Northampton_10-27790_NPC_SedimentMvmt.pdf
September 26, 2018
Matthew A. Beaton, Secretary
Executive Office of Energy and Environmental Affairs
Attention: MEPA Office
Purvi Patel
100 Cambridge Street
Boston, Massachusetts 02114
Project Name: Paradise Pond Sediment Management Protocol
Proponent: The Trustees of Smith College
Location: Paradise Pond, an impoundment of the Mill River
Document Reviewed: Notice of Project Change
EEA Number: 15282
NHESP Tracking No.: 10-27790
Dear Secretary Beaton:
The Natural Heritage & Endangered Species Program and Fisheries Program of the Massachusetts Division
of Fisheries & Wildlife (the Division) have reviewed the Notice of Project Change for the Paradise Pond
Sediment Management Protocol (the Project) and would like to offer the following comments.
The Mill River and Diversion of the River between the Paradise Pond impoundment to the confluence with
the Connecticut River is within mapped Priority & Estimated Habitat of the following state-listed species:
Taxonomic Group Scientific Name Common Name State-Status
Invertebrate Animal: Damselfly Boyeria grafiana Ocellated Darner Special Concern
Invertebrate Animal: Dragonfly Gomphus ventricosus Skillet Clubtail Threatened
Invertebrate Animal: Mussel Alasmidonta heterodon Dwarf Wedgemussel* Endangered*
Invertebrate Animal: Mussel Lampsilis cariosa Yellow Lampmussel Endangered
Invertebrate Animal: Mussel Ligumia nasuta Eastern Pondmussel Special Concern
Invertebrate Animal: Mussel Strophitus undulatus Creeper Special Concern
Vertebrate Animal: Turtle Glyptemys insculpta Wood Turtle Special Concern
These species and their habitats are protected pursuant to the implementing regulations of the MESA (321
CMR 10.00) and the rare species provisions of the WPA. Fact sheets for most state-listed species can be
found at www.mass.gov/nhesp. *The Dwarf Wedgemussel is also listed pursuant to the federal Endangered
Species Act (50 CFR 17.11), which is administered by the United States Fish & Wildlife Service (USFWS).
Over the last several years, the Proponents have conducted a series of experimental impoundment
releases to develop an adaptive management plan for Paradise Pond. The goal was to determine if using
NHESP No. 10-27790, NPC Paradise Pond, page 2 of 2
the low-level outlet to release impounded sediments during higher flow events would both maintain
sufficient depth for the College’s recreation and education needs (a minimum water depth of 3 feet below
the spillway elevation) while not harm (and hopefully improve) downstream habitats. Post management
monitoring results found that only using the low-level outlet would not mobilize sufficient sediment from
the impoundment to be self-sustaining to meet the recreational goals. The Proponents have therefore
modified the adaptive management plan to include the use of a conventional drawdown to allow for
mechanical redistribution of sediments into the “active” channel of the impoundment, which is located
around the north end of the impoundment. The riverine sediments moved into the “active” channel will
them be mobilized out of the low-level outlet during natural high-flow events. The project would conduct a
drawdown to facilitate the mechanical re-distribution of the sediment, which may occur annually. The
Proponents have also reduced the target water depth to 2 feet from the initial 3 feet. The results of the
past studies suggest that a balance in the interests can be found, with some potential benefits to the
overall River habitat below the Smith College Dam.
Based on the data collected to date by the Proponents, we anticipate requiring conditions as to the timing
and frequency of the drawdown, limits to the amount of suspended sediments during high-flow event to
avoid smothering downstream mussels, and ongoing monitoring. We are confident that outstanding
details can be resolved during the MESA review process. We will continue to consult with the Proponent
during the MESA review process to develop conditions to avoid impacts to state-listed species.
The Division will not render a final decision regarding the MESA until the MEPA review process and its
associated public comment period is complete, and until all required application materials have been
submitted to the Division. As the MESA review process has not formally initiated, no alteration to the soil,
surface, or vegetation associated with the Project shall occur until the Division has made a final decision
pursuant to 321 CMR 10.14 and 321 CMR 10.18.
Sincerely,
Thomas W. French, Ph.D.
Assistant Director
cc: Briscoe Lang, Pare Corporation
David Foulis, MA DEP Western Regional Office, Wetlands
Paul Sneeringer, US Army Corps of Engineers
Sarah LaValley, Northampton Conservation Commission