NiddaMan

SCIENTISTS AND WATER MANAGERS ARE WORKING TOGETHER FOR CLEAN RIVERS IN HESSE

Numerous conflicts of use characterise the Nidda catchment in the German state of Hesse, making it in many ways representative of rivers in central Europe. The joint project NiddaMan will focus on developing a computer model for water managers, using the example of the Nidda catchment. The model is intended to support decision-makers both with designing and implementing measures for more sustainable water resources- and catchment management. To achieve these objectives, research work will be carried out in six priority areas. These include developing new methods for monitoring trace substances and evaluating their suitability to serve as lead substances for defined groups of chemicals which represent a risk factor for the chemical water quality. Major stressors on biodiversity will be identified with biological tests in the laboratory and in the field. The development of sustainable water resources management strategies also factor in insights from socio-ecological research. Another project priority area addresses the development of technical measures and adaptation strategies to reduce the emission of problematic substances resulting from wastewater effluents into the aquatic environment. Modelling pollution discharge and water quality while considering demographic and climate change scenarios will tackle important future societal issues. By combining the respective insights, assessments and concepts, an integrated information- and management system can be set up.

GOALS

The overall objective of NiddaMan is to develop a web-based information- and management system (NiddaPro) for water authorities. The intelligent system solution is intended to form the foundation for more sustainable water resources management of riverine systems, using the catchment of the river Nidda as an example. The model will give water managers responsible for decision-making a basis for planning and implementing measures for sustainable water resources- and catchment management – with a particular focus on transdisciplinary concepts and action strategies. The partners thus aim to improve communication and collaboration between scientists, water management practitioners and the general public.

Photo: Goethe-Universität, Abteilung Aquatische Ökotoxikologie

MODEL REGION

With a length of 89.7 kilometres and a catchment area of 1,942 km², the Nidda is one of the key rivers in the German state of Hesse. The Nidda is characterised by agricultural and industrial use, inadequate water structures, high pollution, settlement activity, a poor ecological status, and flood risk in the catchment area.

Key messages

• Measures to improve biological and chemical water quality should include streams and headwaters, even when these are not WFD-relevant, because these water bodies are a crucial source of biodiversity in aquatic systems.
• Isolated measures to renaturalise a river or to eliminate trace substances are by themselves not adequate to improve the chemical-ecological status of a water body.
• Embryotoxic and in vitro toxic activity potentials were already detectable in the rivers’ headwaters, both in the water body and in the sediment. This is why measures should also be targeted at improving the quality of the sediment.
• Percentages of purified wastewater of ≥ 12 % in the annual mean (TITAN analyses) in the Nidda catchment area lead to changes in the species composition of the macrozoobenthos which do not conform to the reference conditions of the Surface Waters Ordinance provided for the defined types of water bodies. Above the calculated annual mean for wastewater, the abundances of particularly sensitive species drop abruptly. Through more effective, pollution-related wastewater purification, the critical percentage of wastewater can be increased.
• When planning water management measures, the participation of interest groups should be enlisted and communication with them should begin early, according to the principles of cooperation management.

Further Information

• Homepage
• App NiddaLand
• Chapter in the ReWaM Brochure (German)
• Project sheet (German)
• Flyer (German
• Poster (German)