Pappy - I think the freeboard height (dirt height above water) will actually depend on the watershed area for the pond. The smaller the watershed the less freeboard height that would be necessary. A pond of your size I would expect the normal free board height to be around 12". But for appearence, less freeboard looks better. 3" -4" is probably okay in your case, just keep the spillway well grassed and maybe don't mow the grass quite as short in this area which will make it better and more durable for erosion control since the spillway could get a lot of use after most rains.


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