Rainwater Catchment Beginning Stage

I built this 4 foot wide by 8 foot long deck then raised it 4 feet of the ground on 4 by 4s. To start I have 2 55 gallon plastic drums connected with clear 1 inch hose so the 1 fills the other. On the opposite side of the overflow being diverted with a long piece of downspout that is to go into a small ditch between the properties. I have a lot more to do but I wanted to get it up and functional for the rain. But also because the rainwater otherwise hits the ground and floods under the floor of the garage and eventually will cause cracks if I don't try to control the water. Normally my yard is fully saturated. So I figured as I divert the water I can also catch some and use it for my garden and chickens. Hard times and you might wish you had rainwater catchment too. My end goal here is to scale up eventually to 2 375 gallon IBC Totes. They are $$$ if you buy em new. Don't want used since you won't know what chemicals might have been stored in that container and leech out later down the road.