Study of Total Maximum Daily Load and Nonpoint Source Pollution Control Strategies for Reservoir Watershed

Abstract

In Taiwan, nonpoint source (NPS) pollution is one of the major causes of the impairment of surface waters. Thus, control of NPS has been considered as one of the major issues in developing watershed management strategies. The reduction in NPS must be implemented in the total watershed in order to achieve a sustainable management of the reservoir. This study employed the BASINS (Better Assessment Science Integrating point and nonpoint Sources) model to evaluate the impacts of NPS in the entire Fei-Tsui Reservoir watershed on the reservoir water quality. Additionally, the Vollenweider model was used to calculate the total phosphorus (TP) reduction. Several NPS reduction schemes had been proposed for the watershed and were tested using this model to develop allocation strategies. The purpose of this study is to estimate the TP yield loading from the entire watershed to Fei-Tsui Reservoir such that an appropriate NPS pollution control strategy can be developed for managing the Reservoir. Results of this study show that a TP reduction of over 55% is necessary in order to prevent the onset of eutrophication in the Reservoir. The information obtained in this study provides baseline information to develop a suitable strategy for managing the Fei-Tsui Reservoir watershed and implementing the proposed total maximum daily load policy in the watershed.