Flood-prone area of the United Weißeritz

The area at risk of flooding, presented in map form, is based on Section 75(1) No.1 and Paragraph 2 of the SächsWG. It is an area that is flooded only when a flood event is exceeded, as is statistically expected once in 100 years. Pursuant to § 75(2) sentence 2 SächsWG, the extreme event became in accordance with the hazard map of the flood protection concept for the Weißeritz (responsibility: Free State of Saxony, state dam obsolete) used. It corresponds to the flooding area of the Weißeritz floods of 12-13 August 2002. The recurrence interval of this event was carried out by the LfULG at the age of 500 (Saxon State Office for Environment and Geology; Event analysis Floods in the Easter Mountains in 2002; (July 2004) indicated that the flow rate was expressed at approximately 450 m³/s. It was the largest flood of the Weißeritz to date. The flow rate was approximately 1.5 times the largest flood of July 30, 1897. In June 2013, the fourth largest Weißeritz flood occurred since observation began. The flow rate was between 150 and 170 m³/s and the final evaluation by the competent authorities of the Free State is still pending. By 2020, the United Weißeritz will be expanded in Dresden in such a way that a flood as in August 2002 can be discharged without large expanses in the riverbed. The efficiency of the water bed is currently approximately HQ100 (flow rate 234 m³/s). Until then, in the event of extreme events, large-scale floods can still be expected and, as a result, risks and impairments to the well-being of the general public and public security and order (endangering life or significant damage to health and property). According to Section 75(5) of the SächsWG, planning and construction measures adapted to the risk must be taken in order to prevent damage caused by penetrating water as far as possible. In particular, structural measures must be taken to prevent the presence of hazardous substances in the event of floods.