20 GPM won't do squat, but keep her capped off.
It may be springs, but spings below the proposed water level ain't good.
Wait and see is not bad, but not fun either.
A feller I know re keyed the back of his one time if I recall. He worked on the front too. Both together worked OK, but nothing like 40 full grown black baldie cows trampling the floor of the pond and dam.
