It is more important that you have unrestricted flow into the cistern.
Cistern no gutters.
Another method calls for gutters to be held in place by straps fastened to the roof.
Remember that the x section of a 4 pipe is twice that of a 3 pipe.
I got the used drum locally for 15 and the wood came from my scrap bin.
The rain will collect in gutters that channel the water into downspouts and then into some sort of storage vessel.
This technique is usually only used when there s no fascia board.
Traditionally this involves harvesting the rain from a roof.
Screwed connections are stronger.
Sweep all debris from the roof and gutters leading to the chosen downspout by using a broom.
Install standard size mesh gutter covers over the entire gutter that will lead into the cistern.
K style gutters can be spiked or screwed to the fascia.
Cistern covers are 2 x2 and are cast in the floor.
The cistern typically located underground may be constructed of various materials including cinderblock reinforced concrete or precast concrete fiberglass or steel.
A system of gutters and downspouts directs the rainwater collected by the roof to the storage cistern.
Put them where they need to be.
This is a cistern i made from some pressure treated 2x6 material and a 55 gallon plastic juice drum.
I chose to use 2x6 material because i had it handy but if you choose to u.