On Tuesday, 15 August 2023 officials from the U.S. Bureau of Reclamation (USBR) presented their 24-Month study reports with projections and operational plans for 2024 (USBR, 15 August 2023). We are still dealing with the drought but there is some improvement in the 2024 plans for Colorado River water allocations for Arizona.
The wet winter and spring experienced in the Southwest in 2023 has provided some relief on the dire situation we were facing on the Colorado River system and reservoir levels have improved. But unfortunately, one good precipitation season does not solve all the problems and they will still need to be dealt with.
The current plan for lower Colorado River water management is basically a return to the Drought Contingency Plan (DCP) Tier 1 schedule (Figure 1).
Fgure 1. Drought Contingency Plan Tier reductions for Arizona.
Tier 1 plans take us back to an 18% reduction or 512,000 acre-feet (KAF) of Arizona’s Colorado River allocation of 2.8 million acre-feet (MAF). Arizona was operating under Tier 1 guidelines in 2022.
The irrigation districts in central Arizona that have lost access to Central Arizona Project (CAP) water will not be receiving any additional water in 2024 based on this plan. The districts immediately adjacent to the mainstem of the Colorado River will continue to receive the same amount of water as they have been receiving the past two years. For Arizona and the other lower basin states, these are basically the same water allocation guidelines that were in place in 2022.
The urban areas and American Indian tribes will not experience any additional reductions based on the USBR plans. However, some cities and tribes have volunteered to reduce their Colorado River water allocations in exchange for payments from the federal government.
For example, in 2023 Arizona, California, and Nevada agreed to a plan that will conserve an additional 3 MAF of Colorado River water through 2026 in exchange for $1.2 billion from the federal government. If approved by the USBR, this plan would reduce Colorado River allocations to the Imperial Irrigation District in California, which has some of the most senior water rights on the river.
The Gila River Indian Community (GRIC), which has a Colorado River allocation of 653 KAF, committed in April 2023 to relinquish temporarily 125 KAF in exchange for $400 per AF from the federal government. The federal government is also funding GRIC infrastructure projects to increase wastewater reuse in irrigation.
Thus, some of the Colorado River water that is technically allocated to Arizona under Tier 1 guidelines will stay in Lake Mead due to previously agreed upon conservation measures.
Regarding other lower basin states and the current USBR plan, Nevada will have slightly more Colorado River water in 2024 than in 2023. Mexico will deal with a 5% reduction in Colorado River water from their base and once again California will not be suffering any required cuts in their Colorado River water allocation.
Overall, this is good news. We have some temporary relief on the Colorado River system and no additional reductions will be required in 2024. This puts the seven Colorado River basin states and Mexico in a better position to negotiate the guidelines and agreements required for 2026 since all the existing agreements expire in two years.
Reference
USBR, 15 August 2023. 24-Month Study reports.
August 2023 Lake Powell and Lake Mead: End of Month Elevation Charts
Frost and freeze damage affect countless fruit and vegetable growers leading to yield losses and occasionally the loss of the entire crop. Frost damage occurs when the temperature briefly dips below freezing (32°F).With a frost, the water within plant tissue may or may not actually freeze, depending on other conditions. A frost becomes a freeze event when ice forms within and between the cell walls of plant tissue. When this occurs, water expands and can burst cell walls. Symptoms of frost damage on vegetables include brown or blackening of plant tissues, dropping of leaves and flowers, translucent limp leaves, and cracking of the fruit. Symptoms are usually vegetable specific and vary depending on the hardiness of the crop and lowest temperature reached. A lot of times frost injury is followed by secondary infection by bacteria or opportunist fungi confusing with plant disease.
Most susceptible to frost and freezing injury: Asparagus, snap beans, Cucumbers, eggplant, lemons, lettuce, limes, okra, peppers, sweet potato
Moderately susceptible to frost and freezing injury: Broccoli, Carrots, Cauliflower, Celery, Grapefruit, Grapes, Oranges, Parsley, Radish, Spinach, Squash
Least susceptible to frost and freezing injury: Brussels sprouts, Cabbage, Dates, Kale, Kohlrabi, Parsnips, Turnips, Beets
More information:
Please watch a demonstration of a spray assembly delivering herbicidal spray (blue dye) to spot spray targeted weeds. The device will be integrated with an imaging system for precision, automated / robotic weed control. Weed targets and crop plants are indicated on paper by green and yellow squares respectively. The same targeting pattern is used for simulated weeds (small plastic plants) and crop plants (white roses). Off target spray on paper is due to liquid splashing on a hard surface and is not observed on plastic weed targets. The travel speed is 2 mph and nozzle height - 5".
Click on the following demonstration link or the picture area:
On Thursday February 23, 2023, the afternoon the SWAS breakout sessions dedicated to Integrated Weed Management and Impact to Desert Agriculture (Located at AS 113) will have participation from Jesse Richardson from Corteva Agriscience. He will give us the historic perspective of Kerb Chemigation research. Samuel Discua Duarte from the U of A has conducted a weed survey for INSV virus hosts for a couple of years and will inform the results in his lecture.
Jose L. Carvalho de Souza from the University of Arizona Maricopa Agricultural Center will give us a lecture on the management of Palmer amaranth, the King of weeds. And I will inform some of the results from our Prefar trials at the Yuma Agricultural Center.
You are cordially invited to the session as well as the other breakout Southwest Ag Summit sessions organized by our Arizona Vegetable IPM Team…hope to see you there!.
INTEGRATED WEED MANAGEMENT AND IMPACT TO DESERT AGRICULTURE
(Requesting 2 CEU and 2 CCA)
Location: AS 113
Sponsor: Green Valley Farm Supply, Inc.
1:30-2:00p Insights from Early Kerb Chemigation Research
Jesse Richardson, Corteva Agriscience, Mesa, AZ
2:00-2:30p Survey of Weeds as Hosts of INSV in Yuma County – Results From Two Year Survey
Samuel Discua Duarte, University of Arizona, Yuma,AZ
2:30-3:00p Integrated Weed Management – Palmer Amaranth
Jose L. Carvalho de Souza, University of Arizona, Maricopa, AZ
3:00-3:30p Herbicide Evaluations at Yuma Agricultural Center
Marco Pena, University of Arizona, Yuma, AZ
Moderated by Marco Pena
Results of pheromone and sticky trap catches can be viewed here.
Corn earworm: CEW moth counts remain at low levels in all areas, well below average for this time of year.
Beet armyworm: Trap increased areawide; above average compared to previous years.
Cabbage looper: Cabbage looper counts decreased in all areas; below average for this time of season.
Diamondback moth: DBM moth counts decreased in most areas. About average for this time of the year.
Whitefly: Adult movement beginning at low levels, average for early spring.
Thrips: Thrips adult counts reached their peak for the season. Above average compared with previous years.
Aphids: Aphid movement decreased in all areas; below average for late-March.
Leafminers: Adults remain low in most locations, below average for March.
