Our old Whole Way Home rainwater catchment system

This was the manifold setup I designed in Las Vegas, NV to capture rainwater. 55 gallon drums were chained together and could be individually shut off for repairs. the water came off a shed roof - there was no pre-dirt-debris "first flush."
The output was only used to water the garden during dryer times. Normally this kind of setup would need to have a cover against sunlight to prevent algae build-up. but in the desert, the water was used up fairly quickly and thus, was not an issue.
I will be building something like this on a much larger scale at the Seed of Life in Texas! And yes, it will include a first flush element.