The loss of El Vado: some followup

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A couple of followup notes related to last week’s post about the news on El Vado Dam on the Rio Chama, crucial to water management on New Mexico’s Rio Grande, thanks to my many alert and thoughtful Inkstain readers….

Rio Grande Compact Debt

In the comments, Norm Gaume made a point that’s worth pulling out and highlighting:

The Middle Rio Grande’s accrued compact debt would prevent storing water this year if El Vado Dam were intact until without first storing the full amount of the compact debt and not using any of it. The compact debt is 122,000 acre-feet and worsening annually. In the last six years, the Middle Rio Grande consumed 154,000 acre-feet of the Lower Rio Grande’s water. The six-year average is 26,000 acre-feet of new debt per year. Why? Middle Rio Grande river flows are way down. Middle Rio Grande water uses are not.

Norm is making an incredibly important point here. El Vado is important in the long run. In the short run, thanks to the Rio Grande Compact’s rules, we wouldn’t be able to use it anyway this year to store spring runoff to stretch out irrigation through the summer. Unless and until we get our Compact debt under control, it doesn’t matter whether, when, or how we fix El Vado.

Rafting the Chama

In an email exchange, my UNM School of Law colleague Reed Benson pointed out the importance of El Vado in managing flows on the Chama for recreational boating and environmental benefits:

Having El Vado offline makes it more difficult to manage flows in the Chama Canyon reach.  That could hurt summer weekend boating flows, which support river recreation on the very popular Wild & Scenic reach.  It could also affect the effort to better manage flows in that reach for environmental benefits.

 

What Happens if there is no Agreement on Post-2026 Colorado River Operations?

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By Eric Kuhn

Given how far apart the competing proposals from the Colorado River Upper and Lower Division States are, a legitimate question is – “what happens if we get to the summer of 2026 and there is still no agreement on the post-2026 operational guidelines?” Well, believe it or not, that is a question upon which the seven basin states and the Secretary of the Interior already agree.  The Upper Division States made the following comment in their proposal:

“As of the date of this submittal, Reclamation has not disclosed the No Action Alternative for this EIS. The No Action Alternative must acknowledge that, upon expiration of the 2007 Interim Guidelines, the operating criteria for Lake Powell and Lake Mead will revert to the Long-Range Operating Criteria (LROC) used to model baseline conditions in the Final Environmental Impact Statement for the Interim Surplus Guidelines dated December 2000.”

The language quoted by the Upper Division States letter comes from the Record of Decision (RoD) for 2007 Interim Guidelines (Section 8. C.). This termination language was included with the consent of the states. So, the obvious questions are – if the operating criteria are to revert to the LROC, what are the LROC, and what specifically do they mean for the operation of Lakes Mead and Powell?

What is the LROC?

The long-range coordinated operating criteria or “LROC” are a requirement of the 1968 Colorado River Basin Project Act, the federal legislation that, among many other things, authorized the Central Arizona Project (CAP). Prior to the creation of the 2007 Interim Guidelines for the coordinated operation of Glen Canyon and Hoover dams, the LROC created the framework for determining how much water to release from Lake Powell to Lake Mead each year.

The 60s were a turbulent decade for the Colorado River Basin.  In 1962 Flaming Gorge and Navajo Reservoirs began filling, then in 1963, Lake Powell began filling. To manage the filling of over 30 million acre-feet of vacant space (25 maf in Lake Powell), in 1962 the Secretary issued filling criteria. And, as luck would have it, the 1960s were relatively dry. The filling criteria were controversial in both basins. A significant concern was power generation. The Upper Basin wanted to fill the reservoirs as fast as possible so the Upper Basin fund would begin accruing revenues that would be used to subsidize irrigation projects under the 1956 Colorado Storage Project Act. The Lower Basin was concerned with the impact of power generation at Hoover Dam – the revenues from which were being used to repay the federal treasury for Hoover Dam and other projects on the lower river.

The Upper Division States became concerned that the Lower Division States would continually interfere with the storage of water in the Upper Basin Reservoirs using Article III(e) of the Colorado River Compact, which states:

“The States of the Upper Division shall not withhold water, and the States of the Lower Division shall not require the delivery of water, which cannot reasonably be applied to domestic and agricultural uses.”

The Upper Division States (via the UCRC) decided they needed to use the federal legislation then pending before Congress to authorize the CAP to clarify the rules under which water would be stored and released from Lake Powell and the other CRSP storage reservoirs. A critical question that needed to be answered was how much holdover storage the Upper Division States would need to meet their compact obligations under Articles III(c) and III(d) of the compact. This was a difficult question to answer given that the two basins had very different interpretations of these provisions, especially the obligation off the Upper Division States to Mexico under the 1944 Treaty. Today the two basins still have very different interpretations of these provisions.

The specific language of Section 6 of the 1968 Act was negotiated by the states with input from Reclamation. With Congressman Aspinall (the House Interior and Insular Affairs Committee Chair from Western Colorado) insisting that operating language be included in any legislation, the UCRC had the better hand. Colorado’s Felix Sparks (its CWCB Director and UCRC Commissioner) said “we wrote every word of Section 6.”

The requirement for the LROC is included in Section 602(a):

“SEC. 602 (a) In order to comply with and carry out the provisions of the Colorado River Compact, the Upper Colorado River Basin Compact, and the Mexican Water Treaty, the Secretary shall propose criteria for the coordinated long-range operation of the reservoir constructed and operated under the authority of the Colorado River Storage Project Act, the Boulder Canyon Project Act, and the Boulder Canyon Project Adjustment Act. To effect in part the purposes expressed in this paragraph, the criteria shall make provision for the storage of water in storage units of the Colorado River storage project and releases of water from Lake Powell in the following listed order of priority:

(1) releases to supply one-half the deficiency described in article III (c) of the Colorado River Compact, if any such deficiency exists and is chargeable to the States of the Upper Division, but in any event such releases, if any, shall not be required in any year, that the Secretary makes the determination and issues the proclamation specified in section 202 of this Act;

(2) releases to comply with article III(d) of the Colorado River Compact, less such quantities of water delivered into the Colorado River below Lee Ferry to the credit of the States of the Upper Division from other sources; and

(3) storage of water not required for the releases specified in clauses (1) and (2) of this subsection to the extent that the Secretary, after consultation with the Upper Colorado River Commission and representatives of the three Lower Division States and taking into consideration all relevant factors (including, but not limited to, historic stream-flows, the most critical period of record, and probabilities of water supply), shall find this to be reasonably necessary to assure deliveries under clauses (1) and (2) without impairment of annual consumptive uses in the upper basin pursuant to the Colorado River Compact: Provided, That water not so required to be stored shall be released from Lake Powell: (i) to the extent it can be reasonably applied in the States of the Lower Division to the uses specified in Article III(e) of the Colorado River Compact, but no such releases shall be made when the active storage in Lake Powell is less than the active storage in Lake Mead, (ii) to maintain, as nearly as practicable, active storage in Lake Mead equal to the active storage in Lake Mead, but no such releases shall be made when the active storage in Lake Powell is less than the active storage in Lake Mead, (ii) to maintain, as nearly as practicable, active storage in Lake Mead equal to the active storage in Lake Powell, and (iii) to avoid anticipated spills from Lake Powell.”

Section 602(b) required that the Secretary submit draft criteria to the states by January 1, 1970, and, after receipt of comments, adopt criteria by July 1, 1970.

The language of the first two priorities for releases from Glen Canyon Dam appears straight forward, but there are still implementation questions. The first priority is to release water to meet the obligation of the Upper Division States to Mexico, if any. Today, the Upper Division States believe they have no obligation to Mexico, but the Lower Division States believe it’s at least 750,000 af per year. Thus, lacking either an agreement among the states or an interpretation of Article III(c) by the Supreme Court, this priority is unquantified. The second priority is to meet the Upper Division State’s 75 maf every ten years non-depletion obligation under III(d). It’s an average of 7.5 maf per year, but the language does not require a specific flow amount in any one year. To add uncertainty, the Upper Division States believe that if climate change, not Upper Basin depletions, is a cause of ten-year flows falling below 75 maf, there is no violation of Article III(d).

The third priority is more complicated (perhaps convoluted). It’s designed to address the question of how much holdover storage the Upper Basin can keep in the Lake Powell and the other CRSP reservoirs. Although the language may be confusing, the intent is simpler. The Upper Basin may keep as much storage as the Secretary determines necessary to allow the States of the Upper Division to meet their compact obligations during the most critical drought of record. If there is more than that amount in storage, then they must share the extra water with the Lower Basin, but only to the extent necessary to equalize active storage in Lakes Mead and Powell. Thus, was borne the term “equalization.”

After the 1968 Act passed, the Department of the Interior immediately began an effort to prepare a draft LROC. The effort involved a federal-state task force. It also involved the first comprehensive use of a computer to simulate numerous different reservoir operational scenarios (I wonder how many of us still remember the days of computer punch-card decks?). Interior officials quickly realized that the effort was going to be complicated and contentious. For Interior’s version of the events, see Chapter VII of the 1978 version of the Hoover Dam Documents. The contentious issues were the annual release amount from Glen Danyon Dam and how to calculate the amount of allowable holdover storage (now commonly referred to as “602(a) storage”). Colorado’s Felix Sparks put it this way: “Everything we do at Glen Canyon Dam is ultimately about the Colorado River Compact.”

After numerous meetings and conferences, on June 9, 1970, Secretary Walter Hickel formally approved the first LROC. Much of the language parroted the 1968 Act provisions for the CRSP reservoirs and for Lake Mead, the language of the 1964 decree implementing the 1963 decision in Arizona v. California. For the Upper Division States, however, the Secretary made three decisions that they strongly opposed. First, the LROC included a provision for an annual “minimum objective release” from Glen Canyon Dam of 8.23 maf. The problem was that this number was derived as 7.5 maf plus 750 kaf (the LB’s interpretation of the UB’s Mexican Treaty obligation) less 20 kaf (the mean flow of the Paria River). The Secretary accepted recommendations from the UCRC for language clarifying that the minimum objective release was an “objective” not a “requirement” and that the Secretary was not interpreting the Compact. The second problem was that the Secretary rejected their recommendation that a probability rule curve be used to set the 602(a) level.  Instead, the Secretary determined that the 602 (a) level would be set on an annual basis. Finally, with the adoption of the LROC, the UCRC recommended that the lake Powell filling criteria be terminated. The problem with the filling criteria from the Upper Division States perspective was that it required revenues from power generation at the CRSP units be used to keep the Lower Basin whole for the impact of filling Lake Powell on power generation at Hoover Dam. The Secretary rejected this recommendation and the filling criteria stayed in effect through 1980.

The rejection of its important recommendations left the UCRC members bitter. New Mexico State Engineer and UCRC Commissioner, Steve Reynolds, put in his plain-spoken language – “they crammed it down our throats” (expletive deleted).

So what happens if we continue to use the LROC?

So, the big question is – if there is no agreement on post-2026 operating guidelines between the basins and the Secretary determines that the annual operation of Lakes Mead and Powell for Water Year 2027 (and perhaps beyond) will be guided by the LROC, what does this mean for the reservoirs?  For Lake Powell, the answer may be not much. It means an annual release of 8.23 maf (or perhaps 8.1 maf -taking into account the river inflows immediately below the dam). Depending on the runoff in 2025 and 2026, there’s a reasonable chance that this would be the amount released under a continuation of the 2007 Interim Guidelines. The differences are that there would be no balancing of the storage levels in Lakes Mead and Powell as is allowed by the three balancing tiers of the 2007 Interim Guidelines and if the next two years are dry, there could be some debate over whether the Secretary has the authority to reduce releases below 8.23 maf – something that might be needed given the need to protect elevations below 3,500 feet at Lake Powell because of concerns about use of its outlet works.. I believe the answer to this question is clearly yes. In a June 2, 2005, letter, Secretary Norton wrote “the Department retains the authority pursuant to applicable law and the Operating Criteria to adjust releases from Glen Canyon Dam to amounts less than 8.23 million acre-feet per year. Specifically, the Department transmitted the following statement to the Governors of each of the Colorado River Basin States on June 9, 1970: “…(T)he operating Criteria imposes no firm or fixed obligation the 8.23 million acre-feet be released each year from lake Powell. That quantity is stated as an “objective” ….”

As for releases greater than 8.23 maf, under the authority referenced in the June 2, 2005, letter the Secretary might also have the authority to increase releases.  The LROC, however, anticipated that the occasional releases greater than 8.23 maf would be made as equalization releases under the Section 602(a)(iii) third priority. The LROC provides that the Secretary determines the equalization or 602(a) storage level annually, but it appears that in the near to mid-term future, there is very little risk that the storage level in Lake Powell will be anywhere near a level that would require a large equalization release (as happened in 2011). Based on the table in the 2007 Interim Guidelines, the end of water year elevation of Lake Powell would have to exceed 3666’ (100’+ higher, or 10+ maf more than the current level). Further, I would argue that the 3666’ level is no longer current. It assumed that 1954-65 was the critical drought. The recent 2000-2022 drought is every bit as dry and twice as long as the 1954-65 drought, therefore, a better estimate of today’s 602(a) level is “all of the available CRSP storage plus a lot more.” The Upper Division State’s proposal, in fact, does not even include an equalization provision.  Furthermore, in separate studies in 1969 and 2004, Reclamation concluded that in the future, the 602(a) level would exceed the available CRSP storage capacity. This is one of the reasons that in 1970, the Secretary rejected the rule curve. Reclamation modelling concluded that with future Upper Basin development, the result of applying the UCRC’s proposed rule curve (98.4%) meant that all available CRSP storage was needed to protect the Upper Basin. For more information on “602(a),” see Reclamation’s 2004 Environmental Assessment on this subject. The Upper Basin depletions have not achieved the level of development anticipated in either 1969 or 2004, but natural flows have been far less. From Lake Powell’s perspective there is no difference between upstream depletions and climate change caused reductions in natural flow.

For Lake Mead, operating under the LROC may be more complicated. The “70R” criteria is a flood control strategy for Lake Mead. Given the current reservoir levels, the chances of encroaching on the flood control space in Lake Mead is very small. The most pressing problem would be that after the termination of the 2007 Interim Guidelines, there would be no “current” guidance on the specifics of when and how much for the shortage levels that would still need to be imposed on Lower Basin mainstem users in 2027 and beyond.  Under the 1964 Decree, however, the Secretary has the clear authority, if not a mandate, to set shortages. I think it’s likely that the Secretary and three Lower Division States would agree on Lake Mead deliveries. A more difficult question may be the level of the annual deliveries to Mexico. If there is no internal U.S. agreement on the post-2026 guidelines, will Mexico be interested in extending Minute 323?

Operating under the LROC might be manageable

The bottom line is that if there is no agreement among the Basin States for consensus post-2026 operating guidelines, it may not be the ideal outcome the states want but given the broad authority and flexibility the Secretary has under the 1970 LROC, the situation would be manageable. In fact, operating Lake Mead and Lake Powell under the flexibility provided by the 1922 Compact, Section 602 of the 1968 Act, and the 1970 LROC might provide opportunities for a more flexible management approach that can be designed to address a broader range of issues, including balancing recreation resources, and addressing environmental conditions in the Grand Canyon.

 

 

 

The Loss of El Vado Dam

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The Bureau of Reclamation’s announcement at Monday’s meeting of the Middle Rio Grande Conservancy District that it is halting work on El Vado Dam repairs raises hugely consequential questions about water management in New Mexico’s Middle Rio Grande Valley.

The short explanation for the halt is that the current approach to repairing the 1930s-era dam wasn’t working. (The meeting audio is here, though at “press time” for this blog post this week’s is not yet up.) I’ll leave it to others to suss out the technical and bureaucratic details of the repair project, and the endless finger-pointing that’s sure to ensue. My interest here is to begin to sketch out the implications here in the Middle Valley of an indefinite period – a decade or more? – without El Vado.

The Middle Rio Grande Conservancy District built El Vado (with substantial federal subsidy) in the 1930s to provide irrigation supplies by storing high spring runoff for use in summer and fall. But while its purpose was irrigation, it completely changed the Middle Valley hydrograph in ways that all the other water uses have adapted to, both human and ecosystem.

Without El Vado (or some interim replacement – see below), we should expect the Rio Grande to routinely go functionally dry in late summer unless propped up by monsoon rains, which are sporadic and unpredictable.

I see impacts in three areas, only one of which is related to El Vado’s initial purpose.

1: Irrigation

This is the obvious one. Until El Vado is repaired or some sort of replacement schemed out, irrigators should expect a high risk of low or no supply in late summer and fall. Alfalfa will remain a reliable if modest crop (it can hunker down and wait out the dry), but the few commercial operators who need a more reliable supply for their crops – think pecans and chile – will have to depend on groundwater, with all the problems that entails.

2: Municipal Supplies

Albuquerque’s use of its imported San Juan-Chama water in summer indirectly depends on El Vado. Without MRGCD water, released from El Vado, as “carriage water”, the Albuquerque Bernalillo County Water Utility has to leave its imported San Juan-Chama water parked in Abiquiu Reservoir, switching to groundwater. This is what we have done over the last few years, and our much-vaunted aquifer recovery has, as a result, stalled.

This poses a huge challenge for the Albuquerque Bernalillo County Water Utility Authority.

3: Environmental Flows

The idea of an agricultural irrigation dam providing the water for environmental flows seems super weird. But that’s basically the way it’s worked for years here in the Middle Valley. Releases from El Vado, sent downstream to irrigators, provide environmental benefits along the way. For the last couple of years, without El Vado water to supplement flows in late summer, the Rio Grande has operated on a knife’s edge between flowing and dry through Albuquerque.

This poses a huge challenge for efforts to nurse the Rio Grande silvery minnow back from extinction.

Storage alternatives

First and foremost, there is a fast-moving and scrambling discussion about storage alternatives.

Abiquiu Reservoir, a flood control facility on the Rio Chama built, owned, and managed by the U.S. Army Corp of Engineers, is an obvious replacement. The part in italics yields knowing nods, or perhaps grimaces, from folks who work in Middle Valley water management, because the Corps is well known for an exceedingly cautious interpretation of its statutory mandates. “Filling in as a water storage facility to replace El Vado” is only sorta barely at the edge of that mandate. Getting the Corps on board to help with this fix will be key.

Heron Reservoir, on a Rio Chama tributary, stores San Juan-Chama water imported through tunnels beneath the continental divide. It physically can’t replace El Vado because it’s in the wrong place. But discussions have already touched on the idea of doing it on paper via accounting swaps – hold back San Juan-Chama water, let SJC customers use native Rio Grande water via an accounting swap, then deliver Heron water as if it had been El Vado water.

Elephant Butte? Again, it’s in the wrong place, but accounting swaps here are also on the table.

Institutional Framework

The most important subtext is the institutional framework behind all of this. The loss of El Vado is not solely an MRGCD/Bureau of Reclamation problem. It implicates all the Middle Valley’s water stakeholders – especially Albuquerque’s Water Utility Authority, but also the Corps of Engineers, the Fish and Wildlife Service (because of ESA issues), the state water agencies, the communities on the valley floor that have avoided responsibility for any of this by depending on the state’s obscenely permissive domestic well statute.

Five Major Proposals for Post-2026 management of the Colorado River

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With the submission of two additional proposals last week, we now have five major proposals for post-2026 Colorado River management.

The folks at the Water and Tribes Intitiative have helpfully organized them in a single place. (Click on the
“Proposed Alternatives for Post-2026 Operating Guidelines” bubble.)

Tribal Principles

A set of guiding principles proposed by 17 of the basin’s sovereign indigenous communities. (click here)

Upper Basin Proposal

What the label says, you already know about this one. (click here)

Lower Basin Proposal

What the label says, you already know about this one. (press release, alternative, presentation)

Environmental NGOs

The “Big Seven” Colorado River Basin environmental groups (click here)

Lake Powell/Grand Canyon/Lake Mead Ecosystem Proposal

A proposal from Jack Schmidt, Eric Kuhn, and John Fleck suggesting ways to manage the storage and distribution of water to provide more flexibility for environmental and other non-water supply benefits. (click here)

Always check the gate. It might be unlocked and lead somewhere interesting!

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This gate was unlocked, and led to a marvelous shortcut.

In our years of urban exploring of Albuquerque on our bicycles, my collaborator and I have learned a number of guiding principles that I realized might be worth sharing.

The realization came at this gate, which of course I checked to see if it was locked. It wasn’t, which led to the discovery of a marvelous new shortcut. (Marvelous shortcuts, graded first on safety and second on interestingness, are a precious gift. They need not actually be shorter.)

This is a work in progress, but here are a few:

“Dead End” signs are an invitation

Beach Road, in Albuquerque, does in fact have an outlet.

“Dead End” and “No Outlet” signs should be viewed as an invitation.

Their placement is generally intended to inform the drivers of automobiles. Not pedestrians and bicycles. I would estimate that roughly half the time I ignore them, I find a way through.

The percentage goes up significantly on Albuquerque’s valley floor, which is spiderwebbed with irrigation and drainage ditches. Consider the delightfully named “Beach Road” in Los Duranes, a neighborhood named after an old village along the Rio Grande. My decision to ignore the “No Outlet” sign was rewarded with a gate designed to allow horses, pedestrians, and cyclists access to the Riverside Drain paralleling the Rio Grande, a delightful dirt path.

Keep an eye out for bollards

A bollard at a gap in a wall with a bicycle in the foreground and a field and houses in the distance, beyond the gap in the wall.

This is a close corollary to the above principle about “No Outlet” signs. Often the cut-throughs at the end of such streets include a space to pass, but with a bollard at the entrance to block motor vehicles. Bollards also guard other gaps in fences and walls.

Consider such bollards an invitation to see what might lie on the other side.

When feasible, take the alley

Irot’s Bird, in the alley behind Central (Route 66) in downtown Albuquerque. November, 2023, photo by John Fleck

Alleys are the most honest part of a city, the back side of things, unadorned. Or, sometimes, spectacularly adorned.

“Graffiti,” Albuquerque city ordinance 11-7-1 explains, “is a form of vandalism which injures and stains Albuquerque.” This is important. In Bogota in 2011, the police killing of a graffiti artist sparked outrage, leading after several years of turmoil to a government decree allowing “responsible and artistic graffiti” in most public spaces. Which triggered deep debates within the community of the artists who made it over the meaning of “true” graffiti.

The deep notion of graffiti as an act of rebellion and place-making is beyond the scope of this blog post, but graffiti has always been at the heart of a “discourse of disorder.” It is place-making, or place-claiming, and it’s delightful, and you’ll find it in alleys. Magnificent work like Irot’s bird, but also ragged tags.

When feasible, take the alley.

Speed Humps

Yellow sign with black lettering reading "speed hump"

Always follow the speed humps

The reason they build speed humps is because cars were driving too fast. Speed humps slow them down.

These signs are thus conveying two important pieces of information.

First, it means the road goes somewhere interesting. That’s why all the cars were going that way and driving too fast, leading to neighborhood meetings and traffic engineering studies and speed hump construction.

Second, it means that what cars still use the street are now likely to be going more slowly.

No Trespassing Signs

Bicycle leaning against a "no trespassing" sign with open desert behind

Thar be dragons.

Criminal trespass consists of unlawfully entering or remaining upon the lands or property of another knowing that any consent to enter or remain has been denied or withdrawn by the person or persons lawfully in possession of the premises or after the request or demand to leave the premises by the authorized representative of the person or persons lawfully in possession of the premises.

– Albuquerque city ordinances, 12-2-3

My first genuine bicycle exploration, at perhaps age ten, involved an old orange grove barn a few blocks from my house. My friends and I packed lunches and began wandering, finding the barn empty and inviting. We climbed the wooden ladder into the loft to dine.

We were wary of being caught, and nervous about the consequences. It was thrilling.

You should of course always be wary of Albuquerque city ordinance 12-2-3 and its kin. I would never encourage urban explorers to ignore signs such as the one above, or to paint over them or shoot them.

However you respond to signs like the one above, the urban explorer must always respect “No Trespassing” signs on lands of indigenous communities. That’s the only really important rule.

 

 

 

 

Otowi flow, without the log scale: 21st century peaks are ~half what they were in 1980-2000

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Graph of flow on the Rio Grande at Otowi, showing significant 21st century decline

Rio Grande Otowi flow using linear rather than log scale

Alert Inkstain reader John correctly questions the impression left by the log scale I used last time ’round in my graph of flow at Otowi:

[W]hile I appreciate the usefulness of logarithmic scales for being able to discern patterns at the low end of the flow range, it does somewhat hide the magnitude of the changes pre/post 2000. The median peak flow since 2000 is barely half of the median peak in the 81-00 period, but you wouldn’t know that without paying close attention to the y-axis scale. And while the 2024 flows are indeed approaching the recent median, they are still roughly 10% below that line (again, something hard to discern from a log plot).

John highlights a fascinating tradeoff that we (the folks who use my graph and I) have been debating since I started doing it. Log scale does a much better job of highlighting the low flow parts of the graph, but John’s right that it hides important intuitions, for example masking the striking difference in peaks between the 1981-2000 period and our climate altered world.

Note that to make this read better, I went back to dropping the max and min lines.

Happy Rio Grande Spring Runoff!

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A complex graph showing rising Rio Grande flows at Otowi, approaching the 21st century median

It is telling that I got excited when I noticed inflow into New Mexico’s Middle Rio Grande Valley approaching “normal”, which I now define as the median of 21st century flow.

Our climate-altered world, y’all.

A note on the evolution of the graph: I’ve added the “max” and “min” lines back. I dropped them because I thought it made things too busy, but it was creating confusion because the top and bottom of the purple looked like the most/least.

New Mexico’s Rio Grande reservoirs: Running on Empty

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A graph with a red line showing New Mexico's northern Rio Grande reservoirs and a red line showing northern reservoirs. Both are extremely low since the early 2000s.

Reservoir storage on New Mexico’s Rio Grande and Rio Chama on April 1, 2024

Inspired by Jack Schmidt’s monthly “how much water is in Colorado River storage” posts (see here for last month’s), I’ve been playing with a similar tool to help me think about the status of our reservoirs on the Rio Grande system here in New Mexico.

The graph above helps me with two important intuitions about how the system is functioning.

At the decadal scale, the water management shift in the early 2000s from a time of plenty to a time of not plenty is dramatic.

At the interannual scale, the decline in water kept in storage upstream of the middle valley (the red line above) goes from bad to worse beginning in the late teens.

Data choices

North and South

Based on a useful conversation with Jack about this, it makes sense here to split things up into two bins – the northern reservoirs (which hold the water available for our use here in New Mexico’s Middle RIo Grande Valley) and the southern reservoirs (which hold storage for the Elephant Butte Irrigation District, El Paso and surrounds, and Mexico).

Time series

Because of a quirk in the data I have access to, and because I am too lazy to do the work to overcome the quirk, it makes sense to start the time series at 1980. But that also makes conceptual sense in terms of how I think about the system – our “modern era” of water management includes these two broad multi-decadal periods – the wet stuff 1980-2000, and the dry stuff ever since.

Time step

I find it most helpful to plot this at an annual time step. How does storage right now compare to last year at this time? So the graph above is the storage as of April 1 (actually March 31). I’ve plotted it both ways (daily as well), but the interannual ups and downs make it harder for me to see what’s going on.

2024 v. 2023

After last year’s unusually wet year:

  • Northern reservoirs are up ~27,000 acre feet on April 1
  • Southern reservoirs are up ~95,000 acre feet.

The Loss of El Vado

Summer maximum versus end of year storage in El Vado Reservoir

The loss of El Vado Reservoir, currently under repair, is striking. But what’s also striking is how significantly we were draining it in recent years, before the current repairs started in 2022.

The Middle Rio Grande Conservancy District built El Vado in the 1930s (with an under-appreciated amount of federal subsidy) to extend the irrigation season, capturing spring runoff for use in the dry months of late summer and fall. (“Canals move water in space, dams move water in time.”)

I’m still playing with how best to illustrate this. The graph above shows how full El Vado gets each year as it swells with spring runoff (blue dot) and how far we’ve drained it by the end of the year (red dot).

Catchy Song Lyric version

Lookin’ back at the years gone by like so many summer fields

Runnin’ on, runnin’ on empty
Runnin’ on, runnin’ blind
Runnin’ on, runnin’ into the sun
But I’m runnin’ behind

– Jackson Brown, “Running on Empty”

 

Tribal sovereignty and pumped storage hydropower in Nevada

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Daniel Rothberg wrote this week about an important case in Nevada that is testing the boundaries of the question of tribal sovereignty:

The Pyramid Lake Paiute Tribe filed a formal motion earlier this month to intervene in a federal regulatory proceeding that could eventually pave the way for a pumped storage hydropower project on the tribe’s land — a project the tribe opposes.

The filing comes only weeks after the Federal Energy Regulatory Commission (FERC) ruled that it would deny permits for hydropower projects on tribal land in cases where projects do not have a tribe’s support.

There’s a lot of enthusiasm right now about pumped storage hydropower – a way to add a sort of battery to the electrical grid to smooth out the fluctuations of solar and wind power. Here’s Daniel:

Pumped storage hydropower projects generate electricity by cycling water between two reservoirs at different elevations. They pump water from a low-elevation reservoir to a higher-elevation reservoir when there is excess energy available. When energy is needed, the water is released back to the lower reservoir and generates electricity as it flows down an elevation gradient and through a turbine — with the help of gravity.

But the sovereignty question here seems straightforward: pumped hydro may be of value broadly, but if the Pyramid Lake Paiute Tribe doesn’t want it on tribal land, isn’t their right to refuse the project inherent in the very concept of sovereignty?

I don’t know FERC legal stuff at all, but I’ve spent a lot of time wrestling with the question of the sovereignty of indigenous communities in the United States. Its evolution in New Mexico is a central question Bob Berrens and I wrestle with in our forthcoming book, Ribbons of Green.

Tribal/Pueblo sovereignty – a nation within a nation, separate but also a part – is inevitably murky. The Pyramid Lake Paiute effort to intervene here is worth following.