You obviously have a major leak within the motor. It is probably as simple as an intake gasket but it could be as serious as a split cylinder wall. Drain the oil (and water) as soon as possible and remove the filter to get as much as possible out. Leave the drain plug out so that it can continue to drain overnight. Remove the manifold carefully to determine if the water leak is actually traceable to that source. If a slipped or defective intake gasket is the problem you should be able to spot it.