Sources of Controversy in the Law of the River – Larry MacDonnell

As we lumber toward a renegotiation of the operating rules on the Colorado River, one of the challenges folks in basin management face is the differing understandings of the Law of the River. There’s stuff we all know, or think we know, or stuff Lower Basin folks think they know that Upper Basin people may disagree with, and stuff Upper Basin folks think they know that Lower Basin people may disagree with.

Larry MacDonnell, one of the Law of the River’s great legal minds, has written a terrific treatise to help us untangle this. It’s clearly written from an Upper Basin perspective (“Yay!” said the guy – me – who drinks Upper Basin water!), so Lower Basin folks may disagree with some of what Larry is saying. That’s OK, the important thing is to understand that the answers to these questions are not given – that there are genuine disagreements on this stuff, and the negotiations to come need to wrestle with these questions.

A few of Larry’s key questions:

Uncertainties Concerning Mainstream Water Use Entitlements in the Lower Basin

The traditional understanding of fixed allocations to the three mainstream states in the Lower Basin must yield to the reality of a declining water supply.

In some sense, this is a “duh”. If the water isn’t there, it doesn’t matter how much water the Compact or the Boulder Canyon Project Act or whatever says you’re entitled to. But Larry is making a more nuanced argument about what the rules themselves say.

Uncertainties Respecting Uses of Water from Lower Basin Tributaries

This is an argument I’m increasingly hearing from Upper Basin folks. Andy Mueller, general manager of the Colorado River District, made it forcefully in a webinar last week (starts around minute 12 in this recording). The current Colorado River accounting norms tend to ignore Arizona’s in-state use of the water from its Colorado River tributaries, but there’s a lot of water involved here. A million acre feet a year? Two million acre feet a year? We don’t know, because it’s not being accounted for right now.

Here’s Larry:

All beneficial consumptive uses of tributary water in the Lower Basin are
included within the Articles III (a) and (b) apportionment and need to be fully identified and accounted for annually. The effect of these uses on water availability in the main Colorado must be taken into account. Uses exceeding 8.5 maf/year may constitute a violation of the Law of the  River under certain circumstances such as if their existence causes a failure to meet treaty obligations with Mexico.

Uncertainties Respecting the Meaning of Article III (d) in an Era of Climate ChangeInduced Water Shortages

Does the Upper Basin have a legal obligation to deliver 7.5 million acre feet a year past Lee Ferry? Or it, as my Upper Basin friends like to say “a non-depletion” obligation. What if it’s climate change that’s depleting the water rather than the diversions to my tap to bring me all that sweet, sweet San Juan-Chama drinking water?

How much is the Upper Basin on the hook for meeting our delivery obligations to Mexico?

The traditional view that the Upper Basin has an obligation to provide 750,000 acrefeet per year to meet the Treaty obligation to Mexico needs to be reconsidered when Lower Basin uses exceed 8.5 maf/year, when Mexico adjusts its delivery requirements to reflect shortages, and in view of the fact that, in some manner, the treaty water is a national obligation.

There’s a lot more, river nerds should really read the whole thing, and as I said there will be smart Lower Basin people who will be happy to explain “Nothing to see here, move along.” But these ambiguities in the Law of the River have to be part of what we sort out in the upcoming negotiations.

“We can’t have land back without water back.” – Julia Bernal

Via Laura Gersony at Circle of Blue, a look at the work of Julia Bernal, leader of the Pueblo Action Alliance and a really interesting thinker on land and water here in the Southwest:

She is an advocate of the Land Back movement, which calls on the U.S. government to allow Indigenous people to continue stewarding the lands as they did before colonization. And in the American Southwest, she has taken up a new refrain: that “we can’t have land back without water back.”

Julia’s also a student in the University of New Mexico Water Resources Program.

Cold Facts … and Death

Cold Facts and Death – Arizona Republic, Jan. 15, 1949

I ran across this Arizona Republic cartoon some years ago while working on my book Water is For Fighting Over etc. I found it in a 1985 book by Frank Welsh called How to Create a Water Crisis. It reared its head this week as I’m working with some colleagues on some stuff about Arizona and the Colorado River. I had not realized until one of said colleagues traced it back to the original that it was part of a paid advertisement, sponsored by Southwestern Sash & Door Co. of Phoenix, Tucson, El Paso, and Albuquerque.

This suggests that a lack of water is bad for the sash and door business.

Albuquerque’s Rio Grande Oxbow

Albuquerque’s Rio Grande Oxbow, July 2021

Mary Harner and I tagged along yesterday morning out in the Rio Grande Oxbow with Wes Noe, a UNM Water Resources Program/Community and Regional Planning student who is doing his masters project at field sites there.

Mary Harner and Wes Noe on the Rio Grande at the Oxbow, July 2021

Loyal readers will remember remember my travels with Mary, a University of Nebraska colleague studying the Rio Grande.

Wes is a masters student in our WRP/CRP dual degree program, drawn to the Oxbow as a study site because of its fascinating linkages between the riparian ecosystem and human communities on the bluffs above. Neighbors banded together to preserve some open space surrounding it, and Wes is connecting that political and community process with years of intermittent scientific study of the Oxbow itself.

Now that Wes has a permit to work at the site, Mary and I asked to tag along on a field visit. He’s doing return sampling at sites that were studied a number of years ago, looking at bugs and measuring depth to groundwater, looking for changes over time, and variations among the sites.

The Oxbow is an amazing outlier in the Albuquerque Rio Grande riparian system. At ~50 acres (~20 hectares), it’s the only river-connected wetland in this stretch of the river.  A fragment of old river stranded, it was stranded by water managers in the 1950s who, desperate to more efficiently more water for human use, dug the channel that you see in the picture of Mary and Wes above. It’s fascinating to me that what passes here for the “natural” river channel is in fact an engineered system. But then, I guess, the whole system is engineered at this point, for better or worse.

Surrounded by bluffs and relatively inaccessible, the Oxbow has oddly thrived, though as a particularly novel ecosystem. I’ve poked around its edges for years, but thanks to Wes’s permits and wayfinding skills (and his cheerful curiosity – best part about students!) Mary and I were able to get into its interior yesterday for the first time.

A remarkable wilderness pocket right in the middle of the city.


New Mexico’s Rio Grande, bailed out by an impressive monsoon

Rio Grande at Albuquerque’s Central Avenue Bridge, 8 a.m. July 28, 2021

A robust July monsoon has allayed our worst fears about central New Mexico’s Rio Grande.

Is it really a “monsoon”?

Back in the days when my paid gig was writing newspaper stories, I loved writing about the monsoon, and every time I did I would get helpful feedback from readers anxious to explain that I was a doofus and didn’t know what I was talking about, a monsoon, no way!

While they may have been right about the doofus part, with respect to the monsoon part, yes way.

Here’s Ben Cook and Richard Seager by way of explanation:

The North American Monsoon (NAM) may be a poor relation of the majestic Asian monsoon but is nonetheless a real monsoon that provides important rainfall to Central America, Mexico and the interior parts of the southwestern U.S. (primarily Arizona and New Mexico). In Mexico and Central America the NAM is critical for water supply and agriculture since winter precipitation in these regions is so small. In the southwest U.S. winter precipitation, arriving at a time of low evapotranspiration, is critical to water supply but the NAM precipitation remains important for soil and groundwater recharge, ecosystems, rainfed and rangeland farming and for fire.

How has this year’s monsoon helped central New Mexico’s Rio Grande?

When last we visited on this topic two weeks ago, I’d just completed a swift bike ride to watch the river dry. Since then, we’ve had two weeks of wet.

Rio Grande flows since mid-July 2021, via USGS


Each one of those little spikes represents runoff from a rain event somewhere in the watershed between the Central Avenue Bridge in Albuquerque and Cochiti Dam to the north. Our monsoon’s spotty that way – the “official” Albuquerque rain gauge at the airport has recorded just a third of an inch of rain during that time. But every couple of days it’s rained somewhere in the watershed feeding the river – sometimes a lot.

(It has been accompanied by tragedy. People with no home of their own often take up residence in Albuquerque’s flood control system. Three people died last week in one flash flood – see Elise Kaplan’s thoughtful effort to memorialize them. Our flood control infrastructure is great at protecting our city, but it has this dark side.)

The latest I have heard in conversation with water management folks is that the rains may have bailed us out of the river drying in the Albuquerque reach – we’re at this point unlikely to be writing about “the first time the Rio Grande has dried through Albuquerque since 1983”, which many of us have been doing.

But what about Elephant Butte?

The good news is that a lot of this monsoon water – flowing past Albuquerque and contributed by arroyos downstream – is making it to Elephant Butte Reservoir, which provides storage for downstream users in southern New Mexico, Texas, and Mexico.

The bad news is that Elephant Butte is really, really big, and really, really empty, and the monsoon inflows are tiny compared with what we need, which is a big winter->spring snowmelt.

A month ago, modelers at the U.S. Bureau of Reclamation were projecting Elephant Butte would bottom out at about 10,000 acre feet of storage in early August. It’s a 2 million acre foot reservoir. That’s just a half a percent full. That would have been the lowest since August 1954.

Updated model runs, incorporating the burst of monsoon moisture, now suggest Elephant Butte will bottom out at around 60,000 acre feet of storage sometime in the first part of August. That’s still just a hair above 1 3 percent full, which illustrates a central feature of the monsoon’s role in Rio Grande water supply: Compared to winter snowpack, monsoon rains’ contributions are tiny, only playing a minor role.

But coming at the right time, they nevertheless matter.

(Huge thanks to Carolyn Donnelly and Mary Carlson at the Bureau of Reclamation for modeling run data and helpful explanations. Tons of data in the  right hand rail here.)

Most Albuquerque: Green Chile in the Bike Lane

Green chile in the eastbound bike lane, Route 66 bridge over the Rio Grande, Albuquerque, New Mexico, July 28, 2021

A most Albuquerque summer morning for a bike ride:

  • Muggy monsoon dewpoint
  • Muddy storm-fed Rio Grande
  • The smell of green chiles roasting, early, in the El Super parking lot
  • This lone green chile in the eastbound bike lane over the Rio Grande

Is the Colorado River “Stress Test” stressful enough?

By Brad Udall and John Fleck

Earlier this year, we argued in a Science magazine editorial that Colorado River forecasting must take the growing risk of climate change seriously. The latest five-year projections from the U.S. Bureau of Reclamation offer a practical example of the challenge.

Published July 8 (see here and here) with an accompanying news release, the projections suggested that if the trends of the last 30-plus years continues, there is a 79 percent chance that Lake Powell could drop next year below elevation 3,525 – a danger zone for managing power production and releases to the Lower Basin going forward. With the reservoirs behind Hoover and Glen Canyon dams expected to drop below 30% by early 2022, these projections take on a new importance — we no longer have a huge water buffer to protect us from future low flow years.

It is stark news. But perhaps not stark enough.

This forecast takes advantage of an important new tool Reclamation has invested in called the “Stress Test” to give us a sense of the future risks we face.

The Stress test goes beyond the old “the future will be like the past” scenario building we have used in the past on the Colorado River. This new tool takes an important step toward incorporating climate change. But we are concerned that it doesn’t go far enough.

The five-year projections come in two flavors. One, “the future will be like the past,” uses the historical hydrology since 1906 with a mean flow of 14.8 maf. In a stationary climate, this hydrology would be fine. But the climate is not stationary, and the only real use for this hydrology is to see just what we’ve lost as climate change saps the river, not what the future might hold.

The alternative ‘Stress Test’ hydrology uses the period from 1988 to 2019 with an annual flow of 13.3 maf. While more reflective of current conditions than the full hydrology, these flows also do not reflect the past 22 years with its annual runoff of 12.4 maf.  When river managers first began using it, the “Stress Test” marked an important step toward taking climate change seriously. But these flows are no longer what they purport to be.

What we really need, and what we argued for in our Science editorial, is a ‘reasonable worst case future’.  This is the future that a prudent person would plan against, knowing what we currently know.

The last 22 years are the best analog for our 5-year future.  And within those 22 years one period stands out as the worst, the period from 2000-2004.  These years averaged 9.4 maf, and during that time Powell and Mead lost ~25 maf.   This period is what a prudent person would pick as a reasonable worst case — it happened before and it can happen again. In fact, the extreme dry of 2020 and 2021 suggests it may be happening now.

It would be interesting to see how Reclamation’s model performs against 2000-2004 and also against 2000-2021.

Within the Colorado River management community, there are questions about these modeling exercises on the demand side as well. Are water uses across the basin overstated? Might that at least partially offset overly optimistic supply estimates?

Pat Mulroy, after being burned by false probabilities, famously said that as a water manager she was only interested in possibilities, not probabilities.  The hydrology from 2000-2004 is a possibility. Let’s learn the lessons it holds.


Walking and chewing gum: mixing crisis narratives and messages of optimism

Not gonna lie – watching Colorado River reservoirs decline so precipitously has been painful.

But it is important to cultivate optimism, and there is, in fact, reason to be hopeful about our ability to deal with the challenges. That’s the message the University of Arizona’s Bonnie Colby and I shared in a recent conversation with Sarah Bardeen at the Public Policy Institute of California:

Bonnie Colby: Everybody knows we’re moving into a serious situation. State and federal officials have been tracking reservoirs and groundwater levels, and tribal nations are involved in a way that they never have been before. That’s much needed, from a social justice perspective, and because they’re holders of the most senior rights in the system. In Southern California, 20 years ago, all the water users were much more likely to lean on their legal entitlements and litigation. We see much more flexibility nowadays—there’s been big progress.

Not just Mead: Powell will soon drop to the lowest level since filling in the 1960s

Lake Powell heads for record low. Source: CBRFC

While the historic June 15 low for Lake Mead has drawn headlines – “its lowest level on record since the reservoir was filled in the 1930” – we’re about to hit a similar milestone upstream at Lake Powell that has received less attention, but may in fact be more important.

It was co-author Eric Kuhn who drew this to my attention – I hadn’t noticed. He notes that sometime around July 24 give or take our eyeballing of the Colorado Basin River Forecasting Center graph, Powell will cross elevation 3,555 feet above sea level. That was the previous post-filling low, on April 8, 2005. From there, you have to go all the way back to the summer of 1969, when Powell was first being filled, for the “last time Powell’s been this low” references.

I say “may be more important” because relative to Mead, Powell is where the Colorado River Basin’s chaos and uncertainty are most clear.

Users who get their water from Mead have a huge reservoir with a predictable inflow above it – the Upper Basin’s releases from Lake Powell. That means if you’re a water manager in Los Angeles or Phoenix or Las Vegas or Imperial, you have a clear picture of what to expect over the next several years. The expectations may be for a reduced supply, but you can operate with pretty clear expectations about what the reductions will look like, and least for the next few years.

Powell is where the real trouble shows up first. 3,555 is a loud and discomforting noise.

A River No More?

Dawn on a dwindling Rio Grande. Albuquerque, New Mexico, July 14, 2021

Between the wildfire smoke and two important meetings for which I am unprepared, I intended to stick to a quick indoor Zwift bike ride this morning before getting on with my day. Until I checked the gauges.

Measuring a shrinking river

57 cubic feet per second.

It’s a morning ritual, the little iPhone app while I’m curled up in my comfy chair with a bowl of Grape Nuts and the first cup of coffee.

57 cfs at Albuquerque’s Central Avenue Bridge is something entirely new to me in my 30-plus year relationship with the Rio Grande. 100 cfs used to be my mental milestone for “going dry”, and in my years of watching the river it’s rarely gone there, and never this early in the summer.

It was still dark, but I’d plugged in my bike lights to recharge last night, so I threw on bike shorts and a shirt, filled a water bottle, and tore down to the river.

I rode fast to try to catch the morning light. (I am old, but it is mostly downhill.)

The shortest route from my house to the river crosses the old abandoned Albuquerque Acequia, which used to irrigate fields north and east of Old Town back as far as the 1700s. Farther west the Alameda Drain, another canal that’s part groundwater drainage, part water supply for folks to the south, was still running.

57 cfs at the Central Avenue Bridge didn’t look much different than 76 cfs last Sunday. You can see the old bridge pilings on the west bank, poking up like sentinels of climate change.

Rio Grande at Central Avenue, Albuquerque, looking west. 57 cfs. July 14, 2021

Around the river’s west side, the Middle Rio Grande Conservancy District is still diverting water through the Atrisco Siphon into the Arenal Main. The gauge readings are down this morning, so I don’t know the number, but I’m guessing more water coming through the siphon than down the river’s main channel.

The egrets hanging out looking for breakfast had chosen canal over river.

The latest note from the river managers this morning suggests the river’s still continuous through the Albuquerque reach, but barely. It’s thinning down near the Albuquerque sewage treatment plant outfall, but doesn’t appear to have broken yet. Dewpoints are high this morning. Maybe it will rain.

On the way home, I swung north through the Duranes neighborhood to check out the Duranes Ditch. It’s one of the old ones, and per a friend in the neighborhood it had nearly gone dry yesterday, but it was running again today at what the gauges suggest is maybe 12 cfs. Such a tiny number, but looming larger right now.

The Duranes, twisty across the valley floor, has been in its present location long enough that its role on our landscape is as much neighborhood creek as it is irrigation canal. We have replaced the natural flood plain with a distributional system that has created a novel ecosystem, rich and diverse and culturally complex, as it spreads across the valley floor, twining through neighborhoods of old farms and newer subdivisions, tree-lined and rich.

I’m not sure if I’ll be sadder when the Duranes and Griegos, my other favorite ditch, go dry, or if I’ll be sadder when the river goes dry.

It’s all just sad.

Duranes Ditch, Duranes, NM (OK, technically Albuquerque?), July 14, 2021. Maybe 12cfs?