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.
Streams and rivers with a gauge whose water joins the Arun above one of its gauges, from the source down. Named streams without a gauge that have a page here are listed at the end.
Named streams on the river map that flow into the Arun 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.
26 storm overflows are traced upstream of Littlehampton, the Arun’s lowest gauge on the river map: on the Arun itself, on its gauged tributaries, and on smaller streams that join above there.
0 report discharging now
24 not discharging
2 offline or silent: 0 monitor offline, 0 status unknown, 2 no live feed
Official figures for 2025, for the overflows traced upstream of Littlehampton: 700 spills over 7,011 hours in total, across all 26.
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 Arun includes the smaller streams that join it there.
Above Provender Mill, the Arun’s highest gauge2 overflows
Mannings Heath WwTWNot discharging Southern Water · into River Arun · 4.3 km by river above Provender Mill · 2025: 76 spills, 1,252 h
Kerves Lane Horsham WpsNot discharging Southern Water · into Horn Brook · 2.4 km by river above Provender Mill · 2025: 7 spills, 49 h
Between Tanbridge and Alfoldean2 overflows
Warnham WwpsNot discharging Southern Water · into Boldings Brook, Trib Of R.arun · 13.8 km by river above Alfoldean · 2025: 29 spills, 276 h
Horsham WwTWNot discharging Southern Water · into Tributary Of The River Arun · 7.3 km by river above Alfoldean · 2025: 27 spills, 268 h
Between Alfoldean and New Bridge2 overflows
Slinfold WwTWNot discharging Southern Water · into Unnamed Trib Of River Arun · 16.9 km by river above New Bridge · 2025: 40 spills, 392 h
Rudgwick Recreation Ground CSONot discharging Southern Water · into Tributary Of River Arun · 12.0 km by river above New Bridge · 2025: 13 spills, 88 h
River Lox, above Drungewickjoins the Arun above New Bridge2 overflows
Turners Mead P.s.Not discharging Southern Water · into Freshwater River · 21.6 km by river above Drungewick · 2025: 13 spills, 84 h · placed on the river by its position alone
Onslow Arms Pumping StationNot discharging Southern Water · into Loxwood Stream · 3.2 km by river above Drungewick · 2025: 30 spills, 321 h
River Rother, above Princes Marshjoins the Arun above Pulborough Swan Bridge1 overflow
Station Road Liss CSONot discharging Southern Water · into River Rother · 1.1 km by river above Princes Marsh · 2025: 2 spills, 11 h
River Rother, above Iping Milljoins the Arun above Pulborough Swan Bridge4 overflows
Liss Wastewater Treatment WorksNot discharging Southern Water · into River Rother & Batt's Brook · 17.9 km by river above Iping Mill · 2025: 25 spills, 271 h
Buriton WwTWNot discharging Southern Water · into Trib Of Stanbridge Stream · 16.4 km by river above Iping Mill · 2025: 4 spills, 31 h
College Street Petersfield CSONot discharging Southern Water · into Unnamed Strm To Tilmore Brook · 14.7 km by river above Iping Mill · 2025: 4 spills, 8.5 h
Rogate WwTWNot discharging Southern Water · into River Rother · 6.2 km by river above Iping Mill · 2025: 25 spills, 194 h
River Rother, above Lodsbridgejoins the Arun above Pulborough Swan Bridge2 overflows
Iping Nort CSONot discharging Southern Water · into Freshwater River · 15.7 km by river above Lodsbridge · 2025: 9 spills, 60 h · placed on the river by its position alone
South Ambersham WwTWNot discharging Southern Water · into Tributary Of The River Rother · 3.4 km by river above Lodsbridge · 2025: 28 spills, 316 h
River Rother, above Hardhamjoins the Arun above Pulborough Swan Bridge3 overflows
Barnetts Bridge Graffham CEONot discharging Southern Water · into Tributary Of River Rother · 14.6 km by river above Hardham · 2025: 64 spills, 989 h
Petworth Wastewater Treatment WorksNot discharging Southern Water · into River Rother · 7.7 km by river above Hardham · 2025: 36 spills, 91 h
Fittleworth S.t.w.Not discharging Southern Water · into River Rother · 3.1 km by river above Hardham · 2025: 92 spills, 599 h
River Lod, above Halfway Bridgejoins the Rother1 overflow
Fernhurst WwTWNot discharging Southern Water · into River Lod · 12.7 km by river above Halfway Bridge · 2025: 34 spills, 323 h
Between Pulborough Swan Bridge and Houghton Bridge1 overflow
Storrington WwTW, StorringtonNot discharging Southern Water · into The River Stor · 15.6 km by river above Houghton Bridge · 2025: 16 spills, 125 h
Between Houghton Bridge and Littlehampton1 overflow
Hobbs Cottage CSO, Climping StreetNot dischargingbathing water Southern Water · into Ryebank Rife Via Surface Sewer · 3.4 km by river above Littlehampton · 2025: 1 spill, 0.5 h · reaches the river through a sewer, so where it enters is approximate
Above PALLINGHAM GS5 overflows
Northchapel WwTWNo live feed Southern Water · into River Kird · 22.8 km by river above PALLINGHAM GS · 2025: 40 spills, 471 h
Bridgefoot Pumping StationNot discharging Southern Water · into Freshwater River · 12.3 km by river above PALLINGHAM GS · 2025: 1 spill, 6.9 h · placed on the river by its position alone
Land Adj. Billingshurst Pump. StnNot discharging Southern Water · into Par Brook · 6.3 km by river above PALLINGHAM GS · 2025: 15 spills, 105 h
Billingshurst WwTWNo live feed Southern Water · into Par Brook · 6.1 km by river above PALLINGHAM GS · 2025: 44 spills, 421 h
Wisborough Green WwTWNot discharging Southern Water · into River Kird · 5.1 km by river above PALLINGHAM GS · 2025: 25 spills, 259 h
Near these gauges, connection not known
Within 3 km of one of the Arun’s gauges in a straight line, but the river map cannot say whether their water reaches it.
CSO East St/Avon Rd LittlehamptonNot dischargingbathing water Southern Water · into Tidal River Arun · 300 m from Littlehampton in a straight line · discharges to the sea, an estuary or tidal water · 2025: 39 spills, 118 h
South Terrace Littlehampton CSONot dischargingbathing water Southern Water · into Tidal River Arun · 680 m from Littlehampton in a straight line · discharges to the sea, an estuary or tidal water · 2025: 32 spills, 202 h
Water Lane/Arundel RoadNo live feedbathing water Southern Water · into Freshwater River · 890 m from Littlehampton in a straight line · its watercourse is not on the river map · 2025: 0 spills, 0 h
Bury WwTWNot discharging Southern Water · into River Arun · 1.2 km from Houghton Bridge in a straight line · discharges into a tidal reach, where the water moves both ways · 2025: 17 spills, 184 h
Pulborough S.t.w.Not discharging Southern Water · into River Stor · 1.7 km from Pulborough Swan Bridge in a straight line · discharges into a tidal reach, where the water moves both ways · 2025: 40 spills, 559 h
Broadmark Pumping StationNot dischargingbathing water Southern Water · into Controlled Sea · 2.6 km from Littlehampton in a straight line · discharges to the sea, an estuary or tidal water · 2025: 0 spills, 0 h
Dated samples taken by the Environment Agency, not live readings. Results are published days to months after the sample is taken, and many points are sampled only a few times a year, or have not been sampled for years.
60 sampling points on the River Arun and the streams that join it above Littlehampton. 32 have a sample from the last 12 months; 39 have any sample banked.
Sampled most recently, anywhere on the Arun and its streams:
Pond Head Lane, North Riverunnamed stream · 20 km above AlfoldeanLast sampled 11 Sep 2026 · 27 days agoOxygen 75%Temp 15.2 °CpH 7.78Ammonia below 0.03 mg/l
Waterland Farm Track, North Riverunnamed stream · 20 km above AlfoldeanLast sampled 11 Sep 2026 · 27 days agoOxygen 87%Temp 15.3 °CpH 7.95Ammonia below 0.03 mg/l
River Rother Durford BridgeRiver Rother · 10 km above Iping MillLast sampled 9 Sep 2026 · 29 days agoOxygen 93.6%Temp 14.9 °CpH 7.41Ammonia 0.055 mg/l
Where, from the source down
Sampling points
Newest sample
River Rother and its streamsjoins the Arun above Pulborough Swan Bridge
England's samples only. Each count opens the list of those points, nearest first, with the date of each one’s latest sample (the gauge’s “Upstream of here” list).
FloodRadar does not grade these results: there is no overall score, and official river classifications are a separate dataset. A sample taken downstream of an overflow does not by itself show where anything in it came from. River connections and distances are traced on OS Open Rivers (edition 2026-04), which leaves out many small channels.
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