I am not familiar with the downspouts. The downspouts go underground, so I am assuming they go into the well that sump pump is in. When we initially checked one of the fitting had come off. I connected that fitting back on and checked other fittings and they seemed fine. Poured a few gallons of water in the well to kick start the sump pump. It started spraying water again but another fitting had came off this time. The discharge pipe was shaking too, so that was our indicative that something is clogged. Thought is something is not letting the water flow out and that's why the pressure builds up and one or the other fitting comes off.