Lakes Restoration Project
Dams Committee Updates
The Bridgeway Lake dam inspection is complete. Three deficiencies exist:
The inspection on the Greenook Lake dam will not be completed until the lake is refilled and checked for seepage. The engineering firm will return to complete the inspection, w/o additional cost if the lake is ready this year. The invasive vegetation will be removed on Greenook dam as well. The committee plans to clear the invasive brush from both dams during the winter months to keep the costs down. There is $2,900 in the budget for this work.
The dam hazard rating reduction is pending decisions and work on Greenook Lake.
The Committee discussed the timing of the upgrades to our dams to meet the State mandated 200-year flood. The remaining issues and work on the lakes project and the fact the two projects are interdependent make it unlikely that engineering will be done in the current budget year. The Committee will recommend to the Board that the $15,000 budgeted for engineering be carried over to the 2004-2005 fiscal year. The Committee will not request an assessment until the 2005 Annual Meeting. The amount required will be assessed equally over the three years, 2005, 2006 and 2007. The assessment is currently estimated at $125 per year but can change, due to economic factors, changes in the dam hazard rating and potential funding from grants.
This timing would allow Bridgeway dam upgrades in 2005 and Greenook dam in 2007.
The Committee will notify the State of these changes.
To Loch Alpine Residents:
The purpose of this informational letter is make each resident aware of how a State mandated regulation applies to our two dams, Bridgeway Lake Dam on Midway Dr. and Greenook Lake Dam on East Loch Alpine Dr.
The State of Michigan has an effort underway to upgrade significant dams to withstand a 200 yr. flood event. Both Loch Alpine dams are considered significant. For the past year our consultant, John Warns of J. C. Warns Engineering, has been working with James Hayes, the State Dam Safety Engineer, to develop rainfall, watershed data and engineering calculations to examine ways to increase our dams overflow capacity. The process includes determining the criteria for a 200 yr. flood in the watershed that drains through our lakes system. Warns evaluated current dam overflow capacity and applied expected flow dynamics during a 200-year event to predict dam and overflow behavior during this type of extreme event.
These calculations showed that dam overflow capacity is greater than was reported in earlier engineering studies but is 25% under the required capacity. Currently, our dams will handle about a 75-year event. The next effort was to provide alternatives for providing the additional capacity. Warns obtained initial approval from Mr. Hayes on 3 practical design options for each dam. On 12/04/02 the Dam Committee met to discuss the design alternatives. All designs are acceptable from a technical standpoint, so the committee has focused on minimizing cost to Loch Alpine. The currently favored designs continue to utilize our current over-the-road method.
Mr. Warns is now developing initial rough cost estimates, which we will present at the Board’s January budget meeting. The estimates will provide an idea of what the near and far term costs will be. More precise cost estimates will only be determined when the required detailed drawings are complete, which we expect to have in 2003.
The State has advised us that an acceptable timeline for this project would be 3 to 5 yrs. Financing will probably put construction into the 5th year. No determination on how to finance this project has been made as the cost is still unknown.
To date we have spent $6,535 on the engineering and consulting work. Many more approvals and permits will be needed during the process and there are variables we can’t control. Continuing development in the watershed will in-turn affect the flow rate our dams must pass during a 200 year event. The economy and other factors can also affect the overall cost of a project such as this.
The Dams Committee separated from the Lakes Committee to better oversee this project. (Approved at the November Board meeting.)
In addition, the State requires a safety inspection of our dams every three years. This needs to be done in 2003 and could require removal of invasive brush and trees, since this will be a detriment to the integrity of the dams.
We intend to keep the residents informed and encourage you to read the Board minutes, check the Loch Alpine web site and the Lore for additional information as it develops.