This is Eileen Wray-McCann for Circle of Blue. And this is What’s Up with Water, your “need-to-know news” of the world’s water, made possible by support from people like you.

In Southeast Asia, the organization that represents four countries in the lower Mekong River basin called on China for greater transparency about its dam operations in the upper reaches of the watershed. Recent reports have blamed China’s dams for curtailing river flows at a time when the lower basin was suffering drought. Those lower basin countries – Cambodia, Laos, Thailand, and Vietnam – are represented by the Mekong River Commission, which is hampered by limited information about water levels and rainfall upstream. The commission says that timely and accurate data-sharing by China is necessary to help the lower Mekong countries plan for adverse conditions.

In Venezuela, the expansion of an informal settlement on the outskirts of the capital Caracas is another sign of the country’s economic collapse. Reuters reports that there are no toilets or running water in a group of several dozen mud and bamboo huts known as Los Trailers. Residents get their water from a well. For toilets, they use the nearby bushes or plastic bags. Venezuela was once the wealthiest country in South America, but living standards have collapsed under the regime of Nicholas Maduro.

In the United States, as society reopens following coronavirus lockdowns, insurers of commercial buildings are taking steps to prevent the spread of Legionnaires’ disease. Reuters reports that insurers are scrutinizing the water management practices of building owners, asking some owners to document their maintenance of plumbing, heating, and cooling systems. Insurers could require higher deductibles for inadequate care. Legionella bacteria, which cause the deadly pneumonia-like disease, grow within building plumbing systems. The fear is that water that sat stagnant in pipes when buildings were unoccupied could be a breeding ground for the bacteria. Legionnaires’ cases typically peak in the late summer and early fall.

Nevada’s top water regulator is restricting groundwater pumping in an area north of Las Vegas. That’s according to the Nevada Independent. The state engineer says water use in the area must be capped at 8,000 acre-feet a year. That’s about 12 percent less than current pumping. The cuts are required to protect the endangered Moapa dace fish and to keep the groundwater basin in balance. The ruling will have a major effect on developments northeast of Las Vegas, including Coyote Springs, a proposed master-planned community.

This week Circle of Blue reports on a remarkable drop in Colorado River water consumption. It’s an encouraging sign for the beleaguered river.

The three states that hold the Colorado River’s lower basin used a lot less of its water last year, a low that hasn’t been seen in 33 years. This comes at a time of growing awareness of the vulnerability of the region’s water in a drying and warming climate. Arizona, California, and Nevada combined to consume just over 6.5 million acre-feet last year, according to an annual audit from the Bureau of Reclamation, the federal agency that oversees the lower basin. That is about 1 million acre-feet less than the three states are entitled to use under a legal compact that divides waters of the Colorado River.

The last time water consumption from the river was that low was in 1986, the year after an enormous canal in Arizona opened, which then allowed the state to lay claim to its full Colorado River entitlement. In the last two decades, the states have grappled with declining water levels in the basin’s main reservoirs — lakes Mead and Powell — while reckoning with clear scientific evidence that climate change is already constricting the iconic river and will do further damage as temperatures rise.

Bill Hasencamp is the manager of Colorado River resources for the Metropolitan Water District of Southern California, which is a regional wholesaler and one of the river’s largest users. For water managers like Hasencamp, the steady drop in water consumption over recent years shows that conservation efforts are working and that managers can respond to daunting environmental changes. He said “It’s quite a turnaround from where we were a decade ago and really, I think, optimistic for dealing with chronic shortages on the river in the future, knowing that we can turn the dial back and reduce demand significantly, all three states combined.”
Observers of the basin’s intricate politics are also impressed with this trend, in a watershed that irrigates about 5 million acres of farmland and supplies a portion of water to 40 million people living in two countries and 29 tribal nations. John Fleck is the director of the University of New Mexico water resources program. He told Circle of Blue that the trend was a powerful demonstration of the fact that people can use less water in an extremely important water-use region. Projections for this year indicate that conservation will continue, though not quite at last year’s pace. Halfway through the year, the Bureau of Reclamation forecasts that water consumption will be roughly 7 million acre-feet. An acre-foot is the amount of water that will flood an acre of land to a depth of one foot, or roughly 326 thousand gallons. Jennifer Gimbel, a senior water policy scholar at Colorado State University, gave a nod to the lower basin states. “I have to give them credit,” she told told Circle of Blue, “They’re working hard to get these numbers.”
The Bureau of Reclamation’s annual audit measures the amount of water consumed by humans, plants, and animals in the lower basin. Consumptive use is calculated by looking at total withdrawals and factoring in water that is returned to the river system, either from irrigation runoff or wastewater treatment plants. As meticulous as it is, the audit neglects a significant piece of the basin’s water budget: evaporation from reservoirs, and system losses. System losses include water consumed by riverside vegetation and absorbed by the ground. Jeremy Dodds, Reclamation’s water accounting and verification group manager, told Circle of Blue that evaporation and system losses add up to about 1 million acre-feet per year. This is part of the lower basin’s “structural deficit,” its inability to replenish supply in order to match demand. Total demand includes use by Arizona, California, and Nevada, plus evaporation and required deliveries to Mexico. That’s more water than flows into Lake Mead, which supplies the lower basin.

Conservation efforts aim to keep Lake Mead from a precipitous decline into what’s called “dead pool” territory, where the reservoir is too low to send water downstream. The dead-pool threshold is at about 900 feet elevation. States have used various tools to cut water use. Cities have offered incentives to remove grass lawns and replace inefficient toilets, showerheads, and washing machines. In Imperial Irrigation District, farmers have lined earthen canals with concrete to prevent seepage and they have agreed to fallow land to save on irrigation. Those measures, in both town and country, have helped to reduce demand. Supplies, on the other hand, have been bolstered by more investment in recycling and reuse, groundwater treatment, and desalination. Last year, the seven states in the Colorado River watershed joined to modify rules for mandatory water-use restrictions that are tied to dropping levels in Lake Mead.

Still, there are obstacles to navigate on the path to sustainability. There are dozens of proposals in the upper basin states that would withdraw more water from the river and further stress supplies. Also, there are existing claims on water that could be called in. Some of the water conserved in Lake Mead is stored as a credit for participating agencies who can theoretically draw upon this “water account” in the future. However, it’s not certain how such withdrawals would be handled, especially if large requests are made as lake levels plummet. On top of that, a warming climate will suck more moisture from the basin, even before rain and snow reach the river.

A hot, dry spring this year in the Colorado River’s upper basin shows what aridity can do. Snowpack in the basin’s headwaters was about average on April 1 and runoff into Lake Powell, a key water supply indicator, was expected to be 78 percent of normal. But April and May brought dry conditions, and dehydrated soils also took their share of water. By June 1st, the runoff water supply estimate for Lake Powell had fallen nearly 20% from the spring forecast. Runoff is now expected to be 57 percent of normal. Those climate signals are the counterbalance to the conservation success so far. Water managers like Hasencamp are aware of the risk. “Just hopefully” he said, “we don’t get a string of dry years coming back.”

And that’s What’s Up With Water from Circle of Blue, which relies on your support for independent water news and analysis. Please visit and make a difference through your tax-deductible donation.