Emergency services staged a rescue at the River Aire in Leeds today after about 31 incidents in five years.
The stretch of the river through the city centre has been responsible for more rescues than any other body of water in West Yorkshire.
Firefighters led a training exercise using boats and ropes to rescue a man floundering in the water behind Asda house.
Police and street angels were also on hand to assist.
Leeds district fire commander Russ Hepton said: “It’s not a controlled environment. If someone gets in there in deep water, potentially they could be in trouble.
“Half of incidents are over the weekend period, which is a concern to me because it suggests people are out enjoying themselves, possibly taking a bit of alcohol and the river, for whatever reason, looks more attractive.
“My clear message is don’t ever entertain getting in the water. If you do it might be the very last thing you do.”
West Yorkshire Fire and Rescue Service has been called to 107 water rescues across the county since 2010, nine of which resulted in fatalities.
There were 47 incidents across Leeds, including five deaths. Two of those were in the Aire.
The exercise was held to coincide with the Chief Fire Officers Association (CFOA) national Water Safety and Drowning Prevention Week.