The difficulty in U.S. municipal water use comparisons

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Kathleen Ferris of the Arizona Municipal Water Users Association on the difficulty of comparative water use analysis:

[C]omprehensive information on conservation and reuse implemented to date is not available. Each of the water providers within the ten metropolitan areas track information about their conservation programs differently. For example, water use in central Arizona is tracked by the state Department of Water Resources based on reports that cities are required to file annually. We have been collecting that data for over 30 years. Most metro areas track their information separately. On top of this, there are no consistent accounting categories or definitions and that makes comparing efforts virtually impossible.

Having wrestled with this problem myself, I “+1” Ferris’s observation.

Not my grandpa’s MWD

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In 1952, Robert Gottlieb and Margaret FitzSimmons explain in their 1991 book Thirst for Growth, the Metropolitan Water District of Southern California essentially extended a promise to the communities it served: build away, we’ll get you the water as needed. It came in the form of the “Laguna Declaration” (so named because of the lovely beach community where the declaration was signed):

When and as additional water resources are required to meet increasing needs for domestic, industrial and municipal water, The Metropolitan Water District of Southern California shall be prepared to deliver such supplies.

Time was, that meant flexing the political muscle needed to build the State Water Project, to bring northern California water south over the Tehachapis to the Southern California coastal plain, or trying to get a Peripheral Canal or a couple of big water-moving tunnels built to run water past the Sacramento Delta. It’s the sort of thing my late grandfather John S. Berry, a Republican Realtor of the old Southern California-building kind, could get behind. He loved the big water projects.

These days, it apparently means tearing out lawns. Bradley Fikes in the Union Tribune:

Southern California’s largest water agency, Metropolitan Water District, will consider dramatically increasing its conservation budget by a record $350 million, which it says will make the water-saving program the nation’s largest.

The additional expense could also raise water rates by 21 percent, according to one of its board members.

With all the attention to drought, MWD has had a huge burst of interest in its subsidized water conservation programs, especially paying residents and businesses to rip out there lawns.

Here’s the meat of the proposal:

 

For comparison, 172 million square feet is just a tad shy of 4,000 acres, the equivalent of less than one percent of the acreage currently under irrigation with Colorado River water in Imperial County. In 2012-13, MWD sold 1.68 million acre feet of water, so the 23,000 acre feet of water savings a year from the lawn piece is a bit more than 1 percent. (Click on the excerpt to see the full staff report.) Not a lot of water, though if you keep doing it year after year, it could add up.

Back in grandpa’s day, “deliver such supplies” meant a new dam and a canal or pipe. These days it’s tearing out lawns, I guess.

Feral alfalfa

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Feral alfalfa, getting an impromptu irrigation as the Rio Grande overbanks through Albuquerque

Feral alfalfa, getting an impromptu irrigation as the Rio Grande overbanks through Albuquerque

I’m not great with plants, so feel a little silly for not realizing the green plants in the foreground (which I’ve been seeing in our Albuquerque riverside bosque for years) are alfalfa. But after spending time in alfalfa farms recently, I snapped to the connection and sent a picture to Tim Lowrey, a University of New Mexico professor who’s my go-to plant helper, to confirm the identification.

Tim’s also one of the coauthors of the Field Guide to the Plants and Animals of the Middle Rio Grande Bosque, which of course I should have realized has alfalfa listed as one of the commonly found bosque plants. It’s not terribly invasive, Tim told me, but it does like a nice bit of disturbed ground and the chance to stick its roots down into the water table. In this case, the alfalfa (and a baby cottonwood) are growing on a shelf next to the river, which is currently a bit underwater with the high flows we’re having.

California ag showing remarkable resilience

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Amid the rhetoric of doom, California agriculture has so far been growing its way through drought:

Even as many farmers cut back their planting, California’s farm economy overall has been surprisingly resilient. Farm employment increased by more than 1 percent last year. Gross farm revenue from crop production actually increased by two-tenths of 1 percent last year, to $33.09 billion, according to the U.S. Department of Agriculture.

That’s from Dale Kasler and Phillip Reese at the Sacramento Bee, who have have had a couple of recent stories challenging the apocalyptic framing around the impact of drought on California agriculture. Last week they noted in more detail the observation that, pockets of trouble notwithstanding, overall agricultural employment in California is up:

Overall, there was more farm work available in California last year than during any other year at least since 1990, when modern record-keeping began, according to the state Employment Development Department. And hired farmworkers collectively made more money, too, separate federal data show.

This is exactly what Bob Young, an agricultural economist, was getting at back in the 1960s when he described the transformation of central Arizona agriculture as water supplies declined. As water runs short, Young argued, its users adapt.

As Kasler and Reese are reporting, it has not been easy for farmers. But this suggests that what I’ve come to think of as “the California experiment” – the deepest shock on this sort of time scale to a large, 21st century agricultural/urban economy – has much to teach us about adaptation and resilience when the water runs low.

In 1973, Mexico worried U.S. would slip radioactive waste into Colorado River drain water?

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Minute 242, an addenda to the U.S.-Mexico Colorado River Treaty, (pdf) contemplated construction of a drain to safely carry high salinity U.S. drainage past municipal and agricultural intakes and dump it into a slough near the Sea of Cortez.

It was a time of tension between the two countries over the salinity issue. (Evan Ward’s Border Oasis tells the tale.) How tense? It is fascinating to imagine the back story that left Mexico to feel this language needed to be included in the 1973 agreement:

It is understood that no radioactive material or nuclear wastes shall be discharged through this drain.

Middle Rio Grande update

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Water managers increased the release this afternoon (Thurs. May 21) from Cochiti Dam into New Mexico’s Middle Rio Grande Valley to 3,000 cubic feet per second, which will increase flows yet more tomorrow through Albuquerque. As I explained yesterday,  May storms and some clever water management twiddling with stored supplies is providing the opportunity for a seasonal “pulse” that looks like the largest spring flow since 2010.

I don’t want to oversell this. The Rio Grande is a system intensively managed for flood control and water delivery such that it bears little resemblance to the meandering flood plain river that once flowed through what is now Albuquerque. Its narrow central channel isolates the river from the flood plain that flanks it, where it once would regularly get up and spread across the land. But there have been modest human efforts to mimic the old natural system, using earth moving equipment to create channels and back waters that inundate at modestly higher flows like we’re seeing now. The managers are trying to take advantage of the natural flow from storms, with some added water they’re throwing in from storage on the Chama (releases from El Vado are way up) to create a miniature version of what the river once did by itself.

I spent the afternoon out looking at the results so far. Here’s one of the newly dug channels near Albuquerque’s Tingley Beach city park:

Overbanking on the Rio Grande near Albuquerque

Overbanking on the Rio Grande near Albuquerque

For the first time since 2011, less than half of New Mexico in drought

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For the first time since January 2011, less than half of New Mexico is classified in “drought” this morning in the weekly federal “Drought Monitor” (“drought” is the oranges and browns):

Drought Monitor

Drought Monitor

Driving back across the state from a meeting in Arizona last week, things looked greener than I’ve seen in a long time, though I realize that much of my drive, in western New Mexico, was still in the “drought zone”. But I’ve been out that way frequently since January, and you can see the change.

In addition, as I wrote yesterday, the May storms have (finally) brought Rio Grande spring runoff to its highest levels since 2010. But it’s important to remember what this does not mean.

Drought is no one thing. While the map above reflects good late spring precipitation, the mountain snowpack was terrible, and there’s no way to make up for that with spring storms. Drought on the landscape (greening of vegetation, shallow soil moisture) and water in the river are related, but they’re not the same. The map reflects drought on the landscape. Water in the rivers is still problematic. Flow on the Rio Grande may be up to levels we haven’t seen in five years, but that’s as much of a measure of how lousy it’s been over the last five years, as it is a measure of how good things are this year.

 

New Mexico’s Rio Grande, on the rise (finally)

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Water from our recent storms, combined with the some clever twiddling by federal and local water managers, is pushing the Rio Grande through Albuquerque in the next few days to the highest spring runoff levels we’ve seen since 2010. Water managers are taking advantage of the May storms to add some water and create a runoff spawning spike for the endangered Rio Grande silvery minnow.

Rio Grande rising, Otowi, NM

Rio Grande rising, Otowi, NM

The U.S. Army Corps of Engineers this morning increased releases from Cochiti Dam, north of Albuquerque, to 2,000 cubic feet per second, with as much as 3,000 to 3,500 cfs by tomorrow (Thurs. 5/21). Much of the water is a pulse of runoff from the mountains north of Santa Fe (Embudo Creek last night peaked at 1,000 cfs), but the U.S. Bureau of Reclamation and the Middle Rio Grande Conservancy District are adding flows on the Rio Chama from El Vado Dam to create the spawning spike, which could hit 3,000 cubic feet per second at Central Avenue in Albuquerque by late this week or this weekend.

The remarkable turnaround is the result of a wet May (already the wettest May since 2007 in Albuquerque). Just three weeks ago, managers were scrambling for water, with little chance for a minnow spawning spike and with farmers in the middle valley on shaky ground. Now the farmers are hoping for it to dry out so they can get their alfalfa cut, and MRGCD storage upstream looks like it could have enough water, between native water and what they’ve been able to store in El Vado Reservoir, to last through the season (depending on the weather, I’m told – always depending on the weather).

The Rio Grande has spiked this high a few times in recent years as a result of summer thunderstorms and an epic September 2013 event, but this is the first time since 2010 that a peak this high has arrived at this time of year, which is the critical time for the minnow, an endangered fish whose status drives a lot of the politics and policy of the river’s management.

 

“Enough water will never be enough”

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California’s water problems will never be solved Faith Kerns and Doug Parker argue, because cities and farms will always expand to the edge of available supply, overshoot, and then face trouble during the dry times:

There are other arenas where this phenomenon is well understood. For example, when it comes to freeways, congestion leads to demand for more lanes to be built. More lanes temporarily reduce congestion and lead to increased housing construction, and over time, that increased housing construction leads to more congestion. That, in turn, leads to demand for more lanes. This is also true with flood control: better levees lead to safer communities, which cause communities to expand and demand even better levees.

Accepting this fundamental paradox doesn’t mean that we should throw our hands in the air and do nothing — and in fact, we aren’t. We should be, and are, looking at augmenting supplies and increasing conservation efforts. We need to pursue all of these options in order to have healthy communities, healthy agriculture and a healthy environment.

We also need to recognize, however, that these options will never fully eliminate future scarcity.

This generalizes across the arid West. The full piece is worth reading.

Update: Forgot the best pull quote:

If it were simple, it would already have been done.

In defense of “vapor pressure deficit”

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If you follow weather forecasts, you’ve heard about “relative humidity” (RH). But it’s one of those maddeningly less-than-useful measures of our weather that probably needs to be just retired. That’s wishful thinking, of course. But in an interesting introduction to their latest research into the increasing dryness of the air and the risk of fire that attends thereto, Richard Seager and his colleagues make another plea. Paraphrasing a 1936 paper by D.B. Anderson, they write:

Anderson (1936) points out that RH is not an absolute measure but merely a ratio of two known quantities expressed as a percentage.

If you can do the math quickly in your head, you can keep an intuitive grasp of the meaning of RH in a given situation. But using a measure that requires your audience to do math in their head to make sense of what you’re telling them is a bad communication strategy. Riffing off of Anderson, Seager and colleagues argue for the importance of a different measure that requires no such math – “vapor pressure deficit”. I’ll skip their equations for this:

VPD gives an absolute measure of the atmospheric moisture state independent of temperature. For example, for a given wind speed and atmospheric stability, above a surface that is not water-limited, a specific VPD leads to the same rate of evaporation, regardless of temperature.

Why should we care? Because vapor pressure deficits are rising in the southwestern United States, and are closely linked to wildfire risk. The public communication element of “VPD” vs. “RH” is really just a sidelight to an important new paper about rising fire risk as the southwest warms. (In particular they look in detail at VPD and the Rodeo-Chediski and Hayman fires.) But I found it intriguing. I’d love to have it added to my daily forecast page.