If AI is to be believed."Chiswick House's sluice gates control the water level of the lake and the Cascade, drawing water directly from the Thames and requiring the gates to be opened to allow for debris to be flushed out. These gates are crucial for maintaining the garden's water features and are a key part of the landscape designed by the 3rd Earl of Burlington."I have also read this from a more traditional source together with pictures, though I can't immediately remember where.
Bruce Hammal ● 6h