ff» NORMANDEAU City of Nashua
BARA ASSOCIATES june 18, 2019
ENVIRONMENTAL a eG age
ENVIRONMENTAL CONSULTANTS
Schedule and Estimated Cost: The adult herring passage evaluation should occur during the spring period
(i.e., May-July) when the Project is operating under normal conditions (i-e., no unit outages, etc.). We propose
this study be conducted during the spring of 2020. Three study approaches were described above which vary
based on the numbers of fish to be tagged and released. These three approaches vary in responsiveness to the
study objectives provided by the resource agencies. The estimated costs for each level effort as described here
is $79,056.50 (full), $64,665.00 (reduced), and $44,632.00 (minimum).
Study: Impact of Project Operations on Downstream Migration of Juvenile Alosines
Requestor: NHFGD
Requestor Goal & Objectives:
e Assess project operation effects of the Mine Falls dam on the timing, orientation, passage routes,
migration rates, and survival of juvenile alewife.
e Determine the proportion of juvenile alewife that select the turbine intakes, downstream bypass or
spill as a passage route;
e Determined if there are delays associated with downstream movement.
Agency Recommended Approach:
e Evaluate turbine passage mortality for juvenile herring using the turbines, downstream bypass and
spillway with the HI-Z balloon tag methodology.
e Evaluate downstream herring passage route selection and potential delay using radio telemetry
Suggested Approach:
e Push back on conducting a HI-Z balloon tag study. Downstream passage survival for juvenile alosines
will be considered as part of the Desktop Impingement/Entrainment Survivability Assessment.
e Approach 1 - Radio-telemetry Study:
o Will provide proportional route usage by juvenile herring at the project as well as estimates on
the duration of residence time spent above the dam prior to passage (i.e., “delay”).
© Collect an adequate number of appropriately sized juvenile herring from a location within the
Merrimack River watershed — we have assumed this can be completed in a period of four
evenings.
o Radio-tag a total of 100 juvenile herring and release upstream of Mine Falls to evaluate
downstream passage.
o Assumes installation and maintenance of approximately 7 radio telemetry receivers for period
September-November.
© Approach 2 - PIT-telemetry Study:
o Will provide an estimate of downstream bypass usage by juvenile herring at the project as well
as ability to infer proportion of fish which have entered the power canal and are entrained at
the turbines.
o Will not inform on passage outside of power canal routes (i.e., bypass or turbines) nor will it
provide any estimates on the duration of residence time spent above the dam prior to passage
(i-e., “delay”).
