So my wife and I are looking to build our final home on 5 acres we bought out in the country. We are considering a net-zero home. This means everything about the home is very efficient such as how it is oriented to the sun, the location of windows, type of insulation, tightly built home, solar panels, and a rain collection system.

This should mean the home will be very energy efficient, we would barely have an electric bill if any, and no water bill. I am concerned about having no water source other than rain for the whole home. I do have the option of a private water company and also the ability to have a well. I have done a lot of research and it seems where I live we should be able to collect enough rainwater during the year for all household use and to make it through months without rain. The builder just needs to make sure they have the proper size storage container, probably 10,000 gallons, and start with at least 1,000 gallons in the container.

I am just curious if anyone has a rainwater only home and what your opinions are. The builder we are really considering is https://www.buildnative.com/

They are not cheap, but they seem to know what they are doing. We visited some completed homes and some under construction and were pretty impressed. I would love to hear from anyone who has experience with these types of homes. They estimate between $200-$250 per square foot for everything in this area. I know that is high, but also they use top quality materials and both the solar panels and rain collection is not cheap.

When hanging out on the Big Island, you discover that many many people live on catchment only. Along with a solar-powered booster pump, they were used to low water consumption habits.

I'd want my catchment and tank well-uphill to have gravity flow into the house. But that can be more expensive than catching off the main structure.

You either have to install a good filtration system or a first flush system. First flush takes the initial rainfall and puts it into a gray water catchment or into the yard/garden - since that water contains particulants and dust and such. After the rain has fallen a while, the runoff should be cleaner and is diverted to your cistern.

If you catch all the runoff, you'd need to clean it up and filter it to a greater extent before drinking or showering with it.

Filters require regular replacement and thus monthly bills. the other way is more expensive up front but probably less long-term.

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Originally posted by SBrooks:
You either have to install a good filtration system or a first flush system. First flush takes the initial rainfall and puts it into a gray water catchment or into the yard/garden - since that water contains particulants and dust and such. After the rain has fallen a while, the runoff should be cleaner and is diverted to your cistern.

If you catch all the runoff, you'd need to clean it up and filter it to a greater extent before drinking or showering with it.

Filters require regular replacement and thus monthly bills. the other way is more expensive up front but probably less long-term.

Quite honestly you're better off with a well. You will need to chlorinate your catch tank to keep it from becoming an algae and bacteria farm, then you have the sediment from the rain water, even if you have a runoff system for the first 10 minutes, and you still need electric to run the pump (same as a well). You really should have 2 equally sized tanks, so you can divert water into one tank, and then pump into one tank, so you can periodically clean the sediment out of the other tank and vice versa.

I would want to have a well. I live on a well water system now and like it very much.

I'd like to do catchment for other uses such as irrigation, wash down, etc., but that's not currently in the budget.

I think a catchment system only would be a constant source of worry. What do you do if somehow it gets contaminated, especially during your dry season?

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Originally posted by ArtieS:
I would want to have a well. I live on a well water system now and like it very much.

I'd like to do catchment for other uses such as irrigation, wash down, etc., but that's not currently in the budget.

I think a catchment system only would be a constant source of worry. What do you do if somehow it gets contaminated, especially during your dry season?

That too is a very real problem. I doubt you'd want to use the water to take a shower if you found a dead racoon or rat floating in it. Then you also need water to disinfect it.

Not a good plan, IMO. Perhaps for garden/lawn watering purposes, but not consumption.

Is finding some property along a river or year-'round creek running through it a possibility? Then you could put a small generator in the flow and get water and electricity.

No way in hell if well or private company is available. Too many concerns with sanitation, filtration, draught, and animals/runoff contamination.

Maybe consider Geothermal HVAC for energy savings and since you may possibly be drilling Wells. No clue on BEP for that especially considering high efficiency home.

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Originally posted by jimmy123x:

quote:

Originally posted by SBrooks:
You either have to install a good filtration system or a first flush system. First flush takes the initial rainfall and puts it into a gray water catchment or into the yard/garden - since that water contains particulants and dust and such. After the rain has fallen a while, the runoff should be cleaner and is diverted to your cistern.

If you catch all the runoff, you'd need to clean it up and filter it to a greater extent before drinking or showering with it.

Filters require regular replacement and thus monthly bills. the other way is more expensive up front but probably less long-term.

Quite honestly you're better off with a well. You will need to chlorinate your catch tank to keep it from becoming an algae and bacteria farm, then you have the sediment from the rain water, even if you have a runoff system for the first 10 minutes, and you still need electric to run the pump (same as a well). You really should have 2 equally sized tanks, so you can divert water into one tank, and then pump into one tank, so you can periodically clean the sediment out of the other tank and vice versa.

Two tanks is a good idea to inquire about.

A well would be a lot cheaper so I may see if I can convince the wife of it. We visited a few homes they built that are 100% rainwater with no other source and each had lived there a few years with no problems, but I do see it as a source of constant worry.

You would probably already know if it were going to be a problem where you are, but there are places in Colorado where rainwater can’t be “caught” and used for any purpose because of water rights issues. Even though the water falls on the landowner’s property, it doesn’t belong to him and can’t be diverted.

I don’t claim to have any knowledge about how these systems work but there are many of them that are being used successfully...especially in parts of Texas where a well isn’t an option. From my (limited) understanding the roof is metal and then there are numerous filters, including in the down spouts, and the water is “sanitized” via UV light. If you really want to learn I would hit some of the Texas resources. Me personally, I would probably drill the well and add another solar panel or two, if needed, to run the well pump.

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Originally posted by Garret Blaine:
I don’t claim to have any knowledge about how these systems work but there are many of them that are being used successfully...especially in parts of Texas where a well isn’t an option. From my (limited) understanding the roof is metal and then there are numerous filters, including in the down spouts, and the water is “sanitized” via UV light. If you really want to learn I would hit some of the Texas resources. Me personally, I would probably drill the well and add another solar panel or two, if needed, to run the well pump.

Yeah the roof will be metal no matter what, but the gutters are specially designed for catching all of the water and transporting it to the storage container. There are different options for container material all with pros and cons of their own and then several options for filtration. You can also do a well/rainwater combo. I have read from several sources that rainwater is very great compared to city or well water. I also have read up on rainwater charts for many areas over many years including drought periods and a rain collection in my area can still yield enough water as long as everything is calculated right. If you live in some other areas then you need a second source of water.

I am still torn on what to do, but there is no way I would do it with just any custom builder, but this builder ONLY builds homes like this. They know what they are doing and have won several awards.

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Originally posted by sigfreund:
You would probably already know if it were going to be a problem where you are, but there are places in Colorado where rainwater can’t be “caught” and used for any purpose because of water rights issues. Even though the water falls on the landowner’s property, it doesn’t belong to him and can’t be diverted.

Yes here you can collect rainwater for this or any purpose. There is a state law that makes the purchase of all rainwater collection equipment and installation costs tax exempt. Also the land area used for the purpose of collection can be exempt from property taxes.

Despite caution on the forum, I cannot see the issue. I've worked around buildings with water tanks for years. Water is pumped into the top story tank off-peak and supplies steady pressure and volume throughout demand periods. Old City Philadelphia is/was routinely sucked dry when the Custom House turned on their pumps to fill their tanks (water there barely makes it to a 4th floor, sometimes not at all).

The tank is drained once an eon for cleaning, a dead bird sometimes found, sometimes not. That's about it. Any rodent who chooses to climb in for a swim can do so, but it does not happen all that often. Same as a reservoir. Many municipalities receive water so clean they are not required by law to disinfect it (chlorine), water collected in a similar manner - the vast natural catchments of creeks, streams, river, reservoir.

I might bypass the tanks for the first few minutes if possible, if it has been a long time since rain, let the dust and dirt rinse off first, save your sediment filters. Whole house will make it drinkable, and finer filters for potable use will filter even further, just in case.

Catchments have been around since Moses.