Ours does that. It's also got a massive wood screw drilled through it corroding away in one corner, because landlords. Fortunately our water is appropriated from Welsh Wales, so is devoid of significant concentrations of Canterbury Carbonate.
The gradient, so much as there is one, is on the other side of the sink, where Tweedledum and Tweedledumber the lowest-bidder gas engineers used the chipboard work surface as a ladder. Any water splashed on that side of the sink gets channelled into the electrickery of the washing machine, or did until I constructed a levee out of Blu-tack to divert the flow towards the upturned lid of a tub of Minty Arse Lard, which is plumbed into the washing machine drain.