Sunday, August 17, 2014
Big Blake dam reconstruction
I went to the Big Blake Lake association meeting yesterday. There was a full house at the Georgetown hall. I took good notes. Then I lost them. I am pretty sure my memory is good and that this is accurate.
A couple interesting things:
The man who is half way through a study of sedimentation in Big Blake (whose name is in my notes) talked about his preliminary findings. He's examined mud cores he's taken from the lake and found that
The lake association board has had engineering work done for a new dam at the north end of the lake. The recommendation is to build a “rip rap rock chute” dam. This is a widely used design and is appropriate for the situation. It can be built without “dewatering” (building a temporary dam to keep water away from the new dam site), requires little maintenance, and is the least expensive option. (A search on the Web will lead to descriptions, designs, and photographs.)
A Sherrard family member at the meeting assured everyone that the transfer of the property to be used for the dam is going to happen ASAP.
The cost is predicted to be $100,000-150,000. The resolution presented by the lake association board to the meeting specified that if costs (bids on the project, I presume) rise above $175,000, a future membership meeting would have to approve further action.
Votes of the membership at the meeting approved the board's actions and authorized the board to proceed on
The cost for owners of lakeshore property (if the dam costs $100,000) would be about $500 per lot. The cost to back lot owners would probably be about $200-300. The exact costs will be determined by the method of assessment. The association was voting on the method of assessment when I left.
If I've made any mistakes in my reconstruction of the meeting, let me know (add a comment).
A couple interesting things:
The man who is half way through a study of sedimentation in Big Blake (whose name is in my notes) talked about his preliminary findings. He's examined mud cores he's taken from the lake and found that
- The lake has been a lake for a LONG time; 300-400 years ago there were plants like coon tail weeds and insects (like one whose name I didn't catch) living in Big Blake. These things don't grow in rivers, so the lake was here before the loggers.
- Sediment is not building up quickly. The sediment at the bottom of a mud core that's about a meter (3 feet) long is over 700 years old.
- Some changes show up in the sediment after World War II. That's when people began building summer cabins around the lake.
- Identifying sediment from the 1950s and '60s is “easy” because there are radioactive elements there left over from above ground nuclear weapons testing.
- Other changes in the sediment show up after 1970, but he hasn't completed enough testing to describe the changes.
- Lake phosphorus levels and water clarity have improved over the past two years, but there's no good explanation for that yet. (He's helped by a local high school science teacher who voluntarily does regular water clarity testing from his kayak.)
The lake association board has had engineering work done for a new dam at the north end of the lake. The recommendation is to build a “rip rap rock chute” dam. This is a widely used design and is appropriate for the situation. It can be built without “dewatering” (building a temporary dam to keep water away from the new dam site), requires little maintenance, and is the least expensive option. (A search on the Web will lead to descriptions, designs, and photographs.)
A Sherrard family member at the meeting assured everyone that the transfer of the property to be used for the dam is going to happen ASAP.
The cost is predicted to be $100,000-150,000. The resolution presented by the lake association board to the meeting specified that if costs (bids on the project, I presume) rise above $175,000, a future membership meeting would have to approve further action.
Votes of the membership at the meeting approved the board's actions and authorized the board to proceed on
- designing the specific dam
- acquiring ownership of the property on which the dam will be built
- establishing a line of credit with a Wisconsin public agency that loans money to groups like the lake association for projects like this
- getting bids on the construction
- hiring a contractor to build the dam
The cost for owners of lakeshore property (if the dam costs $100,000) would be about $500 per lot. The cost to back lot owners would probably be about $200-300. The exact costs will be determined by the method of assessment. The association was voting on the method of assessment when I left.
If I've made any mistakes in my reconstruction of the meeting, let me know (add a comment).
Labels: Big Blake dam
