Stoneflies
Caddisflies
Gammarids
The Derry Water is the eastern headwater of the Aughrim River — a small Wicklow upland stream that meets the Ow at Aughrim village to form the Aughrim. Granite and mixed geology, small wild brown trout averaging six ounces, the river is heavily overgrown and rarely fished outside the small local circle. The Aughrim & District Trout Angling & Conservation Club tickets it together with the Ow and the lower Aughrim — three named waters, one connected system.
EPA river-invertebrate monitoring across the Derry Water confirms mayflies (including Ephemera danica), stoneflies (with the larger Perla carlukiana present), an extensive caddis assemblage, chironomids and blackflies, plus freshwater shrimp and hoglice — evidence of a genuinely food-rich upland freestone.
- Mixed