In the UK, problems of flooding of domestic properties around the turn of the 21st century have been blamed[by whom?] on inadequate planning controls which have permitted development on floodplains. This exposes the properties on the floodplain to flood, and the substitution of concrete for natural strata speeds the run-off of water, which increases the danger of flooding downstream. In the Midwestern United States and the Southern United States the term for this measure is channelization.