UK Car Repair: my car, vauxhall astra, gasket seal

Question
hi my 2 ltre vauxhall astra estate w reg is running fine but however the water is being lost when im driveing around, i got told this could be my head gasket but theres no ovewr heating, i looked under the bonnet other day when the engine was at running tempersture and saw a leak which lookjed like it was coming from the pully the water pump is attached to. can you help me on a diagnostic please.

Answer
The water pump can leak from its gasket or from around it's shaft bearing.
also the pipe leading away from the waterpump can leak and trickle back to the pump, making it look like the pump is leaking.  Best to remove any plastic covers and get hold of a torch, find out where the leak is coming from, inspect the pump/block gasket seal, the pump/shaft/bearing seal and the pipes leading to/from the water pump.

If the waterpump has done more than 45k miles then replace it, even if it is just a gasket leak -  they only last around 70k, not worth putting it back on.