• Abstract and Figures
• Public Full-text

Streamlined Consultation Guidance for Restoration/Recovery Projects (RRP): Format for the Biological Evaluation/Assessment The attached biological evaluation/assessment (BE/BA) was developed pursuant to the Fish and Wildlife Service’s Streamlined Consultation Guidance for Restoration/Recovery Projects. The BE/BA meets all of the criteria for an expedited consultation process set forth in that policy document. Unique Places hereby requests expedited formal consultation for the Hoosier Dam Removal Project. ________________________________________ __________________ Signature of Requesting Action Agency Official Date Biological Evaluation/ Hoosier Dam Removal Project Chatham County, NC Assessment Cape Fear River Basin June 2017 HUC 03030003 Prepared By: Unique Places, LLC PO Box 52357 Prepared For: Durham, NC 27717 US Fish and Wildlife Service Phone: 919‐724‐0676 551 Pylon Drive Raleigh, NC 27606 Wildlands Engineering, Inc Phone: 919‐856‐4520 312 W. Millbrook Rd., Suite 225 Raleigh, NC 27609 Phone: 919‐851‐9986 I. Description of the Proposed Restoration/Recovery Action [include maps, photographs, diagrams, etc. as appropriate] A. Description of the Restoration/Recovery Objective(s) 1. Briefly describe the restoration and specific recovery action (citing source document when applicable) and its intended beneficial impact to the species. The Hoosier Dam is a 94‐year‐old hydroelectric dam located on the Rocky River 5 ½ miles upstream of its confluence with the Deep River in Chatham County, North Carolina (Figure 1). The dam is being proposed for removal as part of a National Fish and Wildlife Foundation (NFWF) grant to restore the Rocky River from its currently impounded state back to a free‐flowing state. Hoosier Dam and its impoundment, Reeves Lake (Figure 2), are responsible for the loss of natural flow regime, sediment regime, and shallow water habitat to approximately 18,138 linear feet of stream ecosystem (16,060 linear feet within the Rocky River and 2,078 linear feet of perennial tributaries). The U.S. Fish & Wildlife Service (USFWS) has designated sections of the Rocky River upstream of the impoundment and downstream from Hoosier Dam, as well as a section of Bear Creek just below the dam, as Critical Habitat for the Cape Fear shiner, a federally listed endangered species (USFWS, 1988) (Figure 3). The non‐impounded sections of the Rocky River and Bear Creek exhibit very high quality riverine habitat that supports a diverse collection of aquatic species including the Cape Fear shiner and other species of concern, such as the eastern creekshell (Villosa delumbis), the Carolina creekshell (Villosa vaughaniana), the Savannah Lilliput (Toxolasma pullus), and an undescribed Lampsilis sp.. (photographs in Appendix A). The dam represents a significant blockage to aquatic species ability to disperse freely and exchange genetic material with neighboring populations and as a result, USFWS has documented declines in the disconnected Cape Fear shiner population upstream of the dam (USFWS, 1988). Removal of the blockage created by the dam to provide access to these high‐quality reaches would be of substantial long‐term benefit to aquatic communities including the Cape Fear shiner. The recovery goals for the Cape Fear shiner, as listed in the 1988 USFWS report are: 1. Protection of existing populations and successful establishment of reintroduced populations and current habitat; 2. Evaluating feasibility of introducing species into historic habitat; 3. Searching for additional suitable habitat for re‐introduction; 4. Monitoring existing populations biannually; and 5. Evaluating the recovery program on an annual basis. The removal of the Hoosier Dam, and restoration of the Rocky River in the vicinity of the dam will address the habitat recovery goals of the Cape Fear shiner listed above. Post‐dam removal, the previously impounded stretch of the Rocky River will return to its historic wide, shallow, and rocky state. This will immediately provide 3.4 additional miles of historic habitat for the Cape Fear shiner that is directly connected to existing habitat and known populations of the species. This expansion of available habitat is expected to be naturally repopulated as shiners move into the area. Impoundments and siltation from impoundments is listed as one of the key elements in the decline of the Cape Fear shiner population (USFWS 1988.) This project will directly address such an impact. Removing the dam will prevent further siltation of habitat within the currently impounded reach of the Rocky River. The construction plan itself will address the existing sediment wedge behind the dam. The wedge will be removed prior to construction if testing of the wedge after dewatering confirms a dominant fine silt/clay/sand texture. Sediment in the wedge will be pulsed through the system during construction if testing confirms the wedge to be a medium gravel to cobble texture (refer to Sediment 1 Management Plan in Appendix C for full description). Removal of the dam will restore a natural sediment regime to the Rocky River. The current impoundment not only traps fine sediment, but also the gravels and cobbles that comprise the preferred Cape Fear shiner habitat. Currently, if gravel and cobbles are washed downstream in the habitat below the dam, they are not being replaced by new material entering the system, damaging existing habitat. 2. Include a description of anticipated habitat improvements, and/or expected increases in species fitness, survivorship, etc. that are consistent with the recovery needs of the species. The impounded portion of the Rocky River, shown in the photo to the left, is an open, freshwater, lentic habitat. Water depth is approximately 25 feet at the upstream face of the dam and gradually decreases in the upstream direction. The impoundment is narrow through the majority of the river length and widens for the last 1,000 feet before the dam. Habitat is suitable for lentic species of fish, macroinvertibrates, vegetation, and waterfowl. Draining the impoundment and removing the Existing Impoundment (Reeves Lake) dam is expected to return the Rocky River to its historic bed conditions. These conditions are likely to mimic those upstream of the impoundment and downstream of Hoosier dam (pictured right). The river will have wide, shallow waters interspersed with bedrock outcrops, pools, natural riffle features, and deposits of large woody debris. This is consistent with the habitat needs of the Cape Fear shiner. In addition to geomorphic habitat restoration, the removal of Hoosier Dam will restore many natural processes that will benefit the Cape Fear shiner and other sensitive aquatic species. Water temperature and oxygen levels will change in the Rocky River’s impounded reach once the dam is removed. Previous temperature and dissolved oxygen stratification testing done by Wildlands Engineering (Wildlands) in 2013 within the impoundment showed stratification of temperatures ranging from 26.8 C at the surface to 22.2 C at a depth of 19 ft. In a study of the Cape Fear shiner by Hewitt et al. (2006), Downstream of Hoosier Dam the habitats with the best survivability and growth rate had temperatures ranging from 26.4C to 28.1C. This range was only achieved on three sampling dates and only within the top four feet of lake depth. Since the river will be restored to a shallow water condition, it is more likely to maintain these temperature ranges preferred by the shiner and provide suitable habitat for species re‐ establishment. Wildlands 2013 dissolved oxygen (DO) samples showed a dramatic decrease in DO concentrations in the first six feet of depth, typically dropping from 8 mg/L to 5 mg/L within the first four feet of depth. The aforementioned study by Hewitt et al. (2006) indicated the best habitat for Cape 2 Fear shiner has a DO range of 5.8 – 12.5 mg/L. Restoration of a shallow free‐flowing river will improve habitat conditions within the vicinity of the impounded reach by increasing DO levels and eliminating the drastic stratification existing in the impoundment. Natural sediment transport processes will be restored through removal of the Hoosier Dam. As discussed in the section above, reintroduction of a natural sediment regime will enhance habitat located in the impoundment by flushing fines and removing the sediment wedge, but it will also allow gravels and cobbles that have been trapped behind the dam to coarsen downstream riffles located in the Critical Habitat Area that have been previously starved of sediment. Pebble Counts conducted above and below the impoundment show that riffles below the dam have smaller amounts of coarse gravel and small cobbles, confirming the effect of an interrupted sediment regime. Additional details on sediment composition can be found in the Sediment Management Plan in Appendix C. 3. Explain why there is a high certainty that implementation of the proposed action is likely to achieve its intended restoration/recovery objective under the second Criterion for Inclusion. This explanation should rely on either a proven track record or a high level of certainty that the habitat improvements are likely to cause the desired species response. Dam removals have been performed extensively throughout the United States to remove barriers to aquatic organism passage and return impounded waters to historic lotic conditions. In North Carolina, the Carbonton Dam was removed under similar conditions and project goals to this project including benefits to Cape Fear shiner habitat. The Carbonton Dam was a run of the river hydroelectric dam facility located on the Deep River approximately nine miles west of Sanford North Carolina. The concrete buttress dam was built in 1921, averaged 27 feet in height, and had a crest of 260 feet (Restoration Systems, 2005). Similarly, the Hoosier Dam is a run of the river hydroelectric dam facility with a concrete buttress structure. Hoosier Dam was built in 1922, averages 25 feet in height, and has a crest of 235 feet. The Carbonton Dam removal was part of a NCDEQ‐Division of Mitigation Services full delivery project created to deliver mitigation credits for impacts to waters of the United States.

Load more

  90

Copy Link