I wanted to take some time to look at several ways to plan your water system. First of all, I would recommend that you establish your own water source that is independent of any metropolitan system if at all possible. Having your own well, spring, creek or river frontage is the best way of securing that you have water when you need it without the limitations that a metropolitan system usually carries with it. I have seen some systems that depend on rain catchment as well. Just think about being able to have water whenever you need it without it being turned off by someone or something.
I will use our system as an example and you can extrapolate off of those ideas. In our case, we have a well. We have been blessed with an abundant well, and even in the middle of our current California drought, we have plenty of water to use. Our land has a slope to it so we decided that we would design a gravity fed system so that we have the minimum number of moving parts and pumps that makes for a system that is easy to maintain.
Different properties will present different challenges. For instance, if you have a flat piece of land, then a gravity system is going to require a water tower of some sort that will require a strong well braced structure to support it. This will be an extra cost, and at that point, you will need to calculate the difference in cost to see if a tower structure is worth the price. It may or may not. If you have a sloped piece like ours, then it is much easier to make a gravity system.
The principle of a gravity system is that for every 100 feet of elevation drop, there is a buildup of 45 pounds per square inch pressure. Most city systems offer about that much pressure in their feed lines so if you can set a tank 100 feet above your home site, you will have the same pressure. Many times, as was in our case, we only had about 50 feet of elevation drop so we only have about 22 pounds pressure. We have found that we can live with that. In our orchard and garden irrigation, we have found low pressure sprinkler heads that work quite well on this lower pressure.
One of the places we needed more pressure was in our hot water circuit. We use an instant/continuous water heater that will not run on 22 pounds of pressure, so we placed a small RV 12 volt booster pump inline before the water heater and that has worked just fine. It only has to run when we want hot water. Otherwise it is on standby.
My method was to run 1 ¼ “ PVC line out of the tank to use as the major feed line. When I branched off of that to supply a particular area, then I reduced it down to 1”. When I plummed in a faucet, I reduced it down to ¾ “ line and finally when we brought the line into the house, we reduced it down to ½ “. This kept the flow at maximum so that if the water was on in a couple of different sites, it did not drop the pressure much at all.
We used schedule 40 PVC pipe for all our water pipes and buried it 18” to keep it out of the way. We do not have freezing issues where we are so that depth was plenty. If you are in a freezing area, then you will need to follow the recommendations of your local plumbing contractors.
Our well pump is a Grundfos solar pump. It can operate on any voltage from 40V to 400V either AC or DC. If you give the supplier your well depth and how far uphill you will need to pump, they will help you size your pump accordingly. Our pump can fill a 2500 gallon tank in about 6 hours of sunshine; pumping it up almost 100 feet of elevation plus the 220 feet up out of the well. So there is about 320 feet of elevation to pump the water up. This requires about 400 watts of Solar panels to accomplish this process. I am quite impressed by how well it works.
The other nice thing is that if you have several days of no sunshine, or you need to pump more water than that, you can plug the pump into a generator and pump on 110 volt and it fills the tanks even faster.
If you are taking your water from a river or other source that could carry contaminates, you will want to have the water checked by a lab to see what you are dealing with. Most areas have water testing labs available and it can be done online as well. You may need to install some sort of filter to make the water safe for drinking but that will only need to be done for the supply that you will be drinking from. Your irrigation and other needs should not be an issue.
I hope I have given you some helpful tips and things to think about. If you have any questions or suggestions, please feel free to contact me.