Excavating a peat bog to create a fish pond?

I have some land in downeast Maine. Most of front of the lot is granite ledge with blueberries, huckleberries and small trees. There is an area that is about 150' long dogleg shaped peat bog that drains at both ends through culverts under my driveway which is a virtual mirror opposite of the shape of the bog.

I've plumbed the bog and it's about 2' deep but the ledge on either side is another couple of feet higher. Could I excavate the center and dump all that peat at each end to create say a 75' long fish pond?

How deep is the soil in that area? I would think that for a pond to not freeze solid in a Maine winter it would need to be at least 10 feet deep in the center.
Peat is not the best material to use when constructing a ponds rim, peat is waterlogged, rotted vegetation, valuable stuff when incorporated into soils.
Rather leaky when used as a substitute for clay soil.

Hi Bryant.
Between the peat and the likely rise up the sides of the ledge, not more than four feet deep I think. We're within a mile of the bay so maybe not as cold as it gets inland, but still pretty cold.

My sister had a coi pond in inland Ct, and it wasn't more than eight feet in diameter, and two feet deep, but they made it through for years.

I see your point about leaky peat, but thought that a 50' long run might clog up eventually.

Thanks for the response.

Bryant : If you were lucky enough to hit a couple of good clean clear springs that will deliver you water that fish can live in that is one thing,

If your pond site is a low piece of ground and the water to maintain it drains from a peat bog upstream from you it may be unsuited for any

aquatic animals, wrong PH and Oxygen deficient !

It sounds like the Road and the culverts running under the road control the height of your potential pond space now, any attempt to raise the height

of your pond will definitely need a very solid Clay wall to seal it. For the Good of the Craft ! Big AL

Hi Alan. This was my question. Bryant was offering some help.

The bog lies in a "dogleg" shaped gap between granite ledges. It's about 40' across and 150' long. The property is at the top of a hill and the ground on one side of the bog is about 10' higher. Because the the hill is really just an enormous mass of granite, solid here and split there, there are lots of random pockets where soil has built up over who knows how long, and a pretty thin layer of soil sustaining shrubs and small trees all over. This also means there is a tremendous amount of runoff when it rains. The culverts in the driveway don't always keep up with the amount of water that flows with the rains. This is why I imagine that if I could dam the ends of the bog, it would end up being maintained without the benefit of a spring. The question of adequate depth to prevent freezing is another question. I'd say 4' would be maximum.

Thanks for the interest.