A state of emergency was declared after extreme weather in Texas and surrounding Oklahoma damaged blocks of houses and destroyed city streets, killing at least 11 people.
Houston residents have been forced to abandon their cars such is the extent of the water levels which has put Thursday's clash between City and the Dynamo at BBVA Compass Stadium in doubt.
"Prior to last night it had been very nice but then it was incredible," said Dynamo boss Owen Coyle.
"I think normally in the month of May five inches of rain falls but there was 10 inches in six hours last night so the whole city has been very badly affected by it. Everybody is trying to make the best of a difficult situation.
"A lot of the roads have looked like rivers. We normally start training at 10am and we had to put that back to 2pm to try and allow the players get into training. But in adversity people stick together and work ever so hard to put things right."
Coyle added: "Everybody at the club and in the city are desperate to see the elite of Manchester City and what we were doing was putting in a new pitch for them but the weather has curtailed that a little.