are you sitting down?
An "acre foot" is the area/volume of 1 acre of land flooded to 1 foot of depth (43,560 cubic feet). An "acre foot" of water is 326,700 gallons of water per acre! If your swamp is exactly 11 acres & the average depth is 2 ft (you said max is 4?) then you will need:
In case you were wondering:
43,560 x 2 (ft) = 87,120 cubic ft per acre.
87,120 x 11 (acres) = 958,320 cubic feet in your 11 acre swamp at 2ft avg water depth.
To answer your question:
326,700 gals per acre foot x 11 acres x 2 (ft) = 7,187,400 gals of water!
That doesn't take into consideration things like evaporation, soil absorption loss (I hope you didn't lose your seal via those dozer holes), actual pump output, pump/equipment failure/breakdowns etc...
If you could actually pump a steady 125gals per min, 24/7 (with none of the above variables) then it would pump 180,000 gals a day which would take 39-40 days to pump 7.2 million gals. (Hope that well is FULL!)