Nutty,
Your description sounds pretty much like what I had to start with. If it has a decent watershed, you are blessed. It can take a long time to find this kind of topography, particularly with the pondsite completely captured within your property boundaries.
I have not perused PPWO? yet, so I can't relate to your findings therein. The one thing I want to define further, tho, is your statement about a "natural wetland escape". It sounds as if you say that the area where a dam would be constructed is currently a wetland or marshy zone. If this is correct, does it actually hold water or are we talking minimal retention only when it rains...then it dissipates and runs off further downstream?
Either way, getting back to our potentially similar pond projects, I had the same 5 ac bowl that ran off and out one end in a small, narrow creek that only had water when it rained. This runoff ran between two opposing hills about 30 feet high, 350' apart near the tops. It was ideal for placement of a dam to cork up the bowl. We cored it. In fact, the forum developed a pretty lengthy and informative thread on
this thread . Looking back, we might very well have gotten away without a core; our clay content was that good. My contractor always cored his ponds and the PB support crew gave me no reason to not go ahead and do it. We did. Yeah, it cost a little more, but I'll never say "what if". Plus, it gave me a look at what is down there, directly below the most important engineering feature of the pond.
