Flow processes in Spring Ecosystems Glenn Longley, Ph.D. Texas State University Flows for the Future Conference October 31, 2005

Springs Are important ecological systems Are important ecological systems They serve as the interface between groundwater and surface water They serve as the interface between groundwater and surface water They often are refuges for species that have been isolated for long periods of time They often are refuges for species that have been isolated for long periods of time As a result they often contain rare or endangered species As a result they often contain rare or endangered species

Springs Best documented in Texas by Gunnar Brune, 1981, “Springs of Texas” Best documented in Texas by Gunnar Brune, 1981, “Springs of Texas” Also Major & Historical Springs of Texas, 1975, TWDB Rpt Also Major & Historical Springs of Texas, 1975, TWDB Rpt Comanche Springs in Fort Stockton have been used by native people, DeVaca in 1535 Comanche Springs in Fort Stockton have been used by native people, DeVaca in 1535 By 1962 they were dry most of the time due to over pumping of the aquifer feeding them. By 1962 they were dry most of the time due to over pumping of the aquifer feeding them.

Threats to Springs West Texas – Consideration by Texas Land Commissioner to lease State lands for Water harvesting West Texas – Consideration by Texas Land Commissioner to lease State lands for Water harvesting Arid region with minimal recharge and more localized aquifers Arid region with minimal recharge and more localized aquifers Potential to dry many of the smaller springs in the region Potential to dry many of the smaller springs in the region

Threats to Springs Central Texas Springs are threatened Central Texas Springs are threatened In the SA Portion of the Aquifer all springs are threatened by inadequate trigger levels in Drought Contingency Plans to assure continued Spring Flow In the SA Portion of the Aquifer all springs are threatened by inadequate trigger levels in Drought Contingency Plans to assure continued Spring Flow Inadequate alternative supplies are being considered by major water users Inadequate alternative supplies are being considered by major water users Agricultural users have been allocated too large amounts of water. Agricultural users have been allocated too large amounts of water.

Threats to Springs Barton Springs – High population growth and inadequate alternative supplies Barton Springs – High population growth and inadequate alternative supplies Jacob’s Well – Large scale development that utilizes a limited aquifer that also feeds the well Jacob’s Well – Large scale development that utilizes a limited aquifer that also feeds the well Historic uses of springs is documented in Brune’s Springs of Texas Historic uses of springs is documented in Brune’s Springs of Texas

Drought recurring but inadequately planned for The drought used for planning purposes is the drought of the 50’s. but drought has been shown to be a recurring phenomenon in this region by the use of tree ring studies. The drought used for planning purposes is the drought of the 50’s. but drought has been shown to be a recurring phenomenon in this region by the use of tree ring studies. There have been droughts of longer duration and greater intensity. There have been droughts of longer duration and greater intensity.

Sampled Spring Sites 1. Santa Rosa15. Caroline 2. Diamond-Y16. Bone 3. East Sandia17. Guadalupe 4. San Salomon18. Upper Pine 5. El Ojo19. Frijole 6. La Morita20. Manzanita 7. Las Cuevas21. Smith 8. Lava Escondido22. Choza 9. Post23. McKittrick 10. Glenn24. Limpia 11. McKinney25. Bridge 12. Burro26. Tobe 13. Oak27. Headquarters 14. Hot Spring #428. Head

Methods Field Measurements Field Measurements Each Spring: Each Spring: –Latitude/Longitude –Water Temperature –Conductivity –pH –Dissolved Oxygen –Flow

Methods Collecting Water Samples Collecting Water Samples –All water samples collected utilizing EPA and TCEQ guidelines for sampling and holding times. –Each site: Nutrients Nutrients Metals; Se, Hg, As, Ag, Mn, Cr, Fe, Ca, Na, Mg, K, Si, P, B, Al, Sr & Ti Metals; Se, Hg, As, Ag, Mn, Cr, Fe, Ca, Na, Mg, K, Si, P, B, Al, Sr & Ti

Piper Tri-linear Diagrams Major cation and anion percentages are plotted on the left and right ternary diagrams, respectively Major cation and anion percentages are plotted on the left and right ternary diagrams, respectively Position of each is projected up into interior diamond- shaped field Position of each is projected up into interior diamond- shaped field

Ca Mg HCO 3

Trans-Pecos Stiff Diagrams

Ca or Na - HCO 3 or SO 4 Ca HCO 3 Ca Mg HCO 3

The Next Step Resample springs and locate new springs to sample. Resample springs and locate new springs to sample. Gather historic data on groundwater resources in the Trans-Pecos area and compare with data collected from this project. Gather historic data on groundwater resources in the Trans-Pecos area and compare with data collected from this project. Look at watershed, geologic and precipitation influences on springs, to better understand the groundwater sources of each spring. Look at watershed, geologic and precipitation influences on springs, to better understand the groundwater sources of each spring.

Biological Assessment An evaluation of water-body conditions using samples of the biota in surface waters. An evaluation of water-body conditions using samples of the biota in surface waters.

History of Rapid Bioassessment Protocols (RBPs) RBPs were developed in response to EPA efforts to find cost-effective approaches for assessing water quality and to develop standard biological monitoring techniques. RBPs were developed in response to EPA efforts to find cost-effective approaches for assessing water quality and to develop standard biological monitoring techniques. The first RBPs were released in 1989 as a compilation of various state agencies’ procedures and are continuously updated. The first RBPs were released in 1989 as a compilation of various state agencies’ procedures and are continuously updated. They were designed as a template for state agencies, which could make appropriate modifications for their area. They were designed as a template for state agencies, which could make appropriate modifications for their area.

Qualitative Sampling Methods A D-frame kicknet is used for a 5-minute sample to collect 100+ organisms A D-frame kicknet is used for a 5-minute sample to collect 100+ organisms The process is repeated one more time if it is not possible to obtain 100 organisms The process is repeated one more time if it is not possible to obtain 100 organisms If it is not practical to use kicknet then 100+ organisms are hand picked from stable substrate If it is not practical to use kicknet then 100+ organisms are hand picked from stable substrate

TCEQ Quantitative Metrics Taxa Richness Taxa Richness Dipteran Taxa Dipteran Taxa Ephemeroptera n Taxa Ephemeroptera n Taxa Intolerant Taxa Intolerant Taxa % EPT Taxa % EPT Taxa % Chironomidae % Chironomidae % Tolerant Taxa % Tolerant Taxa % Grazers % Grazers % Gatherers % Gatherers % Filterers % Filterers % Dominance % Dominance

Metrics and Scoring Criteria (Qualitative)

MetricValueScore Taxa Richness 173 EPT Taxa Abundance 11 Biotic Index (HBI) % Chironomidae % Dominant Taxon % Dominant FFG % Predators Ratio of Intolerant:Tolerant Taxa % of total Trichoptera as Hydropsychidae 01 # of non-insect taxa 32 % Collector-gathers % of total number as Elmidae 01 Total Score: 22 Aquatic Life Use Scores Exceptional: >36 High: Intermediate: Limited:< 22 Post Spring Aquatic Life Use Score: Intermediate

Central Texas Springs San Marcos & Comal San Marcos & Comal Home to several Endangered Species Home to several Endangered Species –Fountain Darter –San Marcos Salamander –Texas Wild Rice –San Marcos Gambusia Smaller springs along the Balcones Escarpment – home to Plethodontid salamanders Smaller springs along the Balcones Escarpment – home to Plethodontid salamanders

Thank you! I will be glad to take questions.  I can be reached at the following:   EARDC homepage:  Phone:  Fax:  Feel free to contact me with questions.