When it comes to managing water in uncertain times, few things are more important than knowing how much is flowing in the river alongside your city, or filling the reservoir that irrigates local farms. That information is crucial to deciding how much water is available to irrigate crops, whether to declare a flood emergency or whether to launch a lazy rafting excursion. But this basic information is at risk across the West because the nation lacks a reliable funding source for the simple stream gages that measure river flows.