Thornton Steward Reservoir

{{Short description|Reservoir in North Yorkshire, England}}

{{Use British English|date=March 2017}}

{{Use dmy dates|date=September 2023}}

{{Infobox body of water

| name = Thornton Steward Reservoir

| image = ThorntonStewardReservoir.JPG

| caption = Thornton Steward Reservoir

| alt = A lake with tree on the far bank

| image_bathymetry =

| caption_bathymetry =

| pushpin_map = North Yorkshire

| pushpin_map_alt = Relief map of North Yorkshire showing location of reservoir

| location = North Yorkshire, England

| coords = {{coord|54|17|17|N|1|43|22|W|type:waterbody_region:GB|display=inline,title}}

| type = Reservoir

| inflow =

| outflow =

| catchment =

| basin_countries = United Kingdom

| length =

| width =

| area = {{convert|33|acre}}

| depth =

| max-depth =

| residence_time =

| shore = {{convert|0.9|mi}}

| elevation = {{convert|495|ft}}

| islands =

| cities =

}}

Thornton Steward Reservoir is a reservoir north of the village of Thornton Steward in North Yorkshire, England.{{cite journal |last1=Farmery |first1=Ian |last2=Hayton |first2=Mark |title=Thornton Steward WTW |url=http://www.waterprojectsonline.com/case_studies/2008/Yorkshire%20Thornton%20Steward%202008.pdf | publisher=Water Projects Ltd. |accessdate=8 March 2017 |page=177 |year=2008 |journal=Water Treatment and Supply}} It is owned by Yorkshire Water, and supplies drinking water to Swaledale, Wensleydale, Northallerton, and Thirsk.{{cite journal |first=Martin |last=Parvin |title=Thornton Steward WTW |url=http://www.waterprojectsonline.com/case_studies/2007/Yorkshire%20Swaledale%20Water%20Supply%202007.pdf | publisher=Water Projects Ltd. |accessdate=9 September 2019 |page=177 |year=2007 |journal=Water Treatment and Supply}}

Thornton Steward Water Treatment Works (WTW) opened in 1977, and was refurbished in the 1990s. It was upgraded in 2003, and its mains connections improved in 2007, allowing Yorkshire Water to close older works in Langthwaite and at Cod Beck Reservoir above Osmotherley.{{cite news |title=Work starts on £1m water main project |url=http://www.darlingtonandstocktontimes.co.uk/news/1822922.Work_starts_on___1m_water_main_project/ |accessdate=8 March 2017 |work=Darlington and Stockton Times |date=11 November 2007 }}{{cite news |title=£6.5m scheme to improve water treatment in county |url=http://www.darlingtonandstocktontimes.co.uk/news/879986.__6_5m_scheme_to_improve_water_treatment_in_county/ |accessdate=8 March 2017 |newspaper=Darlington and Stockton Times |date=16 August 2006 }} The removal of the Langthwaite WTW, which was fed with groundwater from an adit, means that Thornton Steward now meets the needs of the Swaledale settlements formerly provided by Langthwaite.

The majority of the water from Thornton Steward is piped to a pumping station north of Ainderby Steeple and from there to Bullamore Reservoir (a system of four covered concrete cisterns on the hillside east of Northallerton). That in turn supplies Northallerton and Thirsk.{{cite journal | url=http://www.waterprojectsonline.com/case_studies/2004/Yorkshire_Thirsk_2004.pdf | title= Thirsk/Northallerton Supply Strategy – improving supply to 13,000 properties over 700 sq kms | first=Paul |last=Stockhill | journal=Water Treatment & Supply | year=2008 | publisher=Water Projects Ltd. | page=214}}

The reservoir is fed from water pumped from the River Ure, which is extracted at Kilgram Bridge {{convert|2|km|mi|0|order=flip}} to the south.

{{cite web | title=Delivering our commitments – Annual Performance Report 2018/2019 | publisher=Yorkshire Water | date=July 2019 | url=https://www.yorkshirewater.com/media/1548/yorkshire-water-annual-performance-report-apr-2018-2019.pdf | page=309 | quote=Thornton Steward reservoir becomes a new source, even though it does not have its own abstraction licence, because it meets the >15 days storage rule in RAG 4 Appendix 2. This reservoir is a pumped storage reservoir, being supplied from the River Ure at Kilgram Bridge.}} It is also supplied with water from Leighton Reservoir.

The reservoir is host to the Thornton Steward Sailing Club{{cite news |last1=Gleeson |first1=Janet |title=Thornton Steward Sailing Club floats open day |url=http://www.darlingtonandstocktontimes.co.uk/news/10403721.Thornton_Steward_Sailing_Club_floats_open_day/ |accessdate=8 March 2017 |work=Darlington and Stockton Times |date=7 May 2013 }} and is used for fly fishing.{{cite web |title=Thornton Steward Reservoir |url=http://www.fellingflyfishers.co.uk/fishing/thornton-steward-reservoir.html |website=Felling Fly Fishing Club |accessdate=8 March 2017 }}