Some days are hard!
We are currently building an addition on a lake front property. We dug the trenches for our footing and then the next day we came back and instead of a trench we had a moat (minus the dragon).
Fortunately, this addition had no basement or crawl space!
We still needed to be able to set our forms and pour the concrete. We decided the best way to proceed was to lower the water table and proceed in the dry. To do this, we purchased some large plastic barrels that we cut in half and dug below the bottom of our footing. In this way, our pumps could work automatically off a float and keep the ditch dry. Next, we went about the forming and pouring as usual. Once the concrete had set up (6-8 hours, depending on weather) we were able to stop pumping. At that point, the water did not adversely affect the concrete, but did in fact, help strengthen the gain as wet cure.
Not a fun couple of days, but rewarding to get a job done right!