The signature conservation project being developed at the hatchery is a water reuse system called Partial Recirculating Aquaculture Systems (pRAS). The pRAS system utilizes circular tanks that move water around in a whirlpool-like motion allowing for most of the solid waste to be removed from a drain in the center of the tank. Cleaner water is then removed from a drain on the side of the tank, filtered, stripped of carbon dioxide, UV treated to remove pathogens, re-oxygenated, and then returned to the tank. This method has been proven at other hatcheries to grow more and healthier fish with lower quantities of water. 

The LNFH implemented a pilot pRAS project including the construction of four circular tanks. This pRAS pilot project will be monitored for five years to determine whether this new system can rear smolts as well as the conventional raceways, maintain high water quality, mitigate disease risk, reduce water usage, and meet effluent requirements. If pRAS can meet these objectives, LNFH will move forward with rearing all of the salmon in this system.

As indicated in the Leavenworth National Fish Hatchery Climate Vulnerability Report, the effects of climate change in the Icicle Creek basin will mean: warmer water temperatures, changes in high and low flow periods, and higher flood, fire and fish disease risk. All of these components lead to the need for better water conservation and management practices, pRAS playing a crucial role.  

Read more about this system by checking out the Leavenworth National Fish Hatchery PRAS article.