Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? Water loss question

I've owned my property for 1.5 years now. Realized last year the 1 acre pond is losing water. I never really measured it till now. In the past, I just flagged the shore hoping to eventually find the point where it stopped dropping so I could then hunt down the leak. Unfortunately it never stopped before rain would push the level back up. So I'm preparing to apply a sealant and figure I need to measure it more precisely. I found that at 3/4 full, it lost a 1/2 inch on a cloudy day with temps in the 60s. I'm assuming none of that is evaporation.

My question is, if no evaporation takes place, should I expect to see the same drop in water level regardless of how full the pond is? That seems to be the explaination I hear frequently on this board but doesn't make sense to me. If x amount is leaking out and that amount doesn't change then I'd think the drop would accelerate as the surface area and volume shrinks... assuming the pond is bowl shaped. Then there's the hydraulic pressure issue complicating the matter. My problem is that I can't establish a control to measure my pond against. Once I treat it, I will expect no water loss on cool days but we are approaching summer with heavy evaporation exaggering the problem. I was kicking around the idea of measuring water loss in a bucket to that in my pond. Does this approach make sense or is it too oversimplified?

I've got a leak also. We've had very little rain since the first of the year, and I'm down 30". We did have 2" of rain a few weeks ago, but very little runoff.
I've bought some of the soilfloc, but haven't applied it yet. I've heard hydraulic pressure will help it, so I was waiting for it to fill from some big rains, but we aren't getting any.
Then I heard get it down before all the FA covers the bottom, but I don't think I've got that problem. I do have a fair amount of leaves on the bottom, as my pond it tucked into the trees. I guess what I've come to think is, put down the soilfloc, or whatever sealant you are using, when ever you can get it done. I'm trying to line up a little help, at least one additional person to help line up the grid, and pull the boat across.
As long as the wind isn't too strong, I'm going to go for it.
There are so many variables that affect the leak rates (you mentioned most) that measuring it and tracking it, seem a little pointless.
Just my $.02..
Jeff

I'm using soilfloc also. My pond goes down approximately same rate at 1/2 full as it does now nearly full.. At least I believe that to be true. I don't have an accurate measure when it got down below half. My thinking is I want to treat the lower basin only which will be much easier with the pond low. Either I'm waiting for it to drop or I'll be pumping it out before I apply. Hydraulic pressure might work better but less water means I can concentrate the material where I need it. Only problem I have is good ole mother nature is all I get to fill it back up.

Let me know how I can help - here anytime!