Tuesday, January 13, 2009

Wildcatting for water in New Mexico

This joke runs through my head every time I drive to Albuquerque.

Q: What's the easiest thing to grow in the desert?
A: Subdivisions.

In the eight years I've lived here, I've watched the northwestern suburbs of Albuquerque expand along the southwestern side of US 550. It's still a beautiful drive... there are just a lot more houses there, beside the new Home Depot.

Albuquerque sits on the Rio Grande, which you might think would be a great source of water. But water rights along the rivers of the western US are complicated, and Albuquerque has historically used groundwater as its primary water source. This year it began using water pumped across the Continental Divide from tributaries of the Colorado River - New Mexico hadn't historically been using the water it was allocated through the Colorado River Compact. But for a growing city, it's not enough.

So now deeper groundwater - brackish water, saltier than you would want to drink - is being considered as a possible water source.

Albuquerque journalist John Fleck has a fantastic piece (ad-gated) in last weekend's Albuquerque Journal about the laws - or rather, lack of laws - governing the deep water:

All up and down the wild mesa lands and valleys to the west of the Albuquerque metro area, holes are being drilled and claims are being staked by developers who believe they can bring the brackish water to the surface, clean it up and use it to water subdivisions stretching to the horizon.

When the Legislature convenes Jan. 20, it will again be asked to deal with the problem, closing the loophole in state law that leaves the deep, brackish water unregulated, creating what the state's top water official, state Engineer John D'Antonio, has called "a free-for-all."

He also has some more details in discussions in his work blog. It's great thinking, combining an understanding of economics and human behavior with a realistic picture of groundwater:
The most obvious example comes with hydrogeologic connections between the deep brackish water and shallower aquifers, or surface water. Through fractures in the bedrock, it is possible that when you pump out the deep aquifer, water could drain down from shallower aquifers above, or even from surface water.

Hooray for understanding the potential problems associated with fluid flow through fractured media, and for communicating those issues to the rest of the world.

The entire issue - drilling for brackish groundwater - is just stunning to me. I mean, I know that there's water in rock down deeper than the stuff we think of as aquifers. (There's even water in what little pore spaces exist in metamorphic rocks.) But I'm not used to thinking of it as useful to humans. In the coal-bed methane fields south of Durango, brackish water is pumped out to release the methane, and is disposed of as waste. (Not dangerously toxic, but something that generates an outcry when there are rumors of it being pumped into rivers.) But it's water - and it may be useful too.

Albuquerque's already thinking about it. And it makes me wonder how Colorado, or Arizona, or other states in the high desert think about currently useless water - and whether a population that commonly thinks that groundwater consists of underground lakes is prepared to address the problem.


Chris M said...

I wonder how this is connected to the recent ruling about domestic wells impacting water right holders. In NM, you are allowed to pump 3 acre-ft without a water right. I am surprised the developers aren't just selling the house with domestic wells (although this may not be allowed within the city limits?).

Kim said...

I don't know the details, but I think part of the issue may be that Albuquerque already taps the shallow groundwater for its city water supply. And Albuquerque's use of the water affects water flow in the Rio Grande, which means that the use of the aquifer has international implications (because there's a treaty governing the distribution of Rio Grande water between the US and Mexico - although I think Mexico is supposed to make sure water gets to the US, unlike the situation with the Colorado, where we're obligated by treaty to provide a certain amount to Mexico).

Anyway, I think in this case the groundwater that might have been used for domestic wells is already allocated. (I wonder if this will become an issue in other parts of the West - for instance, if Las Vegas gets rights to groundwater in places like the Snake Valley. Similar tectonic/structural settings, actually, there.)

John Fleck said...

The domestic well rules haven't had much of an effect on New Mexico's major urban areas, but they're a factor at the city's edges. It's not really economically feasible to use the domestic well provisions to build subdivisions on the multi-thousand home scale, which is why you see things like brackish desal being considered. There's also a lot of uncertainty about the future of the domestic well rules. The judge's ruling in the Bounds case, which set off the appeal you linked to, is amazingly straightforward, and most folks in the New Mexico water community think it will be upheld, closing off the domestic well-without-water-rights option.