ECN site code: R29
ECN monitoring by: Cyfoeth Naturiol Cymru - Natural Resources Wales
Co-located terrestrial site: Yr Wyddfa - Snowdon (T11)

Nant Teyrn is a small upland stream on Yr Wyddfa/Snowdon NNR. This ECN freshwater site is co-located with the Yr Wyddfa/Snowdon terrestrial site which has been in existence since 1997. The site is on the out flow from Llyn Teyrn. The geology of the catchment is nearly all highly acidic rhyolite and dolerite with a small amount of bedded pyroclastics. Some water chemistry data is available since 1997 with discharge data collected from the weir since 2000.


Nant Teyrn locator

Catchment boundary and gauging location


Sion Parry
Cyfoeth Naturiol Cymru - Natural Resources Wales
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW