My parents have a house about 40 years old, with a sump-pump in one corner and a weird trench drain around the whole basement perimeter. It is weird because it is about 1.5 inches wide (away from the wall) and it is completely exposed to the basement. I could pour sand into it. Their basement is mostly unfinished.
In places the trench drain is clogged, so it doesn't transport water to the sump pump. It looks like it may have been intentionally, but poorly, filled in in places. Either that or remodeling compounds found their way into it accidentally.
My parents basement flooded over the weekend when their hot water heater leaked and if the trench drain had worked they would have had no problem. I would like to clean it out and make use of it but not if that is a bad idea. Were these kind of drains clogged intentionally as a matter of course as this method fell out of vogue, or would you be more inclined to believe that it got clogged by accident, or intentionally to stop a bigger problem somewhere else down the line?