Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations evaporation

I'm trying to decide how much water I'm loosing to evaporation and how much to seepage. I have a 2 1/2 acre pond. With no rain to speak of in a month how much evaporation (drop in level) can I expect? I'm sure there is a formula.

Mike - The weather bureau records or reports the "pan evaporation" rates usu. daily. These amounts indicate how much water will evaporate in your area each day. Keep track, add them up, and you got your evaporation total.

Bill - here's a "crazy" theory that came to mind:
Would a calibrated cylindrical bucket, filled to a specified mark and then floated in a stabilized manner within the pond be a means of distinguishing evaporation from seepage?
After inserting a yard stick into the pond's bottom near the bucket (with the surface level marked on the yard stick), if the surface level on the yard stick drops by a greater degree than the original water level within the partially-filled (yet floating) bucket, the difference between the two fluctuations could be attributed to seepage while the drop within the bucket could be isolated strickly to evaporation. ???? (The reason for floating the bucket in the pond is so the water within it would replicate the pond water temperature.) Do you think this method has any merit? Kelly D

I definitely think that idea has some merit. This is assuming of course that the bucket does not create shade which will reduce evaporation from the bucket.... and any decrease wind effect in the bucket that may slow evaporation. Slight variances aside is certainly seems like it would be a decent starting point. Should at least give enough info to determine if there is a significant seepage.

The bucket's internal "mark" would be near its upper-lip, yet low enough to prevent turbulance from splashing additional pond water into the bucket. Obviously, the selected site would need to be isolated from wave-action (the absence of which may influece the relative rates of evaporation). KD