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.


Interagency Coordinating Group Members

Interagency Coordinating Group Fact Sheet

IGC Meeting Spring 2023

Spring 2023 ICG Meeting Agenda


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.

Spring 2023 Drought ICG Recommendation Letter to the Governor


Spring 2023 ICG Meeting Recording

ICG Meeting Fall 2023




Drought Status Update & Monitoring Technical Committee Activities

Water Year (WY; October 1-September 30) 2023 was the second coldest WY in the last 30 years with an average temperature of 59.7F. The total statewide precipitation average for WY2023 was slightly above the long-term, at 12.49” (the long-term average is 12.27”). The majority of the recorded precipitation occurred during the winter months. WY2023 started with a cold October which lasted until March. A very active series of atmospheric rivers and weather systems resulted in a wet January and March. January 2023 was the wettest January on record since 2010. March storms and precipitation increased the winter snowpack in the Verde Basin. Following a wet 2022 monsoon season, soil moisture levels assisted runoff efficiencies in spring. In fact, March 22, 2023, was the last measurable precipitation recorded at Phoenix Sky Harbor International Airport for the months of April, May, June, July which is the first time that has happened on record. June was very cold and dry which delayed the monsoon season significantly. July was exceptionally hot and dry, breaking many records across the state. Phoenix set a record of 55 days with temperatures 110°F or higher by the end of monsoon season. June and July were the 2nd driest June-July on record. The statewide precipitation average for June-September 2023 was 3.53” and was the 15th driest June-September on record.

Short-term drought improved due to the winter precipitation but degraded following the extremely dry summer. Due to the wet winter, Severe (D2) short-term drought diminished in February but Severe (D2) and Extreme (D3) short-term began again in August and September. Overall, the state has experienced Moderate (D1) and Severe (D2) short-term drought almost continuously over the past 20 years. While long-term drought maps showed some improvement following the winter months in Arizona, Standard Precipitation Evapotranspiration Index (SPEI) data demonstrated a continuation of long-term drought across the state.

Weather Outlook for Winter 2023-2024

The outlook for winter 2023-2024 indicates a greater than 90% chance that the Moderate El Niño that developed over summer will reach the ‘strong’ category with forecast models showing this El Niño decaying sometime in the spring. Historical records indicate that some of the wettest winters in Arizona have occurred during El Niño episodes however, many dry winters have also occurred during El Niño winters. El Niño winters in the Upper Colorado basin historically display a narrower range of possibilities but still include a combination of wet and dry conditions. The three-month temperature outlook for January through March 2024 indicates no tilt in temperature odds and a very slight tilt in odds towards above average precipitation in Northern Arizona and the Upper Colorado River basin. The equal chance of above, below, or near normal temperatures comes as a result of typical cooler El Niño influences counteracting warming trends over the past 40 years.

With the exception of far western and northern Arizona, Monsoon 2023 was much drier than normal with much of the southeast half of the state receiving less than 50% of normal monsoon precipitation. Summer rainfall was variable and/or absent across the Upper Colorado basin. The lack of summer rainfall has been detrimental to soil moisture levels and without ample rainfall before accumulating snowpack, spring runoff may be compromised.

Colorado River Water Supply Update

As of October 22, 2023, total Colorado River system storage was 25.060 million acre-feet (MAF) or 43% full. WY2023 resulted in 13.42 MAF of unregulated inflow into Lake Powell, which is 140% of average (9.60 MAF is the 30-year average). The WY2024 forecast for October projects an unregulated inflow of 9.40 MAF (98% of average) as the Most Probable, 6.00 MAF (62% of average) as the Minimum Probable, and 17.60 MAF (183% of average) as the Maximum Probable.

The Bureau of Reclamation’s (BOR) October 2023 24-Month Study projections for Lake Powell indicate the Most Probable elevation at 3,570.94 feet and Probable Minimum elevation at 3,570.50 feet for the end of CY2023. The end of CY2024 projections for Lake Powell indicate a Most Probable elevation of 3,582.86 feet and a Probable Minimum elevation of 3,549.44 feet. For Lake Mead, the 24-Month Study projections for the end of CY2023 indicate a Most Probable elevation of 1,067.89 feet and a Probable Minimum elevation of 1,067.55 feet. The end of CY2024 projections for Lake Mead indicate a Most Probable elevation of 1,060.53 feet and a Minimum Probable elevation of 1,051.57 feet.

Reclamation published the revised draft Supplemental Environmental Impact Statement (DSEIS) to the 2007 Interim Guidelines on October 25, 2023 that includes an evaluation of the Lower Basin proposal to conserve an additional MAF by the end of 2026. The comment period closes on December 11th for the revised DSEIS. Longer term operations which will cover Colorado River Basin reservoir operations when the current Interim Guidelines expire (commonly referred to as the post-2026 operations), are under discussion. Reclamation has stated it must receive alternative proposals by March 2024.

Salt River & Verde River Watersheds Water Supply Update

The Winter 2023 (January 1-May 31) resulted in 1,802,000 AF of water (398% of normal) into the SRP reservoirs – the highest inflow total since 2005. The total WY2023 observed 2,021,000 AF (290% of median) and was the 15th highest on record. The 2023 monsoon season (July 1-September 30) brought an average of 3.46 inches (55% of normal) of precipitation across the Salt and Verde watersheds with an inflow total of 43,000 AF (46% of normal) into SRP’s reservoirs, the second lowest on record. Total SRP storage is at 82% of total capacity (1,886,835 AF) as of October 30, 2023. Reservoir storage increased from 65% to 100% from January 1st to April 1st.

Impacts of Drought on Hydropower

The Arizona Power Authority receives Arizona’s Hoover Dam hydropower allocation, amounting to nearly 20% of the total output from Hoover. As elevation levels in Lake Powell and Lake Mead decline the ability for power plant generators is reduced. Power capacity has declined roughly 30%. Gross generation by Glen Canyon Dam for WY2022 was the 2nd lowest on record, and 2nd only to the first year of the dam’s construction. Gross hydropower generation at Glen Canyon Dam for WY2023 increased based on the wet winter, but for WY2024 it is expected to decline to almost the WY2022 levels as the water releases from Glen Canyon Dam have already been set based on operation guidelines. The gross generation of hydropower by the Hoover Dam for WY2023 was the lowest in the last 55 years due primarily to water level elevations and conservation agreements. As available hydropower declines, replacement power from the Palo Verde power market has increased in price by roughly 96% since 2020. Drought response programs including the Bipartisan Infrastructure Law and the Inflation Reduction Act, have not included funding allocations for hydropower projects or cost mitigation.

2023 Wildfire Update

The 2023 wildfire season observed high fire activity in southern Arizona, including Cochise, Pima and Santa Cruz Counties. The abundant winter and spring precipitation created an increased fuel load and unseasonably cooler temperatures in June delayed the start of Arizona’s fire season by about a month. The minimal monsoon season and precipitation events throughout the state kept fire activity high from July and well into September. Central and Southern Arizona experienced dry lightning events associated with monsoonal build-up.

As drought increases throughout the state due to recent dryness and above average temperatures particularly in southeastern Arizona with extreme (D3) short-term drought conditions, fire potential and activity increased in October. As of November 7, 2023, 1,756 fires consumed 181,678 acres statewide. There have been approximately 400 more fires for 2023 year to date (YTD) compared to 2022YTD, with 70% of the fires in 2023 being human caused. None of the 2023YTD fires have required a type one incident management team and all fires have been manageable. 

2022-2023 Forest Health Update

The Arizona Department of Forestry & Fire Management (DFFM) partners with the U.S. Forest Service to conduct yearly surveys on dead and dying trees. DFFM confirms findings with ground surveys. Drought and temperature impacts forest health and increases the likelihood of pathogens and insect infestations. Surveys are conducted between July through September. There was a decrease in bark beetle mortality in 2022, however mortality is still elevated. There were 400,000 acres with bark beetle caused tree mortality from July-September 2022, which was a 20% decrease in bark beetle caused tree mortality recorded in 2021. In 2022, 15 million acres in total were surveyed and there were 195,000 acres with drought related damage.

Survey data for 2023 is not yet available but forest and woodland vegetation are showing signs of improvement. Winter precipitation appears to have resulted in a decrease in bark beetle activity and direct drought related mortality. Small outbreaks of pets such as twig beetles, pinyon needle scale and spruce aphid were recorded. Due to months of extreme heat and low moisture, an increase in Mediterranean pine mortality caused by the invasive Mediterranean Pine Engraver (MPE) is expected throughout the Phoenix and Tucson metro areas. Early Detection Rapid Response (EDRR) trapping found MPE has spread to Kingman, Topock, Pinetop-Lakeside, Superior, and Nogales. Management options are being researched to control the spread of these damaging insects.

Impacts of Drought on Wildlife

The Arizona Game and Fish Department (AZGFD) monitors the impacts of long-term drought conditions on sport fish, native fish, hatcheries, and wildlife. In the Colorado River Basin, the research branch has observed low reservoir elevations and warmer water released below Glen Canyon Dam have had negative impacts on the Rainbow Trout Fishery at Lees Ferry. The establishment of Smallmouth Bass below Glen Canyon Dam is a risk to Trout and other native species such as the Humpback Chub. AZGFD is studying reduced flow in springs feeding trout streams along the Mogollon Rim due to drought. Record temperatures have increased water temperatures in streams, which has increased stress amongst native trout species such as the Gila and Apache Trout. AZGFD hatcheries are spring fed and flows at the beginning of 2023 were much above the 1980-2020 average but have reduced to near average flows and are currently much lower than they were at this time last year.

AZGFD has increased communication efforts focusing on best management practices for anglers fishing during summer months and periods of high temperatures. AZGFD is also continuing work on habitation restoration, enhancement, and protection projects for Chiricahua Leopard Frogs (CLF), a species that requires permanent aquatic habitats. Since 2007, AZGFD and partners have completed 43 projects throughout the CLF distribution area. The communications and marketing team are working to increase internal and public awareness of the impact drought has on wildlife, habitat, and recreation. They are also expanding public participation and pursuing funding to support drought mitigation. AZGFD has developed strategic plans to highlight drought responses for wildlife, developed numerous applications to report drought related issues, and has increased drought related messaging. AGFD has hauled over 358,000 gallons of water to wildlife catchments between 2022 and 2023 and raised $900,000 to date.


While there have been drought condition improvements, there are impacts that have accumulated through time. Arizona remains in short- and long-term drought with most of the state experiencing some level of drought condition from abnormally dry to extreme drought. The Drought Interagency Coordinating Group unanimously recommends that both drought declarations (PCA 99006) and (Executive Order 2007-10) be kept in place.

Fall 2023 Drought ICG Recommendation Letter to the Governor


Fall 2023 ICG Meeting Recording