Run the cords in the pond, covered by rock or ???
With pond lights, as with most everything else, you get what you pay for. Don't expect cheepo lights to last very long and you won't be disappointed. Having said that, I spent more than I wanted to on a name brand LED pond lite kit (four 1 watt lights, timer, etc.) and in less than a year, two of them went bad. This is where buying from a reputable dealer and purchasing a product with a solid warranty pays for itself. They replaced the bad lights under warranty. Bit of a hassle but better than tossing out $150.00 worth of lights.