The Aquascape Waterfall Spillways make it easy to create waterfalls or streams, providing smooth, consistent, leak-free water flow. As the incoming water rushes in, the water is diffused by strategically positioned internal barriers to create a smooth flow of water across the length of the spillway lip. Their durable design allows boulders, gravel, soil, or other creative landscape material to be set directly on top, making them easy to camouflage into the surrounding landscape. These spillways are extremely versatile and can be used in a wide variety of water feature applications where bulkier and more expensive biological filters are not necessary, including Pondless® Waterfalls. The spillway can also be installed as an additional waterfall or stream onto a new or existing pond, aiding water circulation and oxygen transfer. Multiple spillways can be used to design larger, more creative configurations. You can also build the spillway into hardscape walls for a formal waterfall design. The 31cm spillway is suitable for flow rates up to 15,000 litres per hour, while the larger 56cm spillway is suitable for 28,000 litres per hour. Installation is quick and easy thanks to the provided 2" threaded bulkhead fitting, creating a water tight seal between to transition through the pond liner, and they come complete with fittings (2” PVC slip and 1½" barbed) for trouble-free connection to pipework. The Waterfall Spillway is backed by a limited lifetime warranty, ensuring year after year of reliable use.