Collaborating to protect sensitive species
Desirable though it may be, biological abundance can sometimes present its own set of unique challenges. The fact is, the incredible richness of species diversity in the Tennessee Valley means there was practically no chance that at least some plants and animals wouldn’t be affected — either positively or negatively — by TVA’s operation of the river system.
As a result of the two-year Reservoir Operations Study — an effort designed to determine if changes in the way TVA managed the reservoir system would result in greater overall public benefits — TVA consulted with the U.S. Fish and Wildlife Service (USFWS) to make certain that routine, ongoing activities necessary to operate dams on the river system were not further endangering species protected by the federal Endangered Species Act.
The task of coordinating this review and reporting back to the USFWS fell to a TVA team led by aquatic biologist Peggy Shute. It was a massive undertaking, considering the geographic scope of the area to be studied and the number of sensitive species present. “And it was complicated by the fact that there was little conclusive data available on which to base the determination about the effects of these ongoing operations activities,” explains Shute.
A series of discussions with representatives from several southeastern offices of the USFWS ensued, with the goal of establishing a scientifically sound process for gathering and presenting sufficient data to be used by the USFWS to make its determination about TVA’s impacts to the species listed by the Endangered Species Act. The first step was to document which sensitive species were represented in which locations — whether on the banks, in the water, or on the land surrounding TVA-managed reservoirs. Shute said she was pleased by the confidence USFWS experts had in the information presented by TVA’s biologists and engineers to support the assessment effort: “That really says something about the rigor of our science.”
Activities/species matrices were set up to identify precisely which actions have the potential to impact specific species by affecting plants and animals directly or the habitats in which they are found. Included were activities such as raising and lowering reservoir levels, varying the amount, timing, location and temperature of dam releases, etc.
Valley-wide, 101 listed species were identified as being potentially affected by TVA’s routine activities when operating dams. Out of that total, some — including a number of freshwater mussel species — were positively affected by TVA operations, such as a program to improve dissolved oxygen levels in reservoir releases.
TVA and USFWS agreed that most of the 101 species were unaffected by reservoir operations and maintenance, but it was determined that 20 species could be adversely affected by TVA’s actions.
Of those, the USFWS came to the conclusion that special requirements would be needed to reverse adverse effects of TVA’s dam operations on four species: a darter in a tributary to Great Falls reservoir, a darter and a mussel in the Tims Ford tailwater, and a mussel in the Wilson tailwater.
As a result of the USFWS findings, TVA has begun a long-term commitment to reduce potential impacts. Operations are being changed at the locations where the four at-risk species are present. Ongoing and detailed monitoring reports will be provided for review by an oversight committee for a period of at least 10 years to determine if the proposed changes are having positive impacts to the listed species or if additional protective measures will be needed. It’s very much a dynamic process, according to Shute. “A lot of attention is going to be focused on these populations. We have a flexible plan in place for these areas that we believe will be effective in preventing or minimizing impacts.”
With regard to the remaining 16 species, reservoir operations at the locations in which they are present will continue with minor modifications for the time being. “We’ll be conducting extensive monitoring and reporting our findings to the Fish and Wildlife Service,” says Shute. “If our data suggest that the status of these plants and animals is being impacted by our operations at some point in the future, we’ll make adjustments accordingly. Meanwhile, we’re participating in conservation projects and partnering with landowners to improve aquatic habitat.”
The process has significant and far-ranging environmental and public benefits. “The things we do to protect endangered species result in improved habitat for those animals and plants,” Shute explains. “The efforts we make to preserve our ecological heritage translate to improved water quality, which, in turn, means drinkable, swimmable, and fishable water for Valley residents.”
Shute says that one of the most valuable things to come out of the collaborative process is a strengthened working relationship with the USFWS. “We decided from the outset that we’d make a concerted effort to help them understand our business — why we manage the reservoir system the way we do, the constraints under which we operate, the extent to which our approach maximizes public benefits. The resulting insights have gone a long way toward helping us work together for the public good.”