SITOR INFORMATION MAP DWORSHAK V NATIONAL FISH HATCHERY

1. MAIN PUMP STATION 6. HOLDING PONDS Supplies water from North Fork to all Receive adult fish and hold until mature and spawned. outside production ponds. Piped water from Dworshak Reservoir is used for egg incubation and inside nursery 7. HATCHERY BUILDING rearing. Spawning room and incubators, displays, viewing balcony, rest rooms, and administrative offices. 2. WATER TREATMENT FACILITY 8. NURSERY BUILDING Has aeration capability if water becomes ovygen deficient or supersaturated with nitrogen. Newly hatched fish are held in smaller tanks until fingerling size, then transferred to the larger outside ponds. 2. MECHANICAL BUILDINGS Dworshak / Kooskia Filters improve water quality and electric boilers adjust 9. FISH HEALTH CENTER National Fish Hatchery temperatures of the three reuse systems. 10. STEELHEAD REARING PONDS P.O. Box 18 11. SPRING CHINOOK REARING PONDS 4. WATER REUSE FILTERS Ahsahka, 83520 12. FOOD SERVICE BUILDING (208) 476-4591 Recondition used water from rearing ponds; 10 percent Refrigerated storage for moist food and space for dry is then returned to river and replaced by an equal amount food storage. Location of IDAHO FISHERY of heated new water. RESOURCE OFFICE. US Army Corps 5. FISH LADDER 13. HATCHERY WASTE WATER TREATMENT of Engineers Adult fish move up the fish ladder to holding ponds. PONDS Walla Walla District ELCOME TO DWORSHAK NATIONAL FISH HATCHERY

controlled systems. In these systems, 10 w percent of the water used in the ponds is added as fresh water after being Dworshak National Fish filtered, supplemented with minerals Hatchery is the largest combina­ and heated. The water goes through tion producer of steelhead trout aerators for re-oxygenation before sup­ and spring chinook salmon in the plying each pond with 600 gallons per world. The harchery, located at minute of flow. When water returns from the confluence of the North Fork the ponds, it flows through biological and the main stem Clearwater, filters where ammonia is oxidized and three miles west of Orofino in then reduced to harmless nitrares. , is operated by the U.S. Fish & Wildlife Ser­ Ability to regulate temperatures and to vice and was designed and built reuse the water enables the hatchery to by the Walla Walla District, U.S. use warm water (54° F) in the winter Army Corps of Engineers. when water temperatures normally run about 39 ° F. Since growth rates are faster Steelhead and rainbow trout pro­ in warmer water, the juvenile steelhead duction, begun in 1969, is in are released the spring following egg hat­ conjunction with Dworshak ching at a length of 8 inches. It would which is the largest and highest take an additional year in colder water straight-axis, concrete-gravity to reach the same size. dam ever built in the United States and second largest in the The hatchery's water system, world. blocks pumping at a total capacity migraring steelhead from natural of 90,000 gallons per spawning grounds on rhe North minute, is comparable to Fork of the Clearwater River. satisfying the daily drinking needs of all the people residing in the State of Idaho.

dditional construction, completed in 1982 under the intensive cooperative effort by the Army A Lower Compensation Plan, expanded Corps of Engineers, Fish and Wildlife Ser­ facilities to rear spring chinook salmon to offset losses caused vice and State of Idaho to perpetuate the by on the lower Snake River. return of fish from the Pacific Ocean to the Clearwater River. Kooskia National Fish Hatchery, 35 miles upriver, became part of the Dworshak National Fish Hatchery Complex in 1978. The two hatcheries are managed closely together for the pro­ he hatchery is unique in that water temperatures for the duction of salmon and steelhead. Toutside steelhead ponds can be controlled through recir­ culation similar to an aquarium. There are 84 circulating water The hatchery, dedicated in 1969, is the culmination of an -type ponds divided into three reuse or environmentally t the time of A release, year­ ling salmon and steelhead are dis­ charged directly dult steelhead may spawn near the ocean or from the ponds A many miles up stream. The famous Clearwater to the river, or "B" strain of steelhead, collected at the hatchery pumped onto trucks and transported to off-site loca­ from October until May, spawn from January tions to begin their downstream migration. through April. The spring chinook brood fish return to the river from May until September with egg To aid the smolts in their journey through the eight collection over a three-week period beginning in late dams on the Snake and Columbia rivers, the August. The returning adult fish move up the migrating young fish (both salmon and steelhead) hatchery fishway, or ladder, directly into large can be collected at Lower Granite, Little Goose and holding ponds. These fish are three to five years in McNary dams and barged or trucked downstream age and weigh from 12 to 15 pounds. beyond Bonneville, the last dam on the lower Columbia. Fifteen million eggs are collected annually from the returning adult fish. Some of these eggs can be used to supply the State of Idaho with fish to various planting programs as well as to provide several million smolts (juvenile fish ready to change from fresh water to a salt water environment) for release the following spring.

Fertilized eggs are placed in incubators for several weeks until hatching occurs and the fish are ready to feed. Baby fish are hatched with yolk sacs attached to their bodies and draw nourishment from this source before learning to feed.

In a good year 6,500 eggs from one steel­ head spawner would account for 55 adult fish back to the Clear­ water River; 3,700 eggs collected from a female spring chinook rerurns 10 fish. monitor instrument records water flow, tem­ A peratures, oxygen levels, pH (acidity or alkalinity of water) and turbidity, (sediment in the water) of each of the different water system in the hatchery. nce the yolk sac is absorbed, the young fish Oare moved to nursery tanks and are fed for the Operational faults are flashed to an annunciator first time. Their first food is very fine particles fed board pinpointing the exact location of a problem. several times daily. As they grow, food size as well An alarm sounds through the public address system as the daily food intake increases. in the hatchery. If the alarm is not acknowledged and reset by a hatchery employee, the telephones Small fingerlings remain in the nursery rearing tanks uring the course of the incubation and rearing begin ringing in employee's homes. until they reach a size of 2 inches. The young fish Dperiods, fish health and water quality are closely are then moved to the outside ponds and held until monitored to help prevent any disease problems. Visitors are welcome to tour the facilities 7:30 a.m. ready for release as yearlings. Fish are periodically sample counted and measured to 4:00 p.m. daily. Exhibits describing the hatchery for growth information and feeding change. activities and a self-guided tour are available.