The cause was the repair of a sluice gate that regulated the flow of water from the pond into a brook.

And have we become weirdly amphibious, in mortal danger when separated from a constant water supply, our gullets open like a sluice gate?

The best bits — the beamed ceilings, the millrace and the pond, now controlled by a modern sluice gate — have been retained, and are joined by five bedrooms and landscaped grounds.

At the moment the sea came into the pond and fishes of every kind entered the sluice gate.

Note, the sluice gate induces a choke in the system, causing a backwater profile just upstream of the gate.