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

 

IGC Meeting Spring 2022

Spring 2022 ICG Meeting Agenda

MEETING SUMMARY

Drought Status Update & Monitoring Technical Committee Activities

The Lower Colorado River Basin (CRB) received below-average precipitation from October 2021 to March 2022, with the Gila and Verde River watersheds receiving 50-70% of average seasonal precipitation. For Water Year 2022 (WY2022), to date (October 1, 2021-April 25, 2022), most of Arizona received 50-70% of average precipitation, with eastern Coconino and central Navajo and Apache counties receiving 80-90% of average precipitation. During the first six months of WY2022, the state received 3.78 inches of precipitation (60% of average). Precipitation for Santa Cruz, Pima, Cochise, and La Paz counties ranked as some of the driest to date (period of record 1895-2022).

While the 2021 monsoon season significantly improved drought conditions in Arizona, drought expanded during winter and spring of 2021-22. As of April 28, 2022, 6% of the state was under Extreme (D3) drought, with 92% of the state experiencing either Moderate (D1) or Severe (D2) drought. While long-term drought maps showed some improvement near central Arizona counties, Standard Precipitation Evapotranspiration Index (SPEI) data demonstrated a continuation of long-term drought across the state.

Weather Outlook for Summer 2022 and Winter 2022-2023

According to trends over the past 30 years and modeling, odds favor a warmer than average summer in Arizona. There is a very slight increase in odds for a wet 2022 monsoon season, however, the randomness of thunderstorms will likely result in some communities not reaching average precipitation. A wet monsoon similar to 2021 would help improve soil moisture profiles, reduce water demand, and contribute to inflow/side flow into reservoirs. While it is too early to tell, El Niño Southern Oscillation (ENSO) models indicate that there is a 40-50% chance of La Niña persisting or redeveloping during Winter 2022-23, 35-45% chance of ENSO neutral, and about 10% chance of El Niño. There is a slight tilt in odds suggesting the potential for another dry winter in 2022-23 though likely contingent on La Niña conditions.

Colorado River Water Supply Update

As of April 25, 2022, the total CRB reservoir system supply was at 20.51 million acre-feet (MAF) or 34% of capacity, compared to 43% of capacity (25.68 MAF) last year. Lake Powell supply was at 5.77 MAF or 24% of capacity (3,522.51 feet) and Lake Mead was at 8.13 MAF or 31% of capacity (1,056.15 feet). According to the Colorado Basin River Forecast Center, as of May 3, 2022, snow water equivalent (SWE) above Lake Powell was at 54% of seasonal median. Despite the presence of good winter conditions towards the end of 2021, a steady decline has occurred, with the April forecast for unregulated inflow into Lake Powell falling to 4.1 MAF.

According to the Bureau of Reclamation (BOR) April 24-Month Study, Lake Powell is projected to end Calendar Year 2022 (CY2022) at 22% of capacity (3,515.05 feet), with a probable minimum of 3,504.04 feet and probable maximum of 3,547.32 feet. Similarly, the end of CY2023 is projected at 3,522.38 feet (24% of capacity), with a probable minimum of 3,494.17 feet and a probable maximum of 3,586.81 feet. BOR April modelling includes 350,000 AF held back in Lake Powell, however modelling still reflects the adjusted release pattern that would send this 350,000 AF to Lake Mead from June to September. Modelling does not reflect the future release of 500,000 AF from Flaming Gorge to Lake Powell. Measures to protect the elevation of both Lake Mead and Lake Powell are anticipated to be incorporated into future modelling. These measures are intended to protect water supply infrastructure, with benefits to hydropower being ancillary.

The April 24-Month Study for Lake Mead projects 29% of capacity (1,047.10 feet) at the end of CY2022, with a probable minimum of 1,045.01 feet and a probable maximum of 1,049.08 feet. Additionally, the end of CY2023 probable projection is 1,037.44 feet (26% of capacity), with a probable minimum of 1,017.07 feet and a probable maximum of 1,043.24 feet. These projections include some, but not all the 500+ plan activities, with system conservation agreements executed by all parties included in modelling. In April 24 month study, such agreements include approximately 232,000 AF with a remaining 67,000 AF to be included in the model as additional agreements are executed.

Salt River & Verde River Watersheds Water Supply Update

Summer 2021monsoon season and December precipitation and runoff helped to improve conditions at the start of 2022, but most of Winter 2022 (January-March) has remained dry with 39% of normal precipitation. WY2022 cumulative watershed precipitation was 7.03 inches (76% of normal) and the total reservoir inflow for January 1-March 31 was 155,000 AF (50% of median), with about 40,000 AF occurring in the first 5 days of January. March snowpack and runoff did favor some parts of the Mogollon Rim and led to a 6,000 AF increase in C.C. Cragin Reservoir. While Salt River Project (SRP) streamflow forecast for January-May 2022 was 205,000 AF (45% of median), reservoir storage remained fairly level during this winter runoff season.

As of April 26, 2022, the total SRP reservoir system was in good condition at 1,636,435 AF (71% of total storage capacity), despite two consecutive dry winters. Verde Reservoirs declined and Roosevelt Lake observed only a small increase in storage (+100,000 AF, 67% to 73%) over the winter. Roosevelt Lake is expected to decline throughout the peak water use summer months through late fall of 2022. Total SRP groundwater use for 2022 remains at 200,000 AF, and is expected to be between 200,000 to 250,000 AF in CY2023.

Impacts of Drought on Hydropower – Irrigation and Electrical Districts Association of Arizona

The Irrigation and Electrical Districts Association of Arizona advocates on behalf of agriculture with an emphasis on hydropower. Energy pricing patterns data shows how energy prices are highly dynamic and have nearly doubled since 2021, this may be further impacted by the loss of energy generation from rivers in Arizona. Hydropower generation is influenced by two major components: hydraulic head (difference between the upper and lower pools) and volume, both variables are impacted by dropping water levels and reduced streamflow.

The Colorado River Storage Project (CRSP) Act (1956) generates about 1,875 megawatts (MW), out of which Arizona gets approximately 10%. As Lake Powell water levels drop, so does the hydraulic head, leading to reduced efficiency of power generators. At 3,500 feet of water elevation, about 35% less energy is generated than when releasing the same volume of water at 3,700 feet elevation. The average cost of purchasing energy from a market, as opposed to paying for hydropower production (replacement power), fluctuates year to year. According to a 1971-2021 market price analysis, average CRSP replacement power cost roughly $63 million dollars in 2021, this is estimated to increase 33-68% in 2022. Based on the lost energy and cost of replacement power, the drought is costing federal power preference customers in Arizona more than $30 million above what they were paying a few years ago. The Boulder Canyon Project Act (1928) created Hoover Dam, which generates about 2,048 MW. Arizona receives about 20% of Hoover Dam energy and due to drought, there has been a 25% reduction in total energy generation. Glen Canyon Dam, Davis Dam, and Parker Dam have also experienced reduced energy generation. Supply chain issues have also impacted hydropower generation by increasing the cost of new capacity additions. Hoover Dam tourism revenue has decreased over the last three years due to drought. Additionally, demand of water supplies has shifted to groundwater, leading to greater energy demand.

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 supplies power from Hoover Dam, Glen Canyon Dam, and Parker Dam. Parker-Davis Project Fiscal Year 2022 data and forecasts of energy supplied show a total estimate of 1,325 gigawatt hours (GWh) generated and 108 GWh of purchased replacement power (about 8%), this is due to a decline in water that can run through the system turbines. Price of replacement power purchases ($/MWh) is higher than sales price for customers and it is expected to increase through time. Average replacement power purchase price can be high and fluctuate depending on different weather phenomena or emergency events (up to $800/MWh) and the estimate certainty for price projections decreases as it is forecasted for longer term. On a system-wide scale, the estimated cost of drought impacts (2022-2030) for Hoover Dam is $939 million, and $42 million for Parker-Davis Project, when broken down, the highest cots are attributed to replacement power. Directly affected Arizona customers include power suppliers, as well as tribal, municipal, and agricultural stakeholders.

Impacts of Drought on the Navajo Nation

The Navajo Nation Department of Water Resources (NNDWR) monitoring efforts and data management processes were challenged by the COVID-19 pandemic, affecting drought condition data collection. NNDWR uses 85 active precipitation cans spread across routine routes on Navajo Nation, to monitor precipitation monthly. According to the National Aeronautics and Space Administration’s (NASA) Climate Engine Drought Severity Evaluation Tool (DSET) data from April 2021-22, all Navajo Nation agencies (Chinle, Crownpoint, Fort Defiance, Shiprock, and Tuba City) average Standard Precipitation Index (SPI) levels have not improved much due to the dry La Niña winter, which also affected streamflow. According to the U.S. Drought Monitor, as of April 26, 2022, northern Navajo County was in Extreme (D3) drought and most of Apache county was in Severe (D2) drought. Coconino County had a range of Abnormally Dry (D0) conditions, and Moderate (D1) and Severe drought, with a small portion at the northeastern corner in Extreme drought. Drought has impacted domestic water haulers, public drinking water systems, irrigators, dryland farmers and ranchers, wildlife, forestry, and recreation. June is the driest month of the year for Navajo Nation and impacts are expected to continue.

Impacts of Drought on the Gila River Indian Community

The Gila River Indian Community (GRIC) has been a major participant in water conservation efforts for the Lower CRB. While the community’s claims are to the Gila River and its tributaries, they have historically elected to take Central Arizona Project (CAP) water in lieu of their claim and are the largest entitlement holder of CAP water at 311,800 AF. The community’s Non-Indian Agricultural (NIA) water, at 120,600 AF, is most at-risk during drought. A Tier 1 Shortage unmitigated impact for this water would translate to a 70,000 AF reduction, and a complete loss of NIA water in case of a Tier 2 Shortage.

The GRIC currently only relies on about 20,000 to 40,000 AF for on-reservation demand, recently providing between 150,000 and 170,000 AF flex supply per year to Lake Mead conservation efforts. Previously, the community has used flex supply to recharge groundwater savings supply in the Phoenix and Pinal Active Management Areas (AMAs) but has shifted towards Lake Mead conservation efforts to ensure shortages remain below Tier 1. Total community contributions towards Lake Mead conservation since 2016 will reach 170,000 AF in 2022. By the end of 2023, the community plans to contribute 173,000 AF to Lake Mead conservation, including 62,000 AF of paid mitigation as part of the DCP, and an additional 111,000 AF in reductions. As part of the community’s plan to reduce its reliance on CAP water as much as possible, the GRIC has reduced some of its farming activity in 2022 to aid in their community water use reductions. Overall, the community is committed to strengthening drought resilience and maintaining the state at or below a Tier 1 Shortage in 2023, allowing continued water contributions and systems conservation.

Recommendation

The 2021 monsoon season helped improve short- and long-term drought conditions in Arizona. However, these conditions increased during the winter and spring (2021-22) due to La Niña. While the total SRP reservoir system is currently in good conditions, Lake Mead and Lake Powell have been steadily declining. The Drought Interagency Coordinating Group unanimously recommended that both drought declarations (PCA 99006) and (Executive Order 2007-10) be kept in place.

Spring 2022 Drought ICG Recommendation Letter to the Governor

Presentations

Spring 2022 ICG Meeting Recording

       

IGC MEETING FALL 2022

Fall 2022 ICG Meeting Agenda       

MEETING SUMMARY

Drought Status Update & Monitoring Technical Committee Activities       

Water Year (WY; October 1-September 30) 2022 precipitation was below average at 11.39 inches (the average is 12.26 inches, period of record starting in1985). Since 1994, there have only been 9 years with a surplus of average precipitation. Statewide temperature for WY2022 was 62.2°F (average is 59.7°F). Temperature has been above average for 28 of the last 29 years, and it has increased by 0.5 degrees per decade since WY1994.

WY2022 started off dry after the 2021 monsoon season. While December was the wettest winter month for the state, April and May were the driest period on record for Arizona. October to May snow water equivalent (SWE) for the Lower Colorado River Basin (CRB) was 34% of the median (1991-2020 median), while the Upper CRB received above-average SWE (76% of median). Peak snowpack in the Upper CRB ended by the second week of April and it had above-average melting rates.

The 2022 monsoon season brought significant precipitation to Arizona and led to short-term drought improvements. The June to September 2022 period was the 9th wettest for Arizona on record, and the wettest for Cochise County. Moderate (D1) and Severe (D2) drought have remained across the state during WY2022. Due to the warm and dry spring, Extreme (D3) drought developed but diminished by the end of the water year. Short-term and long-term drought persisted throughout the western, northern, and southeastern counties. Overall, the state has experienced Moderate and Severe short-term drought almost continuously in the past 20 years. While long-term drought maps showed some improvement throughout central and southern Arizona, Standard Precipitation Evapotranspiration Index (SPEI) data demonstrated a continuation of long-term drought across the state.

Weather Outlook for Winter 2022-2023

The outlook for winter 2022-23 indicates weak to moderate La Niña conditions continuing into early 2023 (70% chance). With a few exceptions, historical La Niña episodes typically result in drier than normal conditions across Arizona. Odds are shifted towards a warmer than normal winter based on a combination of La Niña composites and trends over the past 10-20 years. Climate models and historical La Niña composites indicate a tilt in odds towards a drier than normal winter in Arizona. While soil moisture improvement in central Arizona may aid spring 2022-23 runoff, there is uncertainty about this improvement in the upper parts of the Colorado River Basin.

Colorado River Water Supply Update

WY2022 resulted in 6.08 million acre-feet (MAF) unregulated inflow into Lake Powell, which is 63% of average (9.60 MAF is the 30-year average). The WY2023 forecast for October projects an unregulated inflow of 8.10 MAF (84% of average) as the most probable, 4.80 MAF (50% of average) as the minimum probable, and 15.50 MAF (161% of average) as the maximum probable.

The Bureau of Reclamation’s (BOR) October 2022 24-Month Study projections show the Most Probable elevation at 3,522.63 feet (23% full) and Probable Minimum elevation at 3,522.59 feet for the end of CY2022. The end of CY2023 projections for Lake Powell indicate a Most Probable elevation of 3,523.87 feet (24% full) and a Probable Minimum elevation of 3,483.64 feet. For Lake Mead, the 24-Month Study projections for the end of CY2022 indicate a Most Probable elevation of 1,045.38 feet (28% full) and a Probable Minimum elevation of 1,045.15 feet. The end of CY2023 projections for Lake Mead indicate a Most Probable elevation of 1,026.18 feet (23% full) and a Minimum Probable elevation of 1,016.30 feet.

The U.S. Department of Interior (DOI) continues to work with Lower CRB states on developing voluntary measures and agreements, as well as with Upper CRB states to support their 5-point plan. Additionally, DOI is making investments in drought resilience and water management from the Bipartisan Infrastructure Law and Inflation Reduction Act. DOI issued a Notice of Intent to prepare a Supplemental Environmental Impact Statement (SEIS) to the 2007 Interim Guidelines to analyze at operational alternatives and potential additional actions to reduce deliveries from Glen Canyon Dam and Hoover Dam. The Notice of Intent was published in the Federal Register on November 17, 2022, and the scoping period is open through December 20, 2022.  DOI does not currently have environmental coverage to release less than 7.0 MAF from Glen Canyon Dam or to adjust operational and shortage tiers.

Additional modeling was completed assuming the hydrology for WY2023 will be like that of WY2002.  In order to protect the critical elevation of 3,490 feet at Lake Powell releases from Glen Canyon Dam must be reduced to 5.5 MAF. If no other water is conserved in the Lower Basin, this modeling scenario projects the end of CY2023 Lake Mead elevation at 991.40 feet.

Salt River & Verde River Watersheds Water Supply Update

As of November 1, 2022, reservoir levels were at a total of 63% of storage capacity (69% last year). The monsoon season (June 15–September 30) brought 144% of normal precipitation and 197,000 AF (210% of median) runoff from July-September into SRP reservoirs. August inflows for the Salt River were 3rd highest on record (twice the inflow received in August 2021), but Verde and Tonto inflows are about half. The wet monsoon season kept water in reservoirs, lessening the amount of storage level decline typically observed throughout the higher summer demand season. While the winter outlook is leaning toward a greater chance of drier weather, runoff, conditions are favorable heading into the winter if storms impact the watershed. SRP is predicting a planned groundwater use for 2023 to remain at 200,000 AF.

SRP hosted the Southwest Water Resiliency Conference in October. Scientists, politicians, business owners, and city water managers had the opportunity to get different perspectives on current conditions and climate projections. The conference was meant to highlight the differences of the CRB and the Salt and Verde basins.

Impacts of Drought on Hydropower – Irrigation and Electrical Districts Association of Arizona

IEDA monitors four main energy projects in the Colorado River: Boulder Canyon Project, the Colorado River Storage Project (CRSP), and Parker and Davis Dams. Arizona receives a 20% allocation from the power generated through Hoover Dam, through the Arizona Power Authority. At this project, there has been an over 20% energy decline since 2015. IEDA members represent about 80% of the energy delivered in Arizona. Through the CRSP (which includes 11 dams), Arizona receives about 18% of the power generated, this system has experienced a 15% reduction since last year. Glen Canyon Dam produces 80% of the energy generated by the CRSP system. Parker and Davis Dams have each experienced a 16% loss compared to average production.

Energy production can be calculated if we know how much water volume is pushed through the dams and what the water elevation is. Hydropower generation is influenced by two major components: hydraulic head (difference between the upper and lower pools) and volume, both variables are impacted by dropping water levels and reduced streamflow, therefore it is important to constantly monitor conditions. Lake Powell inflows were 58% of the 1991-2020 average (5.61 MAF) during WY2022.

For every kilowatt hour that does not get generated through hydropower, there is a need to purchase replacement power. Energy pricing has increased compared to last year (from up to about $160/megawatt hour to $210) because of increasing demand and decreasing energy supply. Summer 2022 costs surpassed projections (at least a 40% increase) for most IEDA clients, this is due to energy production supply constraints.

Hydropower impact unknowns include the following: what will be the impact of mitigation? what new mitigations will be proposed? will there be any legislative assistance offered? According to the Western Area Power Administration (WAPA), drought conditions have led to an increase of least a $40M/year energy cost for the total CRB customers. Total cost for Hoover Dam power is typically approximately $20M, this is similar for CRSP customers. In summary, the cost of replacement power for the energy lost, costs as much as the typical annual bill for Hoover and CRSP power.

2022 Wildfire Update

The outlook for the 2022 fire season showed increased potential for early fires caused by last year’s La Niña winter. Below average precipitation, drought, and unburned fuel carryover led to predictions of potential active fires in the southwest portion of Arizona. In April, that outlook expanded up through central Arizona. Increased fuel and dry grass across, and high winds in the desert created favorable conditions for fires to spread. The Tunnel Fire in Flagstaff and the Crooks fire in Prescott were uncommon fires in areas that wouldn’t usually burn in April. May saw above normal fire activity across southern Arizona, June saw increases across the state as predicted with extreme drought. July fire activity dropped due to monsoon season ramp up.

As of November 10, 2022, 1,347 fires, consuming 120,938 acres, burned. 2021 saw 1,760 fires and over 524,428 acres burned, while 2020 saw nearly 1 million acres burned. Bulk of activity occurred in southern Arizona as predicted by models.

The outlook for 2023 shows the potential of a winter fire season in southern Arizona. Upcoming La Niña may contribute to fire conditions, leading to an early start for fire season. What didn’t ignite this year could ignite next year as fine dry grasses could contribute to increased fires.

2021-2022 Forest Health Update

The Arizona DFFM partners with the U.S. Forest Service to conduct yearly surveys on dead and dying trees. They follow up with ground surveys to confirm findings. 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 caused mortality on Ponderosa pines in 2022, however mortality is still elevated. Pinyon has seen increased mortality across the state. There has been extensive tree mortality caused by drought, especially in northern Arizona. And there has been an increase in crown discoloration in Ponderosa pine forests. Continued Cypress and Juniper mortality due to drought. A large increase in the Mediterranean Pine Engraver (MPE) in the metro Phoenix area. The urban forest health conditions show very large increases in MPE outbreaks. The insect is especially attracted to stressed trees. Management options are being researched to control spread of these damaging insects.

Moisture improves forest health; the trees have better defenses from insects and diseases. La Niña winter means that drought stress could increase the damage in forests in the next year.

Impacts of Drought on Wildlife

While drought conditions in Arizona have slightly improved, thanks to the wetter than normal monsoon season, the state will still be contending with this drought for years to come. Three AGFD teams are focusing on mitigating the effects of drought conditions. The infrastructure team is renovating and updating water catchments with new remote sensing technologies to supplement water sources for wildlife. They are also increasing boating access throughout the state to counteract fluctuating water levels. 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. The biological team is continuing research on priority species and habitat to identify actions and monitoring metrics to minimize drought impacts, the team has also developed a strategic plan that will be available to the public in December.

AGFD has developed strategic plans to highlight drought responses for wildlife, developed numerous applications to report drought related issues, and have increased drought related messaging. AGFD has hauled over 2.5 million gallons of water to catchments between 2021 and 2022 and raised $347,000 in Fiscal Year 2022.

Recommendation

The 2022 monsoon season helped improve short-term drought conditions in Arizona. However, data shows a continuation of long-term drought across the state. While the total SRP reservoir system is currently in good conditions, Lake Mead and Lake Powell have been steadily declining. The Drought Interagency Coordinating Group unanimously recommended that both drought declarations (PCA 99006) and (Executive Order 2007-10) be kept in place.

Fall 2022 Drought ICG Recommendation Letter to the Governor

Presentations

Fall 2022 ICG Meeting Recording

 

 

IGC Meeting Spring 2021

ICG Meeting Agenda - May 11, 2021

MEETING SUMMARY

Drought Status Update & Monitoring Technical Committee Activities

The benefits obtained by the 2019-2020 Winter precipitation were eliminated by the 2020 monsoon season (July to September), which was the hottest and driest on record for most of Arizona. Arizona 2020 average precipitation (6.58 inches) ranked as 2nd driest on record for the 1895-2021 period. Dry conditions have persisted and spread throughout the Southwest, the April 2020 to March 2021 period 12-month precipitation ranking (of 126 years) was driest on record for Arizona (4.87 inches), Nevada, Utah, and New Mexico.

As of April 30, 2021, Water Year 2021 precipitation was less than 25% of average throughout most of the state, except for some small areas in Coconino, Yuma, Gila, and Pima counties. Long-term drought conditions have worsened and by April 2021, most of the state was in Extreme (D3) and Exceptional Drought (D4). As for short-term drought conditions, by May 4, 2021, 58% of the state was in Exceptional Drought, 29% was in Extreme Drought, 8% was in Severe Drought (D2), 4% was in Moderate Drought (D1), and just 1% was in Abnormally Dry (D0) conditions. These conditions have increased the need for groundwater use and irrigation throughout Arizona.

2021 Weather Outlook

According to the new set of 30-year “normals” released by the National Center for Environmental Information, Arizona is now over 1.5 degrees warmer than the average last century. The state has experienced some of the driest years on record in the past 20 years combined with temperatures much warmer than the 1950s, conditions that have contributed to the current drought.

Winter 2020-2021 was a typical La Niña winter resulting in above-normal temperatures and below-normal precipitation. While climate models favor a warmer than average summer, there is a possibility of a wetter than normal 2021 monsoon season. This may resolve soil moisture deficits and contribute to inflow into regional reservoirs. However, the random nature of thunderstorms may result in some communities receiving below-average precipitation. There is an approximately 40% chance of La Niña redeveloping during fall/winter 2021-2022 with a 40% chance of El Niño-Southern Oscillation (ENSO). If La Niña does reemerge, drier conditions would be likely again next year.

Colorado River Water Supply Update

According to the Colorado Basin River Forecast Center, as of May 5, 2021, the Lake Powell Snow Water Equivalent (SWE) was at 59% of the median (6.9 inches) for 2021. The peak seasonal SWE typically occurs during the second week of April, however, this year it happened two weeks earlier and it was 89% of the median. If dry conditions persist in the Colorado River Basin (CRB), the April to July 2021 Lake Powell SWE is projected to rank 3rd worst on record.

As of May 5, 2021, the total CRB system supply was 22.46 million acre-feet (MAF) or 37% of capacity. During this time last year, the total system supply was at 30.65 MAF or 50% of capacity. By May 5, 2021, Lake Powell supply was at 8.46 MAF or 35% of capacity (3,561.79 feet (ft)), and Lake Mead was at 9.88 MAF or 38% of capacity (1,078.46 ft).

According to the U.S. Bureau of Reclamation April 2021 24-month Study, water levels are projected to decrease in both Lake Powell and Lake Mead by the end of Water Year and Calendar Year 2021. Lake Mead was projected to end the Calendar Year 2021 at 1,067.24 ft, under 1,075 ft, this means that Arizona will be in a Tier One shortage Drought Contingency Plan (DCP) contribution condition of 512,000 AF during 2022. Furthermore, based on the 24-month Study Inflow Scenarios, there is a projection of Lake Mead reaching a Tier Two shortage going into 2023. Full Hydrology and Stress Test Hydrology 5-year projections indicate that the chance of Lake Mead shortage from 2023 to 2025 exceeds 75% each year, with a 92% to 93% chance of shortage in 2023.

Salt River & Verde River Watersheds Water Supply Update

In May 2020, the Salt and Verde River reservoir system was at 98% of the total storage capacity (2,255,907 AF). This allowed the system to stay above median levels going into the 2020-2021 Winter, despite record warm and dry conditions during the summer of 2020. Dry conditions have persisted, reducing soil moisture throughout the watersheds, and leading to record (or near-record) low inflows into the Salt River Project (SRP) reservoir system.

A storm in January 2021 brought significant precipitation (2.51 inches, 124% of normal) into the Salt and Verde River watersheds, and from late January to early February, the Verde River received significant snowpack (124% of normal). However, any available runoff was soaked into the dry soils, leading to the second lowest ranking SRP streamflow projection on record for January to May 2021 (102,000 AF, 19% of median), after 2018 (100,000 AF).

As of May 1, 2021, the Water Year 2021 cumulative watershed precipitation was 47% of normal (5.19 inches). As of May 4, 2021, the total SRP reservoir system was in good condition at 74% of the total capacity (1,689,760 AF). However, drought conditions have persisted throughout the watersheds, and SRP increased groundwater pumping during February, which is expected to continue in 2022.

2020-2021 Wildfire Season Update

A total of 2,520 fires were reported in 2020, burning approximately 978,519 acres of land (state, federal, and tribal). As of May 3, 2021, about 341 fires have been reported for the year, burning approximately 17,853 acres. Early fire activity was expected due to La Niña dry conditions, drought, and the carryover of fine fuels across the Sonoran Desert. By May 11, 2021, two Type 1 fire incidents were reported in Arizona. On a scale of 1 to 5, Type 1 fires are the most complex and require significant resources.

Widespread activity is predicted by late May and early June and the Arizona Department of Forestry and Fire Management is currently at a Preparedness Level 3 (moderate category). This means that two or more geographic areas (Arizona and New Mexico) require significant amounts of wildfire suppression resources from other states.

During 2020 about 82% of the fires in the state were human-caused, this is more than in 2019 (78%) and 2018 (68%). Human-caused fires are more prevalent in spring and early summer and coincide with windy and dry conditions, therefore fire restrictions are already in place.

2020-2021 Forest Health Update

Aerial surveys were conducted from July to September 2020 and showed an 82% decrease in total acres of bark beetle caused tree mortality (from 459,239 acres in 2019 to 81,031 acres in 2020). Any bark beetle damage that did occur mostly impacted ponderosa pine forests. There was, however, an increase in tree damage caused by forest insect defoliators and sap-feeding insects. Bark beetle caused tree mortality was observed to increase after the survey season due to the lack of monsoonal moisture and the La Niña winter. Therefore, an increase in tree damage is expected for the 2021 season. A wetter than normal 2021 monsoon season may result in improved forest and woodland health.

According to urban forest health surveys throughout the Phoenix Metropolitan area, there was an increase in Aleppo Pine Blight and Mediterranean pine mortality. The latter was caused by the Mediterranean Pine Engraver bark beetle.

Impacts of Drought on Wildlife

High temperatures and dry conditions have prompted the Arizona Game and Fish Commission and the Arizona Game and Fish Department (AZGFD) to monitor drought effects on wildlife with the objectives of responding to severe impacts and achieving sustainable management. As drought conditions increase, so do wildlife incidents. AZGFD staff conduct eagle rescues by providing food, health evaluations, rehabilitation, and rehydration. Additionally, staff and volunteers provide supplemental feeding to black-tailed prairie dog colonies during the dry months (March to June), to increase food availability during nutrient-dependent gestation and pup-rearing seasons, this also helps increase birth rate, by increasing nutrients during reproduction, and decreases predation and mortality.

AZGFD has been monitoring streamflow and water quality under drought conditions for fish stocking purposes as well as salvaging and relocating native fish species from drying habitats to wetter areas. Water hauling serves as an immediate relief for terrestrial wildlife during dry weather conditions, during 2020 a total of 2,393,190 gallons were hauled throughout the entire state. This was done with the help of over 15 partner organizations and more than 50 volunteers. Furthermore, the AZGFD had a “Send Water” campaign in 2019 and 2020, which increased financial support and awareness about the need for water in wildlife management.

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) data from December 2020 to May 2021, all Navajo Nation agencies (Chinle, Crownpoint, Fort Defiance, Shiprock, and Tuba City) average Standard Precipitation Index (SPI) levels have slightly improved from -2.0 or less (Exceptional Drought (D4)) to approximately -1.2 or -1.3 (Moderate (D1) to Severe Drought (D2)) due to winter precipitation. Precipitation data from November 2020 to May 2021 showed minimal rain events, with precipitation averages in Fort Defiance and Chinle agencies peaking at approximately 0.40 inches in January 2021. Drought has impacted domestic water haulers, public drinking water systems, irrigators, dryland farmers and ranchers, wildlife, forestry, and recreation. June is the driest month of the year for Navajo Nation and impacts are expected to continue.

Recommendation

Dry condition trends that started in 2020 have persisted into 2021, increasing short- and long-term drought conditions throughout the state. While the Salt and Verde rivers total reservoir supply is currently in good condition, Lake Powell and Lake Mead are projected to decline by the end of 2021, and there is a 97% chance that Arizona will be in a Tier One shortage in 2022. While there is a probability that the monsoon will be wetter than normal, some areas of the state may be drier than normal due to the random nature of thunderstorms. The Drought Interagency Coordinating Group unanimously recommended that both drought declarations (PCA 99006) and (Executive Order 2007-10) be kept in place.

Spring 2021 Drought ICG Recommendation Letter to the Governor

Presentations

ICG Meeting Recording

IGC MEETING FALL 2021

ICG Meeting Agenda - November 10, 2021

MEETING SUMMARY

Drought Status Update & Monitoring Technical Committee Activities

Total statewide precipitation for Water Year (WY) 2021 (October 1, 2020-September 30, 2021) ranked below average at 10.69 inches. The Mogollon Rim and northeastern Pima County had the highest amounts of precipitation in the state (up to 150% of average) during this period. Mohave County experienced its third driest water year on record. WY 2021 experienced the longest extent of Exceptional (D4) drought recorded across the state in the period of record (years 2000-2021).

The Upper and Lower Colorado River Basin (CRB) received below average seasonal precipitation from October 2020 to March 2021, with Arizona basins receiving less than 50% of seasonal precipitation during this time. Short- and long-term drought conditions at the start of WY 2021 were initiated by the very hot and dry 2020 monsoon season and exacerbated by the dry La Niña winter (2020-2021). Largely due to the very wet 2021 monsoon season where several locations received their wettest monsoon on record, short- and long-term drought conditions improved across much of the state by the end of WY 2021.

Weather Outlook for Winter 2021-2022

Increased monsoonal rainfall in Summer 2021 led to an increase in soil moisture that may aid surface water runoff for Winter/Spring 2021-2022 in parts of the Lower CRB, but likely not as much in the Upper CRB. Establishment of La Niña conditions in Arizona has already been observed, with a greater than 90% chance of persisting in weak to moderate levels through Winter 2021/Spring 2022. La Niña events, with limited historical exceptions, result in drier and warmer than normal conditions across Arizona, which are likely to be expected this winter.

Colorado River Water Supply Update

As of November 3, 2021, the total CRB reservoir system supply was at 22.5 million acre-feet (MAF) or 37% of capacity, compared to 46% of capacity or 28.2 MAF last year. Lake Powell supply was at 7.17 MAF or 29% of capacity (3,544.12 feet) and Lake Mead was at 8.91 MAF or 34% of capacity (1,066.36 feet). According to the Colorado Basin River Forecast Center, snow water equivalent (SWE) above Lake Powell peaked on March 30, 2021, at 89% of median. Dry soils during the spring resulted in low inflow from the snowpack, leading to annual inflow percentages in the low 30s. Unregulated inflow from April-July 2021 ranked 3rd worst on record at 1.83 MAF. The Bureau of Reclamation (BOR) updated the 30-year period of record used to analyze unregulated inflow volumes into Lake Powell to 1991-2020.

According to the BOR October 24-Month Study, Lake Powell is projected to end Calendar Year (CY) 2021 at 6.58 MAF or 27% of capacity (3,535.36 feet), and Lake Mead at 8.89 MAF or 34% of capacity (1,066.06 feet). According to the BOR Operational Table based on the August 24-Month Study, Lake Powell will be at a mid-elevation release tier (below elevation 3,575 feet) and will release 7.48 MAF to Lake Mead in WY 2022. Tier 1 Shortage was declared for Lake Mead for CY 2022, resulting in a 512,000 AF reduction for Arizona. Furthermore, according to the August 2021 Colorado River Simulation System (CRSS) results, there is a 78% probability of Tier 1 Shortage and a 16% probability of Tier 2 Shortage for Lake Mead in 2023. In 2024, there is a 28% probability of Tier 1 Shortage and a 63% probability of Tier 2 Shortage. For 2025 and 2026 there is a 41% probability of Tier 3 Shortage.

According to the Upper CRB Drought Contingency Plan (DCP) Drought Operation Agreement (DROA), 181,000 AF is being released above Lake Powell beginning in July 2021 and occurring through December 2021.

Salt River & Verde River Watersheds Water Supply Update

Short-term drought conditions and runoff efficiencies throughout the Salt and Verde River Watershed have significantly improved going into fall. As of November 2, 2021, the total Salt and Verde River reservoir system was in good condition at 69% of capacity (1,583,088 AF). The monsoon season watershed average precipitation was 11.8 inches (2nd highest on record since 1919), the rain produced a total inflow of 257,898 AF (233% of median, 10th highest). During this monsoon season the Salt River Project (SRP) reservoirs increased 3% over peak demand months and local inflows below reservoirs resulted in 9,250 AF of water spilled from Granite Reef Diversion dam. For WY 2021 cumulative watershed precipitation was 16.95 inches (93% of normal), however, total SRP reservoir inflow was only 420,756 AF (46% of median) due to the dry first 9 months of the water year. As a result of below median runoff into SRP reservoirs, an increase up to 200,000 AF of groundwater is projected to be used by SRP during CY 2022.

2021 Wildfire Update

As of November 2021, around 1,683 fires have been reported, burning approximately 532,412 acres of land (state, federal, tribal, and private). This is much less than the 2,324 fires, burning approximately 954,836 acres, that were reported at this point last year. Fire activity started earlier than usual this year in May, largely due to a winter La Niña event and severe drought conditions, in addition to an overgrowth of unburned vegetation. Statewide fire activity in June was high, as predicted, however, a strong monsoon season in July significantly decreased fire activity and new starts, essentially ending this year’s fire season. The impacts of drought conditions on water transport presented challenges to fighting larger fires such as the Telegraph and Rafael fires. Additionally, monsoon rains, while crucial to ending the fire season, have also presented new challenges for potential flooding and landslides in burn areas. Expected La Niña conditions for Winter 2021 and Spring 2022 will likely bring an earlier start to fire activity in the Sonoran Desert and southern Arizona, aided by an overgrowth of grasses from the 2021 monsoon season.

Impacts of Drought on the Gila River Indian Community

The Gila River Indian Community (GRIC) has been a major participant in water conservation efforts for the Lower CRB. While the community’s claims are to the Gila River and its tributaries, they have historically elected to take Central Arizona Project (CAP) water in lieu of their claim and are the largest entitlement holder of CAP water at 311,800 AF. The community’s Non-Indian Agricultural (NIA) water, at 120,600 AF, is most at-risk during drought. A Tier 1 Shortage unmitigated impact for this water would translate to a 70,000 AF reduction, and a complete loss of NIA water in case of a Tier 2 Shortage.

The GRIC currently only relies on about 20,000 to 40,000 AF for on-reservation demand, recently providing between 150,000 and 170,000 AF flex supply per year to Lake Mead conservation efforts. Previously, the community has used flex supply to recharge groundwater savings supply in the Phoenix and Pinal Active Management Areas (AMAs), but has shifted towards Lake Mead conservation efforts to ensure shortages remain below Tier 1. Total community contributions towards Lake Mead conservation since 2016 will reach 540,000 AF in 2022. By the end of 2023, the community plans to contribute 173,000 AF to Lake Mead conservation, including 62,000 AF of paid mitigation as part of the DCP, and an additional 111,000 AF in reductions. Dialogue with the Gila River Farmboard will seek voluntary fallowing of 4,000 acres of farmland in the community to aid these reductions. Overall, the community is committed to strengthening drought resilience and maintaining the state at or below a Tier 1 Shortage in 2023, allowing continued water contributions and systems conservation.

Recommendation

The 2021 monsoon season brought significant precipitation to Arizona, improving short- and long-term drought conditions. However, drought remains throughout the state and a La Niña winter (2021-2022) will likely result in drier than normal conditions. While the total SRP reservoir system is currently in good conditions, a Tier 1 Shortage was declared for Lake Mead during CY 2022, resulting in a 512,000 AF reduction for Arizona. The Drought Interagency Coordinating Group unanimously recommended that both drought declarations (PCA 99006) and (Executive Order 2007-10) be kept in place.

Fall 2021 Drought ICG Recommendation Letter to the Governor

Presentations

ICG Meeting Recording

 

 

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

 

 

 

ICG Meeting Fall 2019

ICG Agenda - November 12, 2019

Meeting Summary

Drought Status Update

Winter 2018-2019, followed by some spring precipitation in May and June, improved short-term drought conditions throughout the state. However, multiple consecutive years with higher than average precipitation are needed to improve long-term drought conditions. There were very few monsoon storms during the 2019 summer, exacerbating drought conditions throughout the northeast part of the state. By October, about 55% of Arizona experienced Moderate Drought (D1), 26% Severe Drought (D2), 14% Abnormal Dry (D0), and only 5% experienced No Drought conditions. As of November 12th, there has been less than 25% of average precipitation throughout the state for Water Year 2020.

Winter 2019-2020 Weather Outlook

The increased spring precipitation and delayed onset of monsoon thunderstorm activity was the result of lingering El Niño conditions in the Pacific. The relatively dry summer and early fall resulted in dry soils, which may reduce the amount of winter runoff even if an average amount of precipitation occurs. Although forecast models for Arizona depict neutral El Niño-Southern Oscillation (ENSO) conditions through spring 2020, water temperature forecasts in the Pacific and forecast model output suggest that conditions may shift towards a drier and warmer than normal winter.

Colorado River Water Supply Update

Winter 2018-2019 was wetter than average in the Upper Colorado River Basin leading to 120% of average unregulated inflow into Lake Powell, which helped improve Upper Basin reservoir levels. Lower Basin side inflows into Lake Mead were well above average for the beginning of Water Year 2019, but well below average since July 2019. The total Colorado River system reservoir contents increased from 45% (25.84 million acre-feet (MAF)) capacity at the end of Water Year 2018 to 52% (29.45 MAF) at the end of Water Year 2019. According to the United States Bureau of Reclamation October 24-month study, the end of Water Year 2020 projections indicate that Lake Mead and Lake Powell levels will increase, reducing the probability of shortage conditions. However, under the Colorado River Drought Contingency Plan (DCP), Lake Mead will be in Tier Zero, under which Arizona is obligated to contribute 192,000 AF to Lake Mead.

Salt River & Verde River Watersheds Water Supply Update

2018-2019 winter precipitation was much wetter than average, which led to a substantial inflow (210% of median or 1,121,000 AF) in the Salt River and Verde River watersheds. This is a significant improvement from spring 2018, which followed a very dry winter that produced the lowest inflow on record (17% of median or 100,000 AF). As of May 2019, which marks the end of the spring inflow season, the total Salt and Verde system storage was at 81%, compared to 58% in May 2018. Total precipitation over the watersheds during Water Year 2019 was higher than average (114% of normal), with some reservoirs reaching full capacity and spilling. A tropical system in September caused a significant flood event (6-8 inches) on the lower Salt River Watershed and generated some runoff, however, the rest of the monsoon season was the driest on record for some areas of the state and fall inflow was 45% of median. According to tree ring records, the current megadrought is the most severe from the 16th Century to the present.

2019 Wildfire Season Update

There was a total of 1,781 state and federal fires in 2019, which was relatively similar to 2018 with a total of 1,937 fires. However, the number of impacted acres increased from 157,070 in 2018, to 371,940 in 2019 mainly due to the occurrence of 69 significant fires (extending beyond 100 acres) that covered a total of 353,814 acres. The fire season has been prolonged due to the meager monsoon precipitation and wildfires continue to burn across the state in November.

2019 Forest Health Update

Winter 2018-2019 precipitation reduced drought conditions throughout the state, improving forest and woodland health. The observed tree mortality from bark beetles in Water Year 2019 increased by only 65% (compared to 513% last year), from 275,933 to about 455,053 acres. However, this moisture also caused a foliar blight infestation that defoliated approximately 34,000 acres of native aspen across northern Arizona. The Pinyon-juniper woodlands in particular have become increasingly affected by bark beetles and continue to show significant population decline, which is a major point of concern. The minimal 2019 monsoon activity and the remaining bark beetle populations from Water Year 2018 have the potential to continue deteriorating forest and woodland health.

Recommendation

Although the 2018-2019 winter precipitation alleviated drought conditions throughout the state, the monsoon season precipitation was insufficient, and Arizona remains in a long-term drought. A few consecutive wet winters are needed to eliminate the long-term drought conditions that have impacted Arizona since the mid-1990s. The Drought Interagency Coordinating Group unanimously recommends that both drought declarations be kept in place.

Fall 2019 Drought ICG Recommendation Letter to the Governor

Presentations

ICG Meeting spring 2019

ICG Agenda - May 9, 2019

Meeting Summary

Drought Status

In May 2018, 60% of the state was in either Extreme Drought (D3) or Exceptional Drought (D4), and little relief was provided by the monsoon season. In October 2018, heavy rainfall, which lasted well into the winter months, saturated the soil and vegetation throughout Arizona. Precipitation from January through March 2019 improved short-term drought conditions significantly and 83.3% of Arizona became drought-free. Long-term drought, however, is still present in many areas of the State, including, extreme and exceptional drought conditions in the west and northeastern Arizona. As the summer season approaches with higher temperatures, snowmelt is likely to improve soil moisture and may bring further drought relief to these areas.

Weather Outlook
Monsoon activity in the summer will be influenced by the steering of moisture from northern Mexico and by weather disturbances in Arizona. Snow cover and drought conditions since October may have an influence on summer rainfall; high levels of soil moisture may suppress monsoon development while warmer water temperatures in the eastern Pacific Ocean may bring more tropical systems and potential moisture surges into Arizona. Since last summer, equatorial Pacific waters have been warmer than normal, and weak El Niño conditions have aided in the development of frequent storms affecting the Southwest United States. If these conditions persist through the 2019-2020 summer and winter seasons, the odds for above average temperatures and precipitation are likely.

Colorado River – Water Supply Status
As of May 8, 2019, total Colorado River reservoir system content equates to 46% of capacity or 27.63 million acre feet. Unregulated inflow into the Colorado River Basin (CRB) for Water Year 2019 is expected to reach 112% of average. Snowpack accumulation this season peaked on April 8 at 130% of the median with 21 inches of snow water equivalent. Due to the recent wet winter, a first level shortage is not expected for the Lower CRB in 2019 or 2020. However, according to the United States Bureau of Reclamation April 24-Month Study, storage in Lake Mead is projected to decrease to 38% of capacity by January 1, 2021.
Colorado River Drought Contingency Plan Update

Colorado River Drought Contingency Plan Update
The purpose of the Drought Contingency Plan (DCP) is to reduce the probability that Lake Mead will decline to critically low elevations (below 1,020 ft). Implementing the DCP will reduce the probability of a third level shortage by as much as 34% by 2026. Under the DCP, total reductions in Colorado River water use from Arizona, Nevada, California, Mexico, and the U.S equate to 1.475 million acre feet at various elevations. This number more than doubles the reductions outlined in the 2007 shortage guidelines. Congressional approval for the Colorado River DCP Authorization Act (H.R. 2030) was granted on March 19, 2019.

Salt River & Verde River Watersheds – Water Supply Status
The weather in Water Year 2019 brought wetter than average conditions throughout the Salt River and Verde River watersheds with nearly 15 inches of cumulative precipitation as of March 30 (129% of normal). Verde River inflow peaked at 68,500 cubic feet per second after a heavy storm in mid-February, which led to an increase from 30% to 64% in Verde River system reservoir storage levels. In late February, elevations of as low as 2,500 feet received snow with an average snow depth of 12 inches throughout both watersheds, a snow water equivalent of 1.4 million acre feet. Cumulative inflow from January to May is projected to reach 1.1 million acre feet, which is double the median value for this time of year. As of May 7, total Salt River and Verde River reservoir system storage is at 81% of capacity.
Forest Health and Wildfire Season Update

Forest Health and Wildfire Season Update
The 2018 aerial and ground survey conducted by the Department of Forestry and Wildfire Management detected 275,934 acres of trees impacted by bark beetles compared to 45,003 acres in 2017, an increase of 513%. This drastic increase is largely attributed to the dry winter of 2017-2018, which stressed many trees and made them more susceptible to pests. This past wet winter improved forest health across Arizona and because healthier trees are better able to defend against bark beetle activity, reduction in tree mortality levels is anticipated. Drought impacts are starting to ease but still present in the form of dead vegetation, particularly in the White Mountains. Fine fuels (i.e. grasses, pine needles, and small herbaceous growth) that help fire spread quickly and intensely are observed at normal to above normal levels.

Impacts of Drought on Wildlife
Precipitation over the winter has filled water catchments for wildlife and there was no need for water hauling. Aquatic habitats have improved significantly since last year.

Impacts of Drought on the Navajo Nation
The Navajo Nation received average to above average precipitation in Water Year 2019 thus far, with a heavy storm in February which brought precipitation levels to above 200%. This led to a notable recovery in the drought conditions experienced in 2018.

Recommendation
Despite short-term drought improvements, these updates confirm that Arizona remains in a long-term drought and that the drought is expected to continue. The Drought Interagency Coordinating Group unanimously recommends that both drought declarations be kept in place.

Spring 2019 Drought ICG Recommendation Letter to the Governor

Presentations

 

 

 

ICG Meeting Fall 2018

ICG Agenda - November 28, 2018

Meeting Summary

Drought Status

Drought conditions at the end of 2017 water year were minimal due to the relatively wet winter of 2016-17 and a reasonably wet, though short, monsoon season. Only the southwest remained in moderate drought, central and eastern Arizona were abnormally dry, and the northwest and southeast experienced no drought. As the water year began in October 2017 however, the state had dried out and remained dry until mid-December. A few winter storms dropped scant precipitation through March, bringing severe and extreme drought back to the state. By April 2018, the entire state was in moderate drought or worse. The northwest and southern third of the state were in Severe Drought, while central and northeastern Arizona were in Extreme Drought. Spring continued to be quite dry with forest fires around the state, and water hauling for livestock and wildlife. The fire threat became so extreme that state lands were closed to recreational use. Groundwater wells ran dry in a number of places around the state. By the time the 2018 monsoon activity began, the moisture deficits were significant, and the monsoon rainfall was not sufficient to make up the deficits on the Colorado Plateau and in southwestern Arizona. However, the Mogollon Rim, southern Coconino and northern Yavapai counties, and the southeast corner of the state showed one-category drought improvement.

Weather Outlook

Water temperatures in the tropical Pacific have warmed fairly rapidly during the late summer and fall of 2018 leading to the likelihood of an El Niño phase during the winter of 2018-19. There is better than a 90% chance of an El Niño persisting through the winter months and perhaps persisting through spring 2019. While many other factors can influence the winter weather patterns in Arizona, the El Niño phase has historically provided some influence in long-term winter predictions for the Southwest United States. The El Niño phase this winter will likely peak only in a weak category but could briefly touch a moderate stage. A more prolonged moderate El Niño is unlikely, but a period of more heightened warmer Pacific waters could tilt the odds towards a wetter than normal winter. NOAA’s Climate Prediction Center official outlook for January-March 2019 indicates a better chance that the average temperature will be above normal. This is supported by both forecast models and the longer-term trend of distinctly warmer winters in the Southwest over the past 10-20 years (i.e. climate change).

Salt River & Verde River Watersheds – Water Supply Status

In 2018, the Salt River and Verde River watersheds experienced the lowest winter runoff season (January-May) on record dating back to 1913 with only 100,000 acre-feet of inflow. As a result, Roosevelt Lake saw little to no increase in storage remaining at approximately 58% throughout the winter. In addition, Bartlett and Horseshoe reservoirs on the Verde system declined from 59% to 31% following the dry winter. During the monsoon season, slightly above normal precipitation was received; however due to extremely dry conditions throughout the watershed, only minimal additional runoff occurred with little to no impact on overall storage. As of October 3, 2018, total storage of the Salt and Verde system was at 46% capacity compared to 65% at this time last year.

Colorado River – Water Supply Status

Cumulative precipitation received within the Upper Colorado River Basin during water year 2018 was 65% of average. The Colorado River total system storage experienced a net decrease of 4.9 MAF (~8%) and reservoir storage in Lake Powell and Lake Mead decreased by 3.629 MAF and 0.312 MAF respectively in water year 2018 compared to water year 2017. As of November 26, 2018, total system storage was 46% of capacity (27.39 MAF). Snowpack conditions throughout the 2018 snow accumulation season (October - April) also trended below average across most of the Colorado River Basin. On April 1, 2018, basin-wide snow-water equivalent measured 73% of average. April through July unregulated inflow volume to Lake Powell was 2.6 MAF, which is 36% of average. Lower Colorado River Basin tributary inflows upstream and downstream from Lake Mead were also below average for water year 2018. Though no shortage will be declared in 2019, the official operational forecast made by United States Bureau of Reclamation in August 2018 shows a 57% chance of a shortage declaration in 2020.

Impacts of Drought on Wildlife

Over one million gallons of water were hauled to various catchments around Arizona from January through August 2018. Over 400,000 gallons were hauled to the Yuma region alone. Populations of Arizona Toads, Chiricahua Leopard Frogs, and Sonoran Tiger Salamanders have been negatively impacted by the loss of breeding habitats such as streams, ponds, and stock tanks that have gone dry due to drought conditions. Additionally, the drought had likely played a role in an outbreak of epizootic hemorrhagic disease amongst deer populations in the Prescott area. Toxic algal blooms caused by low water levels and warmer temperatures have been observed in numerous lakes throughout the state, posing a threat to fish, wildlife, and people.

Forest Health and Wildfire Season Update

As of November 26, 2018, 1,968 fires damaged 161,356 acres in Arizona in 2018, a decrease from the 419,418 acres burned by numerous large-scale wildfires in 2017. This decrease is mainly attributed to the closure of public lands for recreational activities and not to improved drought conditions, which in fact were much more severe in 2018 than in 2017. Heavy rainfall in October triggered an increased growth of warm weather vegetation, acting as fine fuels that will become susceptible to fire as they go dormant. The current drought stresses forests and urban vegetation and renders trees vulnerable and less capable of deterring pests. Based on historic data, Arizona is experiencing bark beetle conditions similar to the onset of the 2002-2003 infestation that impacted 2.2 million acres of trees during these very dry years. Currently, the 2018 aerial and ground survey detected 275,934 acres of trees impacted by bark beetles compared to 45,003 acres in 2017, which is an increase of 513%. Roughly 90% of the current bark beetle damage is occurring in ponderosa pine, one of the more valuable trees in Arizona.

Impacts of Drought on the Navajo Nation

The Navajo Nation experienced significant drought impacts during the past year, which triggered the renewal of the Nation’s Drought Emergency Declaration in February 2018. Each of the Nation’s five agencies have observed a downward trend in annual average precipitation since 1984. August and September were much drier than average, with areas receiving as little as 32% of average precipitation. Tropical storm activity in October however, brought all five agencies’ annual precipitation to above average. The Navajo Nation is currently updating its 2003 Drought Contingency Plan and is considering other drought indices, such as evapotranspiration.

Fall 2018 Drought ICG Recommendation Letter to the Governor

Presentations

ICG Meeting spring 2018

ICG Agenda - May 29, 2018

Meeting Summary

Drought Status

This water year (WY) has been very dry across the western U. S. and Arizona received very little rain and snow, which exacerbated short-term drought conditions. Monsoon storms were almost entirely limited to the month of July, and from October through December, less than 25% of average precipitation was received. Snow cover is typically highest across the Southwest on March 1st; however, snow cover observed this March was minimal to non-existent, putting the entire basin in a snow drought. As of late May, 3% of the State was in Moderate Drought, 24% in Severe Drought, 57% in Extreme Drought and 16% in Exceptional Drought. This is a stark contrast to May of last year in which the northern half of Arizona was completely free of drought and the southern part was partly in abnormally dry and in moderate drought conditions. This exceptionally dry winter has extended the wildfire season, decimated forage, and led to many wells going dry. Even native desert vegetation, such as creosotes, appear to be dying in some locations. Over the past month, there has been an increase in water hauling, supplementing feed for livestock, and culling of herds. These drought conditions have also led to drought emergency declarations in Yuma County and the Navajo Nation. Long-term statewide average precipitation in WY 2017 seemed to be nearing the mean (12.59 inches) of recorded data, however that trend is now sloping downwards with less than 10 inches of rain in WY 2018 thus far.

Weather Outlook

NOAA’s Climate Prediction Center’s outlook for Summer 2018 suggests slightly enhanced odds for wetter than normal monsoon season due to warmer than average East Pacific waters and likelihood that the typical summer subtropical high-pressure system will be favorably located to frequently bring moisture into the State. However, summer thunderstorms are usually quite erratic and may only provide partial and local relief to long-term drought conditions. Temperatures this summer are likely to be warmer than average based on consistent trends in recent years. The weak to moderate La Niña conditions, which existed last Fall and Winter and were partially responsible for the poor rain and snow in the Southwest, are now transitioning into a neutral state. Based on past winters’ trend, there are better odds for above normal temperatures this winter. There is no large tilt in odds for above, below or near normal precipitation for the upcoming winter.

Salt River & Verde River Watersheds – Water Supply Status

Salt-Verde watershed cumulative precipitation for August through April amounted to 5.17 inches, which is 33% of normal and the driest on record (since 1896). Salt River, Tonto Creek, and Verde River spring runoff from 2011 to 2018 indicate the driest consecutive 8-year period on record. Inflow from January to May amounts to 99,000 acre feet compared to last year’s 970,440 acre feet. Since 2010, reservoir storage has declined 57% from 2.311 million acre feet (MAF) to 1.337 MAF. Utilizing both the gaged record and the University of Arizona’s Tree Ring Laboratory record from 1361 to 2005, SRP has determined that the last 23-years (1996—2018) have been the driest in the entire record (1361—2018), officially making the last few decades the worst megadrought in recorded history for the Salt and Verde basins. Despite the dry conditions, total system storage of Salt River Project (SRP) reservoirs amounts to 1.309 MAF (57% of maximum capacity) as of mid-May due to calculated water management.

Colorado River – Water Supply Status

This winter was exceptionally dry on most of the Colorado River basin, and the entire system reservoirs are at 51% of maximum capacity or 30.434 million acre feet (MAF). This is only a decrease of roughly 1% from last May. Lake Powell and Lake Mead are at 52% (12.679 MAF) and 39% (10.247 MAF) of capacity, respectively. Lake Mead’s elevation is just below 1,083 feet, eight feet above Tier-1 shortage. In the Upper Basin, this year’s snow water equivalent reached 12 inches at its peak, which is 4 inches below the 1981-2010 median, and only 51% (5.5 MAF) of unregulated inflow is projected for Lake Powell. Projected elevations for Lake Powell and Mead by year-end are approximately 3590.43 feet or 45% of capacity (a 13% decrease from December 2017) and 1079.1 feet or 38% of capacity, respectively. Though no shortage on the Lower Basin is currently predicated for 2019, the Bureau of Reclamation predicts a 52% probability of a Tier-1 shortage in 2020. Furthermore, this is the first time that the probability of a double-digit Tier-3 shortage has been projected within a 5-year outlook period.

Impacts of Drought on Wildlife

In the Pinetop Region, 110,150 gallons of water were already hauled so far this spring to 41 catchments. Increased salinity in SRP reservoirs and urban lakes due to low inflows cause growth of golden algae bloom, which is toxic to fish. Low spring inflow into one of the endangered Gila topminnow habitat cause the disappearance of one of its population as the habitat could no longer support the fish.

Forest Health and Wildfire Season Update

Many of last year’s burned acres regrew before the State launched into 120 days of dry weather providing ample fine fuels that invite greater opportunity for fire activity. As of May 20, there have been 611 fires: 604 of these were caused by human activity while 7 by natural conditions. Many state lands are currently closed to recreation, which have helped reduce wildfire occurrence. Drought stress in forest and urban vegetation render trees vulnerable and less capable of deterring pests. Increased juniper mortality due to drought stress has been observed this year. In addition, 80,469 acres of forest trees were killed or damaged due to bark beetles and defoliators/sap feeders in 2017. Yet these figures pale in comparison to the extremely dry years of 2002 and 2003 when bark beetles decimated 570,000 to 763,000 acres of ponderosa pine forest.

Northern Arizona Forest Fund Efforts

The Northern Arizona Forest Fund (NAFF), a regional initiative of the National Forest Foundation, supports watershed restoration projects across five forests in Northern Arizona. Over $2.5 million have already been invested over 4 years, engaging 24 donors and 200 volunteers who donated over 1500 hours. So far, 21 restoration projects have been completed in non-market-value, high-priority locations where restoration work would not have otherwise been funded. The NAFF is working on improving hydrologic functions through restoration of springs, wetlands, streams, and meadows. NAFF projects also focus on minimizing severe fire risk through prescribed burning, small-diameter tree thinning and sediment and erosion control improving the flow and quality of waterways and reservoirs. In program year 2017, NAFF efforts have reduced 31 tons of sediment on 37 miles of roads and trails, replenished 2.3 million gallons of water, and reduced fire risk by 27% on 3,500 acres.

Spring 2018 Drought ICG Recommendation Letter to the Governor

Presentations

 

ICG Meeting Fall 2017

ICG Agenda - November 16. 2017

Meeting Summary

Drought status

The 2016-17 winter through April was quite wet across the western U. S. and the northern two-thirds of the State received sufficient rain and snow to alleviate short-term drought. Southern Arizona did not receive as many winter storms and remained warm through the winter. Spring was also quite dry in southern Arizona, which prevented any short-term drought improvement. By the time the monsoon activity began, the moisture deficits were significant, and the monsoon rainfall was not sufficient to make up the deficits in south central and southwestern Arizona, even though Tucson had the wettest July ever with 6.80” of rain. Much of Graham and Cochise counties had frequent rain showers and short-term drought was eliminated there by the end of the summer. Northern Navajo and Apache counties were in good shape through the winter, but the relatively dry spring and summer brought abnormally dry conditions back by September. Much of the state is still experiencing abnormally dry or moderate drought conditions.

Weather Outlook

The official outlooks from NOAA’s Climate Prediction Center for January-March 2018 show a much better chance that the average temperature will be above normal. This is supported not only by forecast models and the influence of La Niña that is likely to persist through the winter, but more so the fact that Arizona winters are distinctly trending warmer over the past 10-20 years. The precipitation outlook depicts a slight tilt in odds towards drier than average winter, which is primarily a result of the La Niña forecast. Should La Niña conditions become stronger through the fall and winter, these odds may lean even more towards the drier than average side. The Climate Prediction Center’s outlook for July-September 2018 shows much better chances that the average temperature during these three months will be above normal.

Colorado River – Water Supply Status

The entire Colorado River Basin experienced a relatively wet winter, but these gains have weakened due to a warmer and drier than average spring. Total system capacity on the Colorado River Basin has improved from 51% at the end of 2016 water year to 55% at the end of 2017 water year. Reservoirs in the Upper Basin are relatively full, with some receiving over 200% of average inflow, and Lake Powell reached approximately 60% capacity. However, Lake Mead is only about 39% full, with less than 1,081 feet in elevation. Even though this winter helped generating higher-than-normal streamflow, Lake Mead could have declined to as low as 1,065 feet in elevation at the end of this calendar year, if rigorous conservation efforts were not pursued. Cumulatively, these efforts helped conserve about 1.5 million acre-feet in Lake Mead, which is around 18 feet of elevation. Both the conservation efforts and the wet winter helped keep Lake Mead out of a shortage in 2018; however, the probability of shortage in the very near future is still significant at 15% for 2019 and over 40% for the next three years. Furthermore, based on the last 28 years of historical hydrology, there is about 50% chance that Lake Mead will decline to a critically low elevation of 1,025 feet in as early as 2026.

Salt River & Verde River Watersheds – Water Supply Status

This is the first above-median runoff season (January-May) in the last seven years that the Salt and Verde River watersheds have experienced. As a result, Roosevelt Lake increased from 35% to 71% in capacity during the runoff season, and Bartlett and Horseshoe reservoirs on the Verde system increased from 45% to 100% full, and even had to spill some water. For the first time since 2010, water was also spilled over Granite Reef Dam. During the monsoon season, normal precipitation was received for the entire summer; however, its distribution was heavily weighted to July, resulting in well above normal monthly precipitation. The monsoon storms diminished rapidly in August and since then, dry conditions persisted across the entire system. Total storage in the Salt and Verde system has improved to 65% capacity, as of October 1, 2017, compared to 47% at this time last year. However, despite water supply improvements this water year, the wetter conditions were not sufficient to fully rehydrate the watersheds and reservoirs from the many previous years of consecutive drought.

Forest Health and Wildfire Season Update

The relatively wet winter enhanced vegetation growth, however dry conditions during the Spring lead to vegetation die-off which created substantial amounts of fine fuels. Due in part to these conditions, this fire season was extensive across the state; over 418,000 acres burned, compared to the yearly average of 300,000 acres. This year’s fires were also very costly; the Sawmill fire exhausted the yearly State wildfire budget of four million dollars before the season officially started, and so far, 15 million dollars were spent on wildfire abatement this year. Post-fire conditions lead to devastating floods, causing further social and environmental harms. Overall, the trend of acres consumed by fires is going up, and next year’s wildfire season is expected to be destructive as well. Though a lot of beneficial efforts were made to restore health to Arizona forests, much work is still needed. Brush and invasive species continue to reduce Arizona’s grasslands and the high cost of restoration is a big obstacle in improving forest health.

Impacts of Drought on Wildlife

Across the state, there are approximately 1,800 wildlife water structures that help ease some of the drought impacts by increasing water availability for wildlife, especially during the hotter and drier months. Construction of such systems started over six decades ago with smaller catchments, but as drought conditions persist, bigger catchments are being constructed to hold more water. Rainwater is also harvested in some locations to reduce water hauling. Nonetheless, drier than average fall conditions required more water hauling than usual: about 283,000 gallons this year, so far. Drought impacts on fisheries were also reported and significant declines in Rainbow Trout productions were observed in some hatcheries over the past 30 years. This is likely the result of declining spring flows, which rely on precipitation to recharge aquifers feeding these springs. Reduced spring flows have resulted in an increased cost of $230,000 needed to buy replacement trout to be stocked, in addition to increased hatchery operation costs.

Recommendation

The updates confirmed that Arizona remains in a long-term drought, even after this relatively wet winter, and the drought is expected to continue. The Drought Interagency Coordinating Group unanimously recommends that both drought declarations be kept in place.

Fall 2017 Drought ICG Recommendation Letter to the Governor

Presentations:

ICG Meeting spring 2017

Agenda - May 9, 2017

Meeting Summary

Drought status

This winter was considerably wetter across Arizona and throughout the Colorado River Basin than the previous five winters. Early winter storms in November and December combined with later storms in January and February brought significant rain and snow to northern and central Arizona. As a result, long-term drought and water supply conditions in northern Arizona are much better than they were over the past six to ten years. Southern Arizona had benefitted from a wet monsoon but missed out on the winter storm activity, leading to drought status degradation in the southeast part of the state. This winter, though relatively wet, was still not as wet as in late 1980s and early 1990s, before this drought began. While beneficial in the short-term, particularly for surface water supplies, the cumulative deficits to groundwater aquifers have not been alleviated. The drought status maps show much of the state is still abnormally dry and even the areas depicted as no drought have lost significant groundwater resources over the past two decades. Drought conditions are likely to worsen during the next few months, until the monsoon season starts.

Weather Outlook

Very weak La Niña conditions existed during fall 2016 and deteriorated through the winter, having little effect on winter’s temperatures and precipitation. Climate models suggest a 50% chance of El Niño conditions developing by late summer and fall, but these may not develop until September, which in this case will not influence Arizona’s Monsoon season. Sea surface temperatures are currently much warmer than average and could conceivably support more tropical systems and better moisture surges into southern Arizona this summer, especially if El-Niño conditions develop. The official Climate Prediction Center’s summer outlook predicts much better odds for above normal temperatures, continuing the trend of the past ten years of which eight were hotter than average (and the remaining two were near average). Arizona has not experienced a cooler than average summer since 1999. There are equal chances for above, below, or near average precipitation this upcoming summer.

Colorado River – Water Supply Status

The entire Colorado River Basin experienced a relatively wet winter, but these gains have weakened due to a warmer and drier than average spring. The great snowpack accumulated in the Upper Basin during this winter, almost surpassed snowpack conditions in 2011 - the wettest year since this Basin-wide drought began in 2000. This snow, however, is rapidly melting due to the warmer and drier conditions that started in early March. Lower Basin intervening inflows between Lake Powell and Lake Mead are higher than normal, averaging at about 130%, which is 227,000 acre feet above average or 3 ft. of additional elevation in Lake Mead.

Total system capacity on the Colorado River Basin remines at around 51%, similar to last year, with elevations in Lake Mead improving from 1,076 ft. in November 2016 to about 1,085 ft. in early May 2017. Besides wetter conditions that increased flows to the River, rigorous water conservation efforts across the Basin helped keep additional 8 ft. of water elevation in the Lake. Bureau of Reclamation’s April 2017 24-Month Study projections for Mead’s elevations at the end of 2018 range from 1,075 to 1,132 ft., with the most probable elevations of 1,102 ft. Probabilities for Lower Colorado River Basin shortage have drastically decreased since last year from 48% to almost 0% chance of Tier1 shortage in 2018. However, over 30% chance of shortage still exists for 2019, and thus conservation efforts within Arizona and across the Basin should and will continue in order to keep more water in the Lake and reduce shortage probabilities even further.

Salt River & Verde River Watersheds – Water Supply Status

This is the first wet winter after six dry years on the Salt River and Verde River watersheds, improving reservoirs’ storage from 44% before winter to 76% after winter, which is roughly one million acre feet of additional storage. This year’s inflows are above median for the first time in seven years and have almost tripled compared to past few years. This winter storms seemed to have favored the Verde system, and its small reservoirs have filled beyond capacity resulting in over 100,000 acre feet of spill. On the Salt River system, however, conditions were not as favorable as on the Verde, and Roosevelt Lake - the largest reservoir on the Salt - did not fill to capacity, and as of May 8, 2017, held about 71% of storage.

Wildfire Outlook

Winter precipitation lead to substantial vegetation growth that have already dried out in lower elevations due to higher than average spring temperatures. Because of these conditions, higher than normal wildfire incidents are expected in lower elevations with larger acreage consumed by these fires. This year’s wildfire season has already started with significant wildfires – Sawmill and Mulberry fires – burning in southern Arizona, which spread very quickly due to windy conditions, but soil moisture helped preventing more severe damage to infrastructure and surrounding environments. Mid-elevation wildfire activity will depend on precipitation and wind conditions during the upcoming months. Higher elevations, containing most of Arizona’s forested landscape, are in much better shape due to the above normal precipitation received, which translates to a ‘normal’ wildfire danger in these areas; wildfire threat still exists, but those fires will be more manageable than some of the devastating fires experienced in high elevations in the past several years. Fire outlook suggests that Arizona will have an active wildfire season, but predicted early monsoon storms will help mitigate fire outcomes, though these often lead to higher incidents of lightnings, which in turn increase wildfire risk.

Recommendation

The updates confirmed that Arizona remains in a long-term drought, even after this relatively wet winter, and the drought is expected to continue. The Drought Interagency Coordinating Group unanimously recommends that both drought declarations be kept in place.

Spring 2017 Drought ICG Recommendation Letter to the Governor

Presentations:

 

 

 

 

 

 

ICG Meeting Fall 2009

The following reports formed the basis of the ICG's recommendation to maintain both drought declarations (Drought Emergency PCA 99006 & Drought Declaration Executive Order 2007-10):

The State Drought Monitoring Technical Committee’s update showed that long-term drought conditions are much worse than they have been in recent years. During the water year, precipitation was below 70% of average for most of the state. Nearly half of the state is currently in severe drought.

The Arizona State Forestry Division, Natural Resources Conservation Service, and Arizona Game & Fish Department provided their annual updates on forest and rangeland health and impacts to wildlife, which showed the following:

  • Many parts of the state are still suffering from long-term precipitation deficits, which affect vegetation health, wildlife and livestock, water supplies (low-producing springs, surface water flows and well production), and range and pasture conditions.
  • 216,818 acres of wildland fire burned in 2009, the most acres burned since 2005. Lack of regenerative fires and long-term drought are considered major factors in the decline of aspen trees, especially those stands growing at the lower elevations (see 2009 Forest Health Condition Highlights for more information).
  • Impacts due to long-term drought are resulting in crop losses, irrigation water shortages, livestock water and forage shortages and water hauling.
  • Wildlife habitat is still in poor condition after many years of drought. 

ICG Meeting spring 2009

Reports were provided by the Salt River Project (SRP) on the Salt and Verde watersheds, the Arizona Department of Water Resources (ADWR) on the Colorado River Basin, and the State Drought Monitoring Technical Committee on climate conditions. A few of the main points are described below and form the basis of the ICG’s recommendation:

  • Although the Verde and Salt reservoir systems are nearly full, the Colorado reservoir system, which provides 40% of Arizona’s water supply, is still well below its average level.
  • Data show abnormally dry to moderate long-term drought conditions across the state.
  • Precipitation totals have been below normal:
    • In Prescott - 13 of the past 14 years
    • In Springerville - eight of the past 14 years
    • In Flagstaff - 11 of the past 14 years
    • In Phoenix and Tucson - 12 of the past 14 years
  • Winter precipitation amounts have been well below average statewide.
  • In comparison to last year, drought status in a few watersheds has improved; however, precipitation over the last four years has generally been below average for most of Arizona’s watersheds.

The group decided during last year’s spring meeting that Arizona would need at least three consecutive wet winters to consider discontinuing the drought declarations, and unfortunately that did not occur. The updates confirmed that although winter precipitation looked good at the beginning of the season, the winter of 2008 - 2009 turned out to be drier than average. Based on this information, the ICG made a unanimous decision to recommend that both drought declarations be kept in place:

  • Drought Emergency Declaration (PCA 99006) has been in effect since June 1999 and maintains the state’s ability to provide emergency response if needed. It also enables farmers and ranchers to obtain funding assistance through the Farm Service Agency if they experience production losses due to drought.
  • The Drought Declaration for the State of Arizona (Executive Order 2007-10) was issued in May 2007 to raise awareness of Arizona’s continuing long-term drought and encourage conservation.

 

 

ICG Meeting Fall 2010

The State Drought Monitoring Technical Committee’s annual update showed that there was a significant improvement in long-term drought conditions compared to a year ago. Most of the improvement is due to the wet winter, however, the 2010 summer was also wetter than average in most of Arizona’s watersheds. Currently four watersheds have no drought, six watersheds are abnormally dry, and five watersheds are in moderate drought.

Precipitation forecasts for Arizona for the upcoming winter and spring seasons are bleak with a strong La Nina event underway in the Pacific Ocean. La Nina will likely result in increased probabilities for above-normal temperatures and below-normal precipitation. Widespread moderate to severe drought conditions may develop by later this spring.

The Arizona State Forestry Division and Arizona Game and Fish Department provided their annual updates on forest health and impacts to wildlife. The University of Arizona also presented on drought impacts reported through Arizona DroughtWatch, a drought impact reporting system developed by the University, in conjunction with ADWR. The reports showed the following:

  • Many parts of the state are still suffering from long-term precipitation deficits that affect vegetation health and water supplies.
  • Wildlife habitat is still in poor condition after many years of drought.
  • Concern for next spring is the potential for bark beetles to infest the forests damaged from the tornados in northern Arizona, and kill surrounding standing ponderosa pines, followed by fires once all the material has dried out. More on forest health conditions.

Based on this information, the ICG made a unanimous decision to recommend that both drought declarations be kept in place.

ICG Meeting spring 2010

The following reports were provided by the Salt River Project (SRP) on the Salt and Verde watersheds, the Arizona Department of Water Resources (ADWR) on the Colorado River Basin, and the State Drought Monitoring Technical Committee on climate conditions. A few of the main points are described below and form the basis of the ICG’s recommendation:

  • Although the Verde and Salt reservoir systems are full, the Colorado reservoir system, which provides 40% of Arizona’s water supply, is still well below its average level.
  • Data show normal to severe long-term drought conditions across the state.
  • Precipitation totals have been below normal:
    o In the Salt Watershed - 9 of the past 17 years
    o In the Little Colorado Watershed - 12 of the past 17 years
    o In the Santa Cruz Watershed - 12 of the past 17 years
    o In the Upper Gila Watershed - 10 of the past 14 years
  • Although this winter was wetter than average, long-term drought status, in comparison to last year, is worse for most of Arizona’s watersheds due to below average precipitation over the last four years.

The updates confirmed that although winter precipitation was above average, all of Arizona’s watersheds except the Lower Gila remain in long-term drought. Based on this information, the ICG made a unanimous decision to recommend that both drought declarations be kept in place.

 

ICG Meeting Fall 2011

The Monitoring Technical Committee’s annual update indicated that the overall condition for the 2011 water year is moderate drought, with significant degradation from a year ago both in northern Arizona and the southeastern watersheds. Cumulative precipitation was below normal in all of the state’s major river basins, ranging from 65 to 95 percent of the 30-year average. Winter snowpack was well below normal and summer precipitation was very localized. Streamflow decreased in 14 of the 26 basins and stayed the same in 12 basins. The outlook for the 2012 water year indicates that La Niña conditions will emerge again this coming winter favoring a drier than normal winter and a warmer than normal spring. This will likely result in worsening drought conditions.

Monitoring Technical Committee Presentations: Climate Conditions, 2012 Climate Outlook,  Arizona Drought Watch Tree-Ring Record

Reports by the USDA Natural Resources Conservation Service, Arizona State Forestry Division and Arizona Game and Fish Department showed that many parts of the state are still suffering from long-term precipitation deficits that affect vegetation health and water supplies as described below:

  • The average forage production across Arizona was approximately 56 percent of normal, and the outlook for 2012 is 57 percent of normal or less.
  • Wildfires had the largest impact on forest health in 2011, with more than 1,000,000 acres burned. Bark beetles did not present a problem as anticipated, possibly due to a few cold snaps in spring.
  • Livestock water shortages occurred throughout the state, and in many cases livestock operators relied on water hauling or reductions in herds.
  • Several NRCS field offices reported irrigation water shortages and expected crop production losses ranging from 10 to 90 percent, with serious impacts in the northeastern part of the state where dry-farming practices are prevalent.
  • Wildlife habitat is still in poor condition after many years of drought, resulting in diminished wildlife populations.

Based on this information, the ICG made a unanimous decision to recommend that both drought declarations be kept in place:

  • Drought Emergency Declaration (PCA 99006) has been in effect since June 1999 and maintains the state’s ability to provide emergency response if needed. It also enables farmers and ranchers to obtain funding assistance through the Farm Service Agency if they experience production losses due to drought.
  • The Drought Declaration for the State of Arizona (Executive Order 2007-10) was issued in May 2007 to raise awareness of Arizona’s continuing long-term drought and encourage conservation.

November 17, 2011 Recommendation to the Honorable Janice K. Brewer, Arizona Governor 

ICG Meeting spring 2011

The following reports were provided by the Salt River Project (SRP) on the Salt and Verde watersheds, the Arizona Department of Water Resources (ADWR) on the Colorado River Basin, the State Drought Monitoring Technical Committee on climate condition, and the Natural Resources Conservation Service  on livestock water and forage conditions. A few of the main points are described below:

  • Although the Verde and Salt reservoir systems are currently 86% full and increases in the Colorado River reservoirs will forestall drought-related water rationing in Arizona until 2015 or later, data show that much of the state remains in drought conditions.
  • Normal to extreme long-term drought conditions occur across the state, with the driest conditions in the southeastern part of the state. Only Mohave County and the western edge of La Paz County are characterized as not experiencing drought at this time.
  • Of the previous four years, only 2010 was a wetter than average year and did not reverse the effects of the previous dry years. In fact, long-term drought status is worse for most watersheds.
  • According to the Natural Resources Conservation Services (NRCS) Field Offices, less than 64% of normal forage production will occur in 2011. They also reported shortages in livestock water around the state and irrigation water shortages that could result in crop production losses ranging from 10 to 80 percent. In addition to poor rangeland conditions, native desert vegetation also exhibits signs of stress, especially in the western and southern counties.

The updates confirmed that although reservoirs supplying western and central Arizona are adequate, all of Arizona’s watersheds except the Lower Gila and Lower Colorado remain in long-term drought. Based on this information, the ICG made a unanimous decision to recommend that both drought declarations be kept in place.

May 23, 2011 Recommendation to the Office of Governor Janice K. Brewer

 

 

 

ICG Meeting Fall 2012

The updates presented at the November 6, 2012 meeting confirmed that Arizona remains in long term drought with projections for warmer temperatures and increased wildfire risk. Key points include the following:

  • The entire state continues to be in some level of drought, with the driest conditions continuing in the central and southeastern part of the state. The overall condition for the 2012 water year is moderate drought.
  • The current outlook for winter 2012-2013 is slightly better chances for above average temperatures, and equal chances for above, below or near normal precipitation. The outlook for summer 2013 is increased chances of above average temperature, and equal chances for monsoon precipitation to be above, below, or near normal.
  • The impact of drought on range and farmland resulted in a U.S. Department of Agriculture disaster designation for all Arizona counties. The average forage production across Arizona was approximately 63 percent of normal for 2012. Even though monsoon rainfall resulted in significant greening, many areas are still very dry, with drying stockponds and dry grasses in pasture land.
  • Wildfires had less overall impact on forest health in 2012 than 2011, however, areas of reburn are becoming a concern, there has been an increase in defoliating insect activity possibly exacerbated by drought, and the continuing drought increases the state’s vulnerability to wildfires statewide. Also, the intensity of wildfires and their proximity to development are increasing. 

 

Presentations:

Drought-related Disasters and Hazards

Fire Season and Forest Health Update

Impacts of Drought on Wildlife

Range and Forage Health Conditions Update

Based on this information, the ICG unanimously recommended that both drought declarations be kept in place:

  • Drought Emergency Declaration (PCA 99006) has been in effect since June 1999 and maintains the state’s ability to provide emergency response if needed. It also enables farmers and ranchers to obtain funding assistance through the Farm Service Agency if they experience production losses due to drought.
  • The Drought Declaration for the State of Arizona (Executive Order 2007-10) was issued in May 2007 to raise awareness of Arizona’s continuing long-term drought and encourage conservation.

Nov 6, 2012 Drought Recommendation Letter to the Governor

ICG Meeting spring 2012

The updates presented at the May 10, 2012 Interagency Coordinating Group meeting confirmed that Arizona remains in long term drought, with 69% of the state experiencing severe to extreme drought compared to 31% a year ago. Projections include warmer temperatures, increased wildfire risk, and persisting or intensifying drought. Key points include the following:

  • The temperature outlook for this summer is above normal, and the U.S. Drought Monitor Seasonal Drought Outlook predicts that drought in Arizona is likely to persist or intensify through July 2012. It is likely that conditions may continue to deteriorate until the monsoon begins, with little opportunity for notable improvement until at least the upcoming winter.
  • The Verde and Salt River reservoir systems are currently at 64% of capacity, compared to 85% at this time last year (as of 5/17/12).
  • Colorado River inflow into Lake Powell was 33% of normal, the third lowest on record since 1909 for April through June, and is projected to be 51% of normal for the water year (October 2011 through September 2012). The current Colorado River reservoir system storage stands at 62%. It is projected that Lake Powell and Lake Mead storage will generally decline through 2013.
  • The continuing drought conditions have increased the state’s vulnerability to wildfires statewide, and fire restrictions are currently in effect for all counties. Other factors that contribute to the increased wildfire threat are the predicted warmer than normal temperatures, windy periods as upper level systems pass by, and the typically “dry” thunderstorms (lightening with little rain) early in the monsoon.
  •  The impact of drought, high winds, and wildfires on range and farmland have resulted in U.S. Department of Agriculture disaster designations for all counties except for two (Greenlee and Apache). Forage production is reduced and there are shortages in livestock water around the state.

Presentations:

Salt and Verde River System Update

Colorado River Basin Update

Drought Status, Impacts and Outlook

 

 

 

ICG Meeting Fall 2014

The updates presented at the November 13, 2015 meeting confirmed that Arizona remains in long-term drought.

Fall 2014 Drought ICG Recommendation Letter to the Governor

Combined Presentations

  • Drought Status Summary and Outlook - Nancy Selover, MTC Co-chair, Arizona State University
  • Mark O’Malley, MTC Co-chair; National Weather Service
  • Local Drought Impacts on Municipal and Domestic Users - Michael J. Lacey, ICG Co-chair, Arizona Department of Water Resources
  • Colorado River Hydrology Update - Tom Buschatzke, Arizona Department of Water Resources
  • DroughtView: New Tools for Monitoring Drought across Arizona - Michael A. Crimmins, University of Arizona
  • 2014 Fire Season, Forest and Woodland Health - Bob Celaya, David Geyer, Byron Kimball - Arizona State Forestry Division
  • Impacts of 2014 Drought on Wildlife - Ed Jahrke, Arizona Game and Fish Department
  • Recent Effects of Changing Precipitation Patterns on NE Arizona Drought - Margaret Hiza Redsteer, USGS, Flagstaff

ICG Meeting Spring 2014

The updates presented at the May 13, 2014 meeting confirmed that Arizona remains in long-term drought with projections for warmer temperatures. Key points include the following:

  • We have now finished our fourth consecutive dry winter within the state watersheds and the third consecutive dry winter in the Colorado River Basin. The entire state except for the far southwestern edge continues to be in some level of drought, ranging from abnormally dry to severe.
  • The summer monsoon was wetter than normal and wet conditions occurred in November and December. However, warmer than normal late winter temperatures along with dry and windy conditions led to deterioration of all watersheds except the Lower Colorado.
  • Reservoir levels in all the watersheds are near or below 50% of capacity. It is projected that Lake Powell and Lake Mead storage will generally decline through 2016. The Colorado River Basin is experiencing a 14-year drought that is the driest in the historical record dating back to 1906. This is the fourth year that the Salt and Verde watershed experienced below median winter runoff. While communities in some areas of the state are facing water shortages, the major metropolitan areas are not facing immediate water crises.
  • An analysis of drought conditions, fine fuels, weather patterns and the monsoon outlook suggests above normal fire season potential and an earlier onset, especially in the southern and eastern brushlands.
  • The 2014 summer outlook's odds favor above normal temperatures. The outlook also has very slightly enhanced odds for above-average precipitation, but there is no way to estimate monsoon precipitation. 

Based on this information, the ICG unanimously recommended that both drought declarations be kept in place:

Presentations

May 2014 Drought ICG Recommendation Letter to the Governor

 

ICG Meeting Fall 2015

Agenda - November 10, 2015

Meeting Summary

Both winter and summer of 2015 were wetter than in 2014, however, similar to last year, snow accumulation was well below normal across most of the state. While the drought appears to be easing, it is not over. More than two-thirds of the state is abnormally dry or in moderate drought, reservoirs are only approximately half full, and every Arizona county had a disaster designation during water year 2015. It will take several years of above average precipitation to break the grip of the drought that is approaching 21 years.

Strong El Niño conditions are currently in place and will most likely continue into the spring. This means there may be more rain and more rainfall days than usual. Mountain snowfall, however, may or may not be above average.

The current Colorado River reservoir system storage stands at 51% of capacity as of November 8, 2015, approximately the same as last year. The forecast shows a 0% chance of a shortage declaration in 2016 and an 18% chance in 2017. The Salt and Verde reservoirs remain at the same levels as this time last year, approximately 49% full.

Due to the moist conditions, water year 2015 was a light year for fires. However, the above average rainfall has resulted in an abundance of continuous fine fuels in general across the state which could potentially lead to a busy wildfire season, depending on weather patterns in late spring. Extreme fire danger continues to be a threat in forests due to the extreme density of trees.

The impact of drought on range and farmland resulted in disaster designations for all counties in the state. Drought conditions affected dryland farming and irrigation water supply resulting in crop loss, reduced rangeland water supply, and reduced forage supply.

Recommendation

Based on this information, the ICG unanimously recommended that both drought declarations be kept in place:

  • Drought Emergency Declaration (PCA 99006) has been in effect since June 1999 and maintains the state’s ability to provide emergency response if needed. It also enables farmers and ranchers to obtain funding assistance through the Farm Service Agency if they experience production losses due to drought.
  • The Drought Declaration for the State of Arizona (Executive Order 2007-10) was issued in May 2007 to raise awareness of Arizona’s continuing long-term drought and encourage conservation.

Presentations

Fall 2015 Drought ICG Recommendation Letter to the Governor

ICG MEETING SPRING 2015

Agenda - May 5, 2015

Meeting Summary

Although Arizona's long-term drought status has improved somewhat from one year ago, most of the state continues to experience moderate to severe drought. The only drought-free area is in the southwestern part of the state. There is a very slight chance of warmer and wetter weather over much of the state this coming summer. The outlook for next winter calls for equal chances that temperatures will be above, below or near normal and only a very slight chance of above normal precipitation.

The current Colorado River reservoir system storage stands at 47% of total system capacity, and levels are expected to drop due to minimal run-off and dry conditions. The US Bureau of Reclamation’s April projections show a 33% probability of a Tier 1 shortage in the Lower Basin for 2016 and a 75% probability for a Tier 1 shortage in 2017. The Salt and Verde reservoir level remain at approximately 57% of normal due to increased use of groundwater to meet demand.

Fire potential and fuels will have to be carefully monitored as they respond to the typically hot, dry weather in June, changes in drought conditions, and the potential for multiple lightening outbreaks during the monsoon season. There are areas with higher than normal fine fuel loads from two previous monsoon seasons and recent winter/spring moisture.

Combined Presentations- May 5, 2015 ICG Meeting

  •    Drought Status Update and Activities of the Monitoring Technical Committee - Nancy Selover, Arizona State University,
  •    Summer 2014 Outlook and Winter 2015-16 Preview - Mark O’Malley, National Weather Service
  •    Colorado River Water Supply Update -Tom Buschatzke, Arizona Department of Water Resources
  •    Salt & Verde Watersheds- Water Supply Update - James Walter, Salt River Project 
  •    Wildfire Outlook -Jeff Whitney, Arizona State Forestry
  •    Update on California Drought - Chris Harris, California Colorado River Board

Spring 2015 Drought ICG Recommendation Letter to the Governor

 

ICG Meeting Fall 2016

Agenda - November 16, 2016

Meeting Summary

Due to the relatively dry winter and localized summer rainfall, the end of the water year (October 31, 2016) short-term drought is worse than a year ago, in the southwestern quarter of the state, but better than a year ago, in the northwestern quarter. In addition, there were no long-term improvements in drought conditions within any of the watersheds in Arizona, and three watersheds that were not in drought became abnormally dry.

Reservoirs for the Salt and Verde Watersheds continue to hover around 50% of capacity and the additional groundwater pumped during the drought has not been recharged. Additionally, moisture deficit is not currently increasing, but it has not recovered from the drought, so long-term conditions are still poor. Due to such conditions, every county, besides Coconino, had a United States Department of Agriculture disaster designation due to the impacts of drought this water year.

The Colorado River Basin System is experiencing a 17-year drought, which is the driest period in historical record dating back to 1906. In June 2016, Lake Mead levels dropped to 1,071 feet, which is below the first shortage trigger, set at 1,075 feet. Due to water conservation efforts by multiple entities, water levels increased in October, 2016, to 1,076 feet, right above the shortage trigger, and Reclamation’s projection of a Lower Colorado River Basin shortage in 2017 decreased from 37% to 0%. However, the chance of a shortage declaration in 2018 is still very likely and hovers at 48%. As of November 1, 2016, the entire System’s reservoir capacity was at 50%.

As a response to the long-term drought conditions on the Colorado River Basin and the looming shortages for the Lower Basin states, representatives of the three states and Reclamation developed a Drought Contingency Proposal (DCP) in December 2015 to conserve water levels in lake mead. Under the DCP, Arizona and Nevada would begin reducing water deliveries earlier than previously agreed. Reclamation would also agree to conserve water in the system. Additionally, California would agree for the first time to reduce its deliveries when Lake Mead elevations are below 1050 feet.

2016 wildfire season in was very like what was expected based on a ten-year average; Arizona experienced higher number of fires (2,197) than the 10-year average (2,144), however current acres burned (303,057) are lower than the 10-year average (317,781). Looking ahead to 2017, the state still experiences similar wildfires hazards: continuation of drought, fine fuel conditions, highly variable seasonal temperatures and low precipitation. These conditions suggest a similar wildfire season for 2017. However, the threat of catastrophic wildfire remains and Arizonans are urged to exercise extreme caution.

The most likely weather outcome for this winter is weak La Niña conditions developing during the late fall and early winter (around a 70% chance) and becoming neutral in late winter. Odds are shifted towards a warmer and drier than normal winter based on a combination of La Niña, model output, and trends over the past 10-15 years. The Climate Prediction Center’s outlook for July-September 2017 shows somewhat better chances that the average temperature during these three months will be above normal statewide, but there is no precipitation signal.

Recommendation

Based on this information, the ICG unanimously recommended that both drought declarations be kept in place:

  • Drought Emergency Declaration (PCA 99006) has been in effect since June 1999 and maintains the state’s ability to provide emergency response if needed. It also enables farmers and ranchers to obtain funding assistance through the Farm Service Agency if they experience production losses due to drought.
  • The Drought Declaration for the State of Arizona (Executive Order 2007-10) was issued in May 2007 to raise awareness of Arizona’s continuing long-term drought and encourage conservation.
Presentations

Fall 2016 Drought ICG Recommendation Letter to the Governor

ICG Meeting Spring 2016

Agenda - May 17, 2016

Meeting Summary

This winter’s El-Niño did not perform as anticipated and provided below average precipitation. The long-term drought status looks the same as it did one year ago, and as of May, most of the state is in moderate drought, while the Verde River Watershed is in severe drought. Drought conditions will likely exacerbate during the next few months until the monsoon season starts.

Early winter precipitation greened up grasses for a short period before warm temperatures dried them out again, potentially leading to a very busy fire season. Hotter than average late-winter temperatures prematurely melted snowpack in many basins, exposing vegetation, which increase the risk for fires. Fuel loads are heavy and recent warm and windy conditions have already led to numerous wildfires. As temperatures are warming up, wildfire activity starts showing in the Central Highlands and Colorado Plateau, until the monsoon onset.

The Colorado River Basin is experiencing a 16-year drought, which is the driest in historical record dating back to 1906. The average April through July inflow into Lake Powell for the period 2000 - 2015 has been only 5.54 million acre-feet (MAF). This is about 1.6 MAF less than the 1981 - 2010 period average inflow of 7.16 MAF. As of May 1st, the Colorado River reservoirs system storage was at 48% of total system capacity, similarly to last year’s capacity at this time. Lake Powell and Mead storage was at 45% and 37% capacity, respectively.

This is the sixth year that the Salt and Verde watersheds experienced below median winter runoff. The Salt and Verde reservoir levels have remained approximately the same as this time last year, at about 56% of normal, due to reduced demand and the conjunctive use of groundwater to meet demand. If projections for very low inflow hold, this consecutive six-year period will be the driest six-year period on record (1913-2016).

El-Niño conditions will decay through the summer eventually becoming neutral and providing little to no influence on Arizona’s monsoon season. The predominance of models suggests a 60%-70% chance that La-Niña conditions will develop by late fall and winter. There is low confidence on strength, but odds are slightly higher for a warmer and drier winter (40%) as oppose to the odds for a cooler and wetter winter (27%).

 

Recommendation

Based on this information, the ICG unanimously recommended that both drought declarations be kept in place:

  • Drought Emergency Declaration (PCA 99006) has been in effect since June 1999 and maintains the state’s ability to provide emergency response if needed. It also enables famers and ranchers to obtain funding assistance through the Farm Service Agency if they experience production losses due to drought.
  • The Drought Declaration for the State of Arizona (Executive Order 2007-10) was issued in May 2007 to raise awareness of Arizona’s continuing long-term drought and encourage conservation.
Presentations

Spring 2016 Drought ICG Recommendation Letter to the Governor