Drainage in Wembley Market Square

One aspect of Wembley City (the area around Brent Civic Centre) which tends to trouble me is the hardness of the urban landscape.  Unfortunately this is not easy to alter now, as the plans are now fairly set.  One of the problems with this kind of landscape is the drainage.  Water hits the ground and runs off immediately.  When rainfall is heavy, this can often lead to surface water flooding as the water collects quicker than the drains can cope.

One answer to this is to have more porous surfaces like the one pictured above (which is the surface of Wembley Market Square just by Brent Civic Centre).  Here the water drains away between the gaps in the flagstones, reducing the possibility of flooding.  It would also help to have more street trees.