Measured Survey

Date 19 April 2015

Event ID 1024713

Category Recording

Type Measured Survey

Permalink http://canmore.org.uk/event/1024713

NH 46870 51680 A survey of the hydro-electric scheme at Orrin Falls was carried out on 19 Apr 2015. The site is on the S bank of the river and utilises the waterfall within the gorge; which has a total height drop of c15m. The first record of a hydro-electric scheme at this location is in 1898

when ‘John Stirling used estate workmen to build a turbine house at the Orrin Falls… and electric light was installed (in Fairburn House) in 1898’. (http://www.fairburn-estate. co.uk/history.html).

The scheme seems to have gone through several phases before being abandoned in c1961, probably following the building of the Orrin Dam, as part of the Conon Valley hydro-electric scheme, in the higher reaches of the glen. However, the scheme has been recently revived and now

provides electricity for the estate.

The scheme consists of a concrete dam, 3–3.5m in height and c50m in length, with a fish ladder at its N end, the remains of an earlier dam of similar construction but only 1m in height, a lade or concrete box channel c50m in length and c2m deep and 1.5m in width with three wooden sluices, two metal grids for catching floating debris (one controlled by an overhead hoist) and two overspills.

An underground generator house is probably a recent structure on the site of an original one. It is constructed of dressed stone and c11 x 5m x 12m high.

A rock-cut channel on the N bank - probably a salmon ladder, and the abutments of a footbridge - probably ornamental and possibly pre-dating the hydro-scheme are situated in the middle part of the gorge above a waterfall.

Evidence of three abutments (A, B and C) indicated that it was in two sections at a slight angle to one another. Abutment A is 3 x 1.5m x 1m in height and constructed of two large boulders with infill of concrete and small boulders. Abutment B, on top of a rocky knoll on the N side of the gorge, is a small concrete and stone structure with evidence of old cables and pieces of the wooden deck. The N abutment C is a small platform, measuring 2m2, with stone-faced sides built into the N bank of the river.

Archive: NOSAS. Report: Highland HER, NOSAS and local library

Website: NOSAS.co.uk

Meryl Marshall – NOSAS

(Source: DES, Volume 17)