Overflow history upstream of River Medway, Tonbridge

The spot's forecast · For event organisers

This page lists the monitored storm overflows upstream of this spot and how often each spilled in each year. It is not a water test, and it does not say whether the water is fit to swim in. It does not include farm runoff, misconnected drains, treated sewage effluent, wildlife or overflows without a monitor. A year's count depends on how long the monitor worked, shown as monitor uptime.

Each year, all overflows upstream

Year	Overflows with a return	Spills	Spill hours	Spill hours, weighted by reach
2021	54	1,258	9,668	307
2022	62	1,501	12,346	364
2023	65	2,302	22,972	637
2024	65	2,686	26,014	791
2025	66	1,514	11,709	344

Reach is the share of a spill's bacteria SwimSignal's model expects to arrive here, after die-off on the way and dilution by the river. Weighting by it counts an hour of spilling just upstream for far more than one 40 km away. Spills are counted by the Environment Agency's 12/24 method: any discharge in the first 12 hours counts as one spill, then one more for each 24 hours with any discharge. How reach is worked out.

The overflows, by reach

All 67, the one whose spills matter most here first. Hours away is how long sewage takes to arrive at the model's river speed.

Overflow and id	Company	km upstream	Hours away	Reach	Spills 2023	Spills 2024	Spills 2025	Spill hours 2025	Monitor uptime 2025
Ensfield Road Leigh pumping station overflow Ensfield Road Leigh CEO - 108669 · SWS00290	Southern Water	5.0	3	72%	0	0	0	0	100%
Penshurst storm overflow Penshurst CSO - 115997 · SWS00657	Southern Water	8.9	5	60%	67	100	61	350	100%
Chafford Lane Fordcombe pumping station overflow Chafford Lane Fordcombe CEO - 108599 · SWS00153	Southern Water	14.8	8	23%	8	3	0	0	100%
Hawden Road Tonbridge storm overflow Hawden Road Tonbridge CSO - 108736 · SWS00407	Southern Water	0.4	under 1	9%	47	19	4	17	19%
Edenbridge storm sewage overflow Edenbridge SSO - 115738 · SWS00281	Southern Water	24.6	14	8%	75	67	48	416	98%
Hilden Bridge pumping station overflow Hilden Bridge CEO - 108812 · SWS00433	Southern Water	1.2	under 1	4%	17	13	7	61	100%
Leigh Road Hildenborough storm overflow Leigh Road Hildenborough CSO - 109117 · SWS00500	Southern Water	2.0	1	4%	0	0	0	0	76%
Hilden Park Road Hildenborough pumping station overflow Hilden Park Road Hildenborough CEO - 108655 · SWS00434	Southern Water	2.4	1	3%	53	44	19	74	100%
Coldharbour Lane Hildenborough Rear storm overflow 30 Coldharbour Lane Hildenborough Rear 30 CSO - 108612 · SWS00189	Southern Water	4.5	2	3%	–	0	19	233	86%
Forest Row storm sewage overflow Forest ROW SSO - 115718 · SWS00324	Southern Water	27.3	15	3%	57	83	20	233	97%
Hartfield Road Forest Row storm overflow Hartfield Road Forest ROW CSO - 103306 · SWS00402	Southern Water	29.6	16	2%	77	95	56	438	100%
Station Road Forest Row storm overflow Station Road Forest ROW CSO - 108345 · SWS00229	Southern Water	30.8	17	2%	18	29	14	38	49%
Coldharbour Lane Hildenborough pumping station overflow Coldharbour Lane Hildenborough CEO - 108613 · SWS00190	Southern Water	4.9	3	2%	90	89	44	520	100%
Riding Lane Hildenborough storm overflow Riding Lane Hildenborough CSO - 108716 · SWS00708	Southern Water	5.6	3	2%	4	0	3	6	97%
Tunbridge Wells South storm sewage overflow Tunbridge Wells South SSO - 115447 · SWS00888	Southern Water	21.2	12	2%	91	91	52	536	100%
Florence Farm Groombridge EMO - 108643 SWS00370	Southern Water	21.2	12	2%	54	54	21	199	100%
Redgate Mill Crowborough storm sewage overflow Redgate Mill Crowborough SSO - 115803 · SWS00701	Southern Water	29.8	17	2%	82	99	44	491	100%
Redgate Mill Crowborough storm overflow Redgate Mill Crowborough CSO - 115999 · SWS00700	Southern Water	29.8	17	2%	0	0	0	0	33%
Lingfield storm sewage overflow Lingfield SSO - 115415 · SWS00505	Southern Water	34.2	19	1%	124	124	38	350	98%
Cowden storm sewage overflow Cowden SSO - 115723 · SWS00213	Southern Water	21.3	12	1%	68	72	47	506	100%
St Johns Crowborough storm sewage overflow ST Johns Crowborough SSO - 115785 · SWS00821	Southern Water	28.0	16	1%	77	80	38	316	100%
Eggpie Lane Leigh storm overflow Eggpie Lane Leigh CSO - 108633 · SWS00282	Southern Water	7.2	4	1%	33	41	21	92	98%
Tunbridge Wells South storm overflow Tunbridge Wells South CSO - 115448 · SWS00887	Southern Water	23.9	13	1%	71	69	50	167	100%
Fordcombe storm overflow Fordcombe CSO - 115982 · SWS00322	Southern Water	14.0	8	1%	32	50	21	99	98%
Bidborough storm sewage overflow Bidborough SSO - 115882 · SWS00063	Southern Water	14.4	8	1%	41	74	17	126	100%
Maynards Mead Crowborough storm overflow Maynards Mead Crowborough CSO - 103295 · SWS00577	Southern Water	33.9	19	1%	8	13	7	13	100%
Hurstwood Tunbridge Wells pumping station overflow Hurstwood Tunbridge Wells CEO - 108661 · SWS00002	Southern Water	17.3	10	1%	24	33	16	49	99%
Southborough Cemetery Tunbridge Wells storm overflow Southborough Cemetery Tunbridge Wells CSO - 108734 · SWS00797	Southern Water	15.4	9	1%	20	35	37	88	96%
Waterfrets Langton Green storm overflow Waterfrets Langton Green CSO - 108753 · SWS00913	Southern Water	16.0	9	1%	15	26	19	28	100%
Holden Corner Tunbridge Wells storm overflow Holden Corner Tunbridge Wells CSO - 108656 · SWS00440	Southern Water	15.6	9	1%	21	30	37	37	100%
Lake Road Tunbridge Wells storm overflow Lake Road Tunbridge Wells CSO - 111357 · SWS00487	Southern Water	17.4	10	1%	10	11	9	8	100%
Charcott Place pumping station overflow Charcott Place CEO - 108814 · SWS00161	Southern Water	8.5	5	1%	12	13	8	22	97%
Chiddingstone Causeway pumping station overflow Chiddingstone Causeway CEO - 108598 · SWS00176	Southern Water	15.5	9	1%	9	12	6	26	100%
Tanyard Lane Southborough storm overflow Tanyard Lane Southborough CSO - 115160 · SWS00849	Southern Water	15.6	9	1%	1	1	1	0	49%
Oxted storm sewage overflow Oxted SSO - 115423 · SWS00637	Southern Water	39.6	22	0%	69	71	52	427	100%
Godstone storm sewage overflow Godstone SSO - 115799 · SWS00357	Southern Water	41.9	23	0%	42	47	21	163	100%
Oxted storm overflow Oxted CSO - 115422 · SWS00636	Southern Water	39.6	22	0%	29	41	27	76	100%
Hartfield storm sewage overflow Hartfield SSO - 115775 · SWS00403	Southern Water	23.7	13	<1%	61	71	30	312	100%
Nutley storm sewage overflow Nutley SSO - 115724 · SWS00625	Southern Water	35.6	20	<1%	49	32	18	111	100%
Town Row Rotherfield storm overflow 1 Town ROW Rotherfield NO 1 CSO - 103296 · SWS00882	Southern Water	33.3	18	<1%	65	52	32	177	100%
Copthorne Road Domewood pumping station overflow Copthorne Road Domewood CEO - 107391 · SWS00258	Southern Water	42.2	23	<1%	47	35	21	151	99%
Neville Street Tunbridge Wells storm overflow Neville Street Tunbridge Wells CSO - 107370 · SWS00592	Southern Water	27.3	15	<1%	23	20	16	16	100%
Taylor Street Southborough storm overflow Taylor Street Southborough CSO - 108745 · SWS00852	Southern Water	15.6	9	<1%	28	41	31	107	99%
Langholm Road Langton Green storm overflow Langholm Road Langton Green CSO - 109529 · SWS00493	Southern Water	16.0	9	<1%	5	8	4	2	100%
Hammerwood Road Ashurst Wood storm sewage overflow Hammerwood Road Ashurst Wood SSO - 115955 · SWS00396	Southern Water	31.2	17	<1%	103	193	104	2,283	99%
Eden Vale East Grinstead storm sewage overflow Eden Vale East Grinstead SSO - 115912 · SWS00280	Southern Water	39.8	22	<1%	40	48	18	153	100%
Ocklye Crowborough storm overflow Ocklye Crowborough CSO - 111367 · SWS00965	Southern Water	30.4	17	<1%	37	29	28	126	100%
SWS90148 SWS90148	Southern Water	39.8	22	<1%	–	–	–	–	–
Pellings Wood Crowborough storm overflow Pellings Wood Crowborough CSO - 103289 · SWS00236	Southern Water	36.6	20	<1%	42	33	29	100	100%
Maynards Gate Crowborough storm overflow Maynards Gate Crowborough CSO - 103294 · SWS00766	Southern Water	33.6	19	<1%	25	77	32	162	56%
Luxfords Lane East Grinstead storm sewage overflow Luxfords Lane East Grinstead SSO - 115786 · SWS00529	Southern Water	35.0	20	<1%	9	8	15	55	100%
Town Row Rotherfield storm overflow 2 Town ROW Rotherfield NO 2 CSO - 108368 · SWS00883	Southern Water	33.4	19	<1%	8	12	19	70	89%
Alderbrook Way Crowborough storm overflow Alderbrook WAY Crowborough CSO - 103288 · SWS00009	Southern Water	35.9	20	<1%	9	13	3	3	100%
Lingfield Hospital School pumping station overflow Lingfield Hospital School CEO - 108670 · SWS00504	Southern Water	31.8	18	<1%	5	4	3	11	100%
Gleave Close East Grinstead pumping station overflow Gleave Close East Grinstead CEO - 108237 · SWS00348	Southern Water	35.2	20	<1%	0	0	1	5	100%
Jarvis Brook Crowborough storm overflow Jarvis Brook Crowborough CSO - 103293 · SWS00468	Southern Water	34.3	19	<1%	0	5	12	74	100%
Alderbrook Way Crowborough storm overflow 2 Alderbrook WAY Crowborough NO 2 CSO - 116052 · SWS00010	Southern Water	36.2	20	<1%	7	9	3	1	100%
West Hoathly storm sewage overflow West Hoathly SSO - 115792 · SWS00923	Southern Water	38.4	21	<1%	43	54	44	484	100%
Partridge Place Turners Hill pumping station overflow Partridge Place Turners Hill CEO - 108304 · SWS00645	Southern Water	42.7	24	<1%	49	61	34	294	100%
Furzefield Road Baldwins Hill pumping station overflow Furzefield Road Baldwins Hill CEO - 108578 · SWS00036	Southern Water	40.2	22	<1%	40	49	25	129	100%
Withypitts Turners Hill pumping station overflow Withypitts Turners Hill CEO - 108386 · SWS00960	Southern Water	43.8	24	<1%	44	51	29	176	99%
Felbridge storm overflow Felbridge CSO - 116038 · SWS00304	Southern Water	40.4	22	<1%	88	108	55	416	100%
Hazel Way Crawley Down pumping station overflow Hazel WAY Crawley Down CEO - 108245 · SWS00412	Southern Water	42.8	24	<1%	16	18	12	52	100%
Dallaway Gardens East Grinstead storm overflow Dallaway Gardens East Grinstead CSO - 108319 · SWS00243	Southern Water	37.9	21	<1%	9	10	4	6	99%
Fernhill Close Crawley Down Outside storm overflow 10 Fernhill Close Crawley Down Outside 10 CSO - 108289 · SWS00307	Southern Water	44.2	25	<1%	2	–	4	23	18%
Charlwoods Road East Grinstead storm overflow Charlwoods Road East Grinstead CSO - 108203 · SWS00164	Southern Water	40.6	22	<1%	0	15	3	2	99%
Mount Noddy Cemetery East Grinstead storm overflow Mount Noddy Cemetery East Grinstead CSO - 108260 · SWS00588	Southern Water	35.2	20	<1%	2	1	1	1	84%

A dash: no annual return for that overflow in that year.

Sources and credits

Storm overflow annual returns: © Environment Agency copyright and/or database right 2025, Open Government Licence v3.0. Overflow positions: the water companies via the National Storm Overflow Hub, CC BY 4.0. River network: contains OS data © Crown copyright and database right 2026 (OS Open Rivers). Traced and weighted by SwimSignal (swimsignal.co.uk), whose method is at swimsignal.co.uk/methods.html. All credits and licences.