100 



Appendices to Thirty-fourth Annual Report 



In the upper river, however, considerable complaint still exists on 

 account of the coal washings from pits. 



Tummel. 



The Tay District Fishery Board decided to alter the intake of the 

 Tummel Falls Pass, referred to in a previous Report. So far as my actual 

 observation goes, the amount of the lowering at the sill of the intake 

 is 16f inches. In addition to this, the channel from the main river to 

 the intake sill, which is short and protected by cement work, was also 

 deepened. 



I saw the pass a short time after this work had been completed, and 

 a considerable quantity of gravel had already accumulated a short distance 

 from the sill. This is probably inevitable, and in times of flood, if a sluice 

 is at any future time placed at the intake sill, it may be desirable to allow 

 a sufficient force of water into the pass to carry off this superfluous gravel. 



From various sources of information, there appears to be no doubt that 

 a very considerable number of salmon have ascended the fall without 

 taking advantage of the pass since the time the fall was slightly altered. 

 Twenty fish at a time have been observed resting just above the fall but 

 below the intake of the pass, while fish have also been observed in the 

 course of their ascent of the fall. 



Fish usually surmount the fall in quite low conditions of water flow, 

 and it may be found that the recent lowering of the sill of the pass affects 

 this condition. In those circumstances the presence of a sluice might be 

 of advantage. At the Invermoriston Pass, however, where, it should be 

 noted, the ascent of the fall is quite impossible at all states of river, it has 

 been decided that the best results are to be obtained by doing away with 

 sluices altogether, but preventing the direct inrush of the river by a 

 narrow and slightly regurgitating channel. Like the Tummel Pass, the 

 Invermoriston Pass is excavated from the solid rock, and can receive no 

 great damage from flood water. 



The result of the recent lowering of the sill at the intake of the Tummel 

 Falls Pass will be that a considerably greater amount of water will be able 

 to descend, while the action of a sluice would be to keep a surplus out if 

 necessary. From what I have been able to observe in this type of pass, 

 however, a depth approaching 3 feet makes the water unduly rough and 

 rapid. 



It was decided, I understand, to give a slope to the floor of the pass 

 immediately behind the intake, so that the old gradient should be joined by 

 the new at a point about 67 feet below the sill. The pass now, therefore, 

 has two gradients. The original conception was, as I understand, slightly to 

 alter the fall so that, in low river, fish would find the ascent less difficult, 

 and to adjust the level of the pass to the level of the river at which fish 

 would most readily run. The entrance or lower end of the pass remains 

 as before, but with this new alteration of the level of the intake, the 

 original conception is departed from. With an additional supply of water, 

 the results, so far as the ascent of salmon are concerned, will require to be 

 carefully observed. 



In the same river, the Dunalastair Falls have also been altered since 

 last Report. The operation has been done by blasting the lower section of 

 the fall itself. I visited the falls in July, but the debris from the recent 

 blasting was so choking the fall that nothing could be learned as to the 

 actual result. When floods have shifted the shattered rocks into the pool 

 below, it will be possible, I hope, to make another visit. 



The Dalchroy Dam Dyke, lower down, has also been receiving some 

 attention. It was an extremely leaky structure formed of boulders, and in 



