The Impossible's' tsunami scene is one of the well praised example and here are the insiders on it :-
"We started off with a test with like six submergible pumps to try to
get the current," said Costa. "We ended up with 33 submergible pumps,
and each pump weighed like 1,322 pounds." Each pumped about 80 gallons
per second. Four large generators supplied power to the pumps, which
had to be adapted for the tank because they couldn't be visible on
The actors would sit in carts that moved on two rails inside the
channel, and they were pulled by steel cables at the same speed as the
current, said Costa. "They were very protected. They were sitting in
the baskets with their arms and legs sticking out, and we would pull
the camera next to them and behind them." - latimes.com
In behind the scene of Bollywood film Satyam Shivam Sundaram during TV telecast, it is told that they used real flood scene to catch up the intensity for film. They said , on the similar time real flood got happened.
Otherwise CGI is the solution for the rest but it doesn't look as realistic as above methods.