My rainwater is also backup storage for emergency water. It's not potable as is. With only a little treatment, like a T-shirt filter and a splash of Clorox or running some through the travel Berkey, it would be potable. With my main barrel empty, I felt unprepared. So unprepared that I took action this morning.
It was a good time for some periodic maintenance on the barrel, so I gave it a gardenhose-strength pressure wash inside to loosen some algae. I also blasted the coarse filter basket at the inlet to remove debris. The grand finale was to open the main valve and clean it out, along with the hose.
At first the water was murky, but after a few minutes, it ran clean.
Then I filled it halfway up, about 100 gallons. It would be enough to get us through a short interruption, so I should be able to sleep tonight.
Do you have a rain barrel? How does it fit into your preparedness planning?