Hatcheries take many forms and none are fail safe. Pumped stations are the most vulnerable due to power supply but gravity and ground water supply are vulnerable just in diverse ways. All have one thing in common things can fail from plugged screens, power outage, to failure to adjust to ground water supply. All have one commonality the final back up is human eyes that is why all facilities normally have a standby staff or someone on site such as a caretaker. Failure to do the normal fish health and facility maintenance cannot be excused under any circumstance. I know a gentleman who rears fish from spring fed water piped with the usual systems. A few years back he added a remote camera at the intake and outlet so if everything went south without warning due to a system failure he could check on things on his computer from his office or home (now his phone also) just to double check things for peace of mind.

When you run your loadings up (pounds of fish per gallon of flow and total pond volume) it is imperative that the facility be monitored 24-7 by staff. The loss of flow from plugged screens is always visible be it inlet or outlet. The failure that started this thread is NOT excusable in any way shape or form.