Plash can mean a pool or puddle, or a splashing sound. It's usually used in reference to water and I feel it suggests something gentle and refreshing. A fountain plashing water into a large basin where wearry tourists stop to rest. A beach being plashed by the tide. The sound of oars plashing into a sunlit river overhung with willows.
It's the kind of sound we'd enjoy hearing on a hot midsummer's day.