Rebecca,

Welcome to Pond Boss - and the ideas in your post sure look like a good "dream" for your land.

The size of an embankment pond in a ravine or draw also needs to match the amount of run-off expected from the watershed upstream of your dam location.

Most of Michigan only needs 3-5 acres of watershed per surface acre of pond. I can't see what the topography looks like to the east of your land, but your problem should be too much water rather than too little. (Those of us that live in drier areas would love to have that problem.) Too much water just requires some additional spending during the construction phase to build larger spillway structures and increase the height of the dam above your normal pool level.

Generally speaking, a taller dam with a shorter length is cheaper to build. That is why most dams are built in the narrowest section of their respective waterways. It looks like you could move the dam for your north pond 200-300 hundred feet to the east to better utilize the side slopes of those two plateaus. The pond will then have two "coves" to the east (depending on the height of your dam). Some people like that look.

Another option to keep your water cleaner, is to create a series of ponds in the same draw. The uppermost pond will somewhat serve as a settling pond for all of the silt that washes in during big rain events. It can also provide an emergency source of water to your lower pond during a drought. A gravity feed pipe is cheap and easy.

If you like that concept, you might consider moving your southernmost pond to the east of one of your larger ponds. In addition to allowing cleaner water to the lower pond, it can also help with flood control for your largest dam. Any extra freeboard on the "upper" pond helps retain some floodwater that would be going into the "lower" pond.

Finally, I think you could easily create a 4-acre pond at your middle location. Just increase the dam height to the elevation that will create a 4-acre pond WITHOUT impounding water on your neighbor's property. You need to include the flood stage elevation such that it also stays on your property, but it looks to my eye that you might just have enough room.

However, I agree with Theo that more, smaller ponds might be a more enjoyable option. I don't think swimmers could significantly muddy a pond as small as 0.5 acres. Just make some 10-12 foot deep water for the swimmers adjacent to a shallower area for the kids and non-swimmers.

Good luck on your project and have fun planning your dream!

P.S. What is the contour interval on your map?