DREDGES GO BACK TO WORK AS MISSISSIPPI RIVER CONTINUES FALL

ST. LOUIS The St. Louis District Army Corps of Engineers ordered its dredge Potter, and the civilian contract dredge America back to work this month as the Mississippi River continued to drop to its late summer and early fall stages.

The dredging began a few weeks ahead of the busiest time of the year for the barge and towing industry. Between September and December, hundreds of barge loads of corn and soybeans will be shipped from farms to the grain export elevators on the Mississippi River between Baton Rouge, La., and New Orleans.

Claude Strauser, potomologist with the corps' district office in St. Louis, said most of the Potter's work involves dredging along the river's navigation channel between Cape Girardeau and Cairo, Ill.

"We have the two dredges working at this time, and the survey boat Pathfinder is surveying the river between St. Louis and Cairo to looking for potential trouble spots," said Strauser. "As trouble spots are located, smaller survey boats come back in to make detailed surveys. Based on their data, we're able to determine where the dredging is needed and prioritize the work schedule."

Strauser said the two dredges were dispatched from their service bases around the first of August. He said that's the latest in the year the dredges have ever started working since the mid-1980s.

"We've been very fortunate up to now," he explained. "For the past two years, we've had adequate river stages for most of the year, which means there have been no major navigation problems. Now, the river is dropping and it's time to go to work."

Strauser said this year's river stages contrast with those in 1988, when corps' dredges had to be sent out as early as June because of low-water conditions caused by a major drought.

"That was one of several bad years for us," he said. "We had a lot of serious problems. During the summer of 1988, we had at least two closures, at the mouth of the Meramec River, and at Ste. Genevieve."

Strauser is optimistic this year will not be a repeat of the disastrous years from 1987 to 1989 when record-low water levels kept five dredges, a record number, working to keep the river open between St. Louis and Cairo.

"We've been very fortunate the past couple of years," said Strauser. "Mother Nature has smiled on us. Every time the river would start to fall, the rains would come up north and send more water downstream. That's why we haven't had to send the dredges out until now."

Strauser said the navigation channel between Cape Girardeau and Cairo has historically been of great concern to the corps because of the sharp bends in the river and poor alignment of the channel.

On Thursday, the Potter was working at Mile 50, near the Lone Star Industries' dock facility at Cape Girardeau. The dredge was scheduled to move upstream today to Mile 56, near Flora Creek, north of Cape Rock.

The America was working at Mile 290, near Lock and Dam 22 at Saverton, Mo., about 100 miles upstream from St. Louis.

The river stage at St. Louis Thursday was 5.3 feet, up .3 of a foot. It was forecast to drop back to 4.5 feet by Sunday.

At Cape Girardeau, the river was at 12.6 feet on Thursday. It was forecast to fall to 12.0 feet today, and rise slightly to 12.2 feet on Sunday.

In its 30-day river outlook, the National Weather Service at St. Charles is forecasting the Mississippi at St. Louis will drop to 4.1 feet on Wednesday, 3.4 feet on Sept. 4, 2.8 feet on Sept. 11, and 2.3 feet on Sept. 18.

The river at Cape Girardeau is forecast to fall to 10.8 feet on Wednesday, 9.7 feet on Sept. 4, and 8.4 feet on Sept. 18.

The Ohio River at Cairo is forecast to drop to 13.5 feet Wednesday, 12.0 feet on Sept. 4, and 11.0 feet on Sept. 18.

The figures are based on no significant precipitation occurring along the Missouri and upper Mississippi river basins over the next several weeks.

Even as the dredging continues this month, Strauser is watching the calender. On Nov. 1, the corps must cut back the flow of water coming out of the Missouri River reservoir at Gavins Point near Yankton, S.D., from 30,000 cubic feet per second (cfs) to 10,000 cfs.

Although precipitation this year within the Missouri River Basin was the best its been in several years, Strauser said the reservoirs are still at record-low levels. So the corps must again cut back the Missouri River flow 30 days sooner than normal.

When the cutback takes place, Strauser said there will be an automatic drop of about 3 feet on the Mississippi River at St. Louis and Cape Girardeau. The actual amount of the fall will be determined by the current river stages at the time the cutoff occurs, he said.

At that point (Nov. 1) is where the dredging now going on will pay off, he said. "As we dredge the problem spots now, while the water level is still relatively good, we'll be in a better position to keep the river open when that 3-foot drop takes place in early November," he explained.

Strauser said another plus factor for the corps and the barge lines this year is the completion of the $13 million Grand Tower-Thebes Rock Removal Project earlier this year. Now, towboats and loaded barge tows can pass along these areas of the river during times of low water with less danger of hitting rocks along the bottom and edge of the channel, he said.