10 



Appendices to Twenty-fourth Annual Report 



different level, was seldom opened. The rush of water through the 

 tunnels was found to be very great, and the sluices appear to have 

 been unapproachable during floods. In a report on the Doon 

 prepared by Mr. James Leslie, C.E., and Mr. Shaw, Drumlanrig, 

 dated 1855, the area of Loch Doon is stated to be 1240 acres, and 

 a recommendation is made "both for the sake of the mills and of 

 " the fisheries that the storage of Loch Doon should be increased 

 " by raising its high water level ; by which means, without any 

 " damage to property beyond flooding a small portion of moorland 

 " on its shores, there might be an available depth got of 20 feet. 

 " This would give a storage of 1080 millions of cubic feet, which 

 " would give 4000 cubic feet a minute for six months in the year, 

 " in addition to the natural flow of the river. This quantity would 

 "fill a rectangular channel of 12 feet wide and 2 feet 8 inches deep, 

 " falling 1 in 4000, or nearly 16 inches per mile. 



Extensive alterations were proposed for the outlet, but these were 

 not carried out, I am informed by Mr. Thomas Brown, the forester 

 at Craigengillan, till the year 1885, or thirty years after the report 

 above referred to. Instead of a tunnel 66 feet long, the principle 

 salmon pass is now 155 feet long, 17 feet of which is in the form of 

 a deep level canal at the upper end. The difference of level is 

 reported to be 7 feet, so that the gradient of the pass below the 

 canal-like portion is practically 1 in 20. The only portion of the 

 pass now in tunnel is that which is traversed by the roadway at 

 the foot of the loch. I consider that the flow of water in the pass 

 could be improved and checked by the introduction of suitably 

 placed stones to act as brakes to the descending current. This is 

 particularly the case towards the foot or entrance of the pass, where 

 the gradient is a little uneven, and where the water at one part 

 becomes thin and shallow. Fish are apparently prevented at times 

 from ascending the other channel. As in the case of the Helms- 

 dale, upon which I reported last year, I consider that conditions 

 are here ready to hand by which all evils following upon long- 

 continued dry weather in summer, and consequent shrinkage of the 

 river, may be overcome by the storage of water and the regulation 

 of the sluices. In the Helmsdale the tenants act conjointly in 

 the interests of the river, and fish each the other's water by rota- 

 tion, the river being divided into beats. The benefit derived from 

 releasing water during low level conditions, by cleansing the river 

 bed, drawing fish from the sea, and inducing fish to move from pool 

 to pool and rise more fully to the fly, is, I consider, most marked 

 in the case of the Helmsdale, and might in the same way, I believe, 

 be marked in the Doon, if agreement could be come to in the mat- 

 ter of storing the water and regulating the openings of the sluices. 

 In Ness Glen, at Craigengillan, sufficient rough water exists to 

 check the ascent of early -running fish till the temperature of the 

 water has warmed from its wintry conditions. Fish should, there- 

 fore, accumulate in the pools below Ness Glen, and at a later date 

 and for a shorter time in the pool below the fish-pass. With the 

 suitable regulation, by the District Board, of the various points 

 requiring attention in the Doon, I am convinced that the stock of 

 fish would in a few years greatly increase and the value in the 

 fisheries rise accordingly. 



