Texas Springs: leaking into an uncertain future
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Transcript of Texas Springs: leaking into an uncertain future
Texas Springs: Texas Springs: leaking into an leaking into an
uncertain futureuncertain futureChad Norris
Water Resources Branch
(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