Dam Spillway Construction Starting October 7, 2024. Boat Ramp Will be Closed Prior.
After about 10 years of considering various options, engineering, negotiations with the DNR, and planning, the Dam spillway pipe will be lined, and the spillway inlet will be updated to the most recent standards.
Construction will start on October 7, 2024 and is expected to end by December 31, 2024. The lake will need to be drained 60 inches from normal pool for excavation and installation of a stop gate in the spillway inlet structure. Normal pool is considered the lake elevation when the water is right at the spillway inlet weir. Due to excavation and construction of a temporary dam around the spillway inlet, the boat ramp will also be closed during the project. The boat ramp will close after September 8th.
The valve will be opened in early August since the lake level is much higher than normal at this time of the year (the valve will lower the lake approximately 1” per day). The board will keep the lake at a reasonable elevation (24 inches below normal pool) until September 3, 2024 to allow for the summer boating season. If members do not want their boats on the lake during winter, please remove your boat by September 8, 2024 at the latest. Per our current schedule, the lake will be 29 inches below normal pool by this date (similar to the water level in November of previous years). The concern is lake elevation at the boat ramp. It can be a challenge removing certain boats from the lake when the elevation is low enough. If members are going to keep their boats on the lake, the same rules apply as they do every year – they either must be tied to your dock (or a dock you have permission to be at), or the boat must be on your property. Heritage Lake Association owned docks are not acceptable locations for long term boat parking. Lake front members should also be aware that the lake will be 30 to 36 inches lower than previous winter seasons. Docks may need to be moved or secured and checked throughout the winter and spring as the lake level rises.
Please check the website for updates as details about the project may change. The September 3rd, 8th, and October 7th dates are not expected to change. Updates will be provided at the monthly board meetings as well.
Key Dates:
- Early August – Valve opens due to higher than normal water level
- September 3rd – Lake level will not be lower than 24 inches below normal pool on this date (other than through natural water loss).
- September 8th – Last day to remove boats, pumps may be brought in after this date. Water front members should monitor the location and status of their docks. Boat ramp will be closed around this date.
- October 7th – Construction starts
- December 31st – Project complete
Background
This is the first part of a two-part project. The first part consists of lining the existing spillway pipe to significantly lengthen the life of the existing 30 inch corrugated steel pipe and to update the existing inlet structure. The inlet structure updates are required by the DNR to bring the dam up to current standards by adding a gate that can be used to evacuate water from the lake in the case of an emergency. We are also replacing the dewatering valve that has leaked and plugged up over the years. The second part consists of installing a new 60 inch diameter secondary spillway. This part will happen in a few years; the engineering plans will be finalized in the next year and eventually sent out for bid.
Why line the pipe now?
The existing spillway pipe is over 50 years old. While it has been inspected over the years, the board doesn’t want to wait for a failure to line the pipe. Waiting may result in complete replacement of the pipe, which is much more costly. Also, in the case of a spillway pipe failure, the DNR may require us to drain the lake until the pipe is fixed.
Why start the project in October?
There’s never a good time to lower the lake elevation 60 inches or close the boat ramp. October was chosen because it allows for the summer boating season – typically between Memorial Day and Labor Day, but also allows time to lower the lake for the project. There is also time to complete the project before the winter weather starts and allows for any fall weather delays. This date also allows for the lake to fill up over the winter and early spring. Depending on the weather this winter and spring, the lake may still be below normal pool by March or April 2025. Note, the lake is usually lowered in the fall anyway (although not quite this far), and typically fills up past the weir in the spring time.
Will this affect swimming, kayaking, canoeing, and other non-boating activities on the lake?
Minimally. The boat ramp will not be open, so the dam or the beach may need to be used to launch canoes and kayaks. There are members that keep their boats on the lake all winter, other than the lower lake elevation, the effect of the project will be minimal. Due to some of the shallow spots in the lake, certain members may have trouble accessing their docks.
Will Heritage Drive across the dam be closed?
That has not been brought up yet by the contractor. There may be times when the road is closed temporarily to allow construction on the spillway or for pump discharge lines. Check the website frequently for updates. If Heritage Drive needs to be closed along the dam, all parts of Heritage Lake can be accessed via other sections of Heritage Drive.
Will the boat ramp parking lot be closed?
Portions of it will be taken up by construction equipment. Material will also be stored in the lot. At this time, the exact area is unknown, but expect that at least 3/4 of the parking lot will be closed.
Why a 60 inch elevation change?
The contractor needs to excavate to the bottom of the spillway inlet. The bottom is about 60 inches below normal pool.
Will water front members need to disconnect or move their docks?
This is a possibility, and all lake front members should assume they will need to. Ultimately, it will depend upon the dock design and the lake depth near the dock. Docks may need to be beached on your property, or anchored further out from the shore line. Please be courteous to your neighbors.