I do collect rainwater! (In the summer months, at least.) Have a system cobbled together based on bluebarrelsystems.com Though disaster preparedness and water

I do collect rainwater! (In the summer months, at least.) Have a system cobbled together based on bluebarrelsystems.com Though disaster preparedness and water efficiency are a bit at odds. For the former I'd want to keep all my barrels mostly full, but for the latter I want to keep them empty enough that rainfall events aren't overflowing them and wasting water.