Ahascragh Mill Weir is located on the Bunowen River near the town of Ahascragh in Co. Galway.

The weir was identified by Inland Fisheries Ireland for remedial works due to an inadequate existing fish pass facility at the weir. The fish pass at the weir was not effective in providing the free movement of all fish over all periods of the year as stated in Section 116 of the 1959 Fisheries (Consolidation) Act of the requirements of The European Habitats Act. A 3-D topographical survey was used to create a detailed 3-D Model of the proposed site. The preferred design was the provision of a natural rock fish ramp immediately downstream of the weir. Full Planning Permission was granted in 2017. Works on the fish pass will commence in July 2018.