Dams and other hydrological barriers are essential for the production of hydroelectricity and to direct water to water-deficient areas. But the presence of these structures are known to interfere with the ecology of the river, affecting the flora and fauna inhabiting it. The western ghats of India are home to many endemic fish species which are affected by these hydrological structures. Recent study from ATREE shows what can be done to ensure that the biodiversity in the Western Ghats is not lost to hydrological structures.