Lake Aberdeen is primarily used to rear the dam mitigation winter Steelhead inaddition to Summerrun Steelhead for the Wynoochee along with odds and ends. Brood Doc link http://wdfw.wa.gov/publications/01447/

Otherwise from R6 D17 Kirt Hughes:

The Lake Aberdeen fall Chinook program was started using a combination of strays to the hatchery, likely of Wynoochee origin, and wild brood from the Wynoochee River. Adult
collection, spawning, incubation, rearing and release occur on station at Lake Aberdeen. The program goal is to release 50,000 subyearlings at 90 fish per pound.

The Lake Aberdeen Hatchery coho program originated from fish straying to the hatchery, likely of Wynoochee River origin, and from wild brood collected from the Wynoochee. Program size is 30,000 yearlings released on-station.

Now after that is the mitigation production of additional winter Steelhead & Coho that WDF&W has a responsibility to rear, Tacoma City Light put the funds in trust for that purpose, and that bloody agency has spent over 20 years making excuses as to why they are incapable of fulfilling that obligation. They have tried blaming the QIN, TCL, enviro groups, just about anything or anyone rather than just get the job done.