Presentation at the TWCA mid year conference 2012 www.twca.org James Beach LBG-Guyton Associates

1. James Beach
LBG-Guyton Associates

2. Population Growth
 The Census and Population Projections
 License plates
 Little league baseball

3. Texas Population

4. Confirmed sightings…..

5. Incomplete Sampling…..

6. 2011 Texas Drought
 New Data Point
 worst 12-month drought on record
 hottest
 reservoirs lowest since 1978
 huge agriculture losses
 Water right calls - in East Texas!
 Emergency calls
 “out of water” in 8-12 months
 Power and chemical plants, refineries

7. West Texas

8. New “Drought of Record”
Year
Data Courtesy of

9. Reality…. Shifted… (and Still Shifting)

10. West Texas Response
 It will rain and flood again – but until then -
expand the safety net
 CRMWD – new wellfield and pipeline (no GCD)
 Midland - new wellfield and pipeline (no GCD)
 San Angelo – new pipeline to existing wells
(long-term groundwater banking in GCD)
 Odessa – assessing potential groundwater
projects

11. Outcomes of the Situation
 Diversified water supply
 Drought-ready supply to augment surface
water
 Conjunctive use – good use of
groundwater
 Potential to expand supplies through ASR
and brackish treatment
 Not inexpensive
 Similar approach as much of the desert
southwest

12. Important revelations
 Current drought is “outside” of recorded water
history
 Not over yet
 We have not recorded everything there is to see
 There are serious implications of the new data

13. Texas Projected Need in
Drought

14. Per Capita Surface Water
Supply

16. Drought Sensitivity - Major

17. Drought Sensitivity - Minor

18. Drought Impact on
Groundwater
 Water levels declines in drought are
often related to increased pumping to
meet peak demands – not long-term
 Shallow outcrop wells can be sensitive
to drought due to lack of local recharge
 Deep wells are usually not impacted by
drought

20. Edwards Aquifer
NOT a typical Texas Aquifer

21. Historic
Spring
Flows at
Comal

22. the water table

23. unconfined and confined

24. Confined/Dipping Aquifer
 Conceptual x-section

25. Carrizo Aquifer Schematic
Page 25

26. Gulf Coast

28. Outcrop Well
Pumping Well
Middle Wilcox or
Simsboro Aquifer
Outcrop
Page 28

29. Outcrop and Downdip Hydrographs
in Brazos and Robertson Counties
Outcrop Well
Depth to Water (feet)
Pumping Well
State Well Number, Screened Interval
Page 29

30. Atascosa County Monitoring Wells
Monitoring Well
Page 30

31. Carrizo-Wilcox
Volume in Storage ~ 50,000,000 AF
in some counties –
How do we manage?

32. Stream-Aquifer Interaction and
Drought
1. Pumping from the shallow outcrop:
• May reduce water levels in the outcrop
• has the potential to impact streams (especially pumping close
to streams)
2. Pumping from deep confined aquifer:
• may not significantly reduce water levels in outcrop
• may not significantly impact streamflow
3. Historical data confirm this conclusion for Carrizo and
Wilcox
4. Carrizo and Wilcox respond differently than the Edwards
Aquifer
5. Most groundwater models don’t simulate this dynamic
appropriately
Page 32

33. Aquifers and Drought
 Groundwater can offer a constant long-term
supply and/or a drought-ready safety net
 Volumes stored in some aquifer are huge -
and most are not sensitive to drought
 Aquifers are not created the same – and they
don’t respond the same to drought
 The “same” aquifer can respond differently in
different locations

34. Questions for you…..
 Is there a new “Drought of Record” in
your future?
 Do you have a safety net?
 Are we doing what we can to allow
conjunctive use during droughts?

35. Questions for you…..
 Is there a new “Drought of Record” in
your future?
 Do you have a safety net?
 Are we doing what we can to allow
conjunctive use during droughts?