A clogged gutter will allow water to flow over the roof during heavy rainfall., which will then land next to the foundation wall and absorb into the soil.  This can lead to water traveling down to your footer and then lead to water in your basement.  This area is the most vulnerable for soil saturation because during the original excavation to build the home, the soil backfilled next to the foundation is more porous than the undisturbed soil around the home.

The best way to install an underground downspout system is with a debris filter that helps keep the buried pipe clean, which will then allow the homeowner to easily maintain the system.  

To be effective, the underground downspout system should carry water at least 10 feet from the foundation.  This will help keep water from over saturating the soil where it meets the foundation wall. 

A benefit of having a buried downspout system is there won’t be any extensions to fall off or have to be removed every time the lawn is mowed. 

One of the biggest contributors to a wet basement is for the soil to be over-saturated next to the foundation wall. When the soil absorbs this water, it can put pressure on the foundation wall.  This pressure can start cracks to form in the concrete walls, which can lead to structural damage to the foundation.  This pressure can also force water into your basement.