We never had a cistern, but I remeber the one at my Granparents house. It was no longer in use wehn i could remeber it, but all the downspouts were in place. Teh one thing I remeber most was that the downspout had a diverter type contol on it, that when it first started raining you tunred so the first water went on the ground rather than in the cistern. This helped reduce dust, bugs, bird droppings, etc. that went into your drining water. I remeber my Dad talking aobut the rain barrel they caught water in adn drank from. He mad the commnet more than once it was a miracle they lived. He said they would take the dipper and bang the side of the barrel so the wiggle tails (larve) swimming in it would go to the bottom and not be picked up by the dipper.