A vital dam in suburban Houston that protects the central city began overspilling on Tuesday, and officials said the rainfall from Harvey is so unprecedented they do not know what the impact on surrounding communities will be.
Water levels in the Addicks reservoir have reached 108ft, said Jeff Lindner, a Harris County flood control district meteorologist.
He warned that neighbourhoods in the spillway zone would begin to see street and possibly structural flooding.
Houston dam begins to overspill as Harvey triggers unprecedented impact
