ELLSWORTH — Supporters of the Union River dredging project have begun a letter-writing campaign that presses the state’s congressional delegation to come up with more than $1 million to pay for the project.

Although the U.S. Army Corps of Engineers has received all the permits it needs for the project, Congress has not included the money in the early versions of its annual energy and water spending bill.

“For some unknown reason, the funding was not even considered in the federal budget to begin with,” said City Councilor Ralph Buckminster, who also sits on the Union River steering committee.

“I’m at a loss as to why it wasn’t.”

There is some concern that further delay in funding the project could require the corps to begin the permitting process again.

Members of the group Friends of the Union River and the city’s harbor commission have been working with the Corps of Engineers for the past 10 years to get the project approved.

The corps proposes to dredge the three-mile federal channel that runs from the mouth of the river to the rapids just above the city dock. The project would involve dredging 60,000 cubic yards of material — including large quantities of sawdust left over from the city’s heyday as a lumber port. It would provide a 5-foot-deep channel. The channel was last dredged in the early 1900s.

The city also plans to dredge the municipal harbor that lies outside the channel near the dock, and to piggyback the work with the federal project. The federal appropriation would not apply to the city’s portion of the project, which could cost $200,000 to $250,000. The city will have to pay for that itself. But the plan over the past several years has been for the city to do its project at the same time the corps dredged the federal channel.

The dredging is expected to open the river to larger vessels that have been unable to travel up the river in recent years. And it would allow the city to expand the moorings in the harbor and to make other improvements at the municipal dock.

U.S. Rep. John Baldacci sent a letter backing the funding to Rep. Ron Packard, chairman of the House Appropriations Subcommittee on Energy and Water Development. That panel has jurisdiction in the House over the annual spending bill that contains funding for harbor and river projects.

And Sens. Olympia Snowe and Susan Collins have written to Sen. Pete Domenici, R-N.M., who chairs the Senate subcommittee that handles the same issue.

But both houses often wrangle until close to the Oct. 1 start of the federal fiscal year over the 13 spending bills they must approve each year.

Ginny Worrest, an aide to Snowe, said a decision on the Senate’s version of the spending bill may not come until late spring or summer.

Although the federal funding is seen locally as the catalyst for waterfront improvement and development, Buckminster said, he did not think the delay in funding would affect those efforts.