How can I prevent water from leaking on an outlet?
I think the best way to prevent water issues would be to move the outlet and/or valves. If that is not preferable, at least ensure that the outlet is protected by a GFI, or install a GFI receptacle at that location. You could also use a weatherproof "in-use" cover. Keep a close eye on your hoses and valves and repair at first sign of leak. Turn those faucets off when you go on vacation.