Very, very large pond with many problems
Hi, all--I have been a Gardenweb member for many years but haven't been active in awhile. But i'm back with a big one.
My daughter and her husband are buying a house with a very large pond. I have accepted the position of Head Water Gardener with great pleasure and growing trepidition! I used to have a small 800G pond years ago that I loved messing in and I have wanted another ever since. Now I essentially have it.
It measures 110 feet by 50 feet. Depth when full is I think mostly 2' but there is supposedly a 4' deep area, too. So probably at least 80,000 gallons, maybe 110,000 or more. Eeek!
Biggest problem: it is lined ONLY with landscaping cloth. No butyl liner, no betonite, just...synthetic burlap-weave fabric. It is held down around the edges with random rocks. We do not know if the owners installed the pond or if it was there when they bought the house. We do know that it was there in a 1992(ish) land survey so it's at least 20 years old.
We have seen the house twice in the space of a month and at the second visit the water level had dropped at least 8", maybe even 10". So obviously water is seeping out. The second time, more of the liner was visible around the perimeter and there were 1" holes in it here and there.
Nothing is growing in it except wolffia and duckweed that covers the entire surface (mostly wolffia). No algae, not even any cattails. There are numerous old, blackened lotus seed heads floating in the water so something USED to grow there.
I poked with a stick and estimated there to be about 6" of muck on the bottom near the edge---possibly thicker muck farther out? Dunno. It reeked like sewage. Anerobic bacteria are hard at work.
There is electricity to it but all that's left are the ends of the cable sticking out of the ground. We would have an electrician test this for viability before doing anything with it.
We don't know if rainfall is enough to keep it topped off most of the year, or if they also used a hose. They did say something about the water getting low in the summer "due to evaporation" but not much else. There are one or two 4" diameter plastic pipes exiting the ground near the edge, draining into it. These come from the direction of the house and we think may carrying downspout water. Not sure, though. The pond is at the foot of a slope and there's no grading to keep runoff from flowing into the pond.
I think a bog filter is maybe the only practical way to get the water healthy and there is PLENTY of room to build one within the pond. But it seems pointless to do it without putting a real liner under that part of the pond at the very least. Maybe it's pointless to do anything at all without a real liner...???
Of course, money is an issue. They can't afford to do much with it for a year or two (or maybe more), but in the meantime it is a red hot mess and I did see some mosquito larva in there, too. UGH. (No fish that i could see but there are frogs, little ones and a few bullfrogs! Yay!)
So...opinions? Worth restoring? Not possible without lining the whole thing?