Pond Boss Forums GENERAL QUESTIONS Property Projects & Construction Floating Dock question

Hello All,

Due to the drought, my pond has dropped from around 4.6 surface acres to about 2.9 surface acres. Right now, we are guesstimating that we have access to a little over 1.5 acres of 'dry', formerly bottom, silt and sediment that has accumulated over the last 50 years.

Our Biologist Extraordinaire, CJBS has convinced us that we should use this opportunity to clean out as much of the sediment and silt we possibly can before the water returns to full pool.

We are taking his advice and will be doing that very soon. However, we are also considering putting in some posts/pilings that we will use later as 'guides' for two floating docks.

Given that at full pool we are around 4.6 acres, pond is not spring fed, very little surface winds except during major thunderstorms;little, if any, winter ice; and, with the exception of our current extreme drought conditions, water level has been relatively stable, my questions are:

will 4 ea 6 x 6 pilings suffice for stabilizing/'guiding' a 12 x 12 dock and an 20 x 20 dock with a roof? If not, will 4 ea 8 x 8 do the trick?

We want to do the pilings while they are cleaning out the sediment. Was thinking of using a PTO driven post hole digger. I was think of digging holes 4', inserting the piles and then covering with sakrete/etc. Will this work? Is it too deep? Anything I should be thinking about to minimize leaking around the piles?

What other issues should I be thinking about now before putting in the piles? Again, the intent is to put in just the piles now while we have access to the bottom and then build the docks later when we are closer to full pool.

Any and all comments are encouraged and welcomed.

Warmest regards to all,

Paul

Wow. Having had offices in "downtown" King George and Dahlgren back in the '70s and '80s, I think of you as being a neighbor. It is hard to believe that you are in a drought, while my ponds have been over full pool for the last two years.

In any case, I would definitely clean out as much silt as possible. I'd try to clean the edges, and as far beyond the waterline as possible. Whether you do it, or you bring in an excavating company, I don't believe you aren't looking at a major expense.

As I'm sure you and CJ know, the King George area has many transitional zones, ranging from very impervious clay, to an intermediate area, to sandy soil and brackish groundwater from the tidal areas of the lower Potomac.

I wouldn't be concerned about drilling too deep with a PTO augar and losing a pond bottom seal. Even in heavy clay, the left over clay and the concrete will seal it pretty well. If you are in sand, it won't matter. Many years ago, I helped put in a lot of docks in that area using a trash pump to form the hole for the pilings. I haven't been back in recent years, but I'm guessing all these docks are still there.

You've got a lot of "good old boys" in that area. If you've got questions, I'd head to the local Post Office and the local restaurants for breakfast, and I'd make friends with the locals. They can tell you what will and will not work, including what you need for pilings.

(Are the Wilkersons still running restaurants and soft-shell crab raceways in Dahlgren and Colonial Beach?)

Ken

Would simply dropping some very large concrete blocks on stainless chains as anchors do the trick? It would give you some options for moving things around later.

Otherwise drive some heavy metal pipe into the ground. It will stand up to ice much better than square posts. The corners apparently get ground off of wood posts as loose ice bangs around, but the pipe can take the hit.

Putting in heavy posts would be fine though, can always back-fill the holes with some concrete to provide some stability so they don't as easily tilt later.

Dear Ken and LS:

Thanks for your comments and recommendations.

LS, we get very little ice here so its not really a concern. I like your concrete block/chain idea. I may look into that further.

Ken, yes Wilkerson's is still here and thriving. Folks still come from all over God's creation to eat there.

The weather pattern here was very unusual and strange this year. There is about an 11 square mile area of W. King George area that received hardly any rainfall this summer and fall; yet, it was downpouring all around us.

Thanks again for the comments and suggestions.

Warmest regards,
Paul

Hey Paul - I asked Jim Delozier, the dock designer at Wahoo Docks, and here's what he suggested: Have you considered using a pole & sleeve arrangement on your dock? With this setup the poles slide into the lake bottom and has the added benefit that coupled with winches on the sleeves the poles can be pulled up allowing the dock to be re-positioned. We use 4” schedule 40 poles with an angle cut on one end and cable running back up to a winch. The sleeves are 5” schedule 80 and are welded to our frame with mounting brackets for the winch.

Mike, it's a relatively small pond with few areas to have a dock so I am not sure I would ever want to move it but its worth thinking about. Thanks for the suggestion. I am having problems visualizing how that would work. Do you have pics you could share?

Thanks,
Paul