Search something like "solar pump systems for livestock".
That is a pretty mature field with lots of businesses offering products. Many systems even have the panels charge a 12V battery so the water pump will even operate through a stretch of cloudy days. That would also give you juice for a washdown pump.
OTOH, running an armored cable or electric line in a conduit starts to look pretty good for all of the things you can run at your dock or in your pond!
