Optimal integrated operation of reservoir-assisted stormwater treatment areas for estuarine habitat restoration

Significant reductions in pollutant loadings can be achieved through coordinated operation of constructed wetlands or stormwater treatment areas (STAs) when connected to retention reservoirs for maintaining ideal water levels and hydraulic residence times in STAs that maximize treatment efficiency. Reservoir-assisted STA systems can provide additional benefits including maintenance of target frequency distributions of stormwater inflows into coastal estuarine systems for ecosystem rehabilitation, dry season flow augmentation in coastal riverine systems for maintaining the lower salinity zone, and supplemental water supply. An implicit stochastic optimization approach is applied to adaptive, multiobjective control of interconnected reservoir-assisted STAs that optimizes fuzzy rule-based operating rules using a genetic algorithm interacting with a simulation model of the stormwater drainage system. The model is applied to the four interconnected reservoir/STAs in the design configuration of the Indian River Lagoon-South project for the St. Lucie River watershed and estuary, South Florida. Results of simulated long-term performance of the optimal operating rules show attainment of targets for remediation of the aquatic ecology of the St. Lucie estuary, riverine environmental protection, and reliable supplemental water supply.