Fish Passage and Dam Removal in the Tennessee River Watershed

There are no anadromous fish in the tributaries of the Tennessee River in Virginia, but mussel habitat is damaged by silt collecting behind dams. In addition, fish that carry the larval stage of mussells (glochidia) are blocked from stretches of river by various dams in the Powell, Clinch, and Holston rivers.

In 2015, the "ice plant dam" on the Middle Fork of the Holston River was removed to improve habitat and increase river recreational opportunities. The US Fish and Wildlife Service supported the $120,000 dam removal project because the dam blocked sediment from moving downstream, and silt accumulating behind the dam damaged mussel habitat for nearly a half mile upstream. Eight species living in the Holston River were on the Federal list of threatened and endangered species.

Local officials supported the dam removal, anticipating as much as $9 million in economic benefits from rafting trips, more trout fishing, and other recreational activities. The dam had diverted water to an ice plant, but that facility closed 40 years earlier. A 1977 flood breached the dam, but it continued to block the natural movement of sediment until removal in 2015.¹

Also on the Middle Fork Holston River, the U.S. Fish and Wildlife Service also arranged for removal of the low water "Miller Bridge." The concrete for that bridge had been placed directly on top of a mussel bed:²

The river was once home to a multitude of mussels -- freshwater clams -- that help filter the water and disperse nutrients for fish and other aquatic life.

The shells of several now rare species of mussels were found embedded in the concrete of the bridge... such as Slab Side Pearly Mussel, which is federally listed and the Tennessee Pig Toe Mussel, which is state listed.

the US Fish and Wildlife Service proposed listing all 55 miles of the Middle Fork of the Holston River, from its headwaters to South Holston Lake, as critical habitat for the fluted kidneyshell and slabside pearlymussel, two of the increasingly rare southeastern mussel species that benefitted from removal of the ice plant dam in 2015
Source: Federal Register, Endangered and Threatened Wildlife and Plants; Endangered Species Status for the Fluted Kidneyshell and Slabside Pearlymussel and Designation of Critical Habitat (October 4, 2012)

References

1. "USFWS, others partnering to remove dam built for ice plant in Marion," Bristol Herald Courier, December 6, 2014, http://www.tricities.com/news/article_5bd538be-7dbf-11e4-a65e-3732c9f89e5b.html; "Crews begin project to remove Marion ice plant dam," Bristol Herald Courier, March 17, 2015, http://www.tricities.com/news/crews-begin-project-to-remove-marion-ice-plant-dam/article_55ae508a-cd1d-11e4-805b-13a49f27bfb3.html (last checked March 18, 2015)
2. "Chilhowie low-water bridge removed to improve fishing, river conditions," Smyth County News & Messenger, March 25, 2015, http://www.swvatoday.com/news/smyth_county/article_a5b54f88-d269-11e4-a666-9328984c7dd2.html (last checked March 29, 2015)