Oral Presentation International Conference on River Connectivity (Fish Passage 2018)

Monitoring PIT-Tag Passage Through Steel Fish Bypass Baffle at Wells Dam, USA. (#116)

Steve Anglea 1 , Tom Kahler 2
  1. Biomark, Inc., Boise, ID, United States
  2. Biological Monitoring, Douglas County PUD, East Wenatchee, WA, US

Douglas County Public Utility District (DCPUD) owns and operates Wells Dam on the Columbia River, Washington, USA. The Wells project has ten generating units rated at a combined 840 megawatts. Eleven gated spillway openings can pass a flood of over 33,311 m3/s. The hydrocombine structure is 355 m in length and the dam is 1,360 m long overall. ​The unique hydrocombine design incorporates the powerhouse, spillway, switchyard and fish facilities into one unit instead of separate structures. The Wells Dam juvenile bypass system comprises modifications to 5 of the 11 spillways to enhance bypass efficiency. Each bypass bay utilizes a baffle structure consisting of 64 approximately 1.2 m x 1.2 m openings arranged in 4 columns of 16 openings. 

DCPUD installed a juvenile PIT-tag detection system at Wells Dam in 2016 and 2017 to determine compliance with FERC-license obligations. Detections at Wells Dam are used to determine travel time between Wells Dam and Rocky Reach Dam, the next dam downstream, and those data are used to calculate passage date at Wells Dam for the thousands of fish detected at Rocky Reach Dam but not at Wells Dam.

DCPUD worked with Biomark to design and install a PIT-tag array in a subset of the Spill Bay 2 bypass baffle openings. Biomark used thin-wall shielded antennas to minimize the amount of flow constriction and allow placement within the steel structure. Each antenna is connected to a Biomark IS1001 reader housed in a submersible enclosure and mounted to the downstream side of the bypass baffle. The 16-IS1001s are connected to a pair of Biomark IS1001-Master Controllers. Power to the IS1001-MCs is provided using an isolation transformer. All diagnostic and tag-detection data is transmitted to a data-collection computer through a fiber optic cable and then to Biomark’s BioLogic web portal.