Wold Reservoir & Matlock Bank - Sws
Storm overflow run by Severn Trent Water, discharging into Bentley Brook.
"Not discharging" means the company's monitor reports no discharge right now — not that the water is clean. The feed publishes status only; no discharge volume is measured.
Year by year
The Environment Agency's official annual returns, counted the EA's way (12/24-hour spills).
A spill is the EA's 12/24-hour count: the first 12 hours of a discharge count as one, each further 24 hours with discharge as one more. "Monitor" is the share of that year the monitor was working, so a 0 beside a working monitor is a real zero; "no data" means the monitor produced no usable data that year — not zero. Years before 2024 are matched to this site by name and location, because the EA's site IDs changed that year; a monitor figure beside one of them means the outlet's permit confirms the match.
Downstream of this overflow
The next gauge downstream that the river map places is Matlock Lumsdale Rd (Bentley Brook), 580 m along the river.
Water-sampling points downstream
The nearest Environment Agency sampling points the river map places below Matlock Lumsdale Rd. Points between this overflow and that gauge cannot be put in order with it on the map, so they are not listed.
- Bentley Brook at Matlock
1.7 km along the river, below Matlock Lumsdale Rd · Last sampled 5 Mar 2020, before the imported period - River Derwent at Matlock Bath
3.5 km along the river, below Matlock Lumsdale Rd · Last sampled 22 Sep 2026 · 30 days ago - Matlock Bandstand
3.9 km along the river · Last sampled 5 Dec 2023 · 2.9 years ago
A sample is dated: it is not the river now, and its results are on its own page. A sample taken after a discharge does not show that the discharge caused what was measured. Samples: Environment Agency Water Quality Archive, © Environment Agency and/or database right 2026, Open Government Licence v3.0.
A river gauge measures the level of the river; it does not measure this overflow's discharge, and a spill does not by itself explain a change there. Traced on OS Open Rivers (edition 2026-04), which leaves out many small channels.
Contains OS data © Crown copyright and database rights 2026.
What the 2024 return says
From Severn Trent Water's annual return to the Environment Agency for this overflow.
"High spill threshold not met" means this overflow did not spill often enough to trigger the EA's formal high-spill review for that year. It is not a statement that the spills were harmless.
Discharges we have recorded
We hold no discharge periods for this overflow: it has no live feed, and Severn Trent Water has published no event-level log for it that we hold. The official annual figure above is the record to rely on.
Rain nearby last 30 days
Nearest live rain gauge: Rainfall gauge nr Brackenfield CP, 6.9 km away. Brown shading = when this overflow was discharging; ▼ = a discharge start.
Overflow shading is a timing match, not proof of cause — heavy rain and spills share a trigger. Times come from the water company’s event-duration monitor (site status only; no discharge volume is published).
Where it is
Concerned about this overflow?
Report pollution you can see or smell to the regulator straight away; the company handles complaints about the overflow itself.
Annual spill figures: Environment Agency Event Duration Monitoring return, © Environment Agency copyright and/or database right, Open Government Licence (OGL) v3.0. Times are shown in UK local time. FloodRadar republishes the monitor's status and the EA's figures; it does not measure discharges itself. Constituency and council area from the EA's return: contains OS data © Crown copyright and database right 2026.