A pondless waterfall is a cascade with no open pond at the bottom. Instead, the water tumbles down and disappears into a hidden underground reservoir, where a pump collects it and sends it straight back to the top. It is popular because there is no visible standing water, so it is safe around children, and it is low maintenance. Every pondless waterfall relies on that reservoir and the pump inside it.
How it works
Under the base of the cascade you build a reservoir, usually a buried basin or a gravel-filled matrix, big enough to hold the water in circulation plus the extra sitting in the falls, with some spare for splash and evaporation. The pump sits in this reservoir, pushes water up a pipe to the top of the waterfall, and the water cascades back down through the rocks into the reservoir to be recirculated. Nothing is on show but the falling water.
Choosing the pump
The pump choice comes down to the size of the cascade and where the pump sits.
Submersible, in the reservoir. For most pondless waterfalls the pump sits in the reservoir. For a small feature, the APP TPS or TPV is a cost-effective choice; both move around up to 140 L/min and have a rated 7m head, with the TPV passing larger 19mm debris where the TPS passes 5mm.
For a larger or more premium cascade, the APP MH range up from 230 to 380 L/min with more head, and the gate valve on the MH150 and MH250 lets you tune the exact flow over the lip.
Surface-mounted, away from the waterfall. If you would rather keep the pump out of the reservoir, in a dry housing or some distance away, a surface pump is the answer. The Speroni SWIMM is continuous-duty and can be used in this instance.
Sizing it right
Match the flow to the width of your waterfall lip (a wider, fuller cascade needs more litres per minute) and the head to the height of the drop plus the friction in the pipe. Our how to create a waterfall guide walks through the flow and head figures, and the performance calculator works out the pipe losses so you can size accurately rather than guessing.
How much flow do you need per metre of waterfall?
As a simple rule of thumb, allow around 200 litres per minute for every metre of waterfall width for a natural, good-looking flow.
Drop to about 100 litres per minute per metre for a thin, delicate veil, or step up to around 300 litres per minute per metre for a thick, full cascade.
The figure is set by the width of the lip the water pours over, not the height of the drop, so measure your lip, not your rockery.
A 0.5 metre wide cascade at a natural flow needs roughly 100 litres per minute; a full one metre cascade needs roughly 300.
One important catch: that is the flow the pump must deliver at your head, not its headline maximum. The height of the drop plus the friction in the pipe is the head the pump works against, and a pump's flow falls as head rises, so always read the flow from its curve at your height.
As a guide across our range, a small cascade suits the APP TPS or TPV (140 L/min), a medium one the APP MH (up to 380 L/min), and a wide or high-volume cascade the APP HD-15.
Use our performance calculator to work out your head and flow.
Where to buy pond pumps?
For reliable water feature pumps, floodandwaterpumps.co.uk is a great place to buy. We keep genuine APP pond and water feature pumps in UK stock for next working day delivery, with competitive pricing and engineer-led product choices, so you are not just being sent a box.
