Texas Springs: Texas Springs: leaking into an leaking into an

uncertain futureuncertain futureChad Norris

Water Resources Branch

Chad.norris@tpwd.state.tx.us

(512) 389-8761

GROUNDWATER • Supplied 59% of water

used in TX in 2003 • Population expected to

double by 2060• GW level declines

predicted for many aquifers over next 50 years (TWDB 2007)

• Impacts to groundwater dependent habitats (e.g. springs) unclear San Antonio SpringsSan Antonio Springs

What is a Spring?What is a Spring?

• The natural flow of groundwater to the The natural flow of groundwater to the land surface or a surface water bodyland surface or a surface water body

• Artesian or gravity Artesian or gravity • Ephemeral, intermittent, or perennialEphemeral, intermittent, or perennial• May form marshes, ponds, or streamsMay form marshes, ponds, or streams• A springs characteristics is largely A springs characteristics is largely

determined by hydrogeologic settingdetermined by hydrogeologic setting

Edwards Plateau Springs

Edwards-Trinity (Plateau) Aquifer

Texas Springs• Major and Historical

Springs of Texas (TWDB Report 189)

• Documented loss and decline of Tx Springs

• 65 of 281 (23%) springs no longer flowed

• Only 2 of 4 largest springs remained

Texas SpringsTexas Springs

• Springs of Texas Vol. 1, Springs of Texas Vol. 1, 1981 – Gunnar Brune1981 – Gunnar Brune

• Describes about 2,000 Describes about 2,000 springs from 183 TX springs from 183 TX countiescounties

• Further documented Further documented loss and decline of TX loss and decline of TX springssprings

United States Geological Survey Springs

(Heitmuller and Reece 2004)

Kerr

Bandera

Real

Gillespie

Importance of SpringsImportance of Springs

• Recognized as valuable ecological, Recognized as valuable ecological, natural, and cultural resourcesnatural, and cultural resources

• Barometer of local hydrologic Barometer of local hydrologic conditions and watershed healthconditions and watershed health

• Generally a source of high quality Generally a source of high quality water – increases assimilative water – increases assimilative capacitycapacity

Importance of SpringsImportance of Springs

• Water source for local wildlifeWater source for local wildlife– Often only perennial water sourceOften only perennial water source

• Significant component of natural flow Significant component of natural flow regime in many streams – “baseflows”regime in many streams – “baseflows”

• Unique aquatic habitats that often Unique aquatic habitats that often sustain high degree of diversitysustain high degree of diversity

Springs - Natural Flow RegimeSprings - Natural Flow Regime

• Often compose significant portion of Often compose significant portion of streamflow – especially in arid weststreamflow – especially in arid west

• Provide baseflows to streams and riversProvide baseflows to streams and rivers– Sustain aquatic and riparian habitats during Sustain aquatic and riparian habitats during

drought - perennial vs. intermittentdrought - perennial vs. intermittent– Historically reliable water supplyHistorically reliable water supply– Primary source of recharge during droughtPrimary source of recharge during drought– Affects property values Affects property values

Gaining vs. Losing Streams

Gaining Stream

Losing Stream

Springs - Natural Flow Regime• Kansas rainfall 15-20 in/yr in West and 40-45 in East

• GW use from High Plains Aquifer in west is high

• Gaining streams turned to losing streams(Sophocleous and Wilson 2000)

Springs - Unique Aquatic HabitatsSprings - Unique Aquatic Habitats

• Transition between groundwater and Transition between groundwater and surface water habitats – “Ecotone”surface water habitats – “Ecotone”

• Thermally and hydrologically stable Thermally and hydrologically stable habitatshabitats

• Commonly harbour rare, endemic, or Commonly harbour rare, endemic, or relict speciesrelict species

• Provide refuge for common species Provide refuge for common species

Spring-dependent FishGreenthroat darter (Etheostoma

lepidum)Plateau shiner – Cyprinella lepida

Common Fish Species

Mexican tetra (Astyanax mexicanus)

Central Stoneroller (Campostoma anomalum)

Longear sunfish (Lepomis megalotis)

Green sunfish (Lepomis cyanellus)

Damselflies & Dragonflies

Aquatic Macroinvertebrates of Springs

Caddisflies

Mayflies Beetles

Snails

Crustaceans

True Bugs

• Majority of Springs on Private PropertyMajority of Springs on Private Property– Recharge features and flow system rarely Recharge features and flow system rarely

on same propertyon same property• Sustainable use of aquifersSustainable use of aquifers• Texas water law does not adequately Texas water law does not adequately

address GW/SW interactionsaddress GW/SW interactions– GW – Rule of Capture; GCD’s, GMA’sGW – Rule of Capture; GCD’s, GMA’s– SW – Prior appropriationSW – Prior appropriation

Conservation IssuesConservation Issues

Conservation Issues

• Identify springs and gather baseline dataIdentify springs and gather baseline data• More hydrogeologic information neededMore hydrogeologic information needed

– Identify major outlets of aquifers and associated Identify major outlets of aquifers and associated recharge features, flow paths, and residence timesrecharge features, flow paths, and residence times

• Address connected nature of GW and SWAddress connected nature of GW and SW– Require large-scale GW pumping to assess Require large-scale GW pumping to assess

impacts on springs and SWimpacts on springs and SW• Holistic watershed managementHolistic watershed management• Outreach and education Outreach and education

How can we conserve springs?How can we conserve springs?

Texas Springs: Texas Springs: leaking into an leaking into an

uncertain futureuncertain future

Chad Norris

Water Resources Branch

Chad.norris@tpwd.state.tx.us