Drought Status Update & Monitoring Technical Committee Activities
Erinanne Saffell, State Climatologist & Drought Monitoring Technical Committee Co-chair 
October 2024 to April 2025 ranked as the 7th warmest and the 4th driest October-April on record for Arizona. For the 2025 Water Year (WY; October 1-September 30) to date, Arizona has received 38% of the long-term precipitation, amounting to 2.50 inches of precipitation from October 2024 to April 2025. Snow water equivalent (SWE) for the WY2025 to date is also largely below median for the Salt, Verde and Little Colorado Basins. The odds of reaching 100& normal WY precipitation is extremely low (10% chance).  The dry 2024 summer, following the dry 2024 winter has impacted and advanced short-term drought throughout Arizona. In October 2024 there was no extreme (D3) or exceptional (D4) drought in Arizona. As of May 6, 2025, extreme (D3) drought covers 55% of Arizona, moderate (D1) or severe (D2) drought covers 38% of the state and exceptional (D4) short-term drought covers 6% of the total state. Long-term drought advanced after a very hot and dry summer, fall, and winter as well. Statewide, May 2024 to April 2025 was the 2nd hottest and 2nd driest on record. 

2025 Weather Outlook
Mark O’Malley, National Weather Service & Drought Monitoring Technical Committee Co-chair
The La Niña atmospheric event that brought months of dry, warm conditions to the Southwest has dissipated and neutral conditions will persist through summer and fall. Water temperatures are warming in the Gulf of California and Baja which is important for Arizona’s summer monsoon. The moisture in the Gulf of California is a significant contributor to the summer monsoon rains. The warmer the waters are in that region, the more prolific moisture that could come to Arizona.  The temperature outlook for July, August, and September 2025 favors a warmer than average summer. There is a 46% chance that temperatures will be above normal. Based on modeling and trends over the past 50 years, statewide temperatures are warming at a rate of 0.7 degrees Fahrenheit per decade and there is no sign of this warming trend slowing. Three of the past five years have been the three warmest years on record for the State of Arizona. The precipitation outlook for July, August and September 2025 show slightly better odds of above average precipitation totals. Recent monsoon seasons following a dry La Niña, largely have been wet monsoons however the randomness of thunderstorms will likely provide large spatial variations in rainfall coverage and some regions of the state may largely miss out on the summer rainstorms. Modeling and trends over the past 50 years show high variability and very little trend in precipitation totals. Outlook for January, February and March 2026 show a slight shift in odds favoring warmer and drier weather for winter 2025-2026. though uncertainty in ENSO state results in a low to moderate confidence forecast. The best-case scenario is that enough areas in the state and particularly headwater locations, receive above average rainfall such that soil moisture is not overly depleted heading into WY2025-2026.

Colorado River Water Supply Update
 James Heffner, Senior Hydrogeologist, Colorado River Management, Arizona Department of Water Resources 

As of May 11, 2025, Lake Powell was at 3,557.97 feet (ft) with 7.644 million acre-feet (MAF) in storage or 33% full, compared to 34% full at this time last year. Lake Mead was at 1,060.12 ft and 8.432 MAF or 32% full, compared to 35% full at this time last year. Total System Storage in the Colorado River Basin was 23.41 million acre-feet (MAF) or 40% full. Total System Storage at this time last year was 24.54 MAF or 42% full. Lake Powell SWE peaked earlier than normal on March 23 at 97% of median. SWE remained below median due to the relatively warm and dry conditions in April and early acceleration of snowmelt. The 2025 water supply forecast for Lake Powell and Glen Canyon Dam indicate that April through July inflow forecasts are below average and have declined by 800 thousand acre-feet (KAF) between the April 1 and the May 5 forecasts. Likewise, the Lake Powell unregulated inflow forecast for WY2025 (as of May 5) was 5.91 MAF (62% of average, down from 6.78 MAF from the previous month.  The projected end of Calendar Year (EOCY) 2025 elevation for Lake Powell is 3,551.49 ft under the most probable scenario and 3,542.89 ft under the probable minimum scenario. The projected EOCY 2026 elevation for Lake Powell is 3,568.01 ft under the most probable scenario and 3,522.24 ft under the probable minimum scenario. Releases from Lake Powell are projected to be about 7.48 MAF in WY 2025 under the probable minimum and most probable scenarios and 7.48 MAF in WY 2026. The projected EOCY 2025 elevation for Lake Mead is 1,056.07 ft under the most probable scenario and 1,053.37 ft under the probable minimum scenario. The projected EOCY 2026 elevation for Lake Mead is 1,048.40 ft under the most probable scenario and 1,046.54 ft under the probable minimum scenario.

Salt River & Verde River Watersheds Water Supply Update
Stephen Flora, Senior Hydrologist, Salt River Project (SRP)
The cumulative watershed precipitation for the start of Water Year 2025 (WY2025) (October 1-May 11) was 4.92 inches (49% of normal), compared to 10.80 inches at this time last year. Total precipitation from October 1, 2024 to May 11, 2025 for the Verde Watershed was 5.75 inches (57% of normal) and 4.09 inches (41% of normal) for the Salt River Watershed. Despite the overall dry winter, the watershed observed the third consecutive March (2023, 2024, 2025) with above normal precipitation. Almost half of the total precipitation received throughout the WY2025 to date, was received in March (2.38 inches or 159% of normal). The Verde River Watershed snowpack was below median for most of winter 2025 until Mid-March. March and April precipitation across the watersheds was above normal however because of extremely dry antecedent conditions through winter and leading into early spring, very little runoff reached streams and reservoirs. Salt River Watershed snowpack was well below median (15% of median) throughout winter 2025. The 2025 winter runoff season (January 1 to May 31) on the Salt River, Tonto Creek, and Verde River is expected to be a new record low at ~97,000 AF (21% of median) of inflows. The previous record low was 100,013 AF in 2018. Total SRP storage was at 67% of total capacity (1,541,817 AF) as of May 12, 2025, compared to 92% at the same time last year. Reservoir storage decreased from 71% to 67% between January 1 to May 12. SRP reservoirs are expected to be near median by January 1, 2026. SRP total groundwater use for 2025 increased from 100,000 AF to 150,000 AF and is likely to increase again in 2026.

Impacts of Drought on Hydropower – Irrigation and Electrical Districts Association of Arizona
Ed Gerak, Executive Director, Irrigation and Electrical Districts Association of Arizona
Hydropower provides energy to nearly 180,000 homes in Arizona. Arizona receives 410 megawatts (MW) or about 20% of hydropower generated by Hoover Dam, 338MW or 18% of the hydropower generated from CRSP Facilities (including Glen Canyon Dam) and 255MW or 56% of the power generated from the Parker-Davis Dams. There has been a nearly 40% reduction in total power generated from the CRSP Facilities and Glen Canyon, Hoover, Davis, and Parker Dams since 2000. Power generation from Hoover Dam has reduced by over 48% since 2000.  Reduction in average energy production has direct economic impacts. Recent evaluation of Hoover Dam’s capabilities to pass water and generate power at low lake elevations found a potential impact to the hydropower capacity estimates at lower lake levels. At elevation 1,035 ft Hoover Dam’s estimated hydropower capacity reduces from 1,304MW to 382MW however, it is unlikely that water elevation will drop below 1,035ft at least for the next couple of years. There is a 20% chance that water elevation will fall below 1,035ft in 2028. Federal bills and legislation such as the Help Hoover Dam Act (H.R. 3158/S. 1570) are being pursued to secure necessary funds to pay for operations, maintenance, and repairs.

Impacts of Drought on Hydropower – Western Area Power Association
John Paulsen, VP of Power Marketing, 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 FY2025 energy supply data and forecasts indicate that WAPA will need to purchase about 241 gigawatt hour (GWh) of replacement power to supply customers (17% of the power that is sold). The Parker-Davis Project will generate 1,189 GWh of power in Fiscal Year 2025 (FY2025). Average replacement power costs range from $48 to $118 however, some months have experienced peak hour actual costs of $1,000 per MWh. In FY2025, WAPA projects spending $18.3M on replacement power costs, which equates to 50% of the cost of operating and maintaining the dams. To mitigate this issue, WAPA is in the process of changing their marketing plan for Park-Davis Project with the goal of better aligning the actual releases and deliveries from Parker-Davis to the hydropower available. This change is expected to decrease the purchase costs to $5 million dollars by 2029. On a system-wide scale, the estimated cost of drought impacts (2026-2030) for Hoover Dam is $653 million, and $37 million for Parker-Davis Project. When broken down, the highest costs are attributed to replacement power. 

2025 Fire Season Outlook
Tiffany Davila, Public Affairs Officer, Arizona Department of Forestry & Fire Management
For 2025 year-to-date (YTD), 462 fires have burned 38,000 acres. For 2024 YTD, 418 fires burned 27,000 acres. For all of 2024 Arizona had 2,100 fires that burned 280,000 acres of State, Federal, and Tribal Lands. Trends in fire season and fire activity are largely dependent on winter and spring moisture, drought conditions, fuel loading, climate patterns and temperatures. The monsoon season historically signals the end of high fire activity however, Arizona no longer has a typical fire season and now has year-round fires. There is potential for high fire activity statewide in 2025, especially in the areas along and south of the Mogollon Rim because of above normal fuel loads and in northern Arizona because of the minimal snowpack received. Areas in southern and southeastern Arizona could see more intense fires and longer-duration incidents. As of May 19, 2025, the Greer fire had burned 20,308 acres and was 55% contained. The fire was wind driven through drought-stress fuel and started on May 13, 2025. 
On May 17, 2024, Governor Katie Hobbs signed HB 2751 allowing the Arizona Department of Forestry and Fire Management to enter into the Great Plains Interstate Compact for state-to-state sharing of resources for fire season to maintain adequate resources. With the compact, states can coordinate between each other, without the involvement of the federal government.

2024-2025 Forest Health Update
Viridiana Quinonez Nevarez, Forest Health Specialist, Arizona Department of Forestry & Fire Management
The Arizona Department of Forestry & Fire Management (DFFM) partners with the U.S. Forest Service to conduct annual aerial surveys on dead and dying trees around the state and confirms their findings with ground surveys. Drought conditions and high temperatures impact forest health and increase the likelihood of pathogens and insect infestations. In 2024 over 15 million acres were surveyed and findings confirmed an increase in bark beetle related tree mortality. During the summer of 2023 just over 17,000 acres with bark beetle caused mortality were observed. Surveys conducted in the summer of 2024 found that number increased to over 33,000 acres. There was also an increase in drought related tree damage. More than 11,000 acres with defoliator damage were observed last summer. If defoliation is severe enough, it can lead to the death of the host tree. More than half of the acres with defoliation damage were attributed to the non-native Tamarisk leaf beetle along riparian areas. Abiotic disorders and damages can become entry points for pathogens and make the trees more susceptible to other insects and diseases. There were over 9,000 acres with drought damage in 2024 which was an increase from 5,000 acres in 2023. Most of the damage observed was in Ponderosa Pine high elevation forests. 

Recommendation
Arizona remains in a 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. 

Spring 2025 ICG Drought Recommendation

Presentations

• Drought Status & Monitoring Technical Committee Activities  - Erinanne Saffell, State Climatologist, Drought Monitoring Technical Committee Co-chair
• 2025 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 - John Paulsen, Western Area Power Administration
• 2025 Wildfire Outlook - Tiffany Davilla, Arizona Department of Forestry and Fire Management 
• 2025 Forest Health Update - Viridiana Quinonez Nevarez, Arizona Department of Forestry and Fire Management