The Afon Dulas is a river in

Powys Powys (; ) is a Local government in Wales#Principal areas, county and Preserved counties of Wales, preserved county in Wales. It is named after the Kingdom of Powys which was a Welsh succession of states, successor state, petty kingdom and princi ...

, Wales (Afon is Welsh for river). It is a headwater tributary of the

River Severn , name_etymology = , image = SevernFromCastleCB.JPG , image_size = 288 , image_caption = The river seen from Shrewsbury Castle , map = RiverSevernMap.jpg , map_size = 288 , map_c ...

, which it joins at

Llanidloes Llanidloes () is a town and community on the A470 and B4518 roads in Powys, within the historic county boundaries of Montgomeryshire ( cy, Sir Drefaldwyn), Wales. The population in 2011 was 2,929, of whom 15% could speak Welsh. It is the third ...

opposite the confluence with the

Afon Clywedog The Afon Clywedog is an upland headwater tributary of the River Severn in Powys, Wales. It is approximately 29 km long and has its source on the flanks of Plynlimon and has its confluence with the Severn in Llanidloes. The annual rainfall ...

. Its principal tributary is the Afon Brochan. The total length of the Dulas and Brochan is 19.6 km. Other tributaries include Nant Cydros, the Rhydyclwydau Brook and Nant Gynwydd.

Course

It rises at Cwm y Saeson, and flows east past Cefn Llech to Sychnant, where it is joined by the Full Brook. Here it turns north past the ford at Rhyd Myheryn at Glanyrafon, receiving the Rhydyclwydau Brook on the right bank. The old track bed of the

Mid-Wales Railway The Mid-Wales Railway was conceived as a trunk route through Wales connecting industrial areas in north west England with sea ports in south west Wales. The company was prevented from reaching its goal by competing proposals in Parliament, and i ...

follows the course of the Dulas from this point, through the valley towards

Llanidloes railway station Llanidloes railway station is a former junction railway station in Llanidloes, Powys, Wales. The Cambrian Railways, which completed the building in 1864, designed it to be both the station for the town and its company headquarters. This dual p ...

. The Dulas continues flowing north-west past the village of Tylwch beyond which it forms a narrow rocky gorge, which has been used by whitewater kayakers, although fallen trees across the gorge are a reported hazard. At Rhos-y-pentref, where the river is measured, it is joined by Nant Gynwydd, and is crossed by the

A470 road The A470 (also named the Cardiff to Glan Conwy Trunk Road) is a trunk road in Wales. It is the country's longest road at and links the capital Cardiff on the south coast to Llandudno on the north coast. While previously one had to navigate ...

. Turning north once more, the river passes Upper Glandulas where it meets its last tributary the Afon Brochan, before joining the Severn to the south-west of Llanidloes at Felindre. Kayaker in Dulas Gorge - geograph

Hydrology

The flow of the Dulas has been measured at a

flume A flume is a human-made channel for water, in the form of an open declined gravity chute whose walls are raised above the surrounding terrain, in contrast to a trench or ditch. Flumes are not to be confused with aqueducts, which are built to t ...

, in the lower reaches at Rhos-y-pentref since 1969. This long-term record shows that the

catchment A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...

of to the

gauging station A stream gauge, streamgage or stream gauging station is a location used by hydrologists or environmental scientists to monitor and test terrestrial bodies of water. Hydrometric measurements of water level surface elevation ("stage") and/or volu ...

yielded an average flow of . The highest river level recorded at the station occurred in October 1998 with a height of through the flume, giving a corresponding flow of . The Dulas catchment upstream of the station has a substantial average annual rainfall of and a maximum altitude of at Crugyn Llwyd hill on the eastern edge of the watershed, near to the

Pegwn Mawr Pegwn Mawr is a mountain in Powys, Mid Wales, east of Llanidloes. It is 586 m (1,922 ft) high. It is surrounded by a wind farm. There is a trig point A triangulation station, also known as a trigonometrical point, and sometimes info ...

windfarm. Land use within the basin is described as "mainly pasture, forest and moorland".

References

{{authority control Dulas 1Dulas Tributaries of the River Severn Llanidloes

Course

Hydrology

See also

References