small.jpg)
The
spillway under construction, June 1963. Part of the embankment is seen
at right.
Bettye Mohney Collection (S-86-124-38:13)
An earthen embankment spans the gap between the concrete dam and the sloping countryside around it. To build the embankment a keyway was blasted into the bedrock. Then a cutoff wall made of impervious (non-porous) clay was built to resist water seepage from the lake. Pervious (porous) rock from White River gravel bars was piled against the clay core to equalize water pressure.
Rock-and-earth fill material forms the massive sloping sides of the embankment. Fill came from the dam excavation itself and from several nearby pits, some of which contained human graves that first had to be relocated by the Corps of Engineers before the fill could be removed. Riprap (large rocks) was placed on top of the embankment’s slopes to control erosion.
Length
of embankment: 1,242 feet |
|