River Nidd

River Nidd
Railway Viaduct over the River Nidd in Knaresborough
54°10′23″N 1°59′53″W / 54.17306°N 1.99806°W / 54.17306; -1.99806
EtymologyProbably a Celtic word meaning "bright, brilliant, shining"
Location
CountryEngland
Physical characteristics
Source 
  locationNidd Head Spring, 1.3 km north of the summit of Great Whernside
  elevation595 metres (1,952 ft)
Mouth 
  location
River Ouse, Nun Monkton
  coordinates
54°0′51″N 1°13′8″W / 54.01417°N 1.21889°W / 54.01417; -1.21889
  elevation
13 metres (43 ft)
Length94.45 kilometres (58.69 mi)
Basin size516 square kilometres (199 sq mi)
Basin features
River systemSwaleOuse

The River Nidd is a tributary of the River Ouse in the English county of North 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, creating Angram Reservoir, Scar House Reservoir and Gouthwaite Reservoir, which attract a total of around 150,000 visitors a year. It joins the River Ouse at Nun Monkton.

The upper river valley, Nidderdale, was designated as an Area of Outstanding Natural Beauty in 1994.

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