PROGRESS IN BIOLOGICAL INQUIRIES, 1931 491 



Test of the Rock Island fish hidders will be had with the arrival 

 of the 1932 run of Chinook salmon. By that time construction work 

 will have been coini)leted and the condition of initial development 

 will exist. 



North River 'project. — As commented on in onr report for 1930, the 

 Xorth River project proposed the development of 37,500 horsepower 

 by the construction of a concrete dam 112 feet high on the North 

 River, in Pacific County, Wash. Following field inspections and 

 conferences with officials of the Division of Fisheries, State of 

 Washington, and the Pacific coast representatives of the power com- 

 pany, conferences were had in New York in January, 1931, with 

 George Waesche, chief designing engineer of Sanderson & Porter, 

 the engineers for the project, and details of fish-protective devices 

 were worked out. 



The plan proposes mechanical handling of both upstream and 

 downstream migrating fish. For collecting the upstream-migrating 

 fish a trap pool is located on the downstream side of the power house 

 and directly over the tailrace. Entrance to this pool is provided 

 for through an 8-foot weir gate which is float controlled to give auto- 

 matic adjustment to tail- water level. This trap pool leads along the 

 downstream face of the power house to a collecting pool at the toe 

 of the dam. Into this collecting pool a hoisting bucket submerges 

 and water, pumped from the tailrace, flows from the bucket and 

 collecting pool out through the trap pool to serve as an attraction 

 for the fish. When a sufficient number of salmon have entered the 

 bucket it is hoisted on an inclined track up the face of the dam and 

 dumped into the reservoir through a metal chute through which a 

 flow of w^ater is maintained. 



The downstream-migrating fish are to be passed from the reser- 

 voir to tail-water through six 12-inch intake pipes connecting with 

 an 8-foot standpipe on the downstream face of the dam. 



Market conditions have delayed the construction of this project; 

 but when work is undertaken, the action of the fish-protective devices 

 is expected to draw considerable attention, for the operation of this 

 project will afford the first large-scale test of the mechanical handling 

 of both upstream and downstream migrating fish at high dams. 



Ariel development. — This season saw the completion of the initial 

 stage of the Ariel development, planned for an ultimate capacity of 

 180,000 kilowatts and situated on the Lewis River, a tributary of the 

 Columbia River, in Washington. This fall the first 40,000-kilowatt 

 unit went into operation and the initial test of some novel devices 

 for fish protection was afforded with the arrival of the fall run of 

 salmon. Here the dam is 180 feet high, and a carefully planned and 

 comprehensive scheme of mechanical handling has been worked out 

 in lieu of the construction of a fish ladder. The scheme involves 

 trapping of the upstream-migrating salmon and the ripening, spawn- 

 ing, and rearing of these fish on a very large scale. 



The feature of principal interest to designers of fishways is the 

 trap pool for collecting the upstream-migrating fish. This pool 

 extends along the downstream face of the power house directly over 

 the tailrace. Entrance to this pool is afforded through three 10-foot 

 entrance gates, which, by means of float control, automatically adjust 

 themselves to tail-water level. Water pumped from the tailrace is 



