Short Eryri river — under seven miles from Llyn Ogwen above Bethesda to the Menai Strait at Aber. Ogwen Valley AA reports consistent sea trout and a creditable salmon and grilse run for a river so small. Slate-walled pools, quick rise and quicker drop, and a fishery of much more interest than the size suggests. Atlantic salmon are under serious conservation pressure — Natural Resources Wales mandates catch-and-release for salmon on all rivers, so all fish must be returned.
Afon Ogwen drains some of the greatest peaks in Eryri — the Glyderau and Carneddau crowd its head — gathering in Llyn Ogwen from three mountain streams before tipping over the cataracts of Rhaeadr Ogwen and down the glacier-carved trough of Nant Ffrancon. It is a short river, barely seven miles, but a steep and dramatic one, falling fast from lake to sea on the eastern edge of Bangor past the vast slate tips of the Penrhyn quarry. The water is clear, cold and acidic off the high ground, carried over hard rock and boulder through a classic U-shaped glaciated valley. Despite its size it holds a good run of sea trout and a strong run of salmon and grilse, with wild brown trout above. The character is true spate water, quick to rise and fall. Wading is boulder work on uneven, slippery rock, and the falls and steep reaches ask for a careful foot.
Wading: Slippery boulders and steep cataracts
Summer-autumn runs (June–September), primarily nocturnal
- Slate
- Partly confined
- Step pool
- Pool riffle
