upstream and downstream passage of american eels at the medway project, penobscot river, maine scott...
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Upstream and Downstream PassageUpstream and Downstream Passageof American Eels at theof American Eels at the
Medway Project, Penobscot River, MaineMedway Project, Penobscot River, Maine
Scott HallScott Hall——————————————————————————
PPL Maine, LLCPPL Maine, LLC
Milford, MaineMilford, Maine
Steve ShepardSteve Shepard————————————————————————————
Aquatic Science Associates, Inc.Aquatic Science Associates, Inc.
Brewer, MaineBrewer, Maine
FERC Fish Passage Workshop, 13 Nov. 2003, Holden, Mass.
Medway ProjectMedway Project
Located in Medway at the mouth of the West Located in Medway at the mouth of the West Branch, Penobscot River.Branch, Penobscot River.
Fifth dam on river at ~ 60 miles from the mouth.Fifth dam on river at ~ 60 miles from the mouth.
3.4 MW capacity at 19 ft. of head.3.4 MW capacity at 19 ft. of head. 3,450 cfs maximum hydraulic capacity.3,450 cfs maximum hydraulic capacity. Uses 2,000 cfs minimum flow from the West Uses 2,000 cfs minimum flow from the West
Branch Project (Great Lakes Energy).Branch Project (Great Lakes Energy). No anadromous fish passage to West Branch.No anadromous fish passage to West Branch. New license granted in 1999.New license granted in 1999.
General Plan View of Medway Dam
Downstream BypassDownstream Bypass
Bypass is located at the end of the spillway, Bypass is located at the end of the spillway, adjacent to the forebayadjacent to the forebay
Uses existing gate and stop logs in the top Uses existing gate and stop logs in the top half of the water columnhalf of the water column
15 cfs bypass flow15 cfs bypass flow Six foot deep weir openingSix foot deep weir opening Bell mouth weir shape to provide a velocity Bell mouth weir shape to provide a velocity
transitiontransition
Downstream Passage EvaluationsDownstream Passage Evaluations
Video monitoring conducted in 2002Video monitoring conducted in 2002
Video and trapping in 2003Video and trapping in 2003
Downstream Passage EvaluationsDownstream Passage Evaluations
Video monitoring conducted in 2002Video monitoring conducted in 2002– Reflective background usedReflective background used– Infrared lighting and supplemental red lightInfrared lighting and supplemental red light– Tested with drogues Tested with drogues – Real-time recording in six hour blocksReal-time recording in six hour blocks– Monitored from August through mid-NovemberMonitored from August through mid-November
Downstream Passage EvaluationsDownstream Passage Evaluations
Video monitoring conducted in 2002Video monitoring conducted in 2002– Reflective background used.Reflective background used.
– Infrared lighting and supplemental red light.Infrared lighting and supplemental red light.
– Tested with drogues.Tested with drogues.
– Real-time recording in six hour blocks.Real-time recording in six hour blocks.
– Monitored from August through mid-November.Monitored from August through mid-November.
Video and trapping in 2003Video and trapping in 2003– Paired video & trapping to assess video Paired video & trapping to assess video
effectiveness.effectiveness.– An historic weir fishery indicated run timing in An historic weir fishery indicated run timing in
August and September.August and September.
Trapping Set-Trapping Set-Up in 2003Up in 2003
Downstream Results Summary Downstream Results Summary (preliminary)(preliminary)
Video monitoring was not effective. – Optimal lighting is very difficult.
– Turbulence obscures parts of the field of view.
– Rapid passage is the major problem.
Downstream Results Summary Downstream Results Summary (preliminary)(preliminary)
Video monitoring was not effective.
– Optimal lighting is very difficult.
– Turbulence obscures parts of the field of view.
– Rapid passage is the major problem.
Trapping was an effective monitoring method.
– Debris and high tailwater caused some problems.
– Only a few days were trapped in 2003.
Downstream Results Summary Downstream Results Summary (preliminary)(preliminary)
Video monitoring was not effective.
– Optimal lighting is very difficult.
– Turbulence obscures parts of the field of view.
– Rapid passage is the major problem.
Trapping was an effective monitoring method.
– Debris and high tailwater caused problems.
– Very few days were trapped in 2003.
Downstream migrants are using the bypass.
Typical eels trapped in 2003Typical eels trapped in 2003
Upstream Passage Upstream Passage EvaluationEvaluation
GoalsGoals– Determine run timing.Determine run timing.– Document typical size of migrant eels.Document typical size of migrant eels.– Assess migratory behavior with respect Assess migratory behavior with respect
to physical features of the dam.to physical features of the dam.– Design an upstream fishway and Design an upstream fishway and
operating plan for the site.operating plan for the site.
MethodsMethods– Night observations.Night observations.– Trapping.Trapping.
Upstream Passage Study AreaUpstream Passage Study Area
0
5
10
15
20
25
Fre
qu
en
cy
<5 6 8
10
12
14
16
+
Size Category (inches)
2002 Size Distribution of Migrant 2002 Size Distribution of Migrant EelsEels
Seasonal Timing of Medway Eel MigrationSeasonal Timing of Medway Eel Migration
0
200
400
600
800
29-May 8-Jun 18-Jun 28-Jun 8-Jul 18-Jul 28-Jul
Ee
l A
bu
nd
an
ce
2002
2001
Upstream Passage SummaryUpstream Passage Summary
Nearly all migrant eels were associated Nearly all migrant eels were associated with “staging” locations.with “staging” locations.
Several sizes/ages of eels are active at Medway.Several sizes/ages of eels are active at Medway.
Only the smallest eels are currently able to climb wetted Only the smallest eels are currently able to climb wetted surfaces and pass the dam.surfaces and pass the dam.
Very small amounts of spill inhibit passage over wetted Very small amounts of spill inhibit passage over wetted surfaces.surfaces.
There were no obvious effects from ambient light.There were no obvious effects from ambient light.
Migratory activity was not observed until early to mid-June Migratory activity was not observed until early to mid-June
at temperatures above 18 Celsius.at temperatures above 18 Celsius.
Upstream Passage Study AreaUpstream Passage Study Area
Upstream Passage SummaryUpstream Passage Summary
Nearly all migrant eels were associated with “staging” Nearly all migrant eels were associated with “staging” locations.locations.
Several sizes/ages of eels are active at Several sizes/ages of eels are active at Medway.Medway.
Only the smallest eels are currently able to climb wetted Only the smallest eels are currently able to climb wetted surfaces and pass the dam.surfaces and pass the dam.
Very small amounts of spill inhibit passage over wetted Very small amounts of spill inhibit passage over wetted surfaces.surfaces.
There were no obvious effects from ambient light.There were no obvious effects from ambient light.
Migratory activity was not observed until early to mid-June Migratory activity was not observed until early to mid-June
at temperatures above 18 Celsius.at temperatures above 18 Celsius.
Upstream Passage SummaryUpstream Passage Summary
Nearly all migrant eels were associated with “staging” Nearly all migrant eels were associated with “staging” locations.locations.
Several sizes/ages of eels are active at Medway.Several sizes/ages of eels are active at Medway.
Only the smallest eels are currently able to Only the smallest eels are currently able to climb wetted surfaces and pass the dam.climb wetted surfaces and pass the dam.
Very small amounts of spill inhibit Very small amounts of spill inhibit passage over wetted surfaces.passage over wetted surfaces.
There were no obvious effects from ambient light.There were no obvious effects from ambient light.
Migratory activity was not observed until early to mid-June Migratory activity was not observed until early to mid-June
at temperatures above 18 Celsius.at temperatures above 18 Celsius.
Upstream Passage SummaryUpstream Passage Summary
Nearly all migrant eels were associated with “staging” Nearly all migrant eels were associated with “staging” locations.locations.
Several sizes/ages of eels are active at Medway.Several sizes/ages of eels are active at Medway.
Only the smallest eels are currently able to climb wetted Only the smallest eels are currently able to climb wetted surfaces and pass the dam.surfaces and pass the dam.
Very small amounts of spill inhibit passage over wetted Very small amounts of spill inhibit passage over wetted surfaces.surfaces.
There were no obvious effects from ambient light.There were no obvious effects from ambient light.
Migratory activity was not observed until early to Migratory activity was not observed until early to mid-June at temperatures above 18 Celsius.mid-June at temperatures above 18 Celsius.