The Liffey rises in the Wicklow Mountains above Blessington — fast, peaty, granite-sourced, and clear in a way that flatters its surroundings. Poulaphuca Reservoir (Blessington Lakes) interrupts the natural flow, and the fishing below the dam is the most consistent part of the upper river: regulated releases maintain a reasonable level through summer, and the tailwater carries good populations of wild brown trout on the dry fly from April. Above the reservoir, the headwater streams hold smaller fish but in spectacular moorland. The upper Liffey is primarily a dry-fly and nymph river for wild brownies averaging seven to ten inches, with occasional larger fish. Fishing is club-managed with day permits available. A good option for the Wicklow-based angler who prefers moving water to lough fishing.
EPA monitoring on the upper Liffey above Blessington confirms a wide food base, with mayflies (including Ephemera danica), stoneflies, an extensive caddis population, chironomids and blackflies, freshwater shrimp and hoglice, and even native white-clawed crayfish all present in the catchment.
- Granite