It was considered dÃ©classÃ© to refer to one's own townhouses, estates or villas (or those of friends) as mansions and modern etiquette books still advise that the terms house, big house or great house be used instead.
Waste weir. A waste weir on a navigable canal is a slatted gate on each canal level or pound, to remove excess water and to drain the canal for repairs or for the winter shutdown.
The solution to slowing down water flow is to build locks. A lock in a canal is essentially a dam, and it keeps the water at the top and bottom from flowing too fast. To get the boat up or down the required elevation it floats the boat in a tub of water.No power is required for a lock, to get a boat up, water is let into the tub from the upstream (high water) side. canal is a manmade waterway with a minimum depth of water in it. On the Rideau for instance, the minimum depth is 1.5 metres (5 feet). However if you just dig a ditch to the required depth and let the water flow through it you still have the other problem a rapid has, fast flowing water.