River Nidd
Railway Viaduct over the River Nidd inKnaresborough 54°10′23″N1°59′53″W / 54.17306°N 1.99806°W /54.17306; -1.99806
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Etymology	Probably a Celtic word meaning "bright, brilliant, shining"
Location
Country	England
Physical characteristics
Source
• location	Nidd Head Spring, 1.3 km north of the summit ofGreat Whernside
• elevation	595 metres (1,952 ft)
Mouth
• location	River Ouse,Nun Monkton
• coordinates	54°0′51″N1°13′8″W / 54.01417°N 1.21889°W /54.01417; -1.21889
• elevation	13 metres (43 ft)
Length	94.45 kilometres (58.69 mi)
Basin size	516 square kilometres (199 sq mi)
Basin features
River system	Swale–Ouse

v t e River Nidd
Legend
Nidd Head Straight Dike Craven Sike Long Hill Sike Crook Sike Stone Beck Angram Reservoir Scar House Reservoir Twizzling Gill Maddering Gill Foggyshaw Gill Mere Dike Flooding route (above ground) Manchester Pot (subterranean) Limley Gill Goydon Pot (subterranean) How Gill (occupies River Nidd Bed) Intake Gill (Lofthouse) How Stean Beck Nidds Head (waters resurface) Blackston Gill Wath Road Ramsgill Beck Lul Beck Byerbeck Gill Gouthwaite Reservoir Dauber Gill Foster Beck B6265 road Rash Dike Fosse Gill Byril Beck Fell Beck Mill race Loftshaw Gill B6451 road Darley Beck Fingill Dike Lolly Bog Dike Slack Dike Cockhill Beck Ripley Beck A61 road Killinghall Bridge Newton Beck Oak Beck Nidd Viaduct Bilton Beck A59 road Harrogate Line Holbeck A658 road Crimple Beck A168 road A1(M) Harrogate Line A59 road River Ouse

TheRiver Nidd is atributary of theRiver Ouse in theEnglish county ofNorth Yorkshire. It rises in Nidderdale at Nidd Head Spring on the slopes of Great Whernside. In its first few miles it has been dammed three times, creatingAngram Reservoir,Scar House Reservoir andGouthwaite Reservoir, which attract a total of around 150,000 visitors a year.^[1] It joins the River Ouse atNun Monkton.

The upper river valley,Nidderdale, was designated as anArea of Outstanding Natural Beauty in 1994.^[2]

The Yorkshire Dales Rivers Trust has a remit to conserve the ecological condition of the River Nidd from its headwaters to theHumber estuary.

The Nidd rises inNidderdale at Nidd Head Spring on the slopes ofGreat Whernside in theYorkshire Dales. It flows east into Angram and Scar House reservoirs before turning south just downstream of Newhouses. In normal conditions the river disappears underground into thesinkhole known as Manchester Hole. If Scar House reservoir overflows, water flows past Manchester Hole to Goyden Pot, another sinkhole. In severe floods, the river flows past Goyden Pot down the valley. The water sinking into theNidderdale caves reappears at the rising Nidd Head to the south of the village ofLofthouse.

Below Lofthouse the river is joined by How Stean Beck, and turns south-south-east towardsRamsgill before flowing into Gouthwaite Reservoir. Continuing on the same heading, the first major settlement is reached atPateley Bridge. Turning more south-easterly, it flows pastGlasshouses andSummerbridge, where it turns south again pastDacre Banks. Passing byDarley, the river turns east before reachingBirstwith, where it flows south-east toHampsthwaite. A series of large bends in the river take the flow north, east and then south, and east again, to enterNidd Gorge.

Below the gorge, the river meanders south-east through the town ofKnaresborough, heading north and looping south again as it enters flatter terrain. NearLittle Ribston it meanders south-easterly and easterly, crossing underneath theA1 and theA1(M) near the small village ofCowthorpe. The river continues meandering pastCattal north-easterly towardsMoor Monkton, towards its junction with the River Ouse atNun Monkton.

• Low and high water levels are an average figure.

The two most northerly reservoirs on the course of the river were built to provide water to the Bradford area in the early 1900s by way of theNidd Aqueduct. As of 2017, they are maintained byYorkshire Water.^[4]

The reservoir takes its name from Angram, a settlement in the township ofStonebeck Up, submerged when the reservoir was built. Completed in 1919 with a dam height of61 metres (200 ft) covering 34 hectares with a volume of 1,041 million gallons and a depth of 33.4 metres (110 ft).

A temporary village was built at Scar House to house the workers building the reservoirs and some remains can still be seen. The old Village Hall was moved to Darley, where it now serves as the local Village Hall. The dam at Scar House was completed in 1936. The dam height is 71 m (233 ft) with the reservoir covering area 70 hectares and a depth of36.3 metres (119 ft) giving a volume of 2,200 million gallons. The reservoir is fed almost exclusively from the Angram dam.

Gouthwaite reservoir is designated a Site for Special Scientific Interest.^[5] It provides a compensation release for the river.^[6] It covers an area of 312 acres (126 ha).^[7]

The Nidd can overflow the reservoirs, flooding thecaves in the valley.^[8][9] In such cases the river overflows into the normally dry river bed pastLofthouse through toGouthwaite Reservoir.

The head of the river is located on moorland and the river character is affected by the run-off levels from the three reservoirs. The upper valley is primarilymillstone grit withfluvioglacial deposits. The overlying soil is prone to water-logging due to its slow permeability, being composed of loamy soils on top of clay with peat on the top layer. Around Lofthouse there are outcrops ofUpper Yoredale limestone, which is more permeable than millstone grit and has created theNidderdale Caves, where the river flows underground.

Lower down on the flood plain, the nature of the underlying ground isMagnesian Limestone over alluvium and terrace drift deposits. On top of this is a combination of slowly permeable and well drained fine loam over clay.^[10][11]

Where the river passes through theNidd Gorge, Carboniferous (Namurian) andUpper Permian rock is exposed.^[12]

The etymology of the name remains unknown but the name is eitherCeltic orPre-Celtic (as with most rivers in Western Europe). A derivation from Celtic meaningbrilliant orshining has been suggested (as inOld Irishníamda),^[13] as has a link to the olderIndo-European root*-nedi, simply meaning river.^{[14][15][16][17]}

The Nidd likely shares this etymology with theriver andtown of Neath (WelshNedd) in South Wales and the town ofStratton in Cornwall (originally named Strat-Neth), and with many other rivers across Europe, such as theNete in Belgium, theNied in France,Neda in Galicia (NW Spain), theNethe,Nidda andNidder in Germany, and theNida in Poland.^{[18][16][19][20]}

Along the river valley can be found theNidderdale Museum, which is located in Pateley Bridge, and features sections about the traditional agriculture, industries, religion, transport and costume of Nidderdale.

Lower down the river is the town ofKnaresborough, which is home toKnaresborough Castle and Knaresborough Museum.

There are many way-marked walking routes throughout the river valley, including theNidderdale Way, a 55-mile circular walk whose usual starting point is Ripley.

• 
  River Nidd less than 0.6 miles (1 km) from the source
• 
  River Nidd at Lofthouse
• 
  River Nidd near West House Farm
• 
  River Nidd near Pateley Bridge
• 
  River Nidd at Glasshouses
• 
  River Nidd below Dacre
• 
  River Nidd between Birstwith and Hampsthwaite
• 
  River Nidd from Killinghall Bridge
• 
  The River Nidd at Knaresborough
• 
  River Nidd near Tockwith Road

Ordnance Survey Maps

• Lower Wharfedale & Upper Washburn Valley (297)
• Nidderdale (298)
• Yorkshire Dales – Northern & Central Areas (OL 30)

• Nidderdale
• Rivers of North Yorkshire
• Ouse catchment

• Pages using gadget WikiMiniAtlas
• Articles with short description
• Short description is different from Wikidata
• Use British English from June 2017
• Use dmy dates from November 2015
• Coordinates on Wikidata