What Did We Know and When Did We Know It: How Much Water Does the Colorado River Really Have?

I’ll be yammering in public Thursday in Albuquerque, y’all should come!

What Did We Know and When Did We Know It:
How Much Water Does the Colorado River Really Have?

In retrospect, it is clear that the 1922 Colorado River Compact was negotiated during a
historically wet period, and that as a result the agreement allocated more water than the river could actually provide in the long term, leaving problems that remain unresolved today. But what was the state of the hydrologic and paleohydrologic science at the time? Was the information available to make better decisions if the negotiators had chosen to use it? The story of the relationship between science and decision-making on the Colorado River in the 1920s, and in the decades that followed, offers important lessons for coping with the challenge of managing water in the arid Southwest today.

This is the monthly AWWA/RMWEA luncheon, anyone can come just show up:

Le Peep Restaurant
4921 Jefferson St. NE
(South of intersection of I?25 & Jefferson NE)
No RSVP or Fee Required
Attendee Pays for Own Lunch
Thursday Jan. 18, 2018
11:30 ? 1:00 p.m.
Order food at 11:30; technical program starts at 12 noon.

You can check out any time you like, but you can never leave

The palm tree as we know it is, for all practical purposes, non-native to Southern California. It requires a great deal of water, which is generally imported.

Last week I noted the disturbing analogy of 1976-77 for the Colorado River Basin, a year eerily similar in the early months of snowpack development to 2017-18.

In addition to the major drops in reservoir levels, 1976-77 produced four of the eight best-selling albums of all time:

  • Meat Loaf: Bat Out of Hell
  • The Eagles: Greatest Hits (1971-75)
  • Fleetwod Mac: Rumours
  • The Bee Gees and others: Saturday Night Fever

Also, Frank Zappa appeared in December 1976 on Saturday Night Live. Zappa played Peaches En Regalia from his album Hot Rats, which did not sell as well as Bat Out of Hell and the others but was not without its charms.

Initial forecast: Lakes Mead and Powell headed for record low in 2018

With an underwhelming snowpack right now, the U.S. Bureau of Reclamation’s initial 2018 forecast (pdf here) projects combined storage in Lake Mead and Lake Powell, the two primary reservoirs on the Colorado River, will drop to 21.7 million acre feet by the end of 2018. That would be the lowest Mead/Powell combined year end storage since Powell was first filled in the 1960s.

WARNING: Just this afternoon, I was discussing reservoir storage data with some folks working on Colorado River policy analysis and I strongly discouraged using the 2018 forecast yet. It’s early. It could snow a lot. It also could not snow a lot. The error bars on a forecast made in January are huge, it will almost certainly change in one direction or the other. But for what it’s worth, here’s my updated combined storage graph with the 2018 forecast added.

Storage in Lake Mead, Powell

There’s still enough water in storage to prevent a 2019 Lower Basin shortage declaration. But the risk for 2020 is rising.

It finally rained in Albuquerque

It finally rained yesterday morning in Albuquerque, a bit after 8 a.m., ending a 96-day dry streak.

Breaking Albuquerque’s dry streak, which ended Jan. 10 at 96 days

The water in the bottom of my gauge looked like strong tea as the rain washed out three months’ dust, and the relief was not measurable, but large. I ended up with 0.09 inch (2.3 mm) at my house, and the Albuquerque airport gauge run by the National Weather Service got 0.03 inch (0.8 mm).


My skin is cracking, and conversation at the office this week turned to moisturizing techniques. Since Oct. 1, the “water year”, 2017-18 is the third driest year in more than a century of records here, a ranking that only changed slightly among years that, for all practical purposes, saw no meaningful rain on the landscape this far into the winter season.

In my morning paper Kerry Jones (NWS meteorologist, graduate of UNM’s Water Resources Program, skilled communicator of such things) gave these “yeah buts”:

“We would need unprecedented wetness, almost equivalent to the dryness we have experienced, to make up the ground we have lost,” he said.


On the need for federal legislation to implement Colorado River drought plans

Eric Kuhn* of the Colorado River District wrote an interesting memo (pdf here) for his board’s meeting next week that lays out the options and reasoning behind current discussions about whether federal legislation will be needed to implement Colorado River Basin drought plans.

The “Law of the River”, which governs allocation, distribution, and management of the Colorado’s water is an interlocking body of statute, compact, treaty, court decision, and executive branch actions that makes tweaks tricky. If you want to do something in one part of the law – say, for example, adjust allocations to respond to drought – you have to be mindful of the impact it has on other areas of the law, even if everyone’s in agreement on the steps to be taken.

At last month’s Colorado River Water Users Association meeting, there was an interesting discussion (during a panel moderated by Eric) of whether federal legislation is needed to implement the various institutional widgets being developed under the rubric of the “Drought Contingency Plan(s)”.

There is a general consensus that legislation will be needed for the Lower Basin part of the DCP, which sets new guidelines for reducing water deliveries from Lake Mead to California, Nevada, and Arizona under conditions of Lake Mead emptiness. Here’s Eric:

Eric Kuhn on the need for federal legislation for Colorado River Drought Contingency Plan

This piece is relatively straightforward, and those favoring this approach say Congress can probably do this in a relatively straightforward, non-controversial way despite its current dysfunction. Simple stuff can still get done.

But there are other layers of complexity, including the question of whether, once we unlock the Congressional Action on the Colorado River box, we should take the opportunity to put other stuff in it. Maybe, for example, the states of the Upper Basin should ask for legislation creating a more flexible framework for operating Upper Basin reservoirs to ensure we keep enough water in Lake Powell to avoid compact delivery problems. Eric, in his board member, argues for caution in this regard:

Eric Kuhn on the risks of broader federal legislation for Colorado River Drought Contingency Plan

* Disclosure: Eric and I are collaborating on a book.

What happened in the Colorado River Basin in the winter of 1976-77?

At yesterday’s monthly Colorado Basin River Forecast Center briefing, Greg Smith noted, by way of analogy, the winter of 1976-77. Smith explained that he wasn’t forecasting – the fact that the evolution of this year’s forecast is similar to 1976-77 doesn’t mean that the rest of this year will be like that year, or that this year’s runoff will be like 1976-77. But picking analog years is a great communication tool, to give us a sense of what actually happened, historically, in conditions similar to those we might see today.

So let’s look at 1976-77.

  • Naturalized inflow from the Upper Colorado River Basin at Lee Ferry was 5.4 million acre feet, the lowest in the USBR’s Natural Flow Database (which goes back to 1906)
  • Lake Powell dropped 3.4 million acre feet, the fourth largest one-year drop since Glen Canyon Dam was built (1990, 2002, and 2013 had bigger drops)
  • I graduated from high school

None of these are encouraging analogs.


Overcoming “use it or lose it” on the Colorado – an example

Yesterday I pointed out how much water is being stashed in Lake Mead as an example of how folks on the Colorado River are overcoming the old “use it or lose it” problem in western water.

Here’s another example, this time with water taken off of the river and stored underground, in this case excess water in Phoenix’s allocation being stored via a collaborative relationship with Tucson, which has big spreading basins and aquifer storage capability:

“This is Colorado River water that they can’t use today. But if they don’t use it, they don’t have it later in the future,” Molina said. “We worked out an agreement with them where they will store extra water in our recharge facilities at no cost to us.”

The key here is the creation of a new institutional arrangement – a Phoenix-Tucson water banking deal – to overcome a shortcoming in the existing institutional arrangement. Here’s the issue: Phoenix doesn’t currently use its full Colorado River allocation. Four years ago, it toyed with the idea of simply storing its unused allocation in Lake Mead. But that can’t happen, because rules. The rules proved difficult to change, so Phoenix and Tucson developed a side deal, inventing a new institutional widget that allowed them to accomplishment something quite similar under the existing rules.

Overcoming “use it or lose it” on the Colorado River

The “use it or lose it” problem in western water happens when water users who conserve are penalized by having the saved water simply go to another user.

A series of policy innovations over the last decade to overcome this problem are showing up right now in a big way in Lake Mead. In all, through these various mechanisms, more than 700,000 acre feet of water are being left in Lake Mead this year.

Without this water, Mead would probably be under elevation 1,075 right now, and we’d be having our first formal shortage declaration.

Not to alarm you further, but the Jan. 1 runoff forecast for New Mexico is really really bad

As I mentioned, this is the driest start to a water year in a century in Albuquerque. The preliminary Jan. 1 runoff forecast from the federal Natural Resources Conservation Service bears this out. The forecast, based on snow measurements, is stark. NRCS has 40 years of snow records, and for many sites, this is the driest start to a water year on record. In other words, it’s not just down here in the city. It’s up in the mountains of northern New Mexico and southern Colorado, where snowpack feeds New Mexico’s rivers.

With months of snow season yet to come, this should be considered very preliminary in nature. But the statistical probabilities suggest that, for many of New Mexico’s rivers, the chances of a record low year are higher than the chances of an average year.

Some numbers (all of these are median forecast numbers):

  • Rio Grande near Lobatos, near the Colorado-New Mexico border: 15 percent of average
  • Embudo Creek at Dixon: 16 percent of average
  • Rio Grande at Embudo:
  • Rio Grande at Otowi: 24 percent of average
  • Rio Grande at San Marcial, at the head of Elephant Butte reservoir: median forecast of essentially nothing, which is not plausible but the snowpack is so lousy that the model kinda breaks here
  • Pecos at Santa Rosa: 18 percent of average

A few things to remember.

First, it could snow a lot. These numbers could come up. The forecasts for the next month are “meh“, but this could happen.

Second, it could get worse. See previous link to “meh” forecast for the next month, and also recall that both the recent weather and the long term climate have trended on the warm side, which means that for a given amount of snow, paltry as it is, less water is ending up in our rivers.

Third, as I have written before, this is happening in the context of some very important changes in the approach to water management in New Mexico over the last few decades, in terms of conservation and diversification of supply, that leave our human water systems in a very resilient position. That resilience is likely to be very seriously tested this year.