Funding:

• Behörde für Umwelt, Energie, Klima und Agrarwirtschaft
• DVGW Research Centre TUHH
• EnergieConsult

Project management / project work:

Dr. Anissa Grieb

Situation:

A healthy urban climate requires an adequate amount of greenery on public and private areas, which need
sufficient water supply. In addition to the effects of climate change, population growth is leading to an increased
demand for drinking water - clearly noticeable in the Hamburg metropolitan area. The availability of sustainable
freshwater groundwater is already endangered by conflicts of use and geogenic influences (saline aquifers).
Various adaptation strategies are needed to ensure the long-term supply of drinking water. One starting point is
the increased use of alternative water sources, in particular rainwater, for purposes without requirement for
drinking water quality. At the Bergedorf cemetery, the existing rainwater drainage system is converted into a
management system as part of the RISA (RainInfraStructureAdaption) project, a joint project of BUKEA, Hamburg
Wasser and other partners.

For the conversion of the rainwater drainage system into a rainwater management system, the surface drainage of the paved areas of approximately 2 ha on the 53 ha property is collected in a rainwater storage tank in the future. The storage tank will be installed below the existing rainwater retention basin and filtered rainwater will be fed into the existing water distribution system. The distribution system for water supply at the gravesites will be completely separated from the drinking water network. In case of critical water levels in the tank, an automated replenishment with drinking water will be carried out via a free inlet, so that a permanent supply at the tapping points is guaranteed.

DVGW-TUHH will survey the project with scientific monitoring. For this purpose, the plant will be equipped with measuring technology so that the water inflow, drinking water replenishment and withdrawal are continuously recorded and linked with the climate and weather data. In addition to the system monitoring and electronic measurement data acquisition, regular sampling of the water quality and sedimented solids from the sand trap located in the inlet of the rainwater storage tank will be carried out to compare the collected data with the design approaches.