By John Flesher, AP Environmental Writer

TRAVERSE CITY (WWJ/AP) – Water levels across most of the Great Lakes are likely to remain well below average for the next six months, posing continued hardships for commercial vessels and tourist towns that cater to recreational boaters, according to the U.S. Army Corps of Engineers.

The lakes should undergo their usual rise during the warm season, helped by melting of abundant winter snowfall across the region’s northern tier, officials with the Detroit district office said. But it won’t be nearly enough to offset years of declining levels brought on by drought and stepped-up evaporation amid warming temperatures.

“For shipping communities and people that need higher water, this is continued bad news,” said John Allis, chief of hydraulics and hydrology.

Lakes Huron and Michigan, which dropped to their lowest point on record in January, are expected to hover two to four inches above monthly record lows through September, said Keith Kompoltowicz, chief of watershed hydrology with the Corps office. None of the other lakes will set records unless the weather turns unexpectedly dry, he said.

Although the forecast doesn’t reach beyond six months, the officials said it offered no hope for a quick end to the prolonged water slump. Lakes Huron and Michigan, which geologically are considered one water body because they are connected, and Lake Superior have been below average for 14 years — the longest such period since record-keeping began in 1918.

“It takes several seasons of conditions conducive to water-level rises to get back to average,” Kompoltowicz said in a telephone news conference. “One winter of heavy snow followed by one season of heavy rain is not enough.”

Lakes Michigan and Huron were more than two feet below their long-term average in March – and 15 inches lower than they were the same month in 2012, he said. The other lakes — Superior, Erie and Ontario — also were below normal for the month and at least a foot down from a year ago. All are expected to stay below their historical averages in coming months with the possible exception of Ontario, which has partially regulated levels.

The shipping and recreational boating industries have pleaded for stepped-up dredging of harbors choked with sediment, but Corps officials said their hands are tied by a strapped federal budget.

President Barack Obama requested about $31 million to dredge 15 commercial Great Lakes harbors this year. The Corps also got $5.2 million for an additional eight projects in the region under supplemental legislation for recovery from Superstorm Sandy. The state of Michigan last month appropriated $21 million to dredge 58 of its smaller harbors.

The Corps considers 36 of the 60 federally designated commercial harbors in the Great Lakes region in need of dredging, along with 46 of 80 shallow-draft harbors used by recreational craft, said David Wright, operations and maintenance chief.

Shippers believe nearly all the commercial harbors need to be deepened, said Glen Nekvasil, spokesman for the Lake Carriers’ Association, which represents U.S.-flagged cargo haulers. Freighters are reducing their loads an average of 15 percent per trip to avoid scraping bottom in harbors and channels, he said. Ports in St. Joseph, Mich., and Waukegon, Ill., are so shallow that vessels have stopped trying to reach them.

The latest water levels forecast illustrates that “we have to deal with the dredging issue,” Nekvasil said. “We cannot wait for Mother Nature to pull us out of the fire.”

RELATED: Snyder Signs $21M Bill To Dredge Michigan Harbors

Report Predicts Ever-Bigger Lake Erie Algae Blooms

TM and © Copyright 2013 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2013 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.