Modeling the eutrophication of two mature planted stormwater ponds for runoff control

A model, targeting eutrophication of stormwater detention ponds was developed and applied to sim-ulate pH, dissolved oxygen and the development of algae and plant biomass in two mature plantedwetponds for run off control. The model evaluated algal and plant biomass growth into three groupsnamely; phytoplankton, benthic algae and macrophytes. The study evaluated large data sets from anintensive monitoring campaign of two Danish mature stormwater ponds which were used to calibrateand validate the model. One general calibration covering 6 consecutive months together with two addi-tional short-term calibrations during summer (31 days) and winter (56 days) were carried out applyingthe data series from one of the ponds. The calibrations showed a good agreement between measuredand modeled data for the time spans evaluated. The calibration showed that growth rates for the threegroups of primary producers were approximately the same for the two calibrations. The validation forboth trends of DO and pH were well simulated, even though pond Aarhus showed a better agreement ofthe absolute values. The eutrophication model could be successfully calibrated to two stormwater pondsand has the potential of providing a tool for improving the design of stormwater ponds by taking intoaccount the behavior of the plant ecosystem.