Thanks for the feedback. I do believe that I will need to downsize that watershed by building a berm or two to eliminate some of those acres from going into this pond or it would back up on the neighbor's property.
I appreciate the info on an island and the sediment pond.
Hi! Keep in mind that it’s not really the watershed size that will keep water off your neighbor, rather it’s the elevation of your pipe or spillway the will keep water off your neighbor. Example: If your spillway crest is at 1500’ elevation and your property line in the upstream channel is at 1499’, you will flood water over the property line regardless of your watershed size, it just might take a little longer to do so with a smaller watershed.
As a rule of thumb, when laying out a pond, I keep the top of the dam elevation (which is usually about 2’ above the spillway elevation, but can vary based on the amount of flow your spillway is designed to handle) at or below the property line elevation. That way I never have to worry about flooding the upstream neighbor. In the example above, I would set the top of dam about 1498.5’ or so.
Good luck!
