During rain season, our pond collects a vast amount of water; when full it holds about 300,000 gallons. However, we lose quite a bit of this over the rest of the year to evaporation. Although this loss should reduce as trees and water plants increase and provide shade, that may take a while. In the meantime, we are looking for ways to make use of the water before it evaporates.
We have just bought a pump that runs on solar. It can pump about 600 gallons of water a day (more in summer when the days are longer). Our eventual goal is to build a huge tank on the top of the property, which will then be able to provide pressurized water to the whole hill. For now, we will be watering the orchards and gardens directly, as well as filling up the current irrigation tank as it goes down (it's full at the moment).
We plan to hand-dig a hole just off the side of the pond, which will act as a well. We will be able to pull the pump up the casing if maintenance is needed, and add filtration measures to the well itself. The only problem with this is that we need the pond to dry up in order to dig the well! So, we are currently trying to use up the water. We put the pump inside a PVC pipe and wrapped it in a feed sack as a basic filter, and then just sunk it in the middle of the pond, which is currently about 4 feet deep.
We have four months left until rain season begins, so we should be able to use up the water currently held in the pond (evaporation will help us out too). What it means is that the trees we currently have planted will be receiving a LOT more than we usually give them, and we will be planting out the hundreds of little trees and shrubs that we have had growing in our little greenhouses (we would normally wait until rain season to plant them out).
Solar well pump