hmm, that looks like the mechanical seal has failed, it's hard to imagine where else the water is coming from given that you've looked very closely at the most likely hose connection. I suppose it could be spraying from a heater hose or dripping from the head itself (although that's not good news) but they look slim compared to a seal failure.
If you remove the pulley (simple job) then you can see the casing itself & I'd bet you can see water dribbling out from the pump if you turn the shaft by hand. If it's recent you might not have the traditional "wobble" at the water pump pulley because the bearings are still in one piece. (so far). If you have got play at the pulley then I'd stop now and pull it apart because you don't want any further damage.
It is practical to replace the pump without pulling the engine but you still have to remove the head and sump, the only advantage is that you're leaving the block/clutch/gearbox in place. I have heard of people doing the job by just dropping the sump and using lots of instant gasket type stuff to make the joint at the top of the cover - you pays your money and makes your choice... etc.
FWIW I've done the Europa pump twice, both times with the engine in situ. Both times I had the car on axle stands, removed luggage tray to sit on the engine and took off the head/carbs as one unit and then dropped the sump. Once the head is away you have a surprising amount of access to the cover although if you've added extra insulation or otherwise modified the bulkhead it'll obviously change things. Set it all to TDC before you start undoing stuff, it'll make it easier going back together !
Brian (still amazed by this interwebby thing and the technology we have today)
