I have a 9 acre pond that was constructed about 3 years ago. I have a limited amount of drainage, only 75 to 80 acres.
I had a small amount of seepage but treated with benonite, which seemed to help.

Now I notice that I have wet areas that are from 10' to 40' away from the base of the dam on the dry side. These areas are in undisturbed soil. I do not believe that these existed before building the dam. I do have some springs in the area. Could the dam core have blocked the natural course of a spring causing the spring to surface or could this be a leak ?

Any ideas, should I treat with bentonite again?

Is the water level in the pond dropping by a rate that should exceed evaporation?

I believe that is but with the current evaporation rate as high as it is I am having difficulty determining the amount of loss.

Probably need to make a guage of some sort to determine exactly how much water I am losing.

Can you give me an idea of the best way to accurately determine the amount of loss?

Thanks for your response.

Drew, I determine the amount of loss/gain by taking an aluminum powder coated yardstick and attaching it to a stake. I put it in the pond so I can measure water fluctuations.

My pond bounces around so much that I had to go with a 72" "yardstick". The 36" one was high and dry last year.

As long as you can accurately measure your ponds area, you can calculate the # of gallons.

I just compare the ponds drop in inches to the livestock tank drop in inches. I'm using 2 of those tanks for ornamental ponds by the house. One has a fountain, the other one doesn't. The one with the fountain has almost double the evaporation loss as the one without.

You could probably place a 5 gallon bucket that's full to the brim next to the pond and compare that evap. loss to the loss in the pond.

Thank you for the advice. I will use your guidelines and do the same.

Position a partially-filled 5-gal bucket directly IN the pond in such a manner that the bucket's water-line meets the pond's current level. In theory (and excluding the influences of fountains and/or watershed-runoff into the pond), IF the pond's water-level drops below the bucket's water-level ~ you have a leak. Otherwise, the two vessels of water (@ identical temps, due to the bucket being submersed) should evaporate in unison.

Kelly, I thought filled to the brim would allow any wind movement to be the same over the bucket and pond. I didn't think about temps!

I think that you two may have the answer. I appreciate your suggestions and plan to implement this weekend. Glad that I joined the forum. Will keep ypu posted on the results. Thanks

I performed the test as you suggested. The evaporation rates were almost identical and were very close to the last NOAA evaporation rates that I saw for this summer. Approximately .3175" per day.

The ponds rate of evaporation was about .125" greater than the evaporation rate for the bucket. I will continue to monitor.

Thank you for your advice.

Drew:

Thanks for the update. If there are any trees or other plants that could uptake water from the pond, that could be the reason for the difference in water levels. Where can I find the eveap rates for this year? I'd like to try and find the rates for my area.

LSU Agriclimate and NOAA. Hard to find on NOAA but they occasionally publish. I would think that one of the universities in your area or the state will have it.

Sorry for the late response, I have been traveling.

I have a 9 acre pond that was constructed about 3 years ago. I have a limited amount of drainage, only 75 to 80 acres.
I had a small amount of seepage but treated with benonite, which seemed to help.

How did you treat with bentonite? Is the area still wet? I have a similar situation, but do not know how to proceed? With the water way down, this would be the time to fill holes or stop leakage, but it is difficult to find the problem.