Your pics show the leak from the joint between the middle and upper cases. That's not a good place for a leak as fixing a leak there will involve splitting the crankcase, not just between the lower and middle but also the middle and upper. However that's an unlikely place for a leak to suddenly appear and it's likely coming from somewhere else. There are dye kits that involve adding dye to the oil and inspecting with an ultraviolet light. You really ought to use one of those. Your first pic suggests that the engine ought to be cleaned first.
Water pump oil leaks can come from two places. There's an O-ring around the nose of the pump where it inserts into the crankcase. It apparently can harden and be a source for a leak. In that case the leak will run down the side of the crankcase and maybe the outside of the pump. There's also an oil seal inside the nose for the impeller shaft. If it leaks, oil will come out the drain hole in the underside of the nose.
Air currents can move leaked oil around on the engine. Your leak could also be coming from the valve cover gasket, CMP sensor, breather cover gasket, breather hose, clutch push rod, transmission drive shaft, or even the airbox where the breather hose attaches.
