Conditions for the reduction of carboxylic acids by LiAlH4
When the reaction is done, you need to quench it to (1) destroy the remaining LiAlH4 (2) protonate the lithium alkoxide to give you the alcohol. The aluminium salts formed can be separated from the alcohol. If you don't quench the reaction it makes separation essentially impossible.

Of course, if you add the water before the reaction is done, then that defeats the purpose of using an anhydrous environment.