What are disadvantages of using watermills?

Watermills can be limited by their dependence on water flow, making them less effective in periods of drought or low water availability. They also require suitable locations, which may not always be accessible or environmentally sustainable. Additionally, maintenance can be challenging, as machinery and infrastructure may be vulnerable to wear from water and sediment. Lastly, watermills can impact local ecosystems, potentially disrupting fish habitats and water quality.