Lake Red Rock Pool Drawdown This Fall

ROCK ISLAND,Ill. - In an ongoing effort to maintain a safe dam and conservation pool, a 10-

foot pool drawdown to perform repairs and maintenance to Lake Red Rock's tainter gates and

cables will occur this fall, beginning Tuesday, Sept. 4, following Labor Day.

The current elevation of the conservation pool, 742 feetNational Geodetic Vertical Datum,

permanently submerges the tainter gates' cables and brackets. Dewatering the tainter gate bays is

necessary for repairs and replacement of the cables and associated equipment. Conservation

pool is a term that refers to the minimum water level normally kept in the reservoir. The

conservation pool varies through the year.

The fall drawdown will decreaser ecreational opporfunities in the areat hrough diminished sites or

access for wildlife observation, waterfowl hunting, and fishing. Preliminary analysis has

determined that the lake will be accessible by boat ramp at elevation 732 feetNGVD. However,

some ramp options may be limited by siltation, water depth, and boat draft. Availability of the

boat ramps for public use will be reassessedp rior to, and during, the drawdown.

An Environmental Assessment with a Finding of No Significant Impact was completed in

February 2005. The assessmenet valuatedt he impacts associatedw ith the proposedd rawdown

and replacement of the tainter gate lifting cables, as well as periodic inspection and maintenance

of the dam. The Environmental Assessment is available on the Internet at:

http://www2.mw.usace.army.mil/Documents/EAlRedRocllTainterGateCable/. At the request of

the Iowa Department of Natural Resources, the Corps evaluated and coordinateda2T-day

extension of the original drawdown period, from 48 to 75 days. No objections to this extension

were received.

During the drawdown, the Iowa Department of Natural Resources will be placing material to

create fish habitat at several locations, and there will be work on a new boat ramp, access road,

and canoe launch at Elk Rock State Park. The Corps of Engineers will be doing minor repair

work around the lake.

The lake will be lowered 0.5 feet per day, requiring approximately 20 days to complete the 10-

foot drawdown. When repairs and construction activities are completed in mid-December, the

pool will be raised as quickly as possible, while maintaining outflows of at least 300 cubic-feef

per-second. The total time for the drawdown, associatedw ork, and reservoir refilling is

approximately five months, although rainfall and snow amounts will greatly affect the total time

to refill the lake. There must be at least 300 cubic-feet-per-secondo utflows to minimize impacts

to communities downstream of the reservoir.

For more information, please contact Frank Monfeli, the project manager, at 309-794-5640 or by

e-mail at [log in to unmask]. You may also contact Sherri Richardson-Duey, at

Lake Red Rock, at 64l-828-7522 or by e-mail at [log in to unmask].