• Mark L. Johnson

Wet But Dry

Updated: Sep 10





Tortolita Alliance (TA) attended the Pima County Local Drought Impact Group (LDIG) Meeting via Microsoft Team today (September 8, 2021).


LDIG is a bi-monthly gathering of local, state and federal agencies to discuss latest drought conditions across the state of AZ. Attendees include: TA, Marana Water, Tucson Water, Metro Water, National Weather Service-Tucson, Central Arizona Project (CAP), Arizona Department of Water Resources (ADWR), Pima County Office of Sustainability & Conservation (OSC) and more. The following information was gleaned from the meeting.


Local 2021 Monsoon Season



  • Monsoon Season-June 15 to September 30

  • Higher Than Normal Monsoon Rainfall (through 9/7)-all Tucson areas (see chart above)

  • Tucson Airport (12.41" through 9/7)-third wettest Monsoon season rainfall

  • June-warmest on record with 6 days hitting record highs

  • July-wettest July & calendar month on record-8.06" vs 2.21" normal

  • Prolific Vegetation Growth-will provide fuel for wildfires when it dries out



Arizona Drought Conditions Improve



  • June-94% of Arizona was in Severe, Extreme or Exceptional Drought

  • August-54% of Arizona was in Severe, Extreme or Exceptional Drought


Colorado River Basin In Deep Trouble



  • Lake Powell & Lake Mead-31% Combined Capacity

  • Lake Powell Water Year Inflow-second lowest on record at 3.46 million acre-feet (32% of Normal)

  • Lake Powell Hydroelectric Emergency-releasing more water from upstream reservoirs to ensure Lake Powell stays above minimum pool (minimum elevation to generate hydroelectric power) to avoid electric power calamity



  • Tier 1 Shortage-declared for January 2022

  • Tier 2 Shortage-54%-65% chance in 2024

  • Tier 3 Shortage-20%-38% chance in 2025



Western US Weather Forecast


  • La Nina-70% chance La Nina (dry) conditions this coming winter

  • Local Remaining Monsoonal Rain-not predicted to be significant unless tropical storm develops

  • US Drought Forecast-drought will persist in the western US


Summary


This monsoon season is historic and Arizona's drought situation has improved. However, the Colorado River Basin (36% of Arizona's water supply) is still in dire straits and future shortage cuts are becoming more likely as the western drought persists.