Would this body of water stay clear without chemical? Not a NSP

I have a unique situation. I live on a hillside property with a Well water & 100 new trees. Last year I experienced pump failure which made me realize I need a backup plan for irrigation that is not dependent on my well water & electricity. So I like to build a 9000 gallon pool 35'x7'x 5'deep in my backyard which is 20' above the orchard. I will use about 1500 gallon of water a week for irrigation & I like to gravity feed the water from this pool & replace with fresh water. We did not intend to have a swimming pool and we are not going to use this for swimming.

However, we like to have a clean body of water. We wish not to use chemicals, motor & filter, but I can circulate, aerate, other means of cleaning & even go as far as running the water over some water plants for some purification. I can even drain it completely and start over once in awhile.

I would love to hear some experts opinion & feedback as:
1) would using 10% of water per week imitates a running water? hence clear, sanitary water or would you think the water will turn on me.
2) would draining it off and on hurt the shotcrete? what if I do not plaster the pool? can I leave it as shotcrete? Tile?
3) any other method I can add to keep the water clear.

thank you all in advance.
mehrzad