Analysis of Water Leakage in downstream dam toe of Komani Dam-Paper

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The study investigated significant water leakage emerging from the downstream toe of Albania’s Koman Dam, first notably observed during rehabilitation work in December 2014. Researchers used electrical resistivity tomography (“Real Section”), self-potential surveys, water chemistry and stable-isotope analyses, together with ongoing measurements of flow and turbidity.<br /><br />Geophysical surveys identified likely leakage pathways entering the dam body from both abutments and indicated a possible preferential flow axis. Positive self-potential anomalies corresponded with the leakage outlet, while negative anomalies along the abutments suggested water movement near the contacts between the dam and surrounding rock. The geophysical methods helped locate and infer flow directions but could not determine the leakage’s source or quantify inflow.<br /><br />Chemical and isotope results showed that water from the dam toe and grout galleries closely matched lake water, unlike samples from nearby karst springs. Similar chloride concentrations, oxygen-18 and deuterium signatures, and a matching temperature of approximately 9°C support the conclusion that the leakage originates from the lake and is hydraulically connected to it.<br /><br />Leakage flow was reported at approximately 700–1,000 litres per second. Turbidity was low and did not follow changes in lake-water turbidity. The authors recommend continued monitoring of flow, temperature and turbidity, further geophysical investigation of the dam’s concrete face, and additional piezometers to better characterize groundwater pathways and levels.

Keywords

Koman Dam

Albania

water leakage

electrical resistivity tomography

self-potential surveys

water chemistry

stable isotopes

lake water connection

seepage flow

geophysical monitoring