Ministry for Environment to issue heavy rainfall map by end of 2023

Ingo Hannemann, Managing Director of Hamburg Wasser, said: "Our heavy rain map is a an urban hydrological simulation that takes account of heavy rainfall, the surface and drainage systems. We are now offering the people of Hamburg a new tool for anticipating future challenges posed by excessive precipitation."  Accurate forecasts and taking intelligent precautions are important as findings indicate that heavy rainfall is likely to increase. Until now, only higher grounds were analyzed for the impact of heavy rain. The new map simulates specific rainfall scenarios and takes into account the terrain surface, surface runoff, infiltration capacity of the subsoil, and the capacities of Hamburg's sewer network and other drainage systems. The heavy rainfall hazard map of Hamburg's Tarpenbek, Wandse, Osterbeck, Greater Altona and  areas south of the Elbe is already available. 

Heavy rain in Lohbrügge/Bergedorf and Neugraben caused major damage in 2018 and 2020. The City of Hamburg has relied on the sponge city principle to mitigate mass rainwater and the risk of flooding since 2013, according to the senate. That eases urban flooding as well as water shortages. It also improves the environment and biodiversity by absorbing and rainwater. Hamburg also funds roof greening as they retain rainwater and takes heavy rainfall prevention into account when planning new suburbs. 
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