US Army Corps of Engineers
St. Paul District

Projects

Pokegama Dam Slurry Trench Project, Grand Rapids, Minn.

Updated March 2018
Published March 16, 2017

Description

Pokegama Dam and Recreation Area is one of six recreation areas included in the Headwaters Lakes Project. Pokegama Dam is located on the Mississippi River, in Itasca County, approximately three miles upstream of the city of Grand Rapids, MN. The reservoir is operated for flood damage reduction, recreation, fish and wildlife conservation and water quality. 

Background

Pokegama Dam was constructed in 1884.  The main embankment was constructed with a pervious rock and clay-filled timber structure core and covered with sandy material.  In 1941, a sheet pile wall was installed upstream of the timber core to minimize unwanted seepage (flow) through the embankment.  The existing sheet pile wall has been effective at controlling seepage, but its overall condition is currently in question.  Without an effective seepage barrier, the water levels could rise throughout the embankment causing downstream slope instability, which would threaten the integrity of the dam.  

Purpose

An existing sheet pile wall has been in place to control unwanted seepage through the Pokegama Dam main embankment, but its current condition is in question.  A cement-bentonite slurry wall will be installed upstream of the existing sheet pile wall to provide additional seepage control measures.

Status

If funded, the U.S. Army Corps of Engineers team will perform a design charrette focusing on a design concept with cost estimate for a comprehensive solution to the site. When additional funding is available, the plans and specifications will be completed and a contract for construction awarded.

Authority

The project was authorized by the Rivers and Harbors Act of 1880 for the purpose of forming reservoirs and to provide supplemental water during periods of low flow.

Fiscal

Design Charrette                                    $50,000
In-house design/oversight costs           $300,000