Hatlem Pond Dredge
Frequently Asked Questions
1. Where is Hatlem Pond? Hatlem Pond is a man-made pond located
approximately .75 miles upstream from where Hatlem Creek enters Big Glen
Lake. The mouth of Hatlem Creek is located just north of the intersection of Co.
Rd 675 and Plowman Rd. It is the largest surface source of water to Glen Lake.
2. Why dredge Hatlem Pond? – Dredging Hatlem Pond should reduce the
sedimentation in the water flowing into Glen Lake from Hatlem Creek. This
sedimentation can be significant, particularly following significant rainstorms.
Reducing sedimentation should help preserve the present state of bottomland in
Glen Lake. Sedimentation also contributes to the premature aging of the lake by
reducing its depth and inducing aquatic plants and algal growth.
3. What if we did not dredge Hatlem Pond? Since Hatlem Pond is full of
sediments now (6-7 ft. deep), upstream sediments no longer collect in the pond
and will continue to be carried downstream into Glen Lake.
4. Will dredging the pond cause any ecological damage? No. The sediments to
be dredged have been analyzed and no contamination or health risks have been
identified. The dredge plan was designed by Grobbel Environmental, reviewed by
The Spicer Group (a Michigan-based environmental engineering company with
almost 70 years of experience) and approved by the state Department of
Environmental Quality.
5. How will the dredge be implemented? The dredge will be implemented in two
phases. Phase 1 will be completed May 2014 and Phase 2 will be completed 1-2
years later. Each phase will remove about 5,000 cubic yards of sediment---the
equivalent of 500 large truck loads.
6. When is the best time to dredge the pond and how long will it take? The state
permit restricts dredging between March 1st and May 15th and between September
1st and November 30th. Therefore, we are targeting the dredges between May 16th
and May 31st of each of the respective years. These dates are one of the lowest
recreational use periods for the lake. The dredge will take about two weeks.
7. Who will supervise the dredging? The Spicer Group will supervise the dredge.
Rob Karner, GLA watershed biologist, will be the project manager. The Dredger
has significant local experience, including dredging the Fisher channel and the
Glen Lake bridge.
8. Where will the spoils of the dredge be deposited? The landowner adjacent to
the pond has agreed to have the spoils placed on the surrounding uplands. The
spoils storage area is about the size of a football field and will require the removal
of hundreds of trees, construction of a spoils containment berm as tall as 6-7 feet
near the pond. The spoils will be removed after they have dried, and the area will
be available for the second dredge.
9. Who will provide the funds for this project? The project will be supported by
funds from The Glen Lake Association general fund, individual riparians on Glen
Lake, and the Hatlem pond property owner. South shore riparians should benefit
most from the dredging, due to less sedimentation flowing onto their beaches
from Hatlem Creek. We’re looking to these riparians to make significant
contributions toward the project.
10. How will the funds be solicited? Funds for the project will be solicited on a
voluntary basis from all riparians. If there is insufficient financial support from
south shore riparians, the dredge will be reconsidered.
11. Will a Special Tax Assessment District (SAD) be created to support this
project? No. While the GLA initially considered creating a SAD to fund this
project, this was abandoned based upon input from Glen Lake riparians.
12. Why isn’t the full cost of the dredge paid for by the owner of Hatlem Pond?
Since the dredging will benefit many parties, we are attempting to spread costs in
rough proportion to the benefit received. Based upon member concerns, the GLA
approached the pond owner (the owner did not approach GLA), and we were
pleased to obtain the owner’s support for the dredge. The dredging activity
requires destruction of trees, building of access roads for the dredging equipment,
and creation of a spoils storage area about the size of a football field on the
owner’s property. This is a significant contribution to this effort, and the cost of
the dredging would be significantly higher if the spoils could not be stored on the
adjacent property. Separately, the owner is also making a financial contribution
toward the project. Keep in mind that the source of the sedimentation is all
property owners, both on the pond and importantly those properties up stream
along Hatlem Creek, and the beneficiaries are all who passionately care about this
special Glen Lake Watershed.
13. Is the dam separating Hatlem Pond and Hatlem Creek stable? As part of this
dredging project, the owner has had the dam inspected by a state-certified
inspector and implemented recommendations to assure the long-term safety of the
dam. The owner has also agreed to have the dam inspected every five years,
implement any recommended maintenance recommendations, and share the dam
inspection report with the GLA.
14. How often does Hatlem Creek carry a significant amount of sediment into
Glen Lake? Usually the water at the mouth of Hatlem Creek has a good color
and is sediment-free. However, after any significant rain down pour exceeding
approximately two inches or more over a short period of time, the effluent water
is black and heavy sedimentation is loading into Glen Lake. So far this year, we
had 2-3 such rain events. Usually after a few days, the effluent clears up and the
water returns to normal.
15. What will the dredge do to E coli levels? Elevated levels of E coli have always
been associated with rain events. This dredge is not designed to address this longterm problem and the dredging process should not elevate E coli levels in the
creek. The GLA will continue its ongoing efforts to address the E coli problem
separate from this project. These efforts include regular testing for E Coli levels
and identification of intervention opportunities to prevent it.
16. How often will Hatlem Pond need to be dredged? After the initial, two phase
dredge, we estimate the pond will need to be dredged again in 10-20 years. This is
difficult to determine and is dependent upon many factors, including the number
of major rain events and any land clear-cutting events on properties along the
Hatlem Creek watershed at higher elevations. The GLA will also be exploring
other sedimentation reducing approaches (e.g. laminar flow) that could reduce the
need for future dredges.
17. Has Hatlem Pond ever been dredged before? Although we do not have the
complete history, it appears this will be the first time this pond is dredged. We
believe the pond has 50 plus years of built-up sedimentation.
18. Has the GLA obtained a professional assessment of the probable success of
the GLA Plan as well as an assessment of possible alternative plans? Probable
success of the project has been confirmed by: Rob Karner, M.S. Watershed
Biologist; Steve Christensen, Leelanau County Drain Commissioner; Tim Roche,
P.E. Gosling, Czubak & Associates; Chris Grobbel, Ph.D. Grobbel
Environmental & Planning Associates and Shawn Middleton of the Spicer Group.
No viable alternative plans have been identified from any professional that could
take the place of the initial dredge.
19. After completion of the project, is it likely that sediment (with tannin
discoloration) will still wash down from the banks of the stream below the
dam? Currently, there is no effort or management practice that is available to
change the color of the water flowing into Hatlem Creek. The sediment coming
down from the pond after the dredge should be reduced after the dredge.
20. Is there any other reasonably available funding source, like the Township
itself? While Empire Township has gone on record supporting the dredge, it does
not want to spend any township funds towards this project.
21. Do we have engineering assurance that the dredging process will not damage
or undermine the dam and how will the dam be protected during the
project? The dredge design includes safeguards that should eliminate any damage
to the dams (both the beaver dam and the earth dam). There will be on-site,
independent supervision of the dredge, and the dredger, William Crist, has over
30 years of dredging experience.
22. Will the dredging process itself produce substantial sediment discharge into
the lake; if so, can this be prevented or mitigated? Sediment discharge during
the dredge will probably occur but our dredger is taking appropriate steps to
minimize it.