If you have trees in the vicinity of guttering, it's a good idea to fit plastic mesh leafguards to the gutters.  This will keep leaves out of your gutters and ensure, a smooth steady flow of rain water.

If you have water seeping out of a downpipe, then it is very likely that there pipe is blocked between the leakage and the pipe outlet.  It is best to attempt to start unblocking from the lowest level (i.e. ground level), and then work upwards. 

To unblock a downpipe, try forcing a piece of wire up the pipe.  A garden hose could work equally well too.  If you don't meet with any success, try using drain rods from the top of the pipe.

Sometimes, horizontal drain pipes start sagging.  There is a quick fix for this, fortunately.  All you haveto do is fit extra support brackets to the pipe.  Take care the new brackets line up with the old ones, otherwise you'll have a problem.

If you notice a blocked gutter, make haste to clear the blockage.  Failure to do so could result in the gutter collapsing due to the excessive weight of the trapped water.  Scoop out leaves and other obstructions, and if possible fit a plastic mesh to keep leaves out of the gutter.