(Adds Coast Guard relaxing barge draft guidelines)
By Karl Plume
Jan 10 (Reuters) - A storm moving up the Mississippi River valley will help replenish the river, low in parts from drought, and ease concerns that shipping could be halted along a shallow stretch from St. Louis to Cairo, Illinois.
Shipping groups had warned as recently as last week of an effective closure of the river along that busy stretch, through which billions of dollars of grain, coal, fertilizer and other commodities flow every year.
Rain and the brisk pace of efforts to remove underwater rock could help the Army Corps of Engineers keep barge traffic flowing through that section of the Mississippi until at least mid-February when the river's water level rises because of seasonal changes.
The U.S. Coast Guard on Thursday relaxed their previously rigid draft restrictions for vessels transiting the area in response to the improved river forecast.
Boats had been required to have a draft of, at most, nine feet between the water's surface and the lowest point of the vessel. Now, while still recommending nine-foot drafts, the Coast Guard will allow deeper-draft boats if conditions allow.
Most barge tow boats require a draft of at least nine feet.
"The forecasts are looking good," said Lt. Colin Fogarty, public affairs officer for the Coast Guard's upper Mississippi River sector that covers the Cairo area and northward.
Shippers are still watching river gauges along the waterway to make sure they can transit low water areas.
"It doesn't look like we're going to hit those two thresholds of a minus-six feet in St. Louis and plus-two feet in Thebes," Fogarty said on Thursday, referring to low river gauge readings at the two locations that would prompt the Coast Guard to restrict vessel drafts to less than nine feet.
Gauge readings do not reflect the actual depth of the river at a certain location because the gauges are fixed and the river's bottom steadily changes with the current. They aid navigation as a shorter term reference point.
The river gauge at St. Louis was expected to rise from -2.8 feet on Thursday to -1 foot by Sunday, according to the National Weather Service.
At Thebes, Illinois, where the Army Corps has been removing rock pinnacles since mid-December, the gauge was at 3.8 feet on Thursday and expected to rise to 8.2 feet by Tuesday.
Rock clearing at Thebes and another location near Grand Tower, Illinois, was expected to be completed by the end of January, allowing for two additional feet of draft.
The prioritized removal of the most threatening pinnacles at Thebes is expected to be completed later this week, a Corps spokesman said late on Wednesday.
"Basically, the crisis is over. No, we can't run the 12-foot drafts that we would like to run out of St. Louis with 14-foot barges, but we'll have enough water that barges can continue to move," a grain barge trader said. (Reporting by Karl Plume in Chicago; Editing by Toni Reinhold)