DROUGHT INTERAGENCY COORDINATING GROUP
The Interagency Coordinating Group (ICG) is an advisory body to the governor on Arizona drought issues. Comprised of state, federal and non-governmental organizations, this group meets twice a year to evaluate drought conditions and consider recommendations to the governor. Arizona has had a Drought Emergency Declaration (PCA 99006) in effect since June 1999 and a Drought Declaration (Executive Order 2007-10) has been in effect since May 2007.
IGC Meeting Spring 2023
Drought Status Update & Monitoring Technical Committee Activities
A year ago, Arizona experienced a dry winter and spring, making January-May 2022 the third driest period on record. However, the state had an excellent monsoon season followed by anomalous weather patterns, including low-pressure systems and atmospheric rivers. These atmospheric rivers, which are narrow channels of water in the atmosphere, brought significant precipitation to Arizona. Consequently, both the Upper and Lower Colorado River Basins (CRBs) experienced substantial precipitation during the winter, while the west saw cold temperatures. This combination of high precipitation and cold temperatures delayed snowmelt, leading to favorable conditions for water storage. Statewide, precipitation from October 2022 to March 2023 was above average, indicating a positive trend. However, the long-term data still shows a pattern of below-average precipitation, with only nine out of 29 years having above-average rainfall.
The past winter was the coldest in 29 years, benefiting snowpack levels. While the East Coast experienced warmer temperatures and less snow, Arizona and Colorado were able to delay snowmelt due to the cold conditions. In April, Arizona was exceptionally dry, but the overall winter precipitation compensated for it. April tied as the third driest in the southern regions. Current short-term drought conditions have greatly improved, with only 1% of the state in moderate drought. Long-term drought records also indicate improvement in drought conditions, particularly in eastern and southern counties, however, some areas still experience extreme and severe long-term drought.
2023 Weather Outlook
Along the Pacific Coast, there is abnormally cold water that may impact the upcoming monsoon and compromise moisture availability. The Climate Prediction Center (CPC) forecasts a greater than 50% chance of above-average temperatures for the summer, with little chance of being below normal. The past few years have been warmer than in previous decades, with a discernible warming trend of over half a degree per decade. Recent summers have been some of the hottest on record, and water transportation and soil moisture have been negatively impacted. The probability of heading towards an El Niño event is now above 90% for the summer. During El Niño summers, Arizona tends to experience drier conditions overall, with occasional pockets of above-normal precipitation. The CPC predicts a slight tilt in odds towards below-average precipitation during the bulk of the monsoon season, especially in the southern and southeastern parts of the state. The historical data suggests that it is rare to have three consecutive wet monsoons. The impact of El Niño during the winter months is uncertain at this point, outlooks may change in the coming months, and there is currently no shift in the odds for next winter. The previous winter was fortunate, with abundant precipitation and snowfall, but relying on lucky years is not a long-term solution for the ongoing drought cycle. While there might be hope for some larger cities to receive above-average rainfall, alleviating demand and preventing further depletion of soil moisture, it is likely that several areas will still experience compromised soil moisture going into the next water year.
Colorado River Water Supply Update
As of May 7, 2023, Lake Powell was at 3,530.67 feet (ft) with 5.88 million acre-feet (MAF) in storage (25% capacity). Lake Mead was at 1,050.55 ft and 7.72 MAF (30% capacity). Total System Storage in the Colorado River Basin was 20.41 MAF (35%), compared to 20.31 (34%) last year. As of May 8, 2023, Lake Powell snow water equivalent (SWE) was 159% of median. Snowpack peaked in early April at 161%, and the runoff forecast for May was at 11 MAF. The most probable Lake Powell unregulated inflow for Water Year (WY) 2023 (as of April 5) was 14.47 MAF (151% of normal, the 1991-2020 average is 9.60 MAF), the minimum probable is 12.27 MAF (128% of normal), and the maximum probable is 17.86 MAF (186% of normal).
The projected end of Calendar Year (CY) 2023 elevation for Lake Powell is 3,573.20 ft under the most probable scenario and 3,565.83 ft under the probable minimum scenario. Releases from Lake Powell are projected to be about 8.7 to 9.5 MAF under the probable minimum and most probable respectively. The projected end of CY2023 elevation for Lake Mead is 1,067.32 ft under the most probable scenario and 1,057.25 ft under the probable minimum scenario. There is a potential for Tier 1 Operation Condition in 2024, with a 512,000 AF reduction for Arizona, assuming there are no additional reductions. Some factors that could affect the 2024 Lake Mead operations include: the magnitude of balancing releases from Lake Powell, additional water conservation by Lower Basin users, California’s Intentionally Created Surplus, and the final Supplemental Impact Statement (SEIS). The SEIS modeled additional shortage reductions of 533 KAF under Tier 1 and 617 KAF under Tier 2a. These reductions would be distributed either by priority or proportionally to water users in the Lower Basin and would be in addition those from the Interim Guidelines and Drought Contingency Plan contributions.
Salt River & Verde River Watersheds Water Supply Update
The Salt River and Verde River watersheds had the wettest March in 30 years, about 877,000 AF of March runoff (about 550% of median), and the 2nd highest March inflows along the Verde River on record. During March, releases up to 37,000 cubic feet per second (cfs) occurred from Bartlett Dam to manage peak Verde River storm runoff of up to 68,000 cfs. Additionally, nearly up to 10,000 cfs were released from Stewart Mountain Dam, to manage Roosevelt Lake reaching the highest level (+4 ft) within Flood Control Space (FCS) since Modified Roosevelt Dam was completed. During April, the Verde Watershed had the highest April 1st snowpack in 50 years. As of May 9, 2023, reservoir levels were at a total of 99% of storage capacity. SRP Streamflow Forecast (as of April 1, 2023) was 1,822,000 AF (about 400% of median) for the winter runoff season (January 1 – May 31) and reservoir storage is projected to remain full this spring. As a result of the near full reservoirs, SRP total groundwater use for 2023 was decreased to 75,000 AF. SRP continues to work with the U.S. Bureau of Reclamation (BOR) and other stakeholders on several collaborative water projects: SRP/CAP Interconnection Facility (SCIF), Verde Reservoirs Sediment Mitigation Study (VRSMS), and Roosevelt FCS.
2023 Wildfire Outlook
As of May 16, 2023, there have been 229 fires this year (4,695 acres burned), compared to 318 fires and 22,612 acres burned at this time last year (there were two large fires last year). There is a potential for increased fire activity in southern parts of Arizona, which may progress to the northern areas. The region is experiencing a normal fire season, and there is a concern that people's false sense of security due to recent moisture may lead to risky behavior. Since the monsoon season may be delayed in Arizona, there is a warning against burning. In 2022, 66% of fires were human caused, these tend to be more prevalent in spring, coinciding with windy and dry conditions. Arizona is currently at a Preparedness Level 2 (moderate category), which indicates two or more geographic areas (Arizona and New Mexico) are seeing high-extreme fire danger. The state is prepared with a significant number of qualified wildland firefighters and various aircraft resources for fire suppression. Fire restrictions may be implemented in the coming month.
Impacts of Drought on Hydropower – Irrigation and Electrical Districts Association of Arizona
Arizona receives about 18% of the power generated through the Colorado River Storage Project (CRSP). Energy generation at CRSP has been affected by the decrease in lake levels and releases at Glen Canyon Dam due to curtailment. Earlier in the year, contractor rates of delivery (CROD) were expected to decrease from 70.5% in Fiscal Year (FY) 2023, to 64% of production in FY2024. However, above-normal precipitation has led to water level increases and releases, and in turn to the production of about 26% more energy than what was initially projected. While these projections may change, there is a possibility of having a 24% energy production increase, off the initial projections, in 2024.
Some issues impacting hydropower include the April High Flow Experiment downstream of Glen Canyon Dam, with an estimated $1.4 million impact on power customers, and smallmouth bass, a non-native fish species threatening to establish and invade downstream of the dam (realistic estimated impact of $150 million).
Average energy projections show a significant increase in price (about $250 in the summer) when comparing the current on-peak cost to last year, and even to a month ago. This exceeds the estimates used of $135 million for replacement power during the smallmouth bass draft Environmental Assessment, which is concerning. Arizona has a 20% energy allocation from Hoover Dam, through the Arizona Power Authority. Energy production at this dam has declined 13% since 2015. Given drought modeling, Boulder Canyon energy production was projected to decline from 3,098 gigawatts (GWh) in FY2023, to 1,703 GWh in FY2024, when we analyzed the issue earlier in the year. While recent hydrological improvements may aid in mitigating this reduction, there will still be a loss of energy in 2024, compared to this year. With a potential Tier 1 Shortage declaration for the Colorado River in 2024, there is hope that the 480,000 AF being released from Lake Powell may help hydropower production at Hoover Dam.
There is currently a significant distribution transformer shortage due to chain supply issues.
Impacts of Drought on Hydropower – Western Area Power Administration
The Western Area Power Administration (WAPA) is a power marketing administration and wholesale electricity supplier under the United States Department of Energy. WAPA has over 17,000 miles of transmission lines and 700 customers throughout 15 states who, in turn, serve 40 million Americans. WAPA’s Desert Southwest region, located in Phoenix supplies power from Hoover Dam, Glen Canyon Dam, and Parker and Davis Dams. Parker-Davis Project FY2023 energy supply data and forecasts show that WAPA will need to purchase about 218 GWh of replacement power to supply for customers (about 15% of the power that is sold). Average replacement power costs range from $41 to $305 per MWh, however, some months have experienced peak hour actual costs of $1,000 per MWh; this is higher than sales price for customers ($18 MWh) and it is expected to increase through time. It costs about $18 million to operate the Parker and Davis Dams. In 2023, WAPA projects spending $34.1M on replacement power costs, which equates to184% of the cost of operating and maintaining the dams. This is an additional cost that is passed on to the customers. While projections show replacement power costs potentially going down, in response to hydrological and market improvements, there is uncertainty in the projections. On a system-wide scale, the estimated cost of drought impacts (2024-2030) for Hoover Dam is $834 million, and $27 million for Parker-Davis Project, when broken down, the highest cots are attributed to replacement power. The estimates do not consider regulatory reductions or the Colorado River Supplemental Impact Statement.
Impacts of Drought on the Navajo Nation
The Navajo Nation Department of Water Resources (NNDWR) uses 85 active precipitation cans spread across Navajo Nation, including the Chuska Mountains, to monitor precipitation monthly. According to 6-month Standard Precipitation Index (SPI) data (from November 6, 2022-May 5, 2023), the Chinle, Fort Defiance, and Western Navajo agencies, have had similar trends with wet conditions increasing during January and late February. However, precipitation has been variable, with trends towards drier conditions in May. There has been significant snowpack this winter at Fluted Rock, Bowl Canyon, Navajo Whiskey Creek, and Beaver Springs, with most sites getting about 5 ft of snow (over 5 ft for Beaver Springs) by the end of the snow season, in late March and April. High snowpack and rapid snowmelt led to significant flooding in the Town of Chinle, the community is currently in the recovery stage. Since November 2022, there have been short-term drought condition improvements in Navajo Nation, currently, most of the area is in the ‘no drought’ category, with just a small area in the northwest in Abnormally dry (D0) conditions.
Impacts of Drought on the Gila River Indian Community
The Gila River Indian Community (GRIC/Community) has a 311,800 AFY entitlement to Central Arizona Project (CAP) water making it the largest CAP water user in Arizona. The Community is a major participant in water conservation efforts in the Lower CRB, voluntarily contributing substantial portions of its CAP water in recent years to benefit Lake Mead. From 2016-2023, the Community conserved about 733 KAF of Lake Mead water through different conservation efforts, including system conservation and intentionally created surplus. The Community’s CAP water is comprised of Non-Indian Agricultural (NIA) Priority CAP water (120,600 AFY) and higher Indian Priority CAP water (191,200 AF per year). Below a Tier 1 Shortage the Community’s NIA Priority CAP water is eliminated, leaving less water to voluntarily contribute. More concerning to the Community is that much of its NIA Priority CAP water will likely be permanently or semi-permanently cut given future additional curtailments of Colorado River water allocations (e.g., as proposed in the Draft SEIS and through post-2026 guidelines). In April, the Community announced a 3-year system conservation implementation agreement to conserve up to 125 KAF per year. Additionally, the Community entered into a funding agreement with BOR to construct a reclaimed water pipeline to maximize the use of water received from the cities of Chandler and Mesa, resulting in a reduction of around 20 KAF of on-Reservation CAP water demand. Since 2019, the Community has had to curtail its off-Reservation storage activities as it has shifted more water to Lake Mead. While increasing agricultural development on its lands continues to be a long-term goal, the Community has reduced farming activity in 2022 to conserve water and its agricultural growth has leveled off in the past few years. The Community plans to reduce its reliance on CAP water as much as possible to reduce its exposure to future reductions.
While drought conditions have improved significantly, when compared to previous years, the State of Arizona needs at least three consecutive years of above-average precipitation to mitigate long-term cumulative drought impacts. The Drought Interagency Coordinating Group unanimously recommends that both drought declarations (PCA 99006) and (Executive Order 2007-10) be kept in place.
- Drought Status Update & Monitoring Technical Committee Activities - Erin Saffell, State Climatologist, Drought Monitoring Technical Committee Co-chair
- 2023 Weather Outlook - Mark O’Malley, National Weather Service, Drought Monitoring Technical Committee Co-chair
- Colorado River Water Supply Update - James Heffner, Arizona Department of Water Resources
- Salt River & Verde River Watersheds Water Supply Update - Stephen Flora, Salt River Project
- Impacts of Drought on Hydropower-Irrigation and Electrical Districts Association of Arizona - Ed Gerak, Irrigation and Electrical Districts Association of Arizona
- Impacts of Drought on Hydropower-Western Area Power Administration - Jack Murray, Western Area Power Administration
- Impacts of Drought on Navajo Nation - Carlee McClellan, Navajo Nation Department of Water Resources
- Impacts of Drought on the Gila River Indian Community - Jason Hauter, Akin Gump Strauss Hauer & Feld, LLP