If you build an upground reservoir type pond as noted: "build up a big berm as high as you like, and finish off by lining the sides and bottom with compacted clay. You could certainly do a 10-12 foot deep pond in that fashion."
Those type of empoundments often leak through the embankment wall because the berm was not enough compacted the best way using a form of sheepsfoot roller - large heavy knobbed form of equipment designed specially for best soil compaction.
Bill,
I had a long conversation with Mike Otto (Pond Boss pond builder expert), about that type of pond on my property.
He agreed that building "above grade" does increase the likelihood of leaks. He also said that heavy sheepsfoot roller pulled behind large tractors are great for compacting long, mostly straight runs, but not very suitable for compacting the sides of smaller ponds.
He said the vibratory soil compactors (e.g. Cat CP44) are excellent for that type of work. The operator should just keeping working up and down the slope on slightly different runs until they walk out of each lift. Install multiple lifts as needed - especially if you are transporting excess clay spoils out of the pond basin.
(I couldn't find my most recent quote, but I believe a few years back the 100 HP size was about $2,400/week, PLUS transportation, taxes, and insurance - all of which significantly increase the cost.)
Tony,
However, I believe by far the best advice you have received in this thread is the recommendation of a local expert by Bill Cody.
A LOCAL expert plus his eyeballs on your actual ground is by far the best solution to you creating a viable and useful pond on your property!
