Pond Boss Forums POND CONSTRUCTION Selecting a site what about dam heighth and thickness?

Hello, I have recently purchased a property with a 2 acre pond, and it occurs to me that my water level could be made a couple feet higher and give lots more area to the pond. My question is how close to the top of the dam can you allow the water level to be without causing serious risk to the dam? I am sure there is a very straight forward way of figuring this, but darned if I know about it. I have 2 springs supplying the water so water level is not an issue. Any advice would be welcome. jim

Jimmy here is some info out of the NRCS pond guide in regard to height and width:

Top width and alignment�For dams less than 10
feet high, a conservative minimum top width is 6 feet.
As the height of the dam increases, increase the top
width. The recommended minimum top width for
earth embankments of various heights is:
Height of dam Minimum top width
(ft) (ft)
Under 10 6
11 to 14 8
15 to 19 10
20 to 24 12
25 to 34 14

Freeboard is the additional height of the
dam provided as a safety factor to prevent overtopping
by wave action or other causes. It is the vertical distance
between the elevation of the water surface in the
pond when the spillway is discharging at designed
depth and the elevation of the top of the dam after all
settlement. If your pond is less than 660 feet long,
provide a freeboard of no less than l foot. The minimum
freeboard is 1.5 feet for ponds between 660 and
1,320 feet long, and is 2 feet for ponds up to a half mile
long.

Nice research and delivery, BS. Well done.
The other factor that should be considered is the elevation of your emergency spillway (particularly with jimmyt's 2 ac pond). I'm trying to draw on my contractor's expertise when we built our project, but I kind of recall:

• the principal spillway pipe is 18" dia
• the emergency spillway runs when the water is 6" over the top of the 18" principal spillway pipe
  
• The top of the dam is 24" higher than the emergency spillway

...buffer the buffer.