Environmental Engineering Reference
In-Depth Information
FIGURE 3.5
Simple line drawing of valley reservoir; design is also applicable to high valley reservoir.
An upper reservoir must have a design element to deal with floods (nat-
ural inflows) and overpumping. A spillway is designed to allow overflow
waters to vacate the reservoir without damaging it. One serious failure due
to overpumping and inability to drain without damage occurred at the Taum
Sauk pumped storage project. The Federal Energy Regulatory Commission
(FERC) incident description covering the dam breach appears below.
Incident Description: Taum Sauk Pumped Storage Project (No. 2277).
On
December 14, 2005, at approximately 5:20 a.m. CST the northwest corner
of the Taum Sauk Pumped Storage Project No. 2277 upper reservoir rim
dike failed, resulting in a release of the upper reservoir. The reservoir was
reported to have drained in about one-half hour. Approximately 4,300 acre
feet of storage water released. The breach flow passed into East Fork of Black
River (the river upstream of the lower Taum Sauk Dam) through a state park
and campground area and into the lower reservoir. The Lower Taum Sauk
Dam was reported to be overtopped and did not sustain damage. Upon leav-
ing the Lower Taum Sauk Dam area, the high flows proceeded downstream
of the Black River to the town of Lesterville, Missouri, located about 3.5 miles
downstream from the lower dam. The incremental rise in the river level was
about 2 feet which remained within the banks of the river.
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On December 14, 2005, the project's upper reservoir breached, rendering
the facility inoperable. The upper reservoir overtopped when the pumps fill-
ing it failed to shut off. Erosion undercut the rock fill dam, creating a breach
that emptied the reservoir.
6
To avoid overpumping challenges, Kermit Paul
proposed the following recommendations
7
:
• PHES facilities should have a fail-safe overpumping safety design.
• This design should be independent of water level control systems, as
water level and monitoring control and overpumping protection are
separate systems.
