Review of the
Edwards Aquifer Habitat
Committee to Review the Edwards Aquifer Habitat Conservation Plan
Water Science and Technology Board
Division on Earth and Life Studies
A Consensus Study Report of
THE NATIONAL ACADEMIES PRESS
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This activity was supported by the Edwards Aquifer Authority under Contract No. 13-666-HCP. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.
International Standard Book Number-13: 978-0-309-48194-6
International Standard Book Number-10: 0-309-48194-5
Digital Object Identifier: https://doi.org/10.17226/25200
Cover credit: Cover image courtesy of Laura J. Ehlers.
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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2018. Review of the Edwards Aquifer Habitat Conservation Plan: Report 3. Washington, DC: The National Academies Press. doi: https://doi.org/10.17226/25200.
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COMMITTEE TO REVIEW THE EDWARDS AQUIFER HABITAT CONSERVATION PLAN—PHASE 3
DANNY D. REIBLE, NAE, Chair, Texas Tech University, Lubbock
JONATHAN D. ARTHUR, Florida Department of Environmental Protection, Tallahassee
M. ERIC BENBOW, Michigan State University, East Lansing
STUART E.G. FINDLAY, Cary Institute of Ecosystem Studies, Millbrook, New York
K. DAVID HAMBRIGHT, University of Oklahoma, Norman
LORA A. HARRIS, University of Maryland Center for Environmental Science, Solomons
STEVE A. JOHNSON, University of Florida, Gainesville
JAMES A. RICE, North Carolina State University, Raleigh
KENNETH A. ROSE, University of Maryland Center for Environmental Science, Cambridge
J. COURT STEVENSON, University of Maryland Center for Environmental Science, Cambridge
LAURA TORAN, Temple University, Philadelphia, Pennsylvania
National Academies Staff
LAURA J. EHLERS, Study Director
CARLY BRODY, Senior Program Assistant
WATER SCIENCE AND TECHNOLOGY BOARD
CATHERINE L. KLING, NAS, Cornell University, Ithaca, New York
DAVID A. DZOMBAK, NAE, Carnegie Mellon University, Pittsburgh, Pennsylvania
WENDY D. GRAHAM, University of Florida, Gainesville
ARTURO A. KELLER, University of California, Santa Barbara
MARK W. LeCHEVALLIER, Dr. Water Consulting, LLC, Morrison, Colorado
DINAH LOUDA, Veolia Institute, Paris, France
MARGARET A. PALMER, University of Maryland, Annapolis
STEPHEN POLASKY, NAS, University of Minnesota, St. Paul
DAVID L. SEDLAK, NAE, University of California, Berkeley
DAVID L. WEGNER, Jacobs Engineering, Tucson, Arizona
P. KAY WHITLOCK, Christopher B. Burke Engineering, Ltd., Rosemont, Illinois
JAMES W. ZIGLAR, Van Ness Feldman, Potomac, Maryland
ELIZABETH A. EIDE, Director
LAURA J. EHLERS, Senior Staff Officer
STEPHANIE E. JOHNSON, Senior Staff Officer
M. JEANNE AQUILINO, Financial and Administrative Associate
COURTNEY R. DeVANE, Administrative Coordinator
BRENDAN R. McGOVERN, Research Assistant/Senior Program Assistant
CARLY BRODY, Senior Program Assistant
The Edwards Aquifer in south-central Texas is an important water resource that also provides critical habitat for threatened and endangered species in the San Marcos and Comal spring and river systems. The unique habitat afforded by these spring-fed rivers has led to the evolution of species found in no other locations on Earth. Because of the potential for variations in spring flow due to both human and natural causes, the Edwards Aquifer Authority (EAA) and stakeholders have developed a Habitat Conservation Plan (HCP) to protect these unique species. The HCP seeks to effectively manage the river-aquifer system to ensure the viability of the endangered species in the face of future water quantity concerns, such as drought and increased demand from population growth, as well as water quality threats to the system.
The National Academies of Sciences, Engineering, and Medicine were asked by the EAA to assist in this process by reviewing the implementation of HCP activities. The National Academies’ study was planned in three phases, with the first phase being a review of the scientific efforts that are being conducted to help build a better understanding of the river-aquifer system and its relationship to the endangered species, including monitoring and modeling. The first phase led to a report published in 2015 that provided an evaluation and recommendations for strengthening those efforts. The second phase led to a report published in 2017 that built upon recommendations in the 2015 report (and the EAA’s response to them), as well as evaluating both hydrologic and ecological modeling and the minimization and mitigation (M&M) measures being undertaken for the HCP.
This is the third and final report, which evaluates the likelihood of
whether the biological objectives set in the HCP will meet the biological goals and whether the M&M measures will meet the biological objectives. Recognizing that we now have a better understanding of the Edwards Aquifer system as well as the stressors that may impact its condition, the Committee also chose to make recommendations in a final chapter on a path forward that may suggest the need for modifications to the biological goals and objectives. These suggestions are offered in recognition that the ultimate goal is protection of the listed species and not the surrogates for that protection that are identified as biological goals in the HCP.
This study was established under the auspices of the Water Science and Technology Board (WSTB) of the National Academies with the title Committee to Review the Edwards Aquifer Habitat Conservation Program. The Committee included 11 individuals representing expertise in all areas relevant to the statement of task, including the hydrogeology of the aquifer and the chemistry and ecology of river systems. Four meetings were held over the past year. The first two meetings were held in San Antonio and included presentations on current EAA and HCP activities relevant to the Committee’s statement of task. I would like to thank the following individuals for giving presentations to the committee during one or more of its meetings: Nathan Pence, Executive Director of the Habitat Conservation Program, EAA; Chad Furl, Alicia Reinmund-Martinez, Jim Winterle, Mark Hamilton, and Mark Friberg, EAA; Jacob Jackson and Ely Kosnicki, BIO-WEST; and Josh Perkin, Texas A&M Department of Wildlife and Fisheries Sciences. We would also like to thank the many people who helped organize and run the field trips taken by the Committee, particularly Nathan Pence, EAA; Ed Oborny, BIO-WEST; Zac Martin, City of New Braunfels; Lindsay Campbell, U.S. Fish and Wildlife Service; and Melanie Howard, City of San Marcos.
Although Committee members represented many diverse perspectives and expertise that varied from river-aquifer hydrology to biology, they reached consensus on all recommendations included in the report. We hope that the EAA will find these recommendations useful as they guide the scientific initiatives designed to provide a solid foundation for effective management of the river-aquifer system and protection of the endangered species.
This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.
We thank the following individuals for their review of this report: Stephen R. Carpenter, University of Wisconsin, Madison; Wendy D. Graham, University of Florida, Gainesville; Jessie C. Jarvis, University of North Carolina, Wilmington; Peter Kareiva, University of California, Los Angeles; Paul Mayer, U.S. Environmental Protection Agency; Margaret Palmer, University of Maryland, Annapolis; Chris Phillips, University of Illinois and the Illinois Natural History Survey, Champaign; and Robert G. Traver, Villanova University.
Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by Patrick L. Brezonik, University of Minnesota, and R. Rhodes Trussell, Trussell Technologies, Inc. Appointed by the National Academies, they were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee.
Danny D. Reible, Chair
Committee to Review the Edwards Aquifer
Habitat Conservation Plan
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