planninghygiene
Why do splash pads have a recirc tank?
Quick answer
Recirculating splash pads use a holding tank to capture used water, filter and chlorinate it, then pump it back through the features. This dramatically reduces water consumption — a recirc pad uses 5-10% of the water a flow-through pad uses on a hot day.
Splash pads come in two main flavors: flow-through and recirculating. Flow-through pads draw fresh water from the city main, run it through features once, and dump it to storm drain or sewer. They're simpler and cheaper to build but use enormous amounts of water — a busy flow-through pad can burn 10,000-30,000 gallons on a hot summer day. Recirculating pads capture water in an underground holding tank, run it through sand or cartridge filters, dose chlorine to maintain residual, and pump it back through the features. They use 90-95% less water but cost 2-3x more to build and require more maintenance. The recirc tank is the heart of the system and typically holds 1,000-5,000 gallons. State health codes have stricter rules for recirc pads (more frequent water testing, secondary disinfection in some states) because of the contamination risk that comes with reused water.