Backwash
Definition
A maintenance cycle at recirculated splash pads where water flow is reversed through the filter to flush out trapped sunscreen, hair, leaves and debris before being sent to a waste line.
Backwash cycles run daily or every few days depending on bather load. The operator opens a valve that reverses flow through the sand or DE filter, lifting trapped contaminants up and out to a sewer drain. The pad is offline during backwash — typically 5–15 minutes.
Backwash water counts against the pad's daily makeup-water budget, which is why drought-prone cities specify high-efficiency cartridge filters that need less frequent flushing. Skipped backwashes are a leading cause of cloudy water and chlorine demand spikes.