Abstract: An evaluation system models water usage within a region. The evaluation system provides a graphical representation of various water system components. Each water system component has a model describing its water balance and parameters for customizing the model for an instance of the water system component. The evaluation system receives indications of water system components within the region along with connections between the water system components. The evaluation system receives values for parameters of the water system components. The evaluation system then calculates the water demand of the region by calculating the water balance of each water system component within the region based on the models for each water system component and the connections between the water system components. The evaluation system provides a cost-effective solution to manage water usage within the region.

Abstract: A method and system for calculating trading ratios between a buyer and a seller of water quality pollutant load credits. The water quality trading system (“WQTS”) inputs a definition of watershed and land uses of the watershed. The WQTS then calculates the load credits (e.g., the difference between total maximum daily load of the pollutant and the actual load needed) of applying various controls (e.g., best management practices and treatments) to the point sources and non-point sources of the watershed. The load credits take into consideration the uncertainty of the calculated loads.