The Braunschweig Rieselfelder is a facility for near-natural wastewater treatment. The Rieselfelder are located on sandy soils between the district of Watenbüttel and the community of Wendeburg in the northwest of the city of Braunschweig.
As early as 1895, on the area of the Steinhof monastery estate, the trickling of about 11,000 m³ of wastewater (sewer slurry) per day from the sewage system in Braunschweig was put into operation on about 490 hectares. The areas on which the wastewater was recycled were initially used mainly for vegetable cultivation. After the Second World War, the volume of wastewater increased to such an extent that there was no longer sufficient capacity to carry out biological wastewater treatment in the area of the trickle farm alone. For this reason, the Braunschweig Wastewater Association was founded in 1954 and the Steinhof wastewater treatment plant built by it was connected upstream; the Rieselfeld plant was then converted to secondary wastewater treatment. The Aue-Oker canal serves as the receiving water for the treated wastewater (clear water).
Since 1991, the layout of the treatment ponds, which today cover around 60 hectares, has been modeled on a naturally meandering river, so that the already relatively clean wastewater from the upstream treatment plant can once again let its remaining suspended solids settle for a longer period of time. Further downstream, part of the water seeps away and reaches drainage ditches through bank filtration. The clear water that emerges at the end of the system chain meets the highest requirements for wastewater quality. The quality of the clear water is so high that some of it is used to irrigate nearby vegetable fields.
The pond landscape of the Rieselfelder attracts numerous bird species, and for many decades it has also been an area of operation for NABUBraunschweig, which nurtures the waterfowl here and provides nature and ornithological...