City officials are reacting with cautious optimism to news that the Army Corps of Engineers last week received Congressional approval of $500,000 to fund initial planning for a long-overdue dredging of the silt-clogged Petaluma River.

"We are very excited about starting the process of the next dredging project on the river," said Petaluma Public Works Director Dan St. John this week. "With the $500,000 appropriation, the corps will be able to get underway on the permitting and environmental work necessary for the project approval and, hopefully, we'll see additional funding next year to move the plans into design and bidding."

Silt naturally builds up in the river, which is actually a tidal slough, making dredging necessary every five to seven years. If dredging does not occur regularly, the river becomes shallower. This puts recreational boats and commercial vessels at risk for stranding on piles of silt along the river's bottom, and makes it difficult for barges to carry heavy loads.

Jerico, the Petaluma tugboat company that tows close to 700,000 tons of freight down the river annually, said its ability to do so has been seriously compromised by the shallow river conditions. Last year, Jerico estimated that it has had to reduce the amount of freight it carries by about 25 to 30 percent.

Marie McCusker, executive director of the Petaluma Downtown Association, said that tourism is affected too. In 2012, she said, 466 boats visited the Turning Basin, accounting for 1,076 overnight stays and an influx of $1.3 million to the local economy. But with the water getting shallower, word is getting out that sail boats and yachts must carefully time their visits to Petaluma around the tides or risk getting stuck in the mud.

Dredging waterways like the Petaluma River, which are used for commerce, has always fallen to the U.S. Army Corps of Engineers. But as federal funds dried up in recent years and congressional earmarks for such projects disappeared, the corps has been unable to afford dredging maintenance on many of the country's high-traffic waterways. That means less-used channels like Petaluma's 13-mile slough have become long-overdue for the recommended silt removal.

The Petaluma River hasn't been dredged since 2003, aside from a partial silt and debris removal done in 2006 by the Federal Emergency Management Agency to prevent flooding. Fully dredging the river typically costs about $2 million, but because the channel hasn't been regularly maintained in the past 10 years, it could now cost as much as $10 million to complete.

At a meeting last summer, North Coast Congressman Jared Huffman was told by the corps that they could not be counted on to complete the dredging any time soon due to a continued lack of funding from Congress and Petaluma's low priority as a lesser-used commercial waterway.

But the recent announcement of preliminary funds to at least begin planning the dredging, which could not begin any earlier than late 2015, is cause for hope.

"We are grateful to our congressional delegation, including Congressman Hoffman, for making this a priority for our community and working with the corps to get these much needed funds appropriated," said St. John.