The water would run through the "crack" where the lids abut the coaming (seat back) and the fixed seat level boards forward and aft of the lid.
Then the water would channeded to cockpit floor and the lockers would stay dry. The volumn of water let in the cracks would be much less than the natural capacity of the "gutter". Unless you used a pressurized hose, your lockers stay pretty dry.
I think that would be approach I'd use.