1 / 11

Edwards Aquifer 2014 Forecasts: Risk Zones & Water Level Projections

This report analyzes the Edwards Aquifer forecasts for 2014, focusing on risk zones for springs based on historical dry years. It explores three cases of permitted pumping rates with varying probabilities of water flow dropping below critical thresholds (30 cfs and 60 cfs). The report indicates a 25% to 35% chance of falling below these levels and the possible declines in water levels of 10 to 20 feet. Critical period withdrawal limits and improved rainfall are essential for mitigating declines. Probabilities suggest a significant risk for the summer months without adequate rainfall.

nedra
Télécharger la présentation

Edwards Aquifer 2014 Forecasts: Risk Zones & Water Level Projections

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Edwards Aquifer Forecasts for 2014 Jim Winterle—EAA modeling supervisor HCP Stakeholder Committee May 28, 2014

  2. Risk Zones for Springs

  3. 2014 scenarios based on previous dry yearsCase 1: 10-year-average pumping rate of 385,000 acre-ft • 23 Scenarios dip into the 60 cfs risk zone: ≈35% probability • 17 scenarios dip into the 30 cfs risk zone: ≈25% probability

  4. 2014 scenarios based on previous dry yearsCase 1: 10-year-average pumping rate of 385,000 acre-ft • 23 Scenarios dip into the 60 cfs risk zone: ≈35% probability • 17 scenarios dip into the 30 cfs risk zone: ≈25% probability

  5. 2014 scenarios based on previous dry yearsCase 2:40% reduction in permitted pumping = 350,000 acre-ft • 21 Scenarios dip into the 60 cfs risk zone: ≈31% probability • 17 scenarios dip into the 30 cfs risk zone: ≈25% probability

  6. 2014 scenarios based on previous dry yearsCase 3: 44% reduction in permitted pumping = 320,000 acre-ft • 19 Scenarios dip into the 60 cfs risk zone: ≈28% probability • 16 scenarios dip into the 30 cfs risk zone: ≈23% probability

  7. Index Well J-17: analysis of changes from January 1 water levels Median peak summer decline is 15.8 feet Mean is 13.2 feet

  8. J-17 water-level changes for years that started below 650 feet

  9. J-17 maximum water level decline for years that started below 650 feet Greatest J-17 decline of -21 feet was in 1990 when annual pumping was high at 489,000 acre-feet

  10. J-17 Forecast for 2014

  11. Conclusions • Analysis of prior drought scenarios suggests at approximately a 1-in-4 chance that springflow at Comal Springs will fall below 30 cfs by late summer, and a 1-in-3 chance that they will fall below 60 cfs • Without above normal rainfall, we can expect J-17 water levels to decline 10 to 20 feet by late summer, making Stage IV likely and Stage V possible • Critical period withdrawal limits and average or better rainfall will help to reduce the amount of decline • The chances that we will end the year above Stage II restrictions are about 1-in-4 • The chances that we will end the year above Stage I restrictions are about 1-in-8

More Related