70 storm overflows are traced upstream of Mexborough Dearne Mouth, the Dearne Washlands’s lowest gauge on the river map: on the Dearne Washlands itself, on its gauged tributaries, and on smaller streams that join above there.
- 0 report discharging now
- 67 not discharging
- 3 offline or silent: 3 monitor offline, 0 status unknown, 0 no live feed
Official figures for 2025, for the overflows traced upstream of Mexborough Dearne Mouth: 1,495 spills over 9,312 hours in total, across all 70.
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 Dearne Washlands includes the smaller streams that join it there. Where a stretch or a tributary has more than 4, the 3 discharging now or nearest its gauge are listed, the rest are counted, and every one is in that gauge’s “Upstream of here” list. Show every overflow in every stretch →
Above Mexborough Pasture Road Pumping Station, the Dearne Washlands’s highest gauge3 overflows
- Harlington Mill Lane CSO Not discharging
Yorkshire Water · into Culv Trib Of Old River Dearne · 1.7 km by river above Mexborough Pasture Road Pumping Station · 2025: 16 spills, 125 h - Harlington Road CSO Not discharging
Yorkshire Water · into River Dearne · 770 m by river above Mexborough Pasture Road Pumping Station · 2025: 15 spills, 9.0 h - Adwick Road CSO Not discharging
Yorkshire Water · into River Dearne · 770 m by river above Mexborough Pasture Road Pumping Station · 2025: 3 spills, 1.0 h
River Dearne, and the streams that join itjoins the Dearne Washlands above Mexborough Pasture Road Pumping Station67 overflows
- Vicar Road CSO Not discharging
Yorkshire Water · into Dove · 5.3 km by river above Bolton Bridge · 2025: 13 spills, 6.3 h - Darton STW Not discharging
Yorkshire Water · into River Dearne · 3.8 km by river above Barnsley · 2025: 40 spills, 325 h - Silkstone STW Not discharging
Yorkshire Water · into Silkstone Beck · 9.5 km by river above Barnsley · 2025: 68 spills, 555 h
and 64 more: show all 67 overflows on the Dearne and the streams that join it → All above Adwick, nearest first →
Near these gauges, connection not known
Within 3 km of one of the Dearne Washlands’s gauges in a straight line, but the river map cannot say whether their water reaches it.
- Not Matched In Ea Consents Database Not discharging
Yorkshire Water · into Not Matched In Ea Consents Database · 780 m from Mexborough Pasture Road Pumping Station in a straight line · several watercourses close by, nothing to choose between them · 2025: 3 spills, 0.8 h - Yws Unknown Sites Default Not discharging
Yorkshire Water · into Unknown · 790 m from Mexborough Dearne Mouth in a straight line · no mapped watercourse close enough to be sure · 2025: 1 spill, 0.3 h - Yws Unknown Sites Default Not discharging
Yorkshire Water · into Unknown · 790 m from Mexborough Dearne Mouth in a straight line · no mapped watercourse close enough to be sure · 2025: 7 spills, 50 h
2 more near these gauges whose connection is not known.
11 other overflows within 3 km of these gauges are placed below the Dearne Washlands’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: © Yorkshire Water storm overflow activity data, licensed under CC BY 4.0. Annual figures for England: Environment Agency Event Duration Monitoring return, © Environment Agency copyright and/or database right, Open Government Licence v3.0.
