortages in dry years. Without the luxury of large reservoir storage along the rim of the watershed that might store excess runoff in wet years and supplement supplies in dry years, the argument goes, the Upper Basin is limited by the actual mountain snowpack in any given year.
This is certainly true in many places. One of us (Fleck) lives in a community (Albuquerque, New Mexico) that has routinely seen supplies of trans-basin San Juan-Chama Project water shorted because of bad hydrology in a given year.
That is also the case for the oft-cited Dolores Water Conservancy District, which has junior water rights to the supply provided by McPhee Reservoir that is part of the Bureau of Reclamation’s Dolores Project. In contrast, the adjacent Montezuma Valley Irrigation Company has pre-Colorado River Compact water rights and its access to the same water source is relatively unlimited. The argument of the Upper Basin states about using less water in dry times applies in many local settings, especially in the local context of prior appropriation water rights. The argument is certainly logical.
But when one considers the regional scale of the entire Upper Basin, the argument is not supported by the data in the Bureau of Reclamation’s Consumptive Uses and Losses reports.
Our review of those data suggests that, on average, overall Upper Basin use is slightly greater in dry years, and less in wet years. While questions have long been raised about these data, they are the best that we have and, more importantly for this discussion, they are the data that the Upper Colorado River Commission has been using in support of its argument.
Here’s what the reports show for the 21st century concerning total Upper Basin consumptive Uses less net evaporation from the CRSP Initial Units (Lake Powell, Flaming Gorge, and the Aspinall Unit):
Upper Colorado River Basin agricultural water use in wetter and drier years. Graph by Jack Schmidt, Utah State University
Importantly, a scatter plot of Upper Basin agricultural water use since 1981 shows, in general, the opposite of what is being claimed. While agricultural use varies greatly from to year, in general, use has been greater in dry years and less in wet years.
In this plot, the estimated natural flow at Lees Ferry (a good representation of whether any individual year was wet or dry) is plotted against the summed agricultural use of water by all of the Upper Basin states. This simple analysis provides results counter to the assertion of the Upper Colorado River Commission in the sense that agricultural use of water was greater in years of low natural flow at Lees Ferry and was less in years of high natural flow at Lees Ferry. Thus, this simple relationship indicates that agriculture uses less water in wet years and more water in dry years, which is exactly the opposite of the assertion by the Upper Basin community.
Upper Colorado River Basin water use over time. Graph by Jack Schmidt, Utah State University, based on USBR Consumptive Uses and Losses Reports
Another way of looking at this question is to consider the long term temporal trend. If the Upper Basin’s argument was correct, we would see a decline in agricultural water use in the 21st century, because the river’s flow shrank during the aridification of the 21st century. However, use has not decreased.
There are important nuances in the data. In the second year of some consecutive dry years like 2012-2013, the Upper Basin’s total consumptive use drops significantly, perhaps because local storage is depleted in the first year and doesn’t fully refill in the second year. This may be the situation in 2020-2021 as well.
Why do we view the argument as dangerous? Because Lower Basin interests can do the same math we have. They almost certainly already have. That leaves the Upper Basin with a fragile foundation for entering the negotiations over the compromises that are certain to be needed to modify the Colorado River’s allocation rules in the face of climate change.
Authors:
A drying Rio Grande in Albuquerque’s South Valley. July 22, 2022, photo by John Fleck
For the first time in ~40 years (? – see below) New Mexico’s Rio Grande has “broken” – is no longer flowing – in what we call “the Albuquerque reach”.
The river dries not with a bang, but with a muddy whimper and the dawn serenade of awakening birds.
Science watches a river die – the USGS gage on the Rio Grande at Central in Albuquerque
Battered by 100-degree days, with storage above us running out, the river through town has been collapsing all week. When the flow at the Central Avenue Bridge dropped to 50 cfs Wednesday, I made an after-dinner dash to look. After getting word via a friend who had been on a briefing call yesterday that drying was now “imminent”, I got up early, loaded the bike into the Subaru and drove to the South Valley.
Rivers dry from downstream up, and I’d already scouted a path in through the willow thickets behind Harrison Middle School, knowing the drying would start there. Downstream from that point, the Rio Grande gets a break – 75 cfs from Albuquerque’s wastewater treatment plant, a weird way to rejuvenate a dying stream.
My best guess based on the gages is that the “drying” happened some time yesterday. It’s a weird word, because it’s still a lovely puddly mess of mud. But there is no longer water flowing from one puddle to the next. The official word this morning is that there’s a half a mile of drying, which puts the dry stretch starting somewhere around the Rio Bravo bridge (for locals who wanna go see for themselves).
The “bosque”, as we call our riparian forest, is lovely and thick down there, and I had to walk-a-bike quite a few times to push my way through sandy, narrow old foot paths choked with willows to get to the river.
That’s part of what’s weird about this, because what I’m calling “the river” for the purposes of this post is really the surface manifestation of a much more complex hydrologic system, and a big part of the work I’m now doing for the new book bids us to think more broadly about what we mean by “river” here.
The willows and cottonwoods were green and lush. They’ve got roots that easily tap into a shallow aquifer, the “subflow” part of the river. And where the river once spread on its own across a broad flood plain, we now do the job manually with a network of ditches and drains, some of which still had water in them this morning. Along the east side, for example, while the surface manifestation of the Rio Grande itself is now dry, the Albuquerque Drain (really more irrigation main here than “drain”) is flowing today at 120 cfs.
This is a function of our community values. We created an institution a century ago to drain the swampy valley floor and manage a network of irrigation ditches where the river once flowed out on its own (read our new book! as soon as we write it!), and it is functioning as intended.
Even as the river’s surface flows dry, the ditches are drying too. Irrigators have been warned that absent rain, there will be very little to water their land very soon. South Valley horse owners (the biggest consumers of irrigated stuff around here – the horses, I mean) will be buying hay. It’s a very dry year, the agony of climate change dumped atop some water management chaos.
And for the first time in a long time, the river itself here – the part above the ground and between the levees – is going dry.
The standard line we’ve all been using is that this is “the first time the river has dried in the Albuquerque reach since 1983.”
I’ve heard that said repeatedly by my water manager friends, but I’ve not chased down how we know that.
What I do know with certainty is that drying, once far more common in this reach of the river because of the way irrigation was managed in The Old Days (divert the whole river, run the ditches full, irrigate whenever you want) has been rare since the late 1970s.
Here’s a graph of drying days at the Central Avenue gage, where we have records back to the mid-1960s:
Rio Grande drying
Colorado has no plans to make additional cuts to water use next year to meet the Bureau of Reclamation’s demand to conserve millions of acre-feet of water, a step needed to preserve power production in Lake Powell and Lake Mead.
Instead, Colorado officials insist that other states should do the cutting.
“I think that at this point, we stand ready to hear what the Lower Basin has in mind,” said Amy Ostdiek, a section chief with the Colorado Water Conservation Board.
“You can stand on your legal theories and watch the system crash,” (Anne Castle) said. “But that doesn’t help anybody.”