I had the same problem. I had to replace the washer pump which is located in the drivers side wheel arch. You will have to remove the road wheel and arch liners to get to it. Reach up towards the door and lift the small pump out of it's housing. The nozzle of the pump just pushes through a rubber grommet.
When you do this all the water will drain from the tank. Disconnect the connector and 2 small hoses and remove.
When taking the wheel arch liners off you will probably break the fixings, so buy a new set.
I. Knight
March 2007