Leak? Evaporation?

[cerceau]

It's a 5 x 7 oval-shaped pond, about 2' deep, with three fairly large koi and no plants. Watersplash on one side, filter and pump in a well on on the other.

Every week the level drops about an inch - 1 1/2, so I have to add water. Is that more or less normal?

The man who constructed it can't find any tear in the liner. Is there a way to calculate even a very approx. evaporation rate, given the surface area, the fact that the pond is in semi-shade on the NE side, in the Midwest? Or should I still be looking for a leak?

 

[ididntdoit99]

An inch or 2 doesnt sound like alot to me. In fact alot of people dont know this, but you lose alot more water in the fall when temps are warmer during the day and cooler at night, it sucks the water right out of the pond.

The best way to determine the answer is to perform a simple experiment. Figure out the surface area of your pond, and a five gallon bucket of water. Get a bucketful of water from the pond, let it sit for 24 hours or a week or whatever and then measure the drop in the level of water. You can make a pretty good estimate of your evaporation rate by multiplying by the ratio of surface areas of the pond and bucket, times the volume of water that has evaporated from the bucket. (as long as it doesnt rain and ruin your experiment.)

 

[taherrmann4]

I agree with ididntdoit, that is not that much water loss.