[7624U]

As others have said I would move the tanks down hill if that is where the water needs to be used. Preferably on a raised platform so you have gravity pressure does not need to be a lot if just used for toilets and washing dishes.

First thing I would do before I did anything would be hook a 12v surface water pump ran off a car battery and see what refill rates I have in the spring vs GPM pumping and filling of my tanks. if you just goto a farm store and get a cattle water pump or RV pump of around 1-5 GPM flow rate bout $50-70 bucks this will give you a idea if the spring can keep up with demand. No use going out and buying a system if your pump ends up on the bottom of a empty spring sucking in mud. 3GPM flow would be 180 Gallons per hour so would fill your water containers in less than 4 hours on solar if the spring could keep up.

If the well or spring is good and serviceable I would divert the run off with gutter pipes above the spring no need to get crazy just dig a 1-2 foot trench excess dirt to the down hill side throw in the pipe and cover with pea gravel this should keep most of the run off from the hill from sending stuff into the spring box. (unless you have a flash flood coming down the hill this wont work)