The pond rarely overflows, if anything, it's typically lower than the actual bank of the pond by a few inches. I say rarely, because it did overflow last year when we got 15 inches of rain in a 2 hour period!
The natural spring starts up in the middle of my yard and travels about 50 yards underground until it enters the pond. I'd say it's 2 times the water amount compared to when you turn on an outside water hose. I'd say there's probably 5-6 springs on the bottom of the pond, near the side that drains that are about the size of a nickel in diameter that water flows in.
