I recently bought some land in Bandera,TX with seasonal creek fed ~one acre pond on it. It was full this time last year and started dropping in June of this year after the creek stopped flowing. By the end of July it was completely dry! Recent rains earlier this month filled it up about half way, but three weeks later it almost dry again. I suspect it is going through or under the dam because water is collecting behind the dam more than after the before mentioned rains. I could never tell before because there is a larger pond directly below my dam on the adjoining property which dropped in water level enough to see the collecting water. My question is this: I was told that trees on dams are bad and I have a few large cedar trees and one mesquite on the dam. Should I cut them down or will that only make things worse because of the roots rotting and leave spaces in the soil?

Also I heard that a mature cedar can drink up to 60/gallons a day. There are cedars all around the pond. Would clearing all cedars within 50-100 feet of the pond help?
Thanks for any input!