The National Academy of Sciences has released its first review of the Edwards Aquifer Authority's Habitat Conservation Plan. Credit: Courtesy / EAA

The Edwards Aquifer Authority’s (EAA) Habitat Conservation Plan (HCP), designed to guide the protection of water flow and species in the Edwards Aquifer region, is passing muster with a distinguished independent review panel of national experts.

In recent weeks, a National Research Council (NRC) committee, formed by the National Academy of Sciences (NAS), released the first of three reports that evaluate and make recommendations for Habitat Conservation Plan programming.

The EAA developed a conservation plan to obtain an Incidental Take Permit (ITP), which is a provision of the U.S. Endangered Species Act (ESA) that allows private, non-federal entities to carry out legal projects that might otherwise harm endangered species. San Antonio Water System, the cities of San Marcos and New Braunfels, Texas State University, EAA, and Guadalupe-Blanco River Authority are the permittees.

The independent scientific review – the product of a five-year contract between the National Academy of Sciences and the EAA– will continue through Dec. 31, 2018 at a cost not to exceed $1.42 million.

Although the initial 174-page report is highly technical, the review committee has concluded that “… the Edwards Aquifer Authority and the other permittees are doing an excellent job in implementing many aspects of a complex habitat conservation plan, and that addressing several overarching scientific and modeling issues would further strengthen the plan.”

In 2013, the U.S. Fish and Wildlife Service approved the EAA’s concept for the Habitat Conservation Plan, which is a regional, 15-year planning effort.

“It took a number of years to get here, working with our stakeholders,” said EAA General Manager Roland Ruiz. “It was a consensus-driven process. Every party has a voice.”

In January 2014, the EAA asked the Washington, D.C.-based National Research Council to provide a third-party study of the scientific methodology used for implementing the Habitat Conservation Plan.

“The idea was to have a blue-ribbon committee to give us a comprehensive look at what we’re doing and to validate it. It’s to shore up with an outside view,” Ruiz said. “There are recommendations about some of the things that we could do better. We’re looking at which things are feasible and make sense for us.”

Nathan Pence, the plan’s executive director, said the study will add transparency for the public.

“It’s a report of the things we’re doing and going to do with permit holders’ fees,” Pence said.

This map outlines the Edwards Aquifer Authority's jurisdiction and the aquifer recharge zone. Map from EAA
This map outlines the Edwards Aquifer Authority’s jurisdiction and the aquifer recharge zone. Map from EAA.

According to the National Academy of Science’s summary of the plan, the first review of the Edwards Aquifer Authority’s scientific efforts was done to help stakeholders better understand the relationship between the river-aquifer system and the species listed in the Endangered Species Act. The report focuses on the Edwards Aquifer Authority’s hydrologic modeling, ecological modeling, water quality and biological monitoring, and the Habitat Conservation Plan’s applied research program.

“It is hoped that the successful completion of these scientific initiatives will ultimately lead the Edwards Aquifer Authority to an improved understanding of how to manage the system and protect these species,” the report summary stated.

The goal of hydrologic modeling is to create a groundwater model that can reproduce known spring flows. From there, future predictions can be made about the way climate change and droughts might affect spring flow, and how management actions, such as conservation measures, will affect water levels and spring flow.

The review committee commended the authority’s continuing improvement on their use of models and incorporation of new data. The committee then recommended that model uncertainty be quantitatively assessed and presented in formal Edwards Aquifer Authority documents.

“Quantifying model uncertainty increases a model’s defensibility and can provide a reasonable estimate of model error, which is important information when using a model for management decisions,” the report stated.

The ecological modeling would be able to predict species population metrics under various potential future conditions. Such efforts are aimed at what the Edwards Aquifer Authority calls “indicator species,” three identified endangered species in the aquifer’s springs – the fountain darter, the Comal Springs riffle beetle, and Texas wild rice – as well as underwater vegetation.

The review committee concluded that, generally speaking, “combining field data, habitat suitability analyses, and a population dynamics model” could help the Edwards Aquifer Authority’s ecological modeling efforts.

The blind salamander is one of a handful of endangered species found in the Comal and San Marcos river systems. Photo courtesy of EAA.
The blind salamander is one of a handful of endangered species found in the Comal and San Marcos river systems. Photo courtesy of EAA.

The committee did make several recommendations about ecological modeling, chiefly that the EAA develop an ecosystem-based conceptual model or a series of models that show how water quality and quantity – among other factors – may interact with the indicator and species, as well as with all covered species.

Committee members said the EAA monitoring efforts of the physical, chemical, and biological characteristics of the Comal and San Marcos spring and river systems has been ongoing since 2000 and is even more comprehensive because of the Habitat Conservation Plan.

Regardless, the committee made some recommendations for improvement, including enhanced sampling for nutrients, and new quantitative sampling methods for the riffle beetle.

As part of the habitat conservation plan, the EAA is employing an applied research program to fill knowledge gaps about endangered species in the Comal and San Marcos systems, especially under low flow conditions.

For example, according to the report, more is known about fountain darters and Texas wild rice than about the riffle beetle and other Endangered Species Act-listed species.

In response to this, the committee suggested additional studies on fountain darters, and that scientists gather information on the riffle beetle’s life history, life cycle and distribution. Reviewers also recommended more analysis of underwater vegetation and nutrients.

Additionally, the committee suggested that this program would benefit from more transparency and competition when it comes to increasing stakeholders’ involvement and scientific collaboration, respectively.

“Increasing the diversity of thought, understanding, and perspective will serve to strengthen the Habitat Conservation Plan and increase the likelihood that project goals will be met,” the report stated.

Ruiz said in many respects the committee “hit the nail on the head” in making conclusions similar to those that the EAA administrative and scientific staff have made in the early phase of implementing the conservation plan.

“There were no surprises. By and large, it’s what we anticipated,” Ruiz said.

In the final analysis, the committee concluded that the Edwards Aquifer Authority and other permittees are in the “beginning stages of implementing a complex Habitat Conservation Plan and are doing an excellent job in most respects.”

However, committee members said the EAA should consider overarching concerns that, if left unaddressed, may hinder the later stages of the Habitat Conservation Plan, especially future attempts to renew the plan and the Incidental Take Permit.

The committee made four recommendations here, including that the Edwards Aquifer Authority begin planning for possible worst-case scenarios and their potential implications for modeling and plan implementation.

Examples of worst-case scenarios include increased groundwater pumping from exempt/unregulated wells that undermines minimum flow requirements, and conditions that exceed the drought of record of the ’50s.

“The recommendations in the report should not be viewed as critiques of work already performed, but rather advise and suggestions to strengthen the program as we move into the future,” National Academy of Sciences committee Chairman Danny Reible said at a recent meeting of the Habitat Conservation Plan’s Implementing Committee.

Ruiz said that, due to the Edwards Aquifer Authority’s unique role in managing of the nation’s most productive karst aquifers, spring flow and aquifer levels have been sustained and species have been protected even in the most recent period of drought.

“Given the way conditions are today, even with all the rain, users around the Edwards region have helped us get up to a level of recovery,” Ruiz added. “Users also bought into conservation for the greater good.”

A work group is tasked this summer to finalize the implementation plan for the Habitat Conservation Plan, a document that the Implementing Committee will consider for adoption in August. The academy’s second review is due to arrive by December 2016, with the final one coming December 2018.

*Featured/top image: The National Academy of Sciences has released its first review of the Edwards Aquifer Authority’s Habitat Conservation Plan. Photo courtesy of EAA. 

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Edmond Ortiz, a lifelong San Antonian, is a freelance reporter/editor who has worked with the San Antonio Express-News and Prime Time Newspapers.