Dredging Hatlem Pond to save Glen Lake bottomland

From staff reports

At last year’s annual meeting of the Glen Lake Association (GLA), watershed biologist Rob Karner gave a sneak preview of how the dredging of Hatlem Pond was being targeted as one of its major water quality projects for 2012.

Hatlem Pond is a small pond less than a mile upstream from the mouth of Hatlem Creek on the south shore of Big Glen. For the past 50 years, it has served as a silt trap and today the pond is almost completely full of sediment that comes from the steady and gentle sedimentation of the upstream portion of Hatlem Creek and its tributaries.

When Hatlem Pond no longer functions as a trap for sediments and when a significant rain event occurs, large amounts of sediment and organic debris wash down the creek and into Big Glen. This black to brown water eventually clears up in about a week or more but the layers of sediment on the shoals of Big Glen are accumulating and changing the characteristics of the bottomlands from pristine sand to more of a “muck” bottom.

If nothing is done to reduce the sedimentation, Karner said, it won’t be long (perhaps less than a decade) before the south shore of Big Glen will look different that it does now. As layers of sediment accumulate and build up, it will foster rooted aquatic plant growth and the bottomlands will be dark brown or black.

Several riparians have encouraged the GLA Water Quality Committee to try and reduce the sedimentation and therefore preserve the present state of bottomland that is now more suitable and desirable for swimming, and boating. So the committee contacted and secured approval from the riparians of Hatlem Pond and to dredge the pond and remove most of the sediments by hydrological dredging.

In order to dredge Hatlem Pond, a sediment analysis needed to be performed and certain criteria needed to be met in order to secure a valid dredging permit from the Michigan Department of Environmental Quality (MDEQ). Chris Grobbell of Grobbell Environmental, LLC performed a comprehensive sediment study this past spring. This analysis included the delineation of sediment contents and volume of sediments to be dredged.

The lab results for the sediment samples have been evaluated and there are no obstacles to overcome in securing a dredging permit. Furthermore, there is upland adjacent to the pond for all the dredge spoils to be placed. With the application for the permit pending, the GLA awaits the MDEQ’s approval and expects an answer within a month.

Funding for such a project will not be cheap. Often keeping water clean requires effort, foresight, and expense. The GLA has already spent nearly $10,000 for the preliminary steps that were taken for the permit and bidding process. Private funds paid for most of the amount with the GLA contributing as well from the operating budget. Two preliminary and tentative bids have been secured from two separate dredging companies, yielding a total dredging cost of around $165,000. The question is how the GLA will find enough funds to pay for this.

Certainly, the riparians most affected by Hatlem Creek’s effluent are the people on the south shore of Big Glen from Agnew Street in Burdickville to the base of Inspiration Point. However, all of Big Glen is affected to varying degrees.

The GLA has taken initial steps to form a fundraising committee for this project. Interested parties may contact Karner (RKarner(AT)Leelanau.org) or Mike and Sarah Litch — co-chairs of the water quality committee.