DN 24-02                                            DREDGING NOTICE

                                              U.S. ARMY CORPS OF ENGINEERS

                                                            ST. PAUL DISTRICT

NOTICE DATE: April 23^rd, 2024                              DREDGING CATEGORY: Routine

MEETING DATE: If requested                                 MEETING TIME:

BOAT REQUIREMENT:                                          MEETING LOCATION:

DREDGE CUT NAME: Lock and Dam 7 Lock Chamber    RIVER MILE: 702.5

HISTORIC DATA

Frequency: 4%                                                Avg. Quantity/Job: 535 yd³ 

Last Date Dredged: August 11th, 2008                      Avg. Quantity/Year: 20 yd³   

SURVEY DATA

Date Surveyed: April 2^nd, 2024

Water Surface Elevation: 638.5

Low Control Pool Elevation: 638.5

Net Difference: +0.0

5 Day River Forecast: Slight Decline

DREDGING DATA

Recommended Channel Width: 110 chamber width

Recommended Dredging Depth: various 17.0 feet – 22.0 feet below LCP

Estimated Quantity: 688 yd³ 

Type of Dredge: Government Mechanical

Proposed Dredging Date: April 24^th, 2024

Estimated Duration: 2 Dredging Days

Justification for Dredging: The small amount of sediment that has collected upstream of the miter gates in a few areas is affecting the safe operation of the lock chamber miter gates. The sediment in the chamber will also be cleaned up at the same time.

MATERIAL PLACEMENT DATA

Proposed Placement Site: Dakota Island

Location: 7-706.5-RMT

Site Characteristics: This is a historically used temporary island site.  

If you have any questions concerning this project or request an onsite meeting, please call a dredging manager at (651) 290-5155.