SACRAMENTO,
Calif. – The U.S. Army Corps of Engineers and its contractor
Kiewit Co. are moving forward with the next milestone at the Folsom Dam auxiliary
spillway project in Folsom, California, by placing water against the auxiliary spillway
control structure.
The
process, known as impoundment, is expected to begin Wednesday morning and will
continue until lake water reaches equal elevation on both sides of the
temporary construction cofferdam, which is expected to take about 24 hours.
Eight
pumps will push water from the reservoir into the approach channel and against
the control structure through two 24-inch pipes, each capable of pumping up to
16,000 gallons per minute.
This first fill against the auxiliary spillway
control structure is a significant milestone for the project, indicating the
auxiliary spillway is much closer to becoming operational.
Kiewit
reinforced the temporary construction cofferdam last week following the
discovery of a leak that partially filled the approach channel construction
area. Stabilizing the leak allowed crews to safely remove construction machinery
and materials that were abandoned upon discovery of increased seepage. The
Corps and Kiewit continue to constantly monitor the temporary construction
cofferdam to ensure personnel safety.
The temporary construction cofferdam was put in
place to help conduct construction activities under dry conditions rather than
in-the-wet. Removal of the temporary structure was expected to occur by Feb. 8,
2016; however, it was decided to begin the impoundment process and remove it
sooner.
The auxiliary spillway project,
or Joint Federal Project, is being constructed in partnership with the U.S.
Bureau of Reclamation under the Corps’ Folsom Dam Modification Project, to
implement dam safety and flood risk reduction features at Folsom Dam and
associated facilities to help prevent catastrophic flooding in the Sacramento
region. The auxiliary spillway is on track for completion, within budget, in October
2017.
Release no. 16-004