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LAKE RED ROCK DRAWDOWN POSTPONED
SECOND TIME
Based upon flood of 2008
recovery efforts, the Red Rock drawdown scheduled for the fall of 2008
will again be postponed. Efforts by the Corps of Engineers, Rock Island
District, will be focused on analysis and repair of 2008 flood impacts.
The Lake Red Rock drawdown, and associated work, was initially scheduled
for fall 2007 and had been postponed until fall 2008 due to 2007 fall
flooding events. The primary purpose of the drawdown is to replace
the cables on the dam Tainter gates. Several cables failed during the
flood of 1993. The cables were then put on a 15-year replacement schedule.
At the current elevation of Lake Red Rock's conservation pool (742 mean
sea level), the tainter gate cable connection brackets are permanently
submerged. The drawdown will allow access to the cable connection brackets.
When the drawdown process is able to be rescheduled, the reservoir will
be lowered 0.5 feet per day from elevation 742 mean sea level, requiring
approximately twenty days to complete the ten-foot drawdown. The reservoir
will be held at elevation 732 mean sea level for a maximum of 75 days
and then raised as quickly as possible while maintaining outflows of
at least 300 cubic feet per second. The cables will be replaced with
Corps of Engineers labor. Other work to be performed during the drawdown
includes placement of fish habitat structure and completion of a four-lane
boat ramp. Both of these projects are sponsored by the Iowa Department
of Natural Resources. An environmental assessment of the drawdown, with
finding of no significant impact, was completed in February 2005.
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Drawdown Map
(Click on map for
printable version) |
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Drawdown Map
- Back Side
(Click on map for
printable version)
*Note: Drawdown
date/year on map is incorrect - map was created for drawdown's
initial scheduled year of 2007. |
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