Dredge Potter moving to mile 173 UMR

Notice: ERT/BH

Date: 7/22

We received new surveys today for mile 173 and 171 UMR. While these are
typical dredging areas, they look worse than usual. St. Louis gage is
expected to be around 4-ft on Monday, and mile 173 will be approaching 9-ft
of depth with mile 171 only slightly better depth. The Potter's remaining
work on the Illinois Waterway was reviewed, and given the 28 day forecast
for Meredosia, we feel the remaining areas should remain passable. So, we
will have the Dredge Potter depart the Illinois Waterway and move to begin
work at mile 173 UMR. The Potter is expected to arrive at mile 173 on
Sunday morning. Surveys are attached.

Mile 173 has a controlling depth of 2.3-ft at LWRP, 90-ft right of the
sailing line. At 4-ft St. Louis, this is 9.5-ft of depth. There is more
depth, mostly 6-ft at LWRP or better, to the left of the sailing line.
This location typically takes 3 to 4 days to dredge.

Mile 171 has a controlling depth of 3.7-ft at LWRP on the sailing line and
5-ft at LWRP right of the sailing line. We typically spend a week at mile
171, but I would say this will probably take up to 10 days (rough estimate).

I will send out a NTNI.

Lance Engle
Dredging Project Manager
St. Louis District

ERT pt.1

ERT pt.2