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.

 

14 Comments

  1. Any reasonable, prudent planner would consider the worst case scenario, such as 2000-2004. Pat Mulroy is correct; rosy hydrologic estimates are really a failure of imagination. The Bureau’s culture doesn’t lend itself to change, mostly because it requires self-examination, and perhaps an admission that the way things have been done in the past may not be been correct after all.

  2. I personally saw the ‘culture’ within Reclamation change in the two decades while I was there. When I was hired in 1992 the Water Ops Chief told me of the events of 1983 and the issues at Glen Canyon Dam. As water management was concerned, they wanted the reservoirs full – but not to the point of spilling water at the dams. The nightmare being more water coming into the system than what could be controlled.

    Over time, I got to see the level in Lake Mead drop. I also got to see ‘surpluses’ doled out as the lake went down. Internally (to myself), I wondered why this was allowed to happen, Eventually, I guessed that politics was the driving factor.

    Things changed when Terry Fulp moved up from Water Ops Chief to BCOO Director. Terry often networked in scientific circles when it concerned the Colorado River Basin. I remember several workshops and presentations. The most notable being the Jeff Lucas/Connie Woodhouse workshop on tree ring studies https://wwa.colorado.edu/about/reports/WWA_Annual_Report_2006.pdf . The other being the presentation given by the Manager of the Murray-Darling Basin on their situation.

    So yeah, the internal culture within the Lower Colorado Region was aware of Climate Change and the impacts back in the early 2000’s. I also remember that Reclamation requested input from the public on several occasions.

    In fairness to Reclamation, just how do you tell the public abruptly, “We’re closing the Tap this year.”? That happened on the Klamath River some years back. The pushback was, “We’re going to lose the family farm.” Now we see this happening on the Colorado and Rio Grande Basins.

    I’d hate to be a Water Manager in these turbulent times. You are not popular with the stake holders, the media or academia. Things could be worse, the Manager could have been a Police Officer.

  3. Dave,

    These are really great points.

    I remember the presentations and emphasis on climate change, although during the Bush administration climate change was not “officially” acknowledged on high level conference calls. Terry did a great job implementing change, such as the real time accounting system of which you and others were involved.

    I was brought on for a business perspective to river operations–at least that is my understanding. Hence I was tasked with developing the first business plan for operations in the Lower Colorado Region, which was later emulated by Yuma and other offices. My perspective is based on the experience of an outsider looking in, with an attempt to bring business acumen to a Federal system of governance; in hind-sight I’m not entirely sure this was possible, but river operations was the closest I’ve seen in the government that was run like a business. For the three or four years that I was there I must have worked at least 6 or 7 years as I was on 24-7 including the weekends.

    This said, I would naturally ask questions based on what is possible, not necessary probable. This comes from a natural business sense combined with a healthy sense of risk avoidance. So for example, I joined Reclamation in July 2005, an El Nino year. In February 2005, given the drought and large volume of water on the system, operations raised the level of Lake Havasu to the lip of the dam (the level of the Havasu is recorded in the February 2005 24-month study). This was an attempt to save water on the system, versus an excess flow to Mexico which would result if Havasu was operated at a lower level. The questions that came to mind were: what is possible? Is it possible an atmospheric river could inundate the Havasu watershed, causing a pulse of water over the top of the dam? Is it possible a microburst downstream of Alamo Dam could cause a pulse of water over the top of the dam? A landslide.?…, What about a gage error ? (all due resect given, too, by the way). Did anyone contact Dam Safety? I asked these questions in 2005 and never received a technical answer based on risk avoidance, rather, something to the effect that the “director told us to raise the lake level,” a decision based solely for political reasons.

  4. Doug,

    Not to detract from the purpose of the post, I’d like to say that you were a good manager. Someone once told me that being the Water Ops Manager was a stressful job. I believe it. I’ve worked with six of them over the course of the years. It’s a difficult and stressful job. Two of them became assistant Regional Directors. One ultimately became the IBWC Commissioner, the other Regional Director. You were in good company.

    Microbursts in the Valley: Good point. I’ve seen several that made a huge impact in the hydrology. The wash above Needles being the biggie. I literally saw a channel grow to 300 feet across and 10 feet deep that washed away the Needles Hwy. All the gravel washed into the river. Another microburst on the Bill Williams happened in the 30’s while Parker Dam was being constructed. It nearly breached the coffer dams and flooded the project.

    Our field crews would always be aware of the dangers associated with Monsoon Season. The river can be a dangerous place.

  5. Dave,

    Back on point, the other day I had a short conversation with Pat Mulroy, asking her if I could cite her pre-pandemic talk on the Salton Sea pipeline. I’m currently crafting an OP-ED that agrees with her conclusions that a “game-changer” pipeline on the system could connect the Gulf of California to the Salton Sea, and stabilize the Colorado River system. Now this idea has been around for an eternity, but in my estimation it’s a very practical solution given the complexities of water supply, demand, stakeholders, geography, and the current climate emergency. Given the infrastructure bill wending its way through Congress, the Biden Administration’s emphasis on big infrastructure, the urgency associated with a changing climate, the need to demonstrate international good will and engagement, and for other reasons, I believe the time is now to get the pipeline built.
    What is unique to the Colorado River system and its stakeholders is the excellent outreach on an international basis to Mexico. As part of the pre-Minute 319 outreach to Mexico, I believe good relations established by the US and Mexico can be leveraged by the Biden Administration. The outreach and cooperation with Mexico in the form of a Gulf-Salton pipeline, and past cooperation, could be leveraged by the Biden Administration’s current outreach in the Indo-Pacific, where transboundary water issues with the Chinese are problematic on the Mekong, the Brahmaputra, Indus, or Irrawaddy.

  6. bringing more salt to the Salton Sea is like pouring gasoline on a fire.

    bringing more freshwater in from desalinated water from the ocean would be at least worthwhile and if you could use the elevation difference and gravity and wind and solar to give enough energy to make desal water and also end up exporting salt from the Salton Sea to make it an even better lake for fish and wildlife would be the best solution. a long term solution that actually does work.

    build the pipeline big enough and have some of the water used at points locally as it goes across Mexico and California and then you’ve not only got a fix for the Salton Sea, but an actual project that benefits everyone along the whole length, make some of that water available as a flow for the lower Colorado River reach and the delta then you’ve also improved a great of what was destroyed when they made it possible to take all the water at the last dam.

  7. This last post is a good start to long list of benefits that stabilizing the sea could bring. Add to it reduction in dust on western snowpack and a reduction in respiratory illness in and around the Imperial Valley. What we need is strong Federal leadership involving the State Department, Interior, and the Mexican government. We’re lucky to have leaders like Pat Mulroy who have the moxie to call a spade a spade, and communicate ideas in no uncertain terms to the stakeholder community.

    One of Pat Mulroy’s greatest strengths is her sense of community, which stems from her Catholic upbringing and involvement in the Southern Nevada Catholic Community. She has–wisely– extended this sense of community to entire Colorado River stakeholder community. We should be treating stressors on the Colorado River system wherever they are as in our own backyard, not in another state, not borne by others. This is especially true in the Imperial Valley around the Salton Sea area, where the shrinking sea has exasperated respiratory illnesses amongst some of the poorest of citizens. A Gulf-Salton pipeline would necessarily have to engage the community not just on the northern side of the border but also south of the border, with support on a watershed wide basis. What the Gulf-Salton pipeline lacks right now is Federal mandate, which could be provided if integrated into the Biden Administration infrastructure bill. The stars have aligned, the time to act is now.

  8. The stakeholders (Republic of Mexico, States, Tribes, Scientific Community, others) should take out a one page add in the Washington Post or New York Times urgently recommending action to counter the effects of climate change on the Colorado Rive system, demanding Federal action and funding toward a Gulf-Salton pipeline solution as part of the Biden infrastructure bill.

  9. it doesn’t even have to be a pipeline going down, it could be a canal moving most of the water downhill with a few power stations along the way. and then only a much smaller pipeline to move the high density salt waste water back up. i think the waste water from desalinization can be reduced to 15% or less by volume so if you add the export of salts from the Salton Sea being a part of the project even gives a result where the gravity generation of energy from 75% going downhill. boost the energy input by using solar and wind when those are abundant or even use less energy intense technologies (evaporation, etc.) since surface area can be available in places.

    now consider that if you are using desal technology you can also use it at the Salton Sea end to concentrate the brine exported and heading uphill. i’m sure there are engineers and mathematicians can figure out what the effective percents might be here for a project that can run for many hundreds of years to gradually decrease the salt concentrations while maintaining the water level (or even increasing it).

    i’m just winging it here, but to me this sounds so much more of a solution to a problem which improves the situation over the longer term instead of just making it a short term solution which will eventually have to be fixed again later.

    to me, if you are going to make the investment, make it one which helps as many people as possible.

    other potential things that can be done is make the canal big enough that the first part of it becomes a recreation and aquaculture facility. with water flowing one way and salts going back if there are evaporation ponds here or there for salt mining or other minerals that could be an entire industry. taking advantage of the highly concentrated brines in this way would probably be a good thing. also consider that any evaporation off those pans could probably add to cooling and downwind clouds and rains, if enclosed they would also potentially be yet another way to harvest even more fresh water for the energy involved.

    yet another possibility is to make the steps and stages where the water is changing salinities so that means you could have wildlife and other wetlands of sorts along the way.

    there’s a ton of possibilities here.

    it’s nice to think of improving and adding environments for everyone to use and not just limit it to the purely functional water desal moving water down and moving waste brine up. could be an entire cultural green community and some farms and wetands and other things along the ways. small intentional ground water recharges, oasisses, seeps, fountains, splash pads, birdbaths, etc. 🙂

    celebrate and have fun.

  10. Here’s a 2018 article from the Desert Sun, albeit 3 yrs old now
    10 questions about the 11 proposals to save the Salton Sea (https://www.desertsun.com/story/news/politics/2018/04/16/ten-questions-eleven-proposals-save-salton-sea/516602002/ )

    And more from the Pacific Institute, who point out that more immediate measures are needed to stabilize the Sea, as well as long term logistics associated with implementation of a permanent solution.
    https://pacinst.org/salton-sea-import-export-plans/

    Here’s a recent (2/2021) state of affairs from the Calexico Chronicle:
    https://calexicochronicle.com/2021/02/08/salton-sea-could-ocean-water-import-be-fix/

    “Kelley said that he and the Board of Supervisors have continually advocated for the Salton Sea at the state and federal levels but have not been able to garner much support for funding projects that will require billions of dollars and may or may not become financially self-sustaining.

    “I applaud everyone for trying to bring attention to this, but I want to be realistic and say that, you know, you can take a look at the New River (for reference). That’s been sitting here for quite a while, the dirtiest river in North America, and it’s still flowing. … We have advocated in Washington and in Sacramento, and we will continue to advocate, but it doesn’t seem like the wheels have turned in that direction yet,” he said.

    Board of Supervisors Chairman Michael Kelley agreed that the sea-to-sea concept is the best hope for the long-term restoration of the sea, but also expressed frustration at the lack of action from the state and federal governments, saying that the plans have been reviewed several times but “it never seems to go anywhere.”

    “My preference would be the sea-to-sea concept to restore the Salton Sea,” Michael Kelley said on Feb. 1. “And, if it’s financially unfeasible, then get the federal government involved. I told the governor himself — it was Gov. (Jerry) Brown at the time — I guarantee you if the Salton Sea issue was in the Sacramento Valley, or the L.A. basin, or the San Diego area, it would be taken care of in a heartbeat.”

  11. Here’s a recent article (2/2021) from the Calexico Chronicle:
    https://calexicochronicle.com/2021/02/08/salton-sea-could-ocean-water-import-be-fix/

    Kelley said that he and the Board of Supervisors have continually advocated for the Salton Sea at the state and federal levels but have not been able to garner much support for funding projects that will require billions of dollars and may or may not become financially self-sustaining.

    “I applaud everyone for trying to bring attention to this, but I want to be realistic and say that, you know, you can take a look at the New River (for reference). That’s been sitting here for quite a while, the dirtiest river in North America, and it’s still flowing. … We have advocated in Washington and in Sacramento, and we will continue to advocate, but it doesn’t seem like the wheels have turned in that direction yet,” he said.

    Board of Supervisors Chairman Michael Kelley agreed that the sea-to-sea concept is the best hope for the long-term restoration of the sea, but also expressed frustration at the lack of action from the state and federal governments, saying that the plans have been reviewed several times but “it never seems to go anywhere.”

    “My preference would be the sea-to-sea concept to restore the Salton Sea,” Michael Kelley said on Feb. 1. “And, if it’s financially unfeasible, then get the federal government involved. I told the governor himself — it was Gov. (Jerry) Brown at the time — I guarantee you if the Salton Sea issue was in the Sacramento Valley, or the L.A. basin, or the San Diego area, it would be taken care of in a heartbeat.

  12. i’m so glad to see the monsoon rains happening this year.

    this is what did not happen last year and set up the spring snowpack situation where the snowmelt mostly just soaked in but did not actually get much water to the rivers.

    now all we need is a bit more continuing and then a reasonable winter where there is snow in the mountains.

    everyone keep up their rain dancing! 🙂

  13. Here are further, up to date details and opinions on a Sea to Sea connection, June 11, 2021 from the Desert Sun.

    Clock is ticking on dreams of saving Salton Sea with water from Mexico’s Sea of Cortez

    https://www.desertsun.com/in-depth/news/environment/2021/06/11/can-water-mexicos-sea-cortez-save-californias-salton-sea/4977601001/
    _____________________________________
    Great points are made by IID and the Pacific Institute, regarding realistic implementation timelines and project complexities.

    Pacific Institute:
    “These import schemes are a distraction,” said Michael Cohen, a senior researcher at the Oakland-based Pacific Institute think tank. His years of studying the Salton Sea led him to believe that such a plan would require the importation of about 2.8 million acre-feet of water per year (about 910 billion gallons) to balance salinity while raising the lake’s level, and would easily cost billions of dollars — and take years to permit.
    “The time until these projects are functional is decades,” Cohen said, “and I would argue we don’t have decades with the Salton Sea.”
    __________________________________________________
    IID:
    Tina Shields is the water department manager at the Imperial Irrigation District, the single largest user of Colorado River water and an integral player in any Salton Sea fix. She labeled the lake “a challenging piece of nature, and there’s not an easy solution.” To Shields and others, engaging with such a scheme is counter-productive and distracts from tangible fixes.
    _________________________________
    Perhaps a long term solution can be integrated into more immediate, short term fixes.

  14. Pingback: Taking climate change seriously: the Colorado River “stress test” – jfleck at inkstain

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