Transcript SPRING LAKE DAM (SCENARIOS)

THE EDWARDS AQUIFER
and its Unique Ecosystem –
potential threats from
Groundwater Management
Glenn Longley
Director
Edwards Aquifer Research & Data Center
Outline
 Hydrologic Setting of Edwards (BFZ)
Aquifer
 Unique Aquatic Ecosystem
 History of Management
 Current work
 Summary
 Contact information
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Edwards Aquifer
San Antonio portion of FZ
•Elevation near 575 feet ↘
SM
spgs
Comal
spgs
SA spgs
Watershed
Recharge Zone
Leona spgs
Artesian Zone
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San Marcos Springs
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Barton Springs Segment (BFZ) Aquifer
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Unique? How?
 40+ species of Invertebrates
 4+ species of Vertebrates
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Discoveries made in the last
20 years
 Diversity of Amphipods, snails & overall
 Presence of marine relicts
 Monodella
 Some amphipod families
 Foraminiferans
 New species, deep aquifer system
 More detailed information about vertebrates
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Community diversity
 Greatest in Amphipods (12 species-5
families)
 Other Arthropods (13 species representing 8
families)
 Next is Mollusca (10 species of Hydrobiid
snail family)
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More about diversity
 Biological diversity is important Ecological stability
 The species in this system may hold
important genetic information
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Marine relicts
 Amphipods in the families: Hadziidae,
Bogidiellidae, & Sebidae
 These families are primarily marine with few
examples of freshwater sp.
 Hadziids are distributed today around the
Caribbean and Mediterranean
 These areas are important as remnants of the
Tethys Sea
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Marine relicts
 May assist in better understanding of how
the aquifer formed and its relationship with
paleomarine areas
 Additional studies of these species will shed
light on paleogeography
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Other marine relicts in the
Aquifer
 Monodella texana (Only N.A.
Thermosbaenacean)
 M. texana’s marine ancestors are
represented by groups in the W. Indies
 A Foraminiferan from the Lagenidae
(Probably Robulus sp) was found
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Other marine relicts continued
 Foraminiferans have only been found in
fresh water from wells (Trans Caspian
Province)
 Cirolanid isopods (predominantly marine)
are also found
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New species
 8 new snails, 2 others renamed
 10 new amphipods, 1 new family (Artesiidae)
 1 new aquatic beetle - Hadeoporus texanus (larvae
& adult described)
 1 new vertebrate described - Typhlomolge robusta
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Flowing Edwards well with biomass being discharged
southwest of San Antonio, Texas
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Texas State University
Artesian Well
 Drilled in 1895 to
furnish water for
Federal Fish Hatchery
 Five foot cavern at
195 feet
 Source of water is
Edwards Aquifer
 Sampled continuously
since early 70’s
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64 micron mesh net on 12” discharge with removable
sample chamber
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Two day sample out of Texas
State Artesian well net
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Filamentous colonies of fungi and other
organisms
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Placing a net on flowing well at
San Antonio Zoo
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Invertebrate Fauna
 TURBELLARIA: (Flatworms)
 Kenkiidae
 Sphalloplana mohri Hyman
 NEMATODA: (Roundworms)
 Rhabdochonidae
 Rhabdochona longleyi Moravec & Huffman
Sphalloplana mohri
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Gastropods (Snails)
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Hydrobiidae
 Phreatodrobia conica Hershler &
Longley Hueco cavesnail
 P. coronae Hershler & Longley
 P. imitata Hershler & Longley
mimic cavesnail
 P. micra (Pilsbry & Ferris)
flattened cavesnail
 P. nugax inclinata Hershler &
Longley
 P. nugax nugax (Pilsbry & Ferris)
domed cavesnail
 P. plana Hershler & Longley
disc cavesnail
 P. punctata Hershler & Longley
high-hat cavesnail
 P. rotunda Hershler & Longley
beaked cavesnail
 Phreatoceras taylori Hershler &
Longley nymph trumpet
 Balconorbis uvaldensis Hershler &
Longley Balcones ghostsnail
 Stygopyrgus bartonensis Hershler
& Longley Barton cavesnail
 Texapyrgus longleyi Thompson &
Hershler striated hydrobe
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HIRUDINEA
(Leeches)
Erpobdellidae:
 Mooreobdella microstoma Pawlowski
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Crustaceans
 OSTRACODA:
Entocytheridae
 Sphaeromicola
(Hobbsiella) moria
Hart
 ISOPODA:
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Cirolanidae
Caecidotea reddelli (Steeves)
Cirolanides texensis Benedict
Asellidae
Lirceolus pilus (Steeves)
L. smithi (Ulrich) Texas
troglobitic Water Slater
 Mexistenasellus sp.
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Asellid Isopod
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Mexistenasellus sp.
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AMPHIPODS
 Hadziidae
 Allotexiweckelia hirsuta Holsinger
 Holsingerius samacos (Holsinger)
 Texiweckelia texensis (Holsinger)
 Texiweckeliopsis insolita (Holsinger)
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Amphipods continued
 Stygobromus balconis
(Hubricht)
 Crangonyctidae
 S. bifurcatus (Holsinger)
 S. flagellatus (Benedict)
 S. pecki (Holsinger)
 S. russelli (Holsinger)
 Sebidae
 Seborgia relicta Holsinger
 Bogidiellidae
 Artesia subterranea
Holsinger
 Parabogidiella americana
Holsinger
Stygobromus sp.
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CRUSTACEANS continued
 THERMOSBAENACEA:
 Monodellidae
 Monodella texana Maguire
 DECAPODA:
 Palaemonidae
 Palaemonetes
antrorum Benedict
 P. holthuisi Strength
Monodella texana
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Paleomonetes antrorum
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COLEOPTERA:
(Insect – beetles)
 Dryopidae
 Stygoparnus comalensis Barr & Spangler
 Dytiscidae
 Comaldessus stygius Spangler & Barr
 Haideoporus texanus Young & Longley
Edwards Aquifer water beetle
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Haideoporus texanus
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VERTEBRATES
PISCES: (Fish)
 Ictaluridae
 Satan eurystomus Hubbs & Bailey
Widemouth blindcat
 Trogloglanis pattersoni Eigenmann
Toothless blindcat
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Satan eurystomus
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Trogloglanis pattersoni
 Toothless blindcat
 Found in same area of
Widemouth Blindcat
 Shallowest collection
1350’ below surface
 Deepest 2000’
 Only below San
Antonio TX area
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CAUDATA:
Tailed amphibians
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Plethodontidae
Eurycea chisholmensis Chippindale,
Price & Hillis Salado salamander
E. latitans Smith & Potter
Cascade Caverns salamander
E. naufragia Chippindale, Price &
Hillis
E. sp.nov. Comal
E. nana Bishop
San Marcos salamander
E. neotenes Bishop & Wright
Texas salamander
E. pterophila Burger, Smith & Potter
Fernbank salamander
E. rathbuni (Stejneger)
Texas Blind salamander
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E. robusta (Longley)
Blanco Blind salamander
E. sosorum Chippindale, Price & Hillis
Barton Springs salamander
E. tonkawae Chippindale, Price &
HillisJollyville salamander
E. tridentifera Mitchell & Reddell
Comal blind salamander
E. troglodytes Baker
Valdina Farms salamander
E. sp.
Comal Springs salamander
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Eurycea rathbuni
Texas Blind Salamander
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San Antonio portion of the Balcones Fault Zone Edwards Aquifer
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Bexar Co. Texas “Catfish Well”
flows at > 30 MGD
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History of Management
 1983 - EUWD given authority to regulate
transport of water out of district (5 counties)
 1987 – EUWD gains legislative approval
for a drought management plan (DMP)
 1988-90 – DMP requirements set
 1989 – Two western Counties withdraw
from District
 May 1991 – SA defeats construction of
Applewhite Reservoir (Alternate source)
 May 1991 – Sierra Club files suit against
USFWS
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History Continued
 Sierra Club suit asks that USFWS be
required to insure min. springflow to protect
endangered species.
 EUWD and SARA file suit against Living
Waters (Catfish Well owners) for waste and
water quality issues.
 1992 – TWC declares Edwards Aquifer to
be an underground river, therefore regulated
by the state
 Later that year State Court invalidates
TWCs determination
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History continued
 Nov 16, 1992 Trial begins in U.S. District
Court for Sierra Club lawsuit.
 Jan 30, 1993 – U.S. Dist. Judge Bunton rule
for the Sierra Club and orders:
Springflow must be maintained
TWC must submit plan to court by March 1993
to assure Comal & San Marcos Springs do not
drop below Jeopardy levels
USFWS must develop springflow thresholds
for take & jeopardy
Tx Legislature must develop regulations to
limit withdrawals by May 31, 1993.
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History continued
 May 30, 1993 – Texas Legislature adopts
SB 1477 that creates the Edwards Aquifer
Authority (EAA) with a 9 member
appointed board
 Aug. 30, 1993 – U. S. Justice Dept. ruled
legislation may have violated the Voting
Rights Act, in November they determined it
did
 Feb. 1994 – Fed. Court Appointed monitor
to gather information for the court.
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Hydrologic
 Less storage in aquifer (1ft of head = approx.
35,000 acre feet).
 Low flows of San Marcos Springs occur sooner
during critical dry periods.
 Greater potential for saline water intrusion
during critical periods.
Ecological
Lower flows would possibly
jeopardize listed species sooner.
Threats to the system
 Historic lows vs. recent time (recharge &
discharge)
 Increasing water use
 Aquifer Storage & recovery
 Proposed policy to raise pumping caps
 Proposed policy to limit minimal pumping
required during drought
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Summary
Detailed studies
(Past & Continuing)
 Texas Blind Salamander - Typhlomolge rathbuni
 Two blindcatfish from San Antonio area: Satan
eurystomus & Trogloglanis pattersoni
(Ictaluridae)
 Distribution of species throughout the aquifer,
important in showing hydrologic relationships
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Studies currently underway
 Water Quality - investigating
freshwater/saline water interface
 Modeling of groundwater hydrology and the
effect of pumping
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This system is a microcosm of
problems in our world
 Population growth and human demands
threaten the system and the surface
ecosystems (springs) it supports
 We should educate the users of water from
the aquifer about its dynamics
 Its importance as the habitat for a
community of organisms
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Additional studies needed
 Biomagnification of contaminants up the
aquifer food chain
 Toxicity studies of specific members of the
aquifer community
 Additional studies of rarer species
 Energy flow and sources in the deep
confined aquifer
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Acknowledgements
 The work on the aquifer through the years
has been supported by USFWS, TPWD,
USDA, USEPA and numerous other sources
too numerous to mention.
 Staff of the Research Center, Graduate
Students, Collaborators and numerous
others have assisted in developing the
information about the Aquifer community.
 Texas State University has been very
supportive of this work.
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Thank you!
 I can be reached at the following:
 email: [email protected]
 EARDC homepage:
http://www.eardc.txstate.edu
 Phone: 512-245-3581
 Fax: 512-245-2669
 Feel free to contact me with questions.