TRAVERSE CITY, Mich. — The effectiveness of a long-term plan to heal the ailing Great Lakes could be marred by federal spending cuts, which also could make it harder to cope with low water levels that threaten the region’s economy, local leaders said Wednesday during a lobbying trip to Washington.

Representatives of state and local governments, businesses and advocacy groups were pressed Congress for continued funding of the Great Lakes Restoration Initiative, which involves nearly a dozen federal agencies in a push to solve some of the region’s most pressing environmental problems. They also sought money to dredge sand-clogged harbors, and upgrade sewage treatment plants and other aging infrastructure.

However, the annual visit to Washington by Great Lakes advocates ran headlong into a budget stalemate that will force $85 billion in across-the-board cuts unless President Barack Obama and Congress reach a deal soon.

The Great Lakes initiative is designed to make progress on longstanding threats such as invasive species, toxic pollution hotspots, runoff that causes algae blooms, and disappearing fish and wildlife habitat. It has received $1 billion under Obama, including $300 million the past two fiscal years. If threatened cuts are carried out, the 2013 allocation could shrink to $275 million.

Rep. Candice Miller, a Michigan Republican and co-chairwoman of the House Great Lakes Task Force, said the restoration program “must remain a national priority.”

“However, the painful reality is that some federal spending cuts must be made, and all discretionary spending is on the table,” Miller said, adding that the administration should “implement the spending cuts responsibly so our Great Lakes do not bear the brunt of these cuts unfairly.”

Advocates also noted that significant reductions would make the cleanup more expensive in the long run.

“Cutting restoration funds will not save America one penny,” said Jeff Skelding, director of the Healing Our Waters-Great Lakes Coalition.

Their comments came the same day that the U.S. Environmental Protection Agency released a report card on the restoration initiative. It said that during the 2011 fiscal year, federal agencies and grant recipients cleansed 1 million cubic yards of contaminated sediments and continued work on toxic waste hotspots. One of them — Presque Isle Bay in Pennsylvania — is expected to be completed this year.

The program also helped protect or restore 20,000 acres of wetlands, developed technologies to fight invasive species and removed dams that were impeding fish passageways, the report said.

The Great Lakes Commission, an agency that represents the eight states and two Canadian provinces in the region, joined the lobbying campaign after wrapping up its semiannual meeting in Washington. In addition to supporting the restoration initiative, delegates pleaded for more funding to dredge harbors where shallow water is forcing shippers to lighten loads and threatening to ground pleasure boats. Low water also exposes piers and docks to the elements, causing them to deteriorate faster.

Lake Michigan and Lake Huron hit their lowest levels on record in January. They rose slightly in February, but the Army Corps of Engineers predicts they’ll remain below their long-term averages over the next six months.