10 



Appendices to Twenty-second Annual Report 



which passes up the side of the river at this point, two substantial 

 sluices are inserted in the sill of the dyke. During low conditions of 

 water these sluices are kept down, but the gap in the weir so closed 

 is considerable, being twelve feet broad and two feet deep. On the 

 sluices being raised, therefore, a very large volume of water will 

 descend and afford a convenient lead up for ascending fish, since 

 immediately below the sluices a sloping apron is stretched across 

 the angle between the weir and the wall, and serves the double 

 purpose of reducing the gradient and of protecting the compara- 

 tively high river bed from being washed out by the descending 

 rush of water. Moreover, the natural lead for fish ascending 

 towards this Keirfield Dam Dyke is towards this point, and in 

 suitable conditions of water with the sluices raised, I should say 

 that fish will find little difficulty in ascending this obstruction. 



A short distance further up the river another obstruction is met 

 with, viz. the Bridge of Allan Meal Mill Dam. This is a low dyke 

 of loose stones and boulders. It has no gap of any sort, nor are 

 there hecks on the lade which passes off from the right bank. A 

 distinct disadvantage noticeable concerning this lade is that the 

 contained water is not returned to the river above the Keirfield 

 Dam just referred to, but is carried into the lade coming from the 

 Keirfield Dam and so into the river some distance below Bridge of 

 Allan. 



The next dam dyke is a much more serious obstruction, and 

 should certainly be dealt with by the Forth District Fishery Board. 

 I refer to the Airthrie Dylce, by means of which Airthrie paper mill 

 is supplied with water. It is 167 feet in length, and is 9 feet 

 6 inches high in the centre, where the downstream face is 47 feet 

 with a gradient of 1 in 5. At the extreme right, several ledges of 

 rock project upstream and raise the level of the river bed, and 

 upon these rocks the right-hand portion of the dyke rests. The 

 downstream face is here only 28 feet, but owing to the presence of 

 the rocks the gradient is 1 in 6. This dyke has the appearance of 

 being maintained in good repair. It does not leak, and the down- 

 stream face is comparatively smooth and uniform. There is no 

 gap or fish pass of any sort, nor are there hecks to the lade which 

 passes off from the left bank. I am informed by the Superintendent 

 that fish usually attempt to ascend close to the projecting rocks 

 already referred to. These rocks can, however, be reached without 

 much difficulty when the river is not in flood, and I should think 

 that fish lying below the obstruction or failing to ascend are much 

 exposed to the art of poachers who may resort thither. The rocks 

 might well be taken advantage of to construct some convenient 

 form of pass. 



At the rocky cascades which occur at Kippenross, a cruive 

 formerly existed, but this obstruction has long since been removed. 

 Above Kippenross there is a Dam Dyke in connection with the 

 Lower Keir Mill, a large meal mill which stands on the right bank, 

 and from which at the time of my visit much water was uselessly 

 pouring through a bye-wash. The Dyke is however so arranged that 

 slanting well upstream towards the left bank where the level of the 

 river bed rises, the obstruction, comes, as it were, to a vanishing point 



