It sure sounds intentional and slightly taken care of. Otherwise I would think it would have naturally filled in. I assume that you have already poked around with a shovel or something, and not found a rubberized liner at the edge.

I suppose that filling it in would cost some money. Adding a rubber EDPM liner would cost $400+. Perhaps much more or impossible depending on your accuracy on size. I have heard that there are some clay like materials that can help seal natural soils. I have no idea of costs or workability. Perhaps someone here can help on that approach.

Surprisingly little else is really needed. I have a utility pond that I use for watering. It is nothing but a lined ditch fed by a french drain with 3 goldfish (now ~40) and some acqurium plants (seriously invasive if they got into natural water). There is no pump or filtering. There have been periods when the fish got no extra food, but they have grown larger than fish in my smaller maintained and fed decorative pond.

Assuming the object IS a reflecting pool, you could still add an in pond pump just to circulate the water around in the deeper part, but it wouldn't be necessary.

It sounds like there is some sort of underground liner/container that is trapping the water - but it has holes in it - so it's draining slowly. Evaporation hopefully wouldn't account for that much water loss. I agree that carefully poking around in the bottom of it might help you discover what's going on. You could also drain it with a $50 submersible pump from a home improvement store (or hours of bailing it out with a bucket) to see what's underneath. It could be that you could patch the holes in the liner/container. Or you could put down another liner on top of it, like the other poster suggested. If there are no holes in the liner, maybe it was just a poorly-designed pond that needed to be constantly refilled with a hose. Or maybe there was some other source of water piped to it, above or below ground, that has long since been disconnected. If there is no liner underneath, and just hard-packed clay earth, maybe there are cracks in the clay, or maybe it's not as hard-packed as it needs to be. I would definitely try to fix it and see how you like it once it's fixed, before you decide whether to keep it.

I agree that you need to figure out just what is there before making any final decisions. Draining it is probably the only way to find out if you have a Dew Pond that needs repair, a water garden that has filled up with gunk or a rain garden that isn't absorbing rain. It may be an unpleasant cleaning job but it could be well worth it.

Please let us know what happens. Mosquito Dunks can control the mosquitoes.

I agree about the semi cheap submersable pump; Harbor Freight or ebay. These pumps are handy to have around anyway so it shouldn't be a waste. I'm not so sure that it would be that messy a job to empty the 'pond'. Those pumps are powerful when you are not pumping them through long or high distances. You could attach the outlet to a few feet of large diameter flexable tubing that can be pointed back into the mostly emptied pond to disturb and dislodge muck from the bottom or sides. This can then be partially sucked out to get a view of the sides. Of course, this assumes that at least one edge is near an area that can have lots of muck dumped there. Great soil later!

I have to agree with your howling family, it sounds like it could be quite charming. You might want to start with a call to your local county extension office. They might be able to give you some more solid ideas based on your locale and the soil type of your property.

~dianne

Mosquito Dunks are your friend. They work great and are non toxic to wildlife and pets.