Characterization of the Water Quality Status on a Stretch of River Lérez around a Small Hydroelectric Power Station

Abstract

The renewable energy emerged as a solution to the environmental problems caused by the conventional sources of energy. Small hydropower (SHP) is claimed to cause negligible effects on the ecosystem, although some environmental values are threatened and maintenance of an adequate water quality should be ensured. This work provides a characterization of the water quality status in a river stretch around a SHP plant on river Lérez, northwest Spain, for four years after its construction. The ecological and chemical status of the water as well as the ecological quality of the riparian habitat, were used as measures of quality. Data were compared with the water quality requirements. The variations in the quality parameters were analyzed over time and over the river sections with respect to the SHP plant elements. Two years after construction, the temperature and dissolved oxygen values achieved conditions for salmonid water and close to the reference condition, while pH values were low. The Iberian Biological Monitoring Working Party (IBMWP) index showed a positive trend from two years after the construction and stabilized at "unpolluted or not considerably altered water". Quality parameters did not present significant differences between sampling points. The SHP plant construction momentarily altered the quality characteristics of the water.

Identifying the Correlation between Water Quality Data and LOADEST Model Behavior in Annual Sediment Load Estimations

“…The PCHs of water quality datasets based on the regression equation were approximately 30%, except the water quality dataset for station 05291000 since the PCH was 13.6%. Notes: (1) MFE: mean flow (CMS) of estimation data; (2) R. MFC: required MFC (CMS) by the regression equation (Equation (8)); (3) MFC: mean flow (CMS) of calibration data; (4) Original: calibration data from Park and Engel [21]; (5) Regression: calibration data after the exclusion of minimum flow data; (6) Num. data: the number of data in calibration data; (7) PCH: Percentage of calibration data from high flow (%).…”

“…Therefore, water quality samples are collected by various sampling strategies which are based on flow, time, or flow and time composited [1,2]. Fixed frequency sampling strategies collect samples based on time and represent the sampling being conducted with equal time intervals (e.g., 52, 26, and 12 per year in cases of weekly, fortnightly, and monthly, respectively) [3][4][5], while stratified sampling strategies are conducted based on flow proportion (e.g., 10 mm volumetric depth). Water quality data samples may not be consecutive or associated with the range of flow data, and therefore a straightforward annual load estimate (e.g., sum of daily loads) may not be possible.…”

Influence of a Small Hydroelectric Power Station on the River Ecosystem.

“…Despite the environmental benefits of the SHP, some ecological values are still threatened by this form of renewable energy. SHP plants are located in such important stream ecosystems, generally in areas of high ecological value (Valero, 2012). The aim of this research is to describe the quality of the riverine ecosystem on a river stretch which includes a SHP plant, on river Mandeo, Galicia (Spain).…”

Selecting a small run-of-river hydropower plant by the analytic hierarchy process (AHP): A case study of Miño-Sil river basin, Spain

“…The main negative environmental impacts are: lack of proper fish and wildlife passages, inadequate quantity of environmental flow and monthly distribution, mortality of fish due to the turbines, lack of control over environmental flow, high-voltage power lines, inadequate rehabilitation and restoration of habitat, illegal hunting, waste accumulation, dust and noise pollution (Čada, 2001;Trussart et al, 2002;Kucukali and Baris, 2009;Rojanamon et al, 2009;Valero, 2012;Karunarathna, 2013;Kucukali, 2014;Kumar and Katoch, 2014;Vowles et al, 2014).…”