Best of all, here’s the data! Very nicely prepared for use. I tossed some of the California occurrence GeoTIFFs into QGIS for a quick plot. This view is centered on Engelbright Dam with Sacramento to the west, where the American and Feather rivers meet. Blue is year-round water; pink is intermittent (and seems to highlight farmland.)
At a scale of 30m per pixel this dataset doesn’t show small rivers or creeks. But what this map does show is the history of water over 30 years of Landsat imagery. In addition to the basic occurrence map there are also several data layers highlighting changes in the surface water. One showing before and after Jan 1 2000, one showing seasonality, one showing yearly recurrence, and some other more technical measures.
It’s a solid piece of work and nicely packaged. And all free!