I still haven't gotten around to any pictures yet, but I did talk to my contractor today. He's been monitoring the pond level for the past couple weeks. Here in the last week we haven't had any rain, so it was a good week to look at.
He had previously brought a 5 gallon bucket out and put some water in it. He had the bucket down 1 5/8" over the week and the pond down 2 1/8" over the week. So, even if the dam is leaking, it's a half inch per week, at most. It's not hugely surprising to me that the pond would evaporate a bit more than the bucket, due to wind action.
He also heard back on the water tests he had ran. The water below the dam had 800% more iron and manganese than the water in the lake.
So, now I'm back to thinking this is a spring bubbling up right at the base of my dam.
The contractor suggested putting some perforated tile in and draining it off somewhere else. Recall that it is currently draining downhill (big suprise) onto my neighbors land and causing a bit of a mess. There is a ditch nearby I could drain it to, but I'm not sure if I can get a trench that deep to get to the ditch. There's quite a few feet of rise before you get over to the ditch.
I could possibly get permission from my neighbor to run the drain tile through his property, but that'd be at least 600 feet of drain tile to trench in.
My only other thought is to dig out where the water is bubbling up and try to pack clay on top of it. I'm just wondering if that would cause the water to bubble up elsewhere, perhaps higher up on the dam?
Or, I guess I could just haul in a bunch of dirt to put on top of the area and put it back like it was before.
I'm sure stumped on this one.
