Water Quality Trading in Integrated Hydrologic Framework

Abstract

This paper accomplishes three objectives. First, a novel hydrologic modeling approach is used to estimate (i) nonpoint source (NPS) loadings at the field level (rather than at the watershed or sub-watershed levels), and (ii) delivery ratios at the sub-watershed level (rather than being arbitrarily chosen). Second, our study area includes two receptor points (rather than the typical case of a single receptor point), therefore enabling us to demonstrate how multiple receptor points can be incorporated into a water quality trading (WQT) framework. Third, we develop a basin profile that can be used by regulators to identify specific trades, whether point-to-point, point-to-nonpoint, or nonpoint-to-nonpoint. The profile is operational, i.e., it is easily updatable with time-sensitive environmental and economic data, and can be generalized to any watershed. We then demonstrate how the profile can be used to assess potential trading opportunities. As a result, the paper provides an example of adaptive management of water quality in a large, predominantly agricultural river basin.