Performance assessment of different dam discharges schemes influencing river water quality

Abstract

Hydropower energy production policies are usually defined trying to maximize the economical revenue, obeying to environmental restrictions and established downstream water uses requirements. Behind minimum daily averages of river ecological discharges, the hourly nature of the hydropower production schemes presents a pronounced effect on downstream river water quantity and quality. However, the capacity to control the river behaviour can be used to efficiently improve river water quality management practices if we can anticipate the performance of different management strategies. This paper presents a methodology to assess the performance of different turbine discharges schemes related with downstream river water quality. Three different performance indicators are presented and their computation is derived from a hydrodynamic and water quality river model implemented in Sobek. This methodology is applied to a Portuguese river: the river Cávado.