> California’s water board doesn’t have the staff it would need to monitor river levels statewide

Isn't water flow rate automatically collected, at least for larger rivers and creeks? Can't low flow be flagged automatically?

> Even if the state water board had learned of the Merced’s withered conditions earlier that summer, it might still have taken months to enact new regulations to protect the river

This seems like something that shouldn't require enacting new regulations. Enact the regulation once, and enforce the regulation always.