Grafham Water

{{Use dmy dates|date=April 2022}}

{{Infobox body of water

| name = Grafham Water

| image = Water Tower at Grafham Water - geograph.org.uk - 690586.jpg

| caption = Grafham Water

| alt = A vast lake with a water tower out of the water

| location = Cambridgeshire

|pushpin_map=Cambridgeshire

| coords = {{Coord|52.29810|N|0.31504|W|region:GB_type:waterbody_source:enwiki-osgb36(TL150680)|display=inline,title}}

| lake_type = reservoir

| inflow = pumping (River Great Ouse)

| outflow = water treatment

| catchment =

| basin_countries =

| agency = Anglian Water

| date-built = 1965

| length = {{convert|4.3|km|mi|abbr=on}}

| width = {{convert|2.35|km|mi|abbr=on}}

| area = {{convert|6.28|km2|acre|abbr=on}}

| depth =

| max-depth = {{convert|21|m|ft|abbr=on}}

| volume = {{convert|57.8|e6m3|abbr=on}}

| residence_time =

| shore = {{convert|16|km|mi|abbr=on}}

| elevation = {{convert|42|m|ft|abbr=on}}

| islands =

}}

File:cmglee_Grafham_Water_dam_tower.jpg

Grafham Water is an {{convert|806.3|ha|adj=on}} biological Site of Special Scientific Interest (SSSI) north of Perry, Huntingdonshire.{{Cite web|url=https://wikishire.co.uk/map/#Grafham+Water@52.302,-0.32/centre=52.302,-0.320/zoom=11|title=Great Britain and Ireland - interactive county map|website=wikishire.co.uk}} It was designated an SSSI in 1986.{{cite web|url= https://designatedsites.naturalengland.org.uk/SiteDetail.aspx?SiteCode=S1002330&SiteName=grafham&countyCode=&responsiblePerson= |title=Designated Sites View: Grafham Water | series= Sites of Special Scientific Interest|publisher=Natural England|access-date = 7 December 2016}}{{cite web|url=http://magic.defra.gov.uk/MagicMap.aspx?startTopic=Designations&activelayer=sssiIndex&query=HYPERLINK%3D%271002330%27 |title=Map of Grafham Water|series= Sites of Special Scientific Interest|publisher=Natural England|access-date= 7 December 2016}} It is a reservoir with a circumference of about {{convert|10|mi|km|order=flip|abbr=on}}, is {{convert|21|m|ft|abbr=on}} deep at maximum,{{cite web|url=http://www.environmentdata.org/archive/ealit:3129/OBJ/20000051.pdf|title=NRA Ferric Dosing of Grafham Water|access-date=9 August 2019}} and is the eighth largest reservoir in England by volume and the third largest by area at {{convert|1550|acre|km2|2|abbr=on|order=flip}}. An area of {{convert|114|ha|abbr=on}} at the western end is a nature reserve managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire.{{cite web|url= http://www.wildlifebcn.org/reserves/grafham-water |title= Grafham Water |publisher= Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire |access-date= 7 December 2016}}

The lake was created by building an earth and concrete dam, constructed by W. & C. French in 1965,{{cite web|url=http://www.buckdenroundabout.info/Buckden_book/index.html#190|title=Buckden: A Huntingdonshire Village|page=154| access-date=14 September 2015}} and water is extracted and processed at an adjacent Anglian Water treatment plant before being piped away as drinking water. It was shown from the air, before it opened, in 'Look at Life (film series)' ' 1965 episode, 'Will Taps Run Dry ?', narrated by Tim Turner.

The reservoir was immediately colonised by wildlife and a nature reserve was created at the western side of the reservoir. The nature reserve contains semi-natural ancient (at least 400 years old) woodlands and more recent plantation woodlands, grasslands and wetland habitats such as reedbeds, willow and open water.{{cite book|url=https://books.google.com/books?id=88WLT_oPLdcC&q=%22Grafham+Water%22&pg=PA139|title=Contested Environments|author1=Nick Bingham|author2=Andrew Blowers|author3=Christopher Belshaw|publisher=John Wiley and Sons|year=2003|isbn=0-470-85000-0}} The reservoir has nationally important numbers of wintering great crested grebes, tufted ducks and coots, and of moulting mute swans in late summer. A pond has a population of the nationally uncommon warty newt.{{cite web|url=http://www.sssi.naturalengland.org.uk/citation/citation_photo/1002330.pdf|title=Grafham Water citation|series=Sites of Special Scientific Interest|publisher=Natural England|access-date=7 December 2016|archive-date=24 October 2012|archive-url=https://web.archive.org/web/20121024195030/http://www.sssi.naturalengland.org.uk/citation/citation_photo/1002330.pdf|url-status=dead}}

Water is obtained by pumping water from the River Great Ouse nearby. There are two pumping stations associated with the reservoir. One is located just behind the dam, the other at Offord Cluny alongside the River Great Ouse. At times of high potential flood risk, Grafham Water treatment works can increase the amount of water it takes up to maximum capacity to help reduce the risk of flooding along the river.

As of January 2011, it was the only site in England, and the first in the UK, to harbour the invasive killer shrimp (Dikerogammarus villosus).{{cite news|url=https://www.bbc.co.uk/news/science-environment-11246642|title=Alien 'killer' shrimp found in UK|date=September 9, 2010|access-date=September 9, 2010|publisher=BBC News}}{{cite news|url=http://www.environment-agency.gov.uk/news/123215.aspx|title=Invasive shrimp found at Grafham Water|date=September 9, 2010|access-date=May 22, 2011|archive-url=https://web.archive.org/web/20100914141257/http://www.environment-agency.gov.uk/news/123215.aspx|archive-date=September 14, 2010|url-status=dead|publisher=Environment Agency}}

Grafham Water is popular for a range of leisure activities including sailing, fly fishing and cycling. In 2019, a live-action gaming centre, Rumble Live Action Gaming, was opened in the woodland arenas on the edge of the reservoir. {{cite web | url=https://www.stamfordmercury.co.uk/news/are-you-ready-to-rumble-9080763/ | title=Are you ready to 'Rumble'? | date=28 August 2019 }}

{{wide image|20170813-RJPLancaster-GrafhamWater_rotate_crop.jpg|800px|The Grafham Water reservoir from the air}}