Interagency Coordinating Group

Interagency Coordinating Group

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.

Meetings Summaries

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Drought ICG Meeting Dates

 

ICG Meeting Fall 2020

ICG Agenda - November, 10, 2020

Meeting Summary

Drought Status
The benefits obtained by the Winter 2019-2020 precipitation were eliminated by the 2020 monsoon season (July to September), which was the hottest and driest on record for most of Arizona. By October 1, 2020, 3% of the state was in Exceptional Drought (D4), 67% was in Extreme Drought (D3), 24% was in Severe Drought (D2) and 6% was in Moderate Drought (D1). A similar trend was observed for long-term drought conditions, and by October 2020 Extreme and Exceptional Drought spread throughout northeastern, central, and east central Arizona, and Moderate Drought covered most of the state. These drought conditions have increased the need for groundwater use and irrigation throughout Arizona. As of October 31, 2020, Water Year 2021 precipitation was less than 25% of average throughout most of the state (except for a small portion of east central Arizona). At the same time last year, Water Year 2020 precipitation was less than 25% of average precipitation for the entire state.

Winter 2020-2021 Weather Outlook
2020 had the hottest and driest summer on record for Arizona, this follows a long-term trend of warming in the state. The minimal monsoon led to a significant decrease in soil moisture, which may negatively impact runoff in the upcoming water year even if near average snowfall occurs. The outlook for Winter 2020-2021 indicates La Niña conditions persisting through the spring and potentially reaching moderate to strong levels. La Niña events, with a few historical exceptions, result in drier and warmer than normal conditions across Arizona, which might be expected this winter.

Colorado River – Water Supply Status
Observed inflow into the Colorado River Basin (CRB) System for April through July 2020 was 3.76 million acre-feet (MAF), or 52% of average, just under the 5.85 MAF (54%) observed for the entire 2020 Water Year. While the observed inflow for October was at 18% of average, this is projected to increase into the winter and January 2021 inflow may reach 66% of average. As of November 5, 2020, the total CRB System storage was at 28.19 MAF or 46% of capacity. According to the U.S. Bureau of Reclamation October 24-Month study, Lake Powell is projected to be at elevation 3,584.57 feet, with 10.34 MAF (43% capacity) in storage at the end of Calendar Year 2020; Lake Powell operations in Water Year 2021 will be governed by the Upper Elevation Balancing Tier, with an initial water year release volume of 8.23 MAF and the potential for an April adjustment in 2021. As of the October 24-Month Study, Lake Mead is projected to be above 1,075 feet and below 1,090 feet for both the end of Calendar Years 2020 and 2021; this means that Arizona will be in a Tier Zero Drought Contingency Plan (DCP) contribution condition (192,000 AF) during Water Year 2021 and possibly Water Year 2022.

Salt River & Verde River Watersheds – Water Supply Status
The past two winters brought enough inflow into the Salt and Verde River reservoir system to nearly fill it to capacity this year. During March 2020 the reservoir system received 438,705 AF of inflow and by May 4, the total system peaked at 2,255,907 AF (98% of storage capacity). However, the monsoon season (June 15 to September 30) precipitation was 30% of normal (1.93 inches) and the driest over the 121-year record. Dry conditions throughout the summer led to the lowest monsoon season reservoir inflow (32,388 AF). While there was minimal runoff, Salt River Project (SRP) monitored a few storm events where local runoff and water quality into the lower elevation portions of the watershed were impacted by wildfires (ie. Bush Fire). As of November 3, the total Salt River Project surface water supply was at 1,803,570 AF (79% of total storage capacity). Total watershed precipitation for Water Year 2020 was at 91% of normal (16.61 inches) and the total Salt and Verde River reservoirs inflow was 124% of median (1,058,665 AF). Groundwater pumping has been minimal in the SRP service area this year and it is projected to be similar in 2021.

2020 Wildfire Season Update
As of November, about 2,324 fires were reported for 2020, burning approximately 959,000 acres of land (state, federal and tribal). This is more than 2017, 2018, and 2019 combined (about 948,449 total acres). About 81% of fires in 2020 have been human caused. Winter moisture contributed to abundant fine fuels (grasses and brush vegetation) and above normal spring temperatures dried these out quickly and early in the year. There were three large-scale fires that started in June: Bush Fire at Tonto National Forest (human caused), Bighorn Fire at Coronado National Forest (lightning caused) and the Magnum Fire at the Kaibab National Forest (cause unknown). Significant moisture throughout the Central Region of the state would be necessary to improve conditions. While the fire season typically peaks at the end of April and beginning of May in Arizona, fire activity has been observed throughout the year and is expected to continue through December due to La Niña conditions. Fire restrictions were in place up to November 11, 2020.

Impacts of Drought on Wildlife
As drought increased throughout Arizona this summer, the Arizona Game and Fish Department faced challenges hauling water to different water catchments and invested in re-designing these infrastructures to hold water for longer periods of time. Streams, springs, and wetlands have dried up due to drought, impacting wildlife such as Springsnails, which experienced a reduction in their populations, and waterfowl. While there was an increase in fishing license sales in 2020, the lack of precipitation throughout the state reduced water levels and quality in small reservoirs and lakes, affecting fish populations and the ability to stock trout for recreational fishing. Furthermore, the extreme heat and dryness has led to increased human and wildlife accidental interactions.

Impacts of Drought on Navajo Nation
Navajo Nation Department of Water Resources monitoring efforts and data management processes were challenged by the COVID-19 pandemic, affecting drought condition data collection. According to the National Aeronautics and Space Administration’s (NASA) Climate Engine Drought Severity Evaluation Tool (DSET), all Navajo Nation agencies (Chinle, Crownpoint, Fort Defiance, Shiprock, and Tuba City) 6-month average SPI levels were at or below -1.5 by September 2020, which ranges from Extreme Drought to Exceptional Drought conditions. Precipitation data from January to October 2020 showed minimal rain events, with peak precipitation averages in Fort Defiance Agency, which was under 0.55 inches around February 2020. Streamflow data showed little or no flow throughout the Chuska mountain range, Chinle, and the Defiance Plateau. Drought has impacted domestic water haulers, public drinking water systems, irrigators, dryland farmers and ranchers, wildlife, forestry, and recreation. This summer, the Navajo Nation Commissioners on Emergency Management reaffirmed the existing Drought Declaration, and the 2003 Navajo Nation Drought Contingency Plan is being implemented.

Recommendation
Drought in Arizona and reservoir conditions throughout the Colorado River, Salt River, and Verde River watersheds improved at the beginning of 2020. However, the monsoon season was the hottest and driest on record for most of the state and Winter 2020-2021 will likely be warmer and dryer than average due to La Niña conditions in the Pacific Ocean. The Drought Interagency Coordinating Group unanimously recommended that both drought declarations be kept in place.

Fall 2020 Drought ICG Recommendation Letter to the Governor

Presentations

ICG Webinar

ICG Meeting spring 2020

ICG Agenda - June 24, 2020

Meeting Summary

Drought Status
Winter 2019-2020 precipitation was 150% above average, reducing or eliminating drought conditions in all but northeastern Arizona on the short and long-term scales. Northeastern Arizona, western Coconino, Navajo, and most of Apache County have remained drier than average. A combination of minimal precipitation and warmer than average temperatures in June led to an increase of wildfires throughout the state and to the introduction of Abnormally Dry (D0) conditions around central and southeastern Arizona. As of June 16th, about 7% of Arizona was in Severe Drought (D2), 7% was in Moderate Drought (D1), 19% experienced Abnormally Dry (D0) conditions, and 67% was out of drought. On June 26th, the National Oceanic and Atmospheric Administration (NOAA) calculated the new 30-year temperature and precipitation averages. The new “normals” range from 1991-2020 and are warmer and drier than the previous period (1981-1990).

Weather Outlook
According to climate models and past (10—15 year) trends in Arizona, warmer than average temperatures are expected for July, August, and September of 2020. There are currently no strong climate model trends to indicate how wet the monsoon may be this summer. Last year, moisture transport into the Southwest was hindered, likely due to cool sea surface temperatures (SSTs) in the Pacific. This year, there is a mix of warmer and cooler than average SSTs. Neutral tropical Pacific conditions will persist through the summer with La Niña conditions possibly developing by early fall. Should La Niña become the predominant Pacific oscillation, drier and warmer weather would become favored in Arizona during fall and Winter 2020-2021.

Colorado River – Water Supply Status
As of June 19, 2020, the total Colorado River Basin (CRB) System was at 51% of capacity (31.46 million acre-feet (MAF)). These levels were slightly better compared to the same time in 2019 (50% or 30.33 MAF). However, conditions throughout the CRB have been dry and the unregulated inflow into Lake Powell for Water-Year 2020 was forecasted at 62% of average (6,762 thousand acre-feet (KAF)). On April 1st, about two weeks earlier than normal, snow water equivalent in the CRB reached its highest point at 107% of peak seasonal median, and runoff was soaked up by the dry soils. According to a Bureau of Reclamation Stress Test Hydrology Model for the next five years at the Lower Basin and Lake Mead, Arizona is trending towards a drier future. Drought Contingency Plan (DCP) agreements and the resulting conservation measures have prevented any shortage conditions on Lake Mead with about 700,000 AF conserved by the Lower Basin states and Mexico in 2020. While there is no risk for shortage this or next year, there is some (9%) risk of shortage in 2022.

Salt River & Verde River Watersheds – Water Supply Status
Cumulative watershed precipitation this past fall, winter, and spring was at 130% of normal (9.30 inches) with two wet periods and a dry period in between. Winter stream inflow into the Salt, Verde, and Tonto rivers, which normally occurs during January-May, was at 150% of median (782,000 AF). Flows on the Salt River remained high into late April and early May with late season snowmelt. On May 7th, the total system peaked at 98% of storage capacity (2,255,824 AF). As of June 22nd, the total system was at 94% capacity (2,154,640 AF); the Salt River storage capacity was at 96% (1,914,464 AF) and the Verde River was at 84% (240,176 AF). These improved conditions lead to a reduction in SRP projected groundwater use in 2020 from 100,000 AF to 80,000 AF. SRP worked with the Bureau of Reclamation on the Salt and Verde River Reservoir System SECURE Reservoir Operations Pilot Study, which evaluated the reliability of the Salt and Verde River reservoir system for various future conditions and impacts.

Forest Health Update
Winter 2018-2019 precipitation improved drought conditions throughout the state, but the moisture also caused a native foliar blight that defoliated over 33,000 acres of aspen forest across northern Arizona. Bark beetle populations from Water Year 2018 caused tree mortality on approximately 459,239 acres in 2019, an increase of 66% (from 275,934 acres in 2018). Drought conditions have improved in 2020 and so has forest and woodland health. As a result, bark beetle related tree mortality is expected to decrease. The Aleppo Pine Blight and the Mediterranean Pine Engraver beetle populations are being monitored through ongoing urban forest health programs in the Phoenix Metropolitan area. While the Aleppo pine blight population was reduced in 2020, the Mediterranean pine engraver has the potential to spread to other tree species and thus requires control measures that will be tested in 2021.

Arizona Department of Water Resources Interactive Drought Dashboard
The ADWR Interactive Drought Dashboard shows short-term drought conditions in Arizona from 2000 to present and can be used to explore drought conditions for the entire period or for specific time frames; for the whole state or for a selected county. The ADWR Interactive Drought Dashboard can be found on the ADWR Drought website.

Recommendation
Drought in Arizona and reservoir conditions throughout the Colorado River, Salt River, and Verde River watersheds have improved compared to 2019. However, the beginning of the summer has been warm and dry, and these trends are expected to continue into fall and Winter 2020-2021. The Drought Interagency Coordinating Group unanimously recommended that both drought declarations be kept in place.

Spring 2020 Drought ICG Recommendation Letter to the Governor

Presentations