Flooding
One of Semo Port's advantages is the
fact that its facilities are new, modern, and
designed to operate even during times of high floods. As a standard,
they are designed for
a 500-year flood (elevation 354.9), or three feet over 100-year level.
The floods of 1993
and 1995 did not reach the 100-year level: the highest water elevation
was 351.33 in 1995,
versus the 100-year flood elevation of 351.8 feet above sea level.
Highways. The
highways serving Semo Port are completely above
500-year flood elevation. This includes Interstate 55, Route AB, and
Route K through Scott
City. Route AB was opened to traffic in October 1997, and over a mile
of it is built on a
fill (20 feet tall) for flood protection.
Railroads. The Semo Port
Railroad (SE) is above the 500-year flood in the Port's harbor
industrial area and
southward to the Union
Pacific
Railroad connection
at Capedeau Junction MO (east of Scott City MO). Service is available
with UP at any
recorded flood stage.
The Burlington
Northern Santa Fe Railway
(BNSF) and the SE's line northward to the BNSF at Cape Girardeau MO
both close at a 40
gauge. When such a closure occurs, it typically is only for a few days.
If necessary, BNSF
traffic to/from Semo Port can be rerouted via UP.
Utilities.
Utilities in the Semo Port area are designed to
accommodate a 500-year flood. This applies to electric power lines and
substation, natural
gas line, water lines, sanitary sewer system, and telecommunications.
Terminals. Semo
Port's modern terminal facilities are designed
to minimize or alleviate the effects of flooding. During the floods of
1993 and 1995,
barges were worked on an emergency basis even though the river was
temporarily closed to
navigation. Most of the barge facilities at the Port can operate at the
highest flood
stages (Consolidated
Grain,
Midwest AgriChemico, First
Missouri
Terminals). Additional locations around the harbor are suitable for
emergency use when
needed.
The general cargo dock (Girardeau
Stevedores and Contractors, GSC) has an elevation of 345 and closes
at a Cape gauge of
44. It was designed to be open at any time the river is open to
navigation. Typically it
is closed less than one percent of the time. For the unusual times it
is closed by extreme
flooding, work is diverted to other locations around the harbor. The Old Dock
has an elevation of 330 and closes at about
28 gauge.
Reference
River Levels During Flood and Drought Conditions |
|
At Semo Port, the floods of 1993 and
1995 were below the 100-year flood elevation. All new facilities
(streets, railroad tracks, building sites) are built above the 500-year
elevation. The reference elevations and historical river levels are:
|
| High Level: |
elev 354.9 |
500-year flood elevation |
|
elev 351.8 |
100-year flood elevation |
|
elev 351.33 |
level on 5-24-95 (Cape gauge 46.7, with Ohio River over
flood) |
|
elev 351.15 |
level on 8-07-93 (Cape gauge 48.2, with Ohio River low) |
|
| Low Level |
elev 307.39 |
Corps of Engineers Low Water Reference Plane |
|
elev 306.07 |
level on 12-27-89 |
|
elev 305.00 |
harbor design low water level for 9' draft |
|
elev 296.00 |
harbor design bottom |
|
|
Reference
River Gauge & Elevation |
|
This table converts from Cape Gauge
to Semo Port Elevation (Corps of Engineers).
|
Cape Girardeau, MO
River Stage |
Approximate Elevation
NGVD Mile 48.0 |
| 0 |
302.6 |
| 10 |
311.9 |
| 20 |
321.9 |
| 30 |
331.9 |
| 40 |
341.6 |
| 50 |
351.0 |
| |
|