Clogged or above-ground exterior drainage pipes could allow water to puddle next to the home and find its way inside any crack or gap in porous block foundation walls. Above-ground downspout conductor lines are unsightly tripping and safety hazards. Burying these lines under the ground and directing them far away from your home is the best way to keep water from downspout conductor lines out of the house.
You also need to think about the condition of this buried drainage system. These pipes fail to do their job if they crack or collapse, and you could end up with puddles of water in your basement. Older clay pipes commonly split, break, or crack.
Some traditional downspout conductor lines buried underground have no outlet for drainage. Since they are sitting in the ground, they could become clogged with dirt and other debris. This could lead to back-up or overflow of water that will cause additional headaches.