And diversion channels for water might not be big enough, or last long enough.
In 262, a sluice gate was added to control the flow of water into the diversion channel.
The dam diverts water from the river by a 372 m long diversion channel and involves a flooding of only 3.42 km2.
The land in such a diversion channel was kept clear of buildings and obstructions.
The diversion channel was at first called the Po di Ficarolo.
The diversion channel was plugged on 17 December 2010, allowing the dam to begin to fill.
The powerplant replaced a small run-of-river plant, which received water from a diversion channel.
The nearby diversion channel at The Island was cut for a similar purpose in 1859.
They dug diversion channels and built floating dams to stop the pollutant from advancing further downstream.