2001 Citroen Saxo water leak

i have a water leak into the driver side footwell of my saxo and this has now stopped the vehicle from starting - i have cleared out all leaves etc from under the scuttle etc but this doesn't seem to have helped - can anyone advise as to a possible resolution to this? one possible suggestion so far is that this is due to the plenium chamber being blocked but i am having difficulties locating this - any help would be brill