Disconnection and seasonal retention
Disconnection of non-polluted paved surfaces from the sewer system creates a buffer supply in retention basins for drier periods. One of the measures to prevent the intake of foreign water as much as possible is the establishment of seasonal retention basins in an urban area. This can be designed as an open body of water which is able to handle large fluctuations in water level, or by assigning locations which may be flooded, functioning as temporary retention basin and have an alternate function in summertime. The buffered water is available during the dry season.
See also the measure: Seasonal storage.