Small hydropower projects (SHPs) are promoted as low-impact alternatives for large hydropower. SHPs are generally commissioned on small- to medium-sized mountainous rivers, often in biodiverse regions, with backing in the form of subsidies, facultative policies and exemption from impact assessments as they are considered ‘green’. However, the ecological impacts of SHPs are understudied especially in highly seasonal tropical streams of Western Ghats of India, a global biodiversity hotspot and a distinct freshwater fish eco-region.