Oak Beck
[2] The waters of Oak Beck flow through a V-shaped valley covering some 5 square kilometres (1.9 sq mi) west of Harrogate.[9] The lower reaches of the river, back from the Nidd past Knox to the northern part of Harrogate, were originally a lake, dammed by a glacier.The storm drain, near the swimming pool in the northern part of the town, was built to store run-off water which can be screened before being released into Oak Beck.[21][22] Oak Beck was one of a handful of Yorkshire rivers which had a resident population of white-clawed crayfish,[23] and it is also noted to host bullhead and brown trout."[28] Similarly, the Harrogate Gas Company, whose works were adjacent to the beck at the junction of the roads to Ripon and York (now the A59/A61junction), were found to have allowed "deleterious material" to enter the river in early 1890.