The intake for a fuel vapor storage canister separates entrained water from the entering purge flow. A separator in the form of an open ended box includes a series of alternating, interleaved, and downwardly sloped fins, the free edges of which create a series of restricting gaps that decrease in size in the upstream direction. Each gap, for some defined subrange of the total possible range of flow rates, accelerates the flow into the fin above it at the optimal velocity for water stripping.