Monoliths
under construction, December 1961.
Thomas E. Petermann Collection (S-2005-89-98)
Beaver Dam is not made of
solid concrete. Tunnel-like access galleries run along the length of the dam.
To make an opening in the concrete, a wood-and-plywood form was built and positioned
inside the monolith. The concrete was poured around the form and once hardened,
the form was removed.
Equipment is housed in the operator’s gallery. Below it is the
lower gallery which follows the bottom of the dam. To prevent water
seepage, the foundation
rock is pressure-grouted through holes in the gallery floor. Any seepage that
does occur flows down drain holes to a sump pump. To monitor tilt in the dam
caused by the water pressure of the reservoir, a tilt meter (a large plumb
bob) hangs in a vertical gallery and measurements are taken quarterly.
Number
of monoliths: 28 |
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