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HomeMy WebLinkAbout20100904 Ver 1_More Info Received_20110120Mcmillan, Ian From: Goudreau, Chris J. Sent: Thursday, January 20, 2011 9:56 AM To: McRacken Jr., James Cc: Hugh Barwick; Mcmillan, Ian; Besler, Doug A.; Wood, Chris J.; Rash, Jacob M. Subject: RE: Fish Monitoring Plan Linville Dam ESSI_Final Draft 1_17_10 Attachments: 2011-01-17 Fish Monitoring Plan - final draft - wrc comments.doc James, I talked with Hugh this morning about the plan. He agreed that some text about consultation should be explicitly included. Also, with stream flows in the area consistently running below 30%, weekly monitoring of the Calvin gage will not be sufficient to document maintenance of the target flows. I've altered that section giving two options -data loggers or daily visual readings. If the edits are acceptable, we are good with the plan. If not, we should talk again with you and Hugh. Thanks, Chris From: McRacken Jr., James [mailto:James.McRacken(a)hdrinc.com] Sent: Monday, January 17, 2011 12:49 PM To: Goudreau, Chris J. Subject: Fish Monitoring Plan Linville Dam ESSI_Final Draft 1_1710 Chris, Here is the draft monitoring plan again for the Linville ESSI tie-in. It has been edited by Hugh Barwick per your conversation with him. Please review and comment if necessary. Thanks James McRacken Senior Scientist/Terrestrial Lead HDR I DTA 400 South Tryon, Suite 2401 1 Charlotte, NCI 28285 Office: 704.377.4182 1 Direct: 704.342.7373 Fax: 704.377.4185 A, Before printing, please consider the environment Email correspondence to and from this sender is subject to the N.C. Public Records Law and may be disclosed to third parties. LINVILLE DAM EMBANKMENT SEISMIC STABILITY IMPROVEMENT PROJECT FERC NO. 2232 Draft Bridgewater Powerhouse Penstock Tie-In Temporary Fish Relocation and Water Quality and Water Quantity Monitoring Plan Prepared for: DUKE ENERGY CAROLINAS, LLC Charlotte, North Carolina Prepared by: HDR ENGINEERING, INC. OF THE CAROLINAS Charlotte, North Carolina JANUARY 2011 f ?Z DT1 LINVILLE DAM EMBANKMENT SEISMIC STABILITY IMPROVEMENT PROJECT FERC NO. 2232 TABLE OF CONTENTS Section Title Pau No TIE- IN PLAN .................................................................................................. 1 PLAN COMPONENTS ........................................................................................ 2 2.1 Notification ..............................................................................................................2 2.2 Initial Shutoff Monitoring .........................................................................................2 2.3 Water Quality and Quantity Monitoring ....................................................................3 Section 1 Draft Bridgewater Powerhouse Penstock Tie-In Temporary Fish Relocation and Water Quality and Water Quantity Monitoring Plan As part of the Linville Dam Embankment Seismic Stability Improvement (ESSI) Project, a task has to be completed prior to the placement of fill in association with the construction of the stabilization berm. This task is the tying in of the existing Bridgewater hydro-penstock to the penstock of the new Bridgewater powerhouse. The penstock is the pipe that carries water from Lake James to the turbines inside the powerhouse. Due to this tying in of the penstock, two outages (spring and late summer/early fall) of the hydroelectric plant are necessary. These outages will result in a shutoff' of water coming out of the existing Bridgewater power plant, from either generation or seepage. These temporary outages will result in approximately 4,846 linear feet (0.92 miles) of the Linville River Reach (Reach), upstream of the confluence of Muddy Creek/Catawba River channel, being shut off from hydropower flows. The only flows into the Reach will be from potential dam seepage and small tributaries along the Reach. These outages are authorized by the North Carolina Division of Water Quality's, 401 Water Quality Certification (Project # 20100904) dated October 27, 2010, and the U.S. Army Corps of Engineers (USACE) Action ID No. SAW-2008-2753 dated November 23, 2010. As part of the 401/404 permit conditions, Duke Energy Carolinas, LLC (Duke Energy) is to provide a Temporary Fish Relocation and Water Quality Monitoring Plan for North Carolina Wildlife Resource Commission's (NCWRC) approval in order to provide best management practices (BMP) to minimize the low flow and water quality impacts on downstream r anisms especially fish. This plan will provide BMP components such as agency notification, initial shutoff tasks and downstream outage monitoring. Section 2 Draft Temporary Fish Relocation and Water Quality and Water Quantity Monitoring Plan Components The Temporary Fish Relocation and Water Quality and Water Quantity Monitoring Plan for the Linville Dam ESSI Project consists of the following components: 2.1 Notification During the outage planning process, Duke Energy representatives will stay in contact with NCWRC staff to advise the agency of when the potential outages will occur so the NCWRC can suspend their stocking efforts on the hatchery supported waters in the Reach just below the powerhouse and, if necessary, notify the public of the impacts to fishing in the downstream Linville and Catawba rivers. Duke Energy representatives will notify the NCWRC at least 30 days in advance of the outages. Prior to the outages, landowners adjacent to the Reach will be contacted by Duke Energy representatives, if necessary, to gain access to the banks of the Linville River Reach to enable the necessary equipment and personnel to work closer to the river during the outages. 2.2 Initial Shutoff Monitoring At the start of each of the two outages, Duke Energy will decrease flows in the Reach by stepping down the amount of seepage/leakage from the powerhouse over an approximately 16- hour time period. This will be completed by not generating for at least 8 hours which will provide the Reach with normal minimum flows. The turbines in the existing powerhouse will then be isolated from the penstock and the intake on the lake side will be closed. Once closed, an 8- or 10-inch valve will be opened to allow the penstock to drain. This draining of the penstock should take approximately 16 hours to complete. This step-down in flows is designed to allow fish in the Reach to relocate downstream as the water level subsides. Beginning the morning after penstock draining and for two consecutive days following thereafter during each outage, crews will walk the length of the Reach to locate any fish that have become stranded and remove them with dip nets, backpack electro shockers, and seines. Fish will be placed in buckets or tanks and moved downstream of the Muddy Creek confluence. All collected fish that are relocated will be enumerated by species and their range in total length estimated. In addition, on 2 the first two consecutive days following penstock draining, crews will check that-the reach of the Catawba River from the confluence of Muddy Creek to the next downstream bridge for any stressed or dead fish. If stressed or dead fish are noted, the Asheville Regional office of the NCDWQ and the local NCWRC office will be notified immediately to determine what action should be taken. Photographs of the Reach will be taken during the relocation period to document low flow conditions in the area during each of the outages. 2.3 Water Quality and Quantity Monitoring Once the penstock is drained for each outage, there are several monitoring tasks that have to be completed within and downstream of the outage Reach. These tasks include water temperature, dissolved oxygen, and flow volume monitoring. An explanation of each of the tasks is provided below. During the duration of each outage, water temperature in the Reach and below the confluence of Muddy Creek/Catawba River will be monitored using continuous instream data loggers to assess the potential for stress on aquatic organisms. Data loggers will be installed just below the first bridge downstream of the powerhouse, just downstream of the Muddy Creek confluence, and on both sides of the river near the first downstream bridge below the Muddy Creek confluence. The data loggers will be read once a week and the data forwarded by email weekly (within the first two days of the following week) to the assigned NCWRC and NCDWQ personnel every week during the outage. If the temperatures become a concern, the NCWRC will consult with Duke Enemy and NCDWO to discuss options to minimize impacts to aquatic organisms. Dissolved oxygen will be monitored weekly using an oxygen meter at the same locations as temperature. immediately. Theis flow data will also be reported weekly along with the temperature data to the NCWRC and NCDWQ personnel. If dissolved oxygen concentrations fall below 6 mg/l or saturation levels for the observed temperatures, Duke Energy will notify the NCWRC and NCDWO immediately to discuss options to minimize impacts to aquatic organisms. For the duration of the outages, flow volumes at least equal to the 30'h percentile of the flow measured at the former Calvin USGS gage on the Catawba River near Morganton, North Carolina will be sustained. The monthly flows for the 30'h percentile flows of the Calvin gage are noted below in Table 1. The flows at the Calvin gage will be monitored daily) by visually reading the USGS staff gage and determining the flow from the USGS rating curve 6ti8?& ?YC?? Comment [CG2]: This frequency is insufficient. Long periods of low water may occur between by utilizing Femaining staff gage and a disrhafge eur-ve eFeated fi--em past data. Alternatively, a weekly measurements. The inflows to the lake (Catawba at Pleasant Gardens gage) gives us a continuous instream data logger can be placed at the Calvin gage site to record flows on an good idea to what we are likely to experience over the next few months. Since early December 2010, hourly basis with the data downloaded weekly. Theis flow data will also be reported weekly that gage has consistently been in the 20-25% range. along with the temperature and DO data to the NCWRC and NCDWQ personnel. If necessary, Duke Energy will supplement the flows into the Catawba River by utilizing the newly installed minimum flow valve installed within the Catawba Dam Spillway. The amount of water released from the valve will be adjusted weekly depending upon the measurements at the Calvin gage. TABLE 1. 30'-H PERCENTILE FLOWS AT THE USGS CALVIN GAGE March April May June July Aug Sept Oct 159 cfs 154 cfs 120 cfs 100 cfs 96 cfs 78 cfs 90 cfs 87 cfs cfs = cubic feet per second At the conclusion of the each outage, the NCWRC will be notified when the water to the Reach will be restored. A final report detailing the number of fish relocated by species, the number of dead fish fieted-observed by species (including numbers of crayfish and mussels), and the observed water quality measurements collected during the outages will be compiled and reported to the NCWRC and NCDWQ.