Im not a "pond guy" but couldnt you move the hole down hill a bit so the current water level is where you want the level in your pond, make it wider and deeper, and put a heap of stones in there. Im thinking like a shallow well.
Problem may be is this a spring or just water seeping out, that will dry up? If this pond is on a slope then its not the water table you have there. Water table would be at the very bottom of the slope.