Dredging In Leelanau?

After two unusually wet years posed challenges for those who regulate Lake Leelanau water levels, the county will study whether dredging the Leland River could provide relief.

A 1978 court order mandates the Leland Dam Authority to manipulate water levels to keep Lake Leelanau steady at 589.21 feet in the summer and 588.21 feet in the winter. Explains Leelanau County Drain Commissioner Steve Christensen: “You have to have consistency for the recreational use of the lake, so homeowners know where to put their hoists and docks in and boaters can navigate the shallower areas of the lake.” In the winter, a foot drop “helps prevent ice damage” and creates room to “accommodate spring runoff,” according to Christensen.

The Dam Authority controls the lake levels through the Leland Dam in Fishtown, which draws excess water out of the south end of Lake Leelanau, down through the Leland River and Narrows and out the other side into Lake Michigan. The problem? While the dam itself is fairly new – rebuilt in 2006 – an excess amount of moisture in the watershed combined with the long route out to Lake Michigan has made it difficult for officials to lower water levels quickly, posing flooding risks to homeowners on South Lake Leelanau.

“Our systems have become more and more saturated as we’ve moved through the last two years,” says Christensen. “We haven’t seen that in a long time, where the natural sponge ecosystems are full and yet we continue to have large rain events. In that situation, an awful lot of water ends up in the lake system.”

The question being considered by the Dam Authority is whether “dredging portions of the Narrows and/or the Leland River would enhance our ability to draw off water more quickly,” says the drain commissioner.

At a Dam Authority meeting tomorrow (Tuesday), officials will look to finalize language for a request for proposal (RFP) to hire an engineering firm to study the dredging issue. “On a gut level, it seems like dredging would help the water move more quickly,” says Christensen. “But we might also find that we could perform a huge dredge, only to gain a short amount of savings in time. It’s not worth it in that scenario.”

The county will also have to evaluate environmental and funding factors surrounding a potential dredge. “Where do you put the spoils (excess material)? That’s one question,” says Christensen. “There was a dredge 30 years at the Narrows, so we could look at that old spoil site and see if it’s something we could do again. We'd have to figure the spoils out.” And while the county has dollars available to conduct the engineering study, dredging itself would be “quite expensive” and likely require the county to explore outside funding mechanisms, says the drain commissioner.

Should an engineering study ultimately favor dredging, there could potentially be a secondary benefit for homeowners, particularly those located along the Leland River.

“People on the river have voiced their concerns over navigation issues, because the sedimentation and silt in some parts of the river are significant,” says Christensen. “As the Dam Authority, we are tasked with maintaining the court-ordered lake levels, not with navigation. But a side benefit (of dredging) could be improved navigation. Maybe we’ll get lucky and get two birds with one stone.”

After bids are collected - a process likely to begin within the next few weeks - the Dam Authority will need to go before the Leelanau County Board of Commissioners for approval to hire an engineering firm. Christensen says he hopes the Dam Authority could have the dredging study results back as soon as “mid summer.”