Clients ask what a fountain costs to build. Almost nobody asks what it costs to run, and the ratio between those two numbers over twenty years is not what people expect.
Take two of ours. Millrace Court in Rotterdam is a rill with 84 low jets: 21,400 kWh and 340 m³ a year, on two 4 kW variable-speed pumps that spend most of their life at 55 per cent. Nine Fields in Melbourne is an interactive plaza of similar capital cost: 74,000 kWh and 1,900 m³ over a 210-day season, because every litre that touches a child has to be filtered, irradiated and dosed to drinking-water standard.
Neither figure is wrong. They are different products. But a client who signs off the plaza expecting the rill’s running cost will switch it off in year three, and a switched-off fountain is a more expensive mistake than either.
Where the energy actually goes
Not where people think. On a typical ornamental scheme, the display pumps are perhaps 45 per cent of consumption; filtration and circulation, which run whether the display is on or not, are another 35; and UV, dosing, controls and lighting make up the rest. That means turning the display off overnight saves less than half of what people assume, and reducing the basin volume — which reduces circulation duty around the clock — saves more.
Foundry Basin is the clearest case. Taking 65 m³ out of a 1974 civic pool and replacing four fixed-speed pumps with two properly sized variable-speed units took annual consumption from 61,000 kWh to 19,400, without changing a single thing a visitor can see.