Suspended load monitoring for sustainable hydropower development

A huge thread to Hydropower plants (HPP) is incoming sediments in suspension from the rivers upstream. The sediments settle in the reservoir and reduce the effective head as well as the volume and reduce consequently the lifetime of the reservoir. In addition are the fine sediments causing severe damages to turbines and infrastructure of a HPP. For estimating the amount of in-coming sediments in suspension and the consequent planning of efficient counter measures, it is essential to monitor the rivers within the catchment of the HPP for suspended sediments. This work is considerably time consuming and requires highly educated personnel and is therefore expensive. Surrogate-indirect methods using acoustic and optic devices have bee developed since the last decades that may be efficiently applied for the continuous monitoring of suspended sediment loads. The presented study present first results from a research station at a cross section of the Devoll River in Albania which is the main tributary to the Banja’s HPP reservoir. Aiming to quantify continuously concentrations and related flow discharge and level, this monitoring station was equipped with two side-looking ADCPs working at 600 and 1200 kHz. The logger at the research station delivers data automatically to a server. Therefore, it is ensured that also large flood events are covered. Data during flood are of high interest to the HPP planners since they carried the most part of the sediment load in a hydrological year. Theses peaks can hardly be measured with common measurement methods. Preliminary results from the wet season 2015/2016 are presented. The data gives insight in the sediment loads variation and corresponding flow discharge and level, eventually enabling the study of suspended sediment load-water flow correlations during peak events.