Rainwater management
The term rainwater management describes a procedure in which municipalities , companies or other institutions take specific measures to remove accumulated rainwater , but at the same time use it. These include measures of flood prevention , infiltration measures , the (re) activation of trenches , but also z. B. the creation of hedges in the field of agricultural and forestry areas. The creation of an integrated overall concept is recommended , also because of the increase in heavy rain events associated with global warming .
Concepts
Ecological
aims
- Increase in new groundwater formation
- Reduction of rainwater runoff into public drainage systems and bodies of water
- Slowing down of rainwater runoff
- Reducing the risk of flooding
- Sustainability in water management
- Reduction of investment and operating costs
activities
- Promotion of natural but also technical seepage of rainwater, e.g. B. also of green roofs
- Promotion of rainwater use
- Discharge of rainwater into open waters as close as possible
- Naturally designed drainage channels with obstacles (e.g. coarse stones) as well as retention systems in drainage systems
- Restoration of developed bodies of water to a natural or near-natural state (slowing down the runoff; increase in plants and animals in the body of water; improvement of the self-cleaning powers and the repopulation potential in the body of water)
- Awareness-raising measures for the sustainable use of rainwater
- a comprehensive on-site consultation concept, with reference to the fact that an exemption from the compulsory connection and use of rainwater can be made upon request
- Creation of fee incentives for rainwater use and infiltration (→ split wastewater fee )
Results
According to investigations by the Institute for Technical-Scientific Hydrology Hanover , a reduction in the flood retention volume of 25% can be achieved if the degree of decoupling is reached by 20%.
In a model project in Hameln / Tündern , the investment costs for drainage could be reduced by 66% thanks to an environmentally friendly drainage concept.
According to a study from Berlin , 7–12% of the drinking water in densely populated city districts could be replaced by extensive use of rainwater . The amount of rainwater that runs off annually in the combined sewer system could be reduced by 31% and peak runoffs cut by 17–19%.
Investigations in the ecological model district of Freiburg-Vauban showed that decentralized measures in the area (green roofs, permeable surface paving, green areas, trees) combined with a downstream infiltration via a ditch- infiltration system reduced the area runoff by 87% (2011) or 66% ( 2012). Gravel-filled or green roof structures were able to reduce the roof drainage by 40 to 70% and at the same time delayed the flow peaks.
See also
literature
- [1] (PDF file; 131 kB), Stadtentwässerung und Gewässerschutz magazine , itwh GmbH, Hanover.
- [2] , German Institute for Urbanity and Urban Development, Berlin, graduate engineer Armin Stecker, Hanover: Possibilities of rainwater infiltration and rainwater management , with further references.
Web links
- general: [3]
- on ecological concepts: [4] , company water management, hydraulic engineering, project management
- Determine the dimensioning of the rainwater tank interactively
- Dimensioning of cisterns
- Intewa company , rainwater management, rainwater and gray water use
- Fachvereinigung Betriebs- und Regenwassernutzen eV, Darmstadt
Individual evidence
- ↑ a b BUND Lemgo - Homepage
- ↑ a b c http://kmertens.de/index.php?option=com_content&view=article&id=49&Itemid=54
- ↑ Nicole Jackisch, Thomas Brendt, Markus Weiler, Jörg Lange (2013): Evaluation of rainwater management in the Vaubangelände - with special consideration of green roofs and vegetation. Final report of the Institute for Earth and Environmental Sciences. Professorship for hydrology at the University of Freiburg (project number: 2009-09), 96 pp.