Growth, Drought, and Groundwater in Texas... What are we learning?

James BeachLBG-Guyton Associates

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

Texas Population

Confirmed sightings…..

Incomplete Sampling…..

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

West Texas

New “Drought of Record” Year Data Courtesy of

Reality…. Shifted… (and Still Shifting)

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

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

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

Texas Projected Need inDrought

Per Capita Surface WaterSupply

Drought Sensitivity - Major

Drought Sensitivity - Minor

Drought Impact onGroundwater 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

Edwards AquiferNOT a typical Texas Aquifer

HistoricSpringFlows atComal

the water table

unconfined and confined

Confined/Dipping Aquifer Conceptual x-section

Carrizo Aquifer SchematicPage 25

Gulf Coast

Outcrop Well Pumping Well Middle Wilcox or Simsboro Aquifer OutcropPage 28

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

Atascosa County Monitoring Wells Monitoring Well Page 30

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

Stream-Aquifer Interaction andDrought1. 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 streamflow3. Historical data confirm this conclusion for Carrizo and Wilcox4. Carrizo and Wilcox respond differently than the Edwards Aquifer5. Most groundwater models don’t simulate this dynamic appropriately Page 32

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

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?

http://www.twca.org	130
http://www.texaswca.com	51
http://pinterest.com	9
http://twca.org	6

Growth, Drought, and Groundwater in Texas... What are we learning?

by The Texas Network on Jun 21, 2012

Accessibility

Categories

Upload Details

Usage Rights

4 Embeds 196

Statistics