A scour test involves slowly opening and closing the outlet valve, which causes the release of water into the stream. This is likely to cause increased turbulence and deterioration of water quality immediately downstream for the duration of the test and for a short while after.
On the day, tests generally commence between 7-10am and may last for up to 4 hours in total, with a release at full flow rate for about half an hour. If you might be affected by a particular test, please check a week beforehand as there is a small chance for test dates to be moved to a later date or for additional tests to be required.
Aire
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| LOWER LAITHE/IRE | 12/01/2023 | Sladen Beck |
| STUBDEN/IRE | 17/01/2023 | Stubden Beck |
| THORNTON MOOR/IRE | 17/01/2023 | Stubden Beck |
| LEEMING/IRE | 24/01/2023 | Leeming Water |
| LEESHAW/IRE | 24/01/2023 | Dunkirk Beck |
| GILSTEAD/ESR | 09/02/2023 | Little Beck |
| PONDEN/IRE | 09/02/2023 | River Worth |
| ELDWICK/IRE | 14/02/2023 | Eldwick Beck |
| EMBSAY/IRE | 21/02/2023 | Embsay Beck |
| SILSDEN/IRE | 28/02/2023 | Silsden Beck |
| WEECHER/IRE | 02/03/2023 | Gill Beck |
| HEWENDEN/IRE | 28/03/2023 | Hewenden Beck |
| GRAINCLIFFE/IRE | 04/04/2023 | Eldwick Beck |
| ELSLACK/IRE | 18/04/2023 | Elslack Beck |
| WHINNY GILL/IRE | 18/04/2023 | Little Brook |
| FARNLEY STORM/SLK | 26/04/2023 | Wortley Beck |
| REVA/IRE | 02/05/2023 | Jum Beck |
| WINDLEDEN LOWER/IRE | 02/05/2023 | Embsay Beck |
| DOE PARK/IRE | 09/05/2023 | Denholme Beck |
| WATER SHEDDLES/IRE | 20/06/2023 | River Worth |
| LOWER LAITHE/IRE | 06/07/2023 | Sladen Beck |
| LEEMING/IRE | 20/07/2023 | Leeming Water |
| LEESHAW/IRE | 20/07/2023 | Dunkirk Beck |
| KEIGHLEY MOOR/IRE | 25/07/2023 | Morkin Beck |
| SILSDEN/IRE | 15/08/2023 | Silsden Beck |
| WEECHER/IRE | 22/08/2023 | Gill Beck |
| EMBSAY/IRE | 24/08/2023 | Embsay Beck |
| STUBDEN/IRE | 05/09/2023 | Stubden Beck |
| DOE PARK/IRE | 26/09/2023 | Denholme Beck |
| HEWENDEN/IRE | 26/09/2023 | Hewenden Beck |
| THORNTON MOOR/IRE | 27/09/2023 | Stubden Beck |
| ELDWICK/IRE | 28/09/2023 | Eldwick Beck |
| GRAINCLIFFE/IRE | 28/09/2023 | Eldwick Beck |
| ELSLACK/IRE | 03/10/2023 | Elslack Beck |
| WHINNY GILL/IRE | 03/10/2023 | Little Brook |
| REVA/IRE | 05/10/2023 | Jum Beck |
| PONDEN/IRE | 17/10/2023 | River Worth |
| GILSTEAD/ESR | 19/10/2023 | Little Beck |
| WATER SHEDDLES/IRE | 05/12/2023 | River Worth |
| KEIGHLEY MOOR/IRE | 07/12/2023 | Morkin Beck |
Upper Calder
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| GORPLE LOWER/IRE | 19/01/2023 | Hebden Stream |
| GORPLE UPPER/IRE | 19/01/2023 | Gorple Lower |
| WALSHAW DEAN MIDDLE/IRE | 31/01/2023 | Walshaw Dean Lower |
| WALSHAW DEAN UPPER/IRE | 31/01/2023 | Walshaw Dean Middle |
| GORPLEY/IRE | 04/04/2023 | Gorpley Clough |
| WALSHAW DEAN LOWER/IRE | 20/06/2023 | Hebden Stream |
| WIDDOP/IRE | 27/06/2023 | Hebden Stream |
| GORPLE LOWER/IRE | 24/08/2023 | Hebden Stream |
| GORPLE UPPER/IRE | 24/08/2023 | Gorple Lower |
| WALSHAW DEAN MIDDLE/IRE | 29/08/2023 | Walshaw Dean Lower |
| WALSHAW DEAN UPPER/IRE | 29/08/2023 | Walshaw Dean Middle |
| GORPLEY/IRE | 03/10/2023 | Gorpley Clough |
| WIDDOP/IRE | 07/12/2023 | Hebden Stream |
| WALSHAW DEAN LOWER/IRE | 14/12/2023 | Hebden Stream |
Middle Calder
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| MIXENDEN/IRE | 26/01/2023 | Hebble Brook |
| OGDEN/IRE | 26/01/2023 | Hebble Brook |
| RYBURN/IRE | 07/02/2023 | River Ryburn |
| DEANHEAD/IRE | 23/02/2023 | Black Burne Brook |
| SCAMMONDEN/IRE | 23/02/2023 | Black Brook |
| ALBERT/ESR | 07/03/2023 | To Sewer |
| RAMSDEN WOOD/ESR | 07/03/2023 | To Sewer |
| WITHENS CLOUGH/IRE | 30/03/2023 | Turvin Clough |
| BAITINGS/IRE | 06/04/2023 | River Ryburn |
| BOOTH DEAN LOWER/IRE | 25/04/2023 | Boothwood IRE |
| BOOTH DEAN UPPER/IRE | 25/04/2023 | Boothdean Lower IRE |
| BOOTH WOOD/IRE | 25/04/2023 | Booth Dean Clough |
| RINGSTONE/IRE | 06/06/2023 | Butts Clough |
| GREEN WITHENS/IRE | 13/06/2023 | Booth Dean |
| SPA CLOUGH/ESR | 13/06/2023 | Spa Clough |
| DEAN HEAD LOWER/IRE | 22/06/2023 | Luddenden Dean |
| DEAN HEAD UPPER/IRE | 22/06/2023 | Luddenden Dean |
| WARLEY MOOR/IRE | 22/06/2023 | Deanhead Upper |
| MIXENDEN/IRE | 20/07/2023 | Hebble Brook |
| OGDEN/IRE | 20/07/2023 | Hebble Brook |
| RYBURN/IRE | 01/08/2023 | River Ryburn |
| BAITINGS/IRE | 14/09/2023 | River Ryburn |
| BOOTH DEAN LOWER/IRE | 26/09/2023 | Boothwood IRE |
| BOOTH DEAN UPPER/IRE | 26/09/2023 | Boothdean Lower IRE |
| BOOTH WOOD/IRE | 26/09/2023 | Booth Dean Clough |
| DEANHEAD/IRE | 12/10/2023 | Black Burne Brook |
| SCAMMONDEN/IRE | 12/10/2023 | Black Brook |
| ALBERT/ESR | 17/10/2023 | To Sewer |
| RAMSDEN WOOD/ESR | 17/10/2023 | To Sewer |
| WITHENS CLOUGH/IRE | 31/10/2023 | Turvin Clough |
| RINGSTONE/IRE | 21/11/2023 | Butts Clough |
| DEAN HEAD LOWER/IRE | 05/12/2023 | Luddenden Dean |
| DEAN HEAD UPPER/IRE | 05/12/2023 | Luddenden Dean |
| WARLEY MOOR/IRE | 05/12/2023 | Deanhead Upper |
| GREEN WITHENS/IRE | 12/12/2023 | Booth Dean |
| SPA CLOUGH/ESR | 12/12/2023 | Spa Clough |
Lower Calder
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| WHITLEY/ESR | 23/03/2023 | Whitley Wood |
| ARDSLEY/ESR | 20/04/2023 | Haigh Moor Beck |
| ARDSLEY/ESR | 28/09/2023 | Haigh Moor Beck |
| WHITLEY/ESR | 19/10/2023 | Whitley Wood |
Colne & Holme
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| BLAKELEY/IRE | 03/01/2023 | Butterley IRE |
| BUTTERLEY/IRE | 03/01/2023 | Wessenden Brook |
| BOSHAW WHAMS/IRE | 31/01/2023 | Upper House Dyke |
| HOLMESTYES/IRE | 31/01/2023 | River Ribble |
| BILBERRY/IRE | 02/02/2023 | Digley IRE |
| DIGLEY/IRE | 02/02/2023 | Digley Brook |
| WESSENDEN HEAD/IRE | 14/02/2023 | Wessenden Brook |
| WESSENDEN OLD/IRE | 14/02/2023 | Blakeley IRE |
| LONGWOOD COMP/IRE | 16/02/2023 | Longwood Brook |
| LONGWOOD/ESR | 16/02/2023 | Longwood Brook |
| RIDING WOOD/IRE | 21/02/2023 | Ramsden IRE |
| YATEHOLME/IRE | 21/02/2023 | Netherley Clough |
| BROWNHILL/IRE | 11/04/2023 | River Holme |
| RAMSDEN/IRE | 11/04/2023 | Brownhill IRE |
| BLACKMOORFOOT/IRE (NORTH SIDE) | 13/04/2023 | Brow Grains Dyke |
| DEERHILL/IRE | 13/04/2023 | Bradley Brook |
| SNAILSDEN/IRE | 13/06/2023 | Harden Beck |
| BLAKELEY/IRE | 15/06/2023 | Butterley IRE |
| BUTTERLEY/IRE | 15/06/2023 | Wessenden Brook |
| RIDING WOOD/IRE | 08/08/2023 | Ramsden IRE |
| YATEHOLME/IRE | 08/08/2023 | Netherley Clough |
| WESSENDEN HEAD/IRE | 15/08/2023 | Wessenden Brook |
| WESSENDEN OLD/IRE | 15/08/2023 | Blakeley IRE |
| BOSHAW WHAMS/IRE | 17/08/2023 | Upper House Dyke |
| HOLMESTYES/IRE | 17/08/2023 | River Ribble |
| BILBERRY/IRE | 19/09/2023 | Digley IRE |
| DIGLEY/IRE | 19/09/2023 | Digley Brook |
| LONGWOOD COMP/IRE | 24/10/2023 | Longwood Brook |
| LONGWOOD/ESR | 24/10/2023 | Longwood Brook |
| BLACKMOORFOOT/IRE (NORTH SIDE) | 02/11/2023 | Brow Grains Dyke |
| DEERHILL/IRE | 02/11/2023 | Bradley Brook |
| BROWNHILL/IRE | 14/11/2023 | River Holme |
| RAMSDEN/IRE | 14/11/2023 | Brownhill IRE |
| SNAILSDEN/IRE | 12/12/2023 | Harden Beck |
Derwent
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| ELVINGTON/NO 1 ESR | 09/03/2023 | River Derwent |
| LOFTSOME BRIDGE/ESR | 14/03/2023 | River Derwent |
| TOPHILL LOW/NO 1 ESR | 18/05/2023 | River Hull |
| TOPHILL LOW/NO 2 ESR | 18/05/2023 | Barmston Drain |
| ELVINGTON/NO 1 ESR | 07/09/2023 | River Derwent |
| LOFTSOME BRIDGE/ESR | 10/10/2023 | River Derwent |
| TOPHILL LOW/NO 1 ESR | 16/11/2023 | River Hull |
| TOPHILL LOW/NO 2 ESR | 16/11/2023 | Barmston Drain |
Upper Don
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| BROADSTONES/ESR | 05/01/2023 | Broadstones Dike |
| AGDEN/IRE | 19/01/2023 | Agden Beck |
| DALE DIKE/IRE | 24/01/2023 | River Loxley |
| RIVELIN LOWER/IRE | 26/01/2023 | River Rivelin |
| DAMFLASK/IRE | 02/02/2023 | River Loxley |
| RIVELIN UPPER/IRE | 07/02/2023 | Rivelin Lower IRE |
| RIVELIN/DEP POND IRE | 07/02/2023 | River Rivelin |
| REDMIRES LOWER/IRE | 09/02/2023 | Wyming Brook |
| REDMIRES MIDDLE/IRE | 09/02/2023 | Redmires Lower IRE |
| REDMIRES UPPER/IRE | 09/02/2023 | Redmires Middle IRE |
| UNDERBANK/IRE | 16/02/2023 | River Little Don |
| MOREHALL/IRE | 02/03/2023 | Ewden Beck |
| INGBIRCHWORTH/IRE | 07/03/2023 | Ingbirchworth Dike |
| SCOUT DIKE/IRE | 09/03/2023 | River Don |
| ROYD MOOR/IRE | 30/03/2023 | River Don |
| STRINES/IRE | 04/04/2023 | Dale Dike IRE |
| WINDLEDEN UPPER/IRE | 02/05/2023 | Windleden Lower IRE |
| WINSCAR/IRE | 11/05/2023 | River Don |
| MIDHOPE/IRE | 06/06/2023 | River Little Don |
| LANGSETT/IRE | 08/06/2023 | River Little Don |
| HARDEN/IRE | 13/06/2023 | Winscar IRE |
| BROADSTONES/ESR | 15/06/2023 | Broadstones Dike |
| AGDEN/IRE | 20/06/2023 | Agden Beck |
| DALE DIKE/IRE | 22/06/2023 | River Loxley |
| BROOMHEAD/IRE | 27/06/2023 | Morehall IRE |
| RIVELIN LOWER/IRE | 20/07/2023 | River Rivelin |
| DAMFLASK/IRE | 01/08/2023 | River Loxley |
| RIVELIN UPPER/IRE | 03/08/2023 | Rivelin Lower IRE |
| RIVELIN/DEP POND IRE | 03/08/2023 | River Rivelin |
| REDMIRES LOWER/IRE | 10/08/2023 | Wyming Brook |
| REDMIRES MIDDLE/IRE | 10/08/2023 | Redmires Lower IRE |
| REDMIRES UPPER/IRE | 10/08/2023 | Redmires Middle IRE |
| MOREHALL/IRE | 05/09/2023 | Ewden Beck |
| STRINES/IRE | 03/10/2023 | Dale Dike IRE |
| WINSCAR/IRE | 10/10/2023 | River Don |
| UNDERBANK/IRE | 17/10/2023 | River Little Don |
| WINDLEDEN LOWER/IRE | 26/10/2023 | Clough Beck |
| WINDLEDEN UPPER/IRE | 26/10/2023 | Windleden Lower IRE |
| ROYD MOOR/IRE | 31/10/2023 | River Don |
| INGBIRCHWORTH/IRE | 07/11/2023 | Ingbirchworth Dike |
| SCOUT DIKE/IRE | 09/11/2023 | River Don |
Esk
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| RANDY MERE/ESR | 27/04/2023 | Oakley Beck |
| RANDY MERE/ESR | 07/12/2023 | Oakley Beck |
Lower Hull
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| BRANSHOLME/SLK | 19/01/2023 | River Hull |
| BRANSHOLME/SLK | 20/07/2023 | River Hull |
Nidd
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| ANGRAM/IRE | 07/02/2023 | Scar House IRE |
| SCAR HOUSE/IRE | 07/02/2023 | River Nidd |
| GOUTHWAITE/IRE | 08/02/2023 | River Nidd |
| JOHN O GAUNTS/IRE | 11/04/2023 | Oak Beck |
| SCARGILL/IRE | 11/04/2023 | Oak Beck |
| GOUTHWAITE/IRE | 27/07/2023 | River Nidd |
| ANGRAM/IRE | 14/09/2023 | Scar House IRE |
| SCAR HOUSE/IRE | 14/09/2023 | River Nidd |
| JOHN O GAUNTS/IRE | 24/10/2023 | Oak Beck |
| SCARGILL/IRE | 24/10/2023 | Oak Beck |
Upper Ouse
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| CLIFTON LAKE/SLK | 16/03/2023 | Drain |
| CLIFTON LAKE/SLK | 28/09/2023 | Drain |
Middle & Lower Swale
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| THORNTON STEWARD/ESR | 09/03/2023 | Finghall Beck |
| COD BECK/IRE | 16/05/2023 | Cod Beck |
| THORNTON STEWARD/ESR | 26/10/2023 | Finghall Beck |
| COD BECK/IRE | 31/10/2023 | Cod Beck |
Middle & Lower Ure
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| LUMLEY MOOR/IRE | 30/03/2023 | Holborn Beck |
| LEIGHTON/IRE | 06/06/2023 | River Burn |
| ROUNDHILL/IRE | 06/06/2023 | Leighton IRE |
| LUMLEY MOOR/IRE | 14/11/2023 | Holborn Beck |
| ROUNDHILL/IRE | 30/11/2023 | Leighton IRE |
| LEIGHTON/IRE | 05/12/2023 | River Burn |
Wharfe & Washburn
| RESERVOIR | DATE | NAME OF WATERCOURSE AFFECTED |
|---|---|---|
| CHELKER/IRE | 05/01/2023 | Bank Gill Beck |
| FEWSTON/IRE | 05/01/2023 | Swinsty IRE |
| MARCH GHYLL/IRE | 19/01/2023 | Bow Beck |
| BARDEN LOWER/IRE | 02/02/2023 | Barden Beck |
| CARR BOTTOM/IRE | 16/02/2023 | Carr Beck |
| PANORAMA/IRE | 16/02/2023 | Black Beck |
| GRIMWITH/IRE | 23/02/2023 | River Dibb |
| ECCUP/ESR | 28/02/2023 | Eccup Beck, Harewood Estate Ponds, River Wharfe |
| SWINSTY/IRE | 01/06/2023 | River Washburn |
| THRUSCROSS/IRE | 08/06/2023 | River Washburn |
| CHELKER/IRE | 15/06/2023 | Bank Gill Beck |
| LINDLEY WOOD/IRE | 20/06/2023 | River Washburn |
| BARDEN UPPER/IRE | 22/06/2023 | Barden Beck |
| MARCH GHYLL/IRE | 18/07/2023 | Bow Beck |
| FEWSTON/IRE | 20/07/2023 | Swinsty IRE |
| BARDEN LOWER/IRE | 17/08/2023 | Barden Beck |
| GRIMWITH/IRE | 12/09/2023 | River Dibb |
| CARR BOTTOM/IRE | 19/09/2023 | Carr Beck |
| PANORAMA/IRE | 19/09/2023 | Black Beck |
| ECCUP/ESR | 07/11/2023 | Eccup Beck, Harewood Estate Ponds, River Wharfe |
| LINDLEY WOOD/IRE | 07/12/2023 | River Washburn |
| BARDEN UPPER/IRE | 12/12/2023 | Barden Beck |
| THRUSCROSS/IRE | 12/12/2023 | River Washburn |
| SWINSTY/IRE | 14/12/2023 | River Washburn |