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Ithon water levels

2 gauges from Llandewi River Station to Disserth River Station. None is above its typical high. 1 storm overflow upstream is discharging now. Gauges in Powys; levels are checked every 15 minutes.

2gauges
0above normal
1overflow upstream discharging

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Gauges

Monitoring stations, source to mouth

StationTownLevel nowStatusTrend
Llandewi River Station—0.33 m 32m agoWithin its typical range▽
Disserth River Station 32.5 km by river—0.78 m 32m agoWithin its typical range▼

Stations are listed from source to mouth as the water flows, traced on the river map (OS Open Rivers) and the Environment Agency’s own links between its gauges. A distance “by river” is along the river, and is shown only where the map traces the path.

Contains OS data © Crown copyright and database rights 2026.

Gauged tributaries

Streams and rivers with a gauge whose water joins the Ithon above one of its gauges, from the source down. Named streams without a gauge that have a page here are listed at the end.

No gauged tributary joins the Ithon above Disserth River Station on the river map. Streams without a gauge are not counted here.

Where the Ithon goes

Below Disserth River Station, its water next reaches Builth Wells River Station, a gauge on River Wye, 10.3 km by river downstream.

Tributaries and where they join are traced on the river map (OS Open Rivers, edition 2026-04) and the Environment Agency’s links between its gauges. The map holds distances between gauges, not the junctions themselves, so a junction is placed between two gauges, and no further up than the tributary’s own lowest gauge. Contains OS data © Crown copyright and database rights 2026.

Streams without a gauge

Named streams on the river map that flow into the Ithon and have no gauge of their own. Each has a page with what is known about it: the next gauge downstream, and any storm overflows or water-sampling points placed on it.

  • Arlais Brook (joins about 6.7 km above Disserth River Station)
  • Howey Brook (joins about 3.0 km above Disserth River Station)

Storm overflows upstream

11 storm overflows are traced upstream of Disserth River Station, the Ithon’s lowest gauge on the river map: on the Ithon itself, on its gauged tributaries, and on smaller streams that join above there.

  • 1 reports discharging now
  • 10 not discharging
  • 0 offline or silent: 0 monitor offline, 0 status unknown, 0 no live feed

Official figures for 2025, for the overflows traced upstream of Disserth River Station: 515 spills over 3,249 hours in total, across the 10 that have a figure. 1 has no 2025 figure.

Each overflow is listed in the stretch above the first gauge its water reaches, from the source down, as on the Gauges tab. A stretch of the Ithon includes the smaller streams that join it there.

Above Llandewi River Station, the Ithon’s highest gauge1 overflow
Between Llandewi River Station and Disserth River Station10 overflows · 1 discharging now

1 other overflow within 3 km of these gauges is placed below the Ithon’s lowest gauge or on another river, so not listed.

A status is the water company’s own monitor: it says whether an overflow is discharging, never how much or why, and a spill does not by itself explain a change in a river level. A status older than two hours is shown as unknown. Annual figures are the official returns: 12/24-hour spills for England and Wales, overflow events for Scotland (Scottish Water counts differently, so the two cannot be compared). “No data” means the monitor produced no usable data that year, not zero. Overflows are placed on OS Open Rivers (edition 2026-04), which leaves out many small channels: an overflow the map cannot place may still drain here. Contains OS data © Crown copyright and database rights 2026. Sewage in Britain’s rivers →

Live status: © Dŵr Cymru Welsh Water, from its Storm Overflow Map. Annual figures for Wales: Dŵr Cymru Welsh Water’s return to Natural Resources Wales, as compiled by The Rivers Trust, Open Government Licence.