Operational Plan for the Restoration of Diadromous Fishes to the ...

(i.e., total exclusion of the target exclusion species) would require thorough and ongoing
oversight of facility operations. Based on the information and analyses presented herein, it is
apparently unrealistic to expect a TSCF to provide total exclusion of the target exclusion
species over a period of years.
While apparently successful efforts have been made to modify the existing fishpass facilities
at Howland Dam and at the West Enfield Dam to exclude upstream passage of northern
pike, it is understood that these modifications prevent upstream passage of target passage
species such as alewife and American shad. Such exclusionary measures are apparently
not consistent with the overall restoration goals for the Penobscot River watershed. In
addition, the efficacy of a TSCF for exclusion would be difficult to evaluate due to the
potential for illegal, anthropogenic introduction of target exclusion species upstream from
Howland Dam.
Based on information and analyses performed for this study, incorporating a TSCF into the
Proposed Bypass would have substantial impacts on the project objective of safe, timely
and effective fish passage at Howland Dam. Additionally, a TSCF would apparently negate
any benefits associated with the use of a nature-like fishway as the model for the Proposed
Bypass due the need to trap and sort and otherwise hinder the free movement of migrating
fishes at Howland Dam.
5 SUMMARY
The initial concept of a bypass channel on the Piscataquis River at Howland Dam was
based upon successful European installations that provide simple, high capacity, and
relatively low maintenance upstream fish passage. These European bypass channels are
intentionally used to allow upstream and downstream passage of all species and all life
stages. Inquiries have been made concerning potential means to exclude upstream passage
of target exclusion species (i.e., northern pike and black crappy) through the Proposed
Bypass and into the Piscataquis River watershed while providing safe, timely, and effective
upstream and downstream passage of native diadromous fishes.
The project team has evaluated several conceptual methods to prevent upstream passage
of the target exclusion species, and determined that a conventional basket or chamber trap
combined with manual sorting operations is the preferred procedure to attempt to achieve
the objective of total exclusion. The following comments are noted for consideration of
whether to use a trap and sort facility:
a) There is no certainty that a trap and sort facility would be 100 percent effective. A
successful combination of dam removal on the main stem of the Penobscot River and
bypass channel at Howland dam could result in the restoration of millions of diadromous fish
to the Piscataquis River watershed.
b) A TSCF does not protect against intentional placement of non-native fish in the basin.
c) A trap and sort facility would require significant operational and maintenance costs.
d) A trap and sort facility would likely interfere with all upstream fish passage.
Appendix A: Figures
Figure 1 Conceptual Parallel TSCF System Plan
Figure 2 Conceptual TSCF System Profiles
Figure 3 Conceptual Series TSCF System Plan
Figure 4 Conceptual Fish Handling in Parallel TSCF System
Figure 5 Conceptual Fish Handling in Series TSCF System
PRFP Page 279