The outflow at the bottom of Navajo Dam in New Mexico. Photo: Brent Gardner-Smith/Aspen Journalism
From email from Reclamation (Susan Novak Behery):
As the forecast weather becomes warmer and drier again, the Bureau of Reclamation has scheduled an increase in the release from Navajo Dam from 350 cubic feet per second (cfs) to 500 cfs for tonight, July 3rd, at 9:00 PM.
Releases are made for the authorized purposes of the Navajo Unit, and to attempt to maintain a target base flow through the endangered fish critical habitat reach of the San Juan River (Farmington to Lake Powell). The San Juan River Basin Recovery Implementation Program recommends a target base flow of between 500 cfs and 1,000 cfs through the critical habitat area. The target base flow is calculated as the weekly average of gaged flows throughout the critical habitat area from Farmington to Lake Powell.
This scheduled release change is subject to changes in river flows and weather conditions. If you have any questions, please contact Susan Behery (sbehery@usbr.gov or 970-385-6560), or visit Reclamation’s Navajo Dam website athttps://www.usbr.gov/uc/water/crsp/cs/nvd.html
Ridgway’s Rail. Photo: Robert Groos/Audubon Photography Awards
Click the link to read the release on the Audubon website (Jennifer Pitt):
May 21, 2024
The Colorado River is flowing again in its delta. While this is welcome news for birds and people, the long-term progress to keep the Colorado River alive in Mexico with habitat restoration and water deliveries depends on high stakes negotiations currently underway.
For the third time since 2021, the United States and Mexico are collaborating to deliver water to improve conditions in the long-desiccated delta. Environmental water deliveries began mid-March and will continue into October, ensuring the river flows through the summer’s heat, making restored riverside forests and wetlands more hospitable to birds like Abert’s Towhees and Crissal Thrashers and other wildlife including beavers and lynxes. We know that birds rely on water in the Delta as they migrate to locations all over the United States.
Restoration in the Colorado River Delta is implemented by Raise the River, a coalition of NGOs including Audubon, in partnership with U.S. and Mexican federal agencies. Funds, water, and collaboration for this work were committed first in Minute 319 and again in Minute 323, the United States–Mexico treaty agreements that have been widely hailed for modernizing Colorado River management with a host of benefits to water users in both countries including rules for sharing water shortages, as well as work to use relatively small volumes of water to revive the delta for wildlife and people. The terms of Minute 323 sunset in 2026, but delta restoration efforts remain a work in progress.
The good news: the United States and Mexico are poised to negotiate a successor agreement to Minute 323 in parallel with new federal rulemaking in the United States for Colorado River management. Domestic Colorado River rules, like the binational agreements, have for decades been the result of consensus-based negotiations, in this setting between the seven Colorado River Basin States with concurrence of the U.S. Bureau of Reclamation. This domestic rulemaking also has a 2026 deadline.
The bad news: at the moment, the Colorado River Basin states appear to be nowhere near consensus, with disagreements about which states, and which water users, will cut back when there’s not enough to satisfy all. These are difficult and high stakes negotiations. Failure to reach agreement increases the risk of water supply crises and could even throw the dispute in front of the U.S. Supreme Court.
That brings me back to the Abert’s Towhees and Crissal Thrashers, the beavers and lynxes in the Delta. If the Colorado River Basin states fail to reach consensus, there’s considerable risk that the work of restoring the Colorado River in its delta comes to a halt. Delta restoration depends on binational consensus, and binational consensus depends on a U.S. domestic consensus. It’s an extraordinarily complex decision-making framework for governance of water supply for 40 million people. The failure to reach consensus may create problems for some people who use Colorado River water, but it is certain to create collateral damage in Colorado River ecosystems including the Delta.
East of the Rocky Mountains, there was a mixture of worsening and improving drought conditions this week. With the passage of a couple of frontal boundaries across the eastern contiguous U.S. (CONUS), in addition to a steady moisture flow from the southwestern CONUS into parts of the Central Plains, several areas across the eastern two-thirds of the U.S. received heavy precipitation. However, heavier amounts varied greatly from region to region and were highly localized east of the Mississippi River. Rates of evaporation of moisture from land and vegetation (known as evapotranspiration) are high across the eastern CONUS, due in large part to several days of excessive heat. Therefore, targeted improvements are depicted in regions picking up above normal precipitation (at least 1 inch above normal rainfall for the week) and where improvements to soil moisture and stream flows were apparent. Given the very dry and hot antecedent conditions leading up to this week, drought degradation is merely halted in most other areas receiving above normal rainfall, as indicators did not show marked improvements. Conversely, for locations receiving below normal rainfall, another week of degradation is warranted. In the West, the Four Corners region was the beneficiary of yet another wet week, aided by a couple of low pressure systems bringing an influx of moisture into the region. Elsewhere in the West, conditions worsened, with several pockets of abnormal dryness (D0) popping up and the expansion of drought conditions, particularly across the northern Rockies. A slight westward expansion of abnormal dryness and moderate drought (D1) in the Alaska Mainland and the introduction of abnormal dryness near the Kenai Peninsula is warranted, supported by short-term derived drought indicators and precipitation deficits. A status-quo drought depiction is depicted in Hawaii this week, but stream flows are slowly falling as the trade winds continue to lack meaningful moisture. Puerto Rico continues to remain drought-free…
The High Plains region experienced a mixture of both deteriorating and improving drought conditions this week, which has also predominantly been the case over at least the last month. A couple of troughs of low pressure moved across the western and central U.S. this week, helping to tap into some moisture from the Pacific Ocean and draw it into the region. This resulted in heavy rainfall across parts of the Four Corners and extending eastward into the Central and Eastern Plains. Parts of Kansas and eastern Nebraska received well in excess of 3 inches of rainfall. Unfortunately, several locations across the western High Plains region were not so lucky and received below normal weekly rainfall. Temperatures were also unseasonably warm, running anywhere from 4°F to 8°F above average for the week in many areas, helping to exacerbate worsening conditions…
Colorado Drought Monitor one week change map ending July 2, 2024.
In the Western U.S., drought improvements were limited to southern parts of the region, where a couple of troughs of low pressure were able to bring some moisture from the Pacific Ocean northward into the Desert Southwest and Four Corners. Elsewhere across the West, conditions have slowly dried out in recent weeks. With another week of below normal precipitation and above normal temperatures, with much of the Great Basin running 4°F to 8°F above average for the week, conditions worsened…
Expansion of drought and abnormal dryness is warranted this week in the South, as much of the region experienced another week of hot and dry conditions, and this has been the case since the start of June for many locations. The only areas where improving conditions were observed is across northern Oklahoma, extending into Kansas, where another week of heavy rain fell (locally more than 3 inches in north-central Oklahoma). After a very wet May, precipitation has been lacking entirely across large parts of central and eastern Texas, extending eastward into Louisiana. Indicators have shown a drying trend and topsoil moisture has really started to dry out. These areas will bear watching in the coming weeks…
Looking Ahead
During the next five days (July 3 – July 7), High pressure is likely to build over the western U.S., leading to hot, potentially record-breaking temperatures and below normal precipitation. Farther eastward, East of the Rockies, temperatures are forecast to become more seasonal for the most part. In addition, parts of the Middle and Upper Mississippi Valley are likely to experience a couple of rounds of heavy rainfall. Rainfall in excess of 1 inch is favored across parts of the Ohio Valley, Mid-Atlantic, and Southeast.
The Climate Prediction Center’s 6-10 day outlook (valid July 8 – 12), favors enhanced chances of above average, potentially record-breaking, temperatures across parts of the Intermountain West, with above normal temperatures changes extending into the Western Plains, along the Gulf Coast, and into the eastern U.S. Below normal temperatures are favored in the interior central U.S. Near and below normal precipitation is likeliest across the western and north-central U.S., with above normal precipitation favored elsewhere. Eyes will be on the tropics over the next 6 to 10 days, with enhanced chances for above normal precipitation across southern Texas and the western Gulf Coast. Near to below normal temperatures and above normal precipitation is favored in Alaska and Hawaii.
US Drought Monitor one week change map ending July 2, 2024.
Just for grins here’s a slideshow of early July US Drought Monitor map for the past few years.
