West Boggs Drawdown Complete

[MikeAxsom]

Yes, we will refill the washed out areas and cap them with concrete to try to prevent them from washing out again. Those holes are the result of prop wash while boaters power their boats onto trailers. That is a design problem that people building new ramps should take into consideration.

[Moose1am]

Hey Mike:
I talked to the people down at Hovey's lake and they said they have the same problem with their ramp. ie the end of their ramp gets washed out by the boat's motors pushing the boats back on the trailer. Hovey's has a 10hp motor size limit.

Now I wonder if putting large rip rap stones at the end of the boat ramp would help prevent the washing effect. Like putting large stones right at the interface of the end of the concrete and the mud. Is the end of the ramp in deep enough water to do that or would the rip ramp stones hurt the boat props?

It would not take a very thick layer of rip rap to stop the errosion problem. Somehow I must be missing something. This sure seems to me like an easy way to fix this problem but surely I am missing something as this does not seem to be done.

Regards,

Moose1am

[MikeAxsom]

Hi Moose1am-

We have placed stone in the holes several times, including large revetment rip-rap. It is pretty amazing how far some of those large stones get moved. Part of the problem is that rip-rap does not stop erosion. We know that on shoreline work and use a geo-tex fabric underlayment to hold the soil in place; and the rip-rap basically holds the fabric in place. On a ramp, the prop wash is so strong that it goes between the spaces in the rip-rap and blows the mud out from underneath. Then any stone that so large that it can’t be blown away ends up at the bottom of the resulting hole.

Our best success is with something that we will be extending this winter while the lake is down. That consists of refilling the holes with rip-rap, and then grouting the rip-rap in place with concrete. The places we have tried this seems to hold up well and are smooth enough when finished to not cause problems with props or trailers. And it doesn’t really cost much to do when the lake is down anyway.