Minimum ecological water management

The ecologically justified minimum water management (Qök) describes the minimum water requirements of the flow-sensitive species macrozoobenthos and/or fish necessary to enable grade 2 (good) for these biological quality components if other parameters do not disagree. A long-term below of this flow value is highly likely to result in a target failure. The Qök values are minimum flow values calculated by means of LAWA-type-specific minimum water orientation values (MOW in l/s*km²) and the catchment area size of the water sections of natural or significantly modified flow water ODCs. For the comprehensibility of the calculations, these necessary data bases are listed per flowing water section. In addition, ArcEGMO modeled quasi-natural mean outflows and mean low-water outflows for the 1991-2015 series. This allows the comparison of the ecologically necessary minimum outflows with the simulated hydrologically possible water supply in low water times and thus — possibly after comparison with measured MNQ values — the determination of the ecologically justified minimum discharge (Qmin,ök) as the starting point for the official definition of a WFD-compliant minimum water management in water law procedures.