...Splash blocks...These concrete blocks are intended to divert the water coming out of the downspout next to the house away from the house. They are simple and inexpensive to install and "rarely work".
...Storm sewers...Where storm sewers exist, water from the gutters, downspouts, and drain systems should be diverted to this storm water system.
...storm sewers...It is important to check with the local water department in your area. If a storm water system exists in your area, they are likely to have a map showing where the lines run and approximately how deep they are. Many jurisdictions require on-site systems for storm water dispersal.