In attendance: Gene Benson, Bill Eykamp, Cathy
Garnett, Jane Howard, Elizabeth Karpati, Ann LeRoyer, Chris Loret, Leslie
Mayer, Oakes Plimpton, John Sanchez (DPW), Sharon Stafford, Nathaniel Stevens,
David White; Mark Mitch (Weston & Sampson), Roberto Scalese (Arlington
Advocate). The meeting was facilitated by Gene Benson. The minutes are
by Elizabeth Karpati.
Next meetings: February 25 at 6:30 p.m. (2), March 22 (2),
April 27 (1), May 25 (1), June 29 (2).
All except Feb. 25 at 7:30 p.m., Town Hall Annex in conference room
Report on the Dam Plans
Mark Mitch reported on the status of plans for the dam:
He consulted 8 agencies (FEMA, Corps of
Engineers, etc) and university researchers; all opposed trees on an
But an alternative to removing the
trees turned up in Minnesota: there a much bigger earthen dam was made
safe by an “I-wall” of linked steel plates driven vertically into the dam
and topped by a concrete cap.
The state Office of Dam Safety seems
receptive to the I-wall solution and has already agreed to having the dam work
designed to withstand a 500-year storm rather than the “1/2 PMF” storm
(8” rather than 18” of rain in a 24-hour period).
The cost of installing an I-wall is
estimated to be no more and possibly a bit less than the original plan of
removing the trees. (The capital plan – just a plan – now shows $2.3
million for the dam.)
A few trees could be lost to damage
from the installation work or having their roots cut by the I-wall, but most
of the trees, and therefore the appearance and habitat value of the Res, would
The top of the concrete cap would be at
elevation 163; the water level in the Res is 158 in the swimming season,
153 in the off-season.
The concrete cap would be level with
the ground, and the wall would be off-center, closer to the water rather than
in the middle of the path on the dam, so if erosion exposes a bit of the cap,
it would not be a tripping hazard.
The width of the emergency spillway
would still need to be increased by about 50 feet. Mr. Mitch suggests
doing this by adding a second spillway on the downstream side of the bridge
from Hurd Field. The committee agreed to this location. (The Hurd Field
bridge is in bad shape: Mr. Sanchez will look into possibilities for
repairing or replacing it.)
The I-wall solution minimizes
disruption and therefore the need for landscaping after the work is done. The
plan should include leveling the stump dump, though, so that the area of the
present dump could be planted. Jim Marzilli is organizing volunteers to
plant and maintain open spaces in town. Cathy Garnett is a landscape
architect and will look into landscaping issues for the stump dump.
Mark Mitch will start work on the final
design and hopes to have fairly detailed drawings by the end of March.
The lower-level outlet will need
repairs before this summer.
A lot of permits will be needed for the
dam work. The Reservoir Committee can offer citizen support at permit
Lexington authorities will need to be
Arlington will need to submit an ENF to
MEPA. The ENF will have to be open to public review (but an EIR will
probably not need be required).
We need to have a public meeting on the
plans, preferably before going to the Con Com and before Town Meeting –
possibly the week of April 19. Mr. Mitch and Mr. Sanchez to suggest timing.
Mr. Mitch hopes to be ready to put the
project out to bid in late August and to have construction start in October or
November. Installing the I-wall would take a couple of months. If
construction is delayed into next year, it should not take place when it would
disrupt the breeding season for birds. It would not interfere with
swimming but construction vehicles could take up space in the parking lot.
Publicity: Mr. Scalese is
reporting for the Advocate. Leslie and Gene will draft a follow-up