SEDIMENT SOUNDINGS TAKEN TO MEASURE MARINA REPAIRS

CAPE GIRARDEAU -- Survey boats from the Army Corps of Engineers took depth soundings in the John L. Wescoat Marina and Mississippi River Access Point at Trail of Tears State Park Sunday.

A Corps spokesman said the soundings of the bottom of the marina will determine if modifications made nearly four years ago to a wing dike on the north side of the harbor has reduced the sedimentation problem.

The marina was constructed in 1974-75 but never officially opened because flooding on the river in the spring of 1975 left several feet of mud and silt in the marina, making it almost impossible for most boats to use.

A study by the Corps' Waterways Experiment Station at Vicksburg, Miss., later determined the problem was caused by the varying height of the dikes that surround the marina.

Claude Strauser, chief of the Potomology Branch of the Corps' St. Louis District Office, said the Vicksburg study revealed the spur dike that extends out from the shore into the river was five feet higher than the trailing section of dike that extends in a north-south direction between the marina and the river.

Stauser said when the river was high enough to flow over the trail dike, but not the spur dike, the water was diverted into the marina harbor where it slowed down and dropped its suspended solids to the bottom of the marina. The result was an accumulation of sediment.

In an attempt to resolve the problem, the Corps shaved five feet off the top of the rock spur dike to make it the same height as the trailing dike. The idea was to keep the water moving through the marina fast enough to prevent the suspended solids from dropping to the bottom of the harbor.

The dike work was done in the summer of 1987. Later that year, a civilian contract dredge was brought in during December to dredge the accumulated sediment in the harbor, at a cost of about $200,000. The Corps agreed to bear the cost of the dredging.

The Corps then waited for the expected annual high water on the river the following spring to determine if the dike modification would actually do the job.

What they, and everyone else in the river industry, did not anticipate were three consecutive years of record-low water levels on the Mississippi River. The Corps and the river industry had to use every means available to keep the water-starved river open to navigation between St. Louis and Cairo. The marina project became a casualty as the water level fell.

It was three years before the river finally rose high enough to overtop the marina dikes in 1990.

On Sunday, the St. Louis District Motor Vessel Moore, accompanied by Launch 19 from the Corps' St. Paul District, set up electronic gear on the dikes and shore to begin sounding the bottom of the harbor.

Greg Henson, assistant park superintendent at Trail of Tears State Park, is one of those waiting to hear the results of the soundings.

"The river access point has become an important part of our park, but it could play an even more important role if the sedimentation problem can be resolved," said Henson.

"Last year, during the low water periods, we had to use up to half to three-quarters of our manpower to remove the mud and sediment to keep the boat launch ramp open. The time we spent there took away from other park operations, but we couldn't shut it down because so many people now depend on it for access to the river."

In addition to commercial fishermen who regularly use the boat ramp to put in and take out their large jon boats, Henson said the river access ramp is also used by duck hunters, recreational boaters and other boaters.

Henson said the Corps of Engineers and Missouri Department of Conservation game wardens also use the access ramp. "Several barge lines use the marina to make their crew changes, " he added. "They bring their small outboard motorboats into the harbor to pick up and drop off crewmen and take them out to the towboat as it goes by the park."

Henson said during the spring and fall, the marina takes on the appearance of an aquatic campground. "We get a lot of the larger pleasure boats and yachts that travel up and down the river who use the marina because it's a safe harbor for an overnight stay," Henson said.

Although there are no fueling or servicing facilities at the marina, it is the only secure harbor on the river between Kimmswick, Mo., and Cairo.

"The Corps and the other boaters like to dock in the marina because we lock the gates to the park at night," he explained.

When the marina was completed in 1975, the Missouri Department of Natural Resources constructed a 96-boat docking facility in the harbor. However, when the sediment problem developed, it was dismantled and taken to Truman Reservoir in Southwest Missouri.

State officials considered constructing a small courtesy dock in the harbor after the dredging was completed in 1988, but the project never got beyond the planning stage. Henson said until the sedimentation problem is solved, no additional improvements are planned at the marina.

Corps officials say on the average, over one million tons of suspended sand, silt and other particles in the river pass the marina each day. They caution that even with the dike modification and initial dredging of the harbor, about one percent of that one million tons of sediment will eventually get into the marina. That means some maintenance dredging of the harbor will still be needed after unusually high water.