Quote Originally Posted by Vindec View Post
the most likely cause of a blockage is the stones filling up with earth and weeds preventing water from draining through - a problem which can sometimes be resolved through jetting.

Fitting a shoe is a good idea as long as the water drains away from the house. A water butt is not such a good idea as the butt will fill up after a brief shower unless you leave the butt tap open which is no better than the shoe solution mentioned above.
oppps i see you mentioned the earth and weeds, i didnt see it in my first reply

the water butt idea with 2 overflow hoses would help disperse the water over a great area though