Co-ordinated environmental regulation: Controlling non-point nitrate pollution while maintaining river flows

Abstract

Environmental policy often addresses multiple targets, yet much economic analysis of pollution control is based on a single-target objective. In this paper, we present an analysis of policies to control non-point source nitrate pollution in the presence of minimum river flow restrictions. A non-linear bio-physical economic optimisation model of an intensively cultivated Scottish agricultural catchment was constructed. The presence of minimum river flow controls in the catchment was found to reduce nitrogen pollution. However, by themselves, river flow controls were found not to be a cost effective means to reduce non-point pollution. We quantify the improved social welfare from coordinating the environmental regulation of river flows and pollution, and determine the conditions under which such coordination is beneficial. The paper also investigates whether the benefits of such coordination can be sustained under wetter (winter) weather conditions implied by current climate change predictions.