Breaking a flash drought: Aug. 8, 2023 rainfall in Albuquerque, Courtesy CoCoRaHS

August 8 is more than a little late for Albuquerque’s first solid monsoon rains to break our weirdly hot flash drought, but we’ll take it.

Typical monsoon onset here is early July, plus or minus a week-ish. At the risk of overstating because of a lack of precision, Aug. 8 is record late.

I was on a Zoom yesterday with a group of Colorado River colleagues when my phone started pinging insistently with the family’s traditional “rain here!” and “thunder!” from the various Fleck and Co. outposts scattered around Albuquerque’s city center. The rainfall numbers from CoCoRaHS volunteers, shown above, show a classic monsoon storm variability, but you can see the numbers growing as the cell(s) rolled up toward the foothills on the eastern side of the map.

Biggest Monsoon Storm by Fleck’s favorite measure in a decade

One good measure of the scale of these storms with respect to the city is Albuquerque’s North Diversion Channel, which collects runoff from the city’s built-up Northeast Heights, where most of us live. The channel integrates across a much more meaningful area than any single rain gage – the area where a bunch of us (including me!) live. The NDC peaked yesterday afternoon a bit after 3 p.m., just after my Zoom ended, at 7,630 cubic feet per second. That’s not a meaningful number for lots of you, so by point of comparison it’s our biggest NDC flow (and therefore the biggest single monsoon storm across this part of the city) since July 2013. (USGS data sources: NDC gage)

Ribbons of Green

For the new book, we’re writing a series of vignettes that track the Rio Grande over the course of a single year. For convenience sake, we’ve chosen this one (duh), so this stuff’ll go into the book. One of the tricks I’m using – this may not go into the book, it’s one of those “Danger, Fleck Doing Math!” things – is to monitor gages at the north end of the Albuquerque reach and the south end, a crude mass balance metric of how much water is being consumed in our stretch of the middle valley. This morning’s additions to my spreadsheet showed the reach adding water for the first time since I started keeping track. Usually we subtract water – which is to say, evaporation in this stretch of the river is what keep’s the valley green.

All of the storm’s water dumps into the Rio Grande in a hurry, through a network of concrete diversions channels mostly built in the 1970s as the city spread up onto the mesa on the river’s east side. It’s a sharp peak at the NDC outfall, but by the time the pulse reached the Central Avenue Bridge ~8 p.m. (five hours’ travel time) it was down to ~2,500 cfs. The volume of water probably shrank as some of it spread out into the bosque, but mostly it just spreads out in time, a sort of sloshing effect.

July 22, 2022, when wastewater from Albuquerque’s sewage treatment plant was the only thing keeping the Rio Grande here wet

Area water managers were informed this morning that the Albuquerque Bernalillo County Water Utility Authority will shut down its diversion of water from the Rio Grande for use in the municipal drinking water system, switching over to groundwater pumping to meet municipal needs.

The reason is low flows in the river. Albuquerque is constrained by a 2004 “biological opinion” from the U.S. Fish and Wildlife Service, which requires the municipal utility to shut down to minimize impact on the endangered Rio Grande Silvery Minnow.

The water Albuquerque diverts – when we’re diverting – is half water from our San Juan-Chama Project transbasin diversion (Colorado River water!) and half native water. We then kinda sorta return the native water to the river via the wastewater treatment plant. The idea is that half of it we consumptively use by dumping the Colorado River water on our lawns and trees, while the native water we run down the sink, clean up, and return to the river – an accounting exercise intended to leave the river whole.

The creates a weird bonus in the short run for the river when this happens, because now we pump groundwater to meet all those needs, and then dump some of that into the Rio Grande, thereby increasing the river’s flows in the short run.

Last summer, for a brief period of time, that pumped groundwater/wastewater was the only thing keeping the Rio Grand wet through the southern end of the Albuquerque reach,.

Rio Grande in Albuquerque, Aug. 4, 2023. Photo by John Fleck

The Rio Grande, already dry in the San Acacia reach south of Socorro, has begun drying in the Isleta reach south of Albuquerque. And with a record hot dry summer, we could see it dry in Albuquerque again this year, as it did last year for the first time in 40 years.

Via Dani Prokop:

New Mexico’s largest river could dry again through the state’s largest city, for the second time in about forty years, if the monsoons continue to be weak.

“We could see drying in Albuquerque as early as mid-August,” (the USBR’s Carolyn Donnelly) said.

Problem 1 this year is that it’s hot and dry. Problem 2 is that El Vado Reservoir, built in the 1930s to store spring runoff for use at times like this, is under repair. So the stored water that would provide both irrigation and environmental benefits is unavailable.

This morning’s water management notes from the USBR noted 30 miles dry in the San Acacia Reach and a mile of dry riverbed in the Isleta reach.

Flow this morning through Albuquerque was a bit above 300 cubic feet per second. The median for this point in August is ~600 cfs.

The interstate bridge being built across the Rio Grande, Albuquerque New Mexico, 1969, photo by Walter McDonald, courtesy Albuquerque Museum

Breaking out of my old “water policy writer” habits is hard.

The bridges of Albuquerque are helping.

Counting and Measuring

Prepping for an appearance on this Friday’s New Mexico In Focus on NMPBS, I’ve spent a bunch of time the last few days digging through agricultural water use data. (Spoiler alert: Ag water use has been declining in New Mexico for decades. Climate change adaptation is happening. When people have less water, they use less water.)

That’s long been a staple of my water policy writing – USDA NASS, and Cropscape, my beloved USGS Water Use in the United States data series, and on and on and on. You can’t manage what you don’t measure, amiright?

But our new book Ribbons of Green: The Rio Grande and the Making of a Modern American City, has me staring down the limitations of approaches I’ve used for so long.

Bridges

My coauthor Bob Berrens and I are deep into bridges right now. The literal physical objects that get you from one side of a river to the other. You can’t build a city on a river valley floor without confronting the collective action challenge of bridges.

Who builds (read “pays for”) them? Where do you put them?

In the 1920s, people in Albuquerque engaged in political struggles between neighborhoods that wanted bridges. Sixty-seventy years later, there were political struggles based on communities that didn’t want them.

Defining “water policy”

Bridges are not the only example of our attempt in Ribbons of Green to embrace an expansive definition. We’re writing about parks and recreation. We’re writing about evolving cultural relationships with the Rio Grande, including deep and diverse relationships with the act of irrigating and growing food. We’re writing about trees, and fish.

I’m reading Rudolfo Anaya right now. His characters go down to the river. That’s admissible evidence.

Establishing parks, and building bike trails, helps shape a community’s relationship with the river. That’s water policy.

Building fences to keep kids from drowning in irrigation canals helps shape a community’s relationship with the river. That’s water policy too.

Protecting wetlands? Water policy.

Regulating waterfront development (either encouraging it or prohibiting it)? Water policy.

Cutting down trees along an irrigation ditch to conserve water (or leaving them there as shade for the ditch walkers)? Water policy.

Fishing rules, canal trails, historic preservation and commemoration of the old canal headings at Atrisco? Water policy.

All of these things have a common characteristic: they reflect the tradeoffs we must make, the often competing and conflicting values we must articulate, things lying at the intersection of economic resources, ecological resources, and public infrastructure that define what Albuquerque has become as a modern city.