benefits of rainfall collection

Another set of calculations
Rainfall is about 25mm per week across 12 months
So you have about 80 sq m of roof [ 780 sq ft ] x 10 weeks x 25mm
= 80 x 250mm
= 80 x .25M
Total volume captured over 10 weeks is
= 20 cubic M which is 20,000 Litres or about 5000 gals.


My source of data for water consumption is water consumption
Essentially from that data an efficient house would use 1000L per person in a very water efficient house per week.

GOING BACK TO THE QUESTION OF WHAT VOLUME OF WATER NEEDS TO BE STORED FOR A FAMILY OF 4 OVER 3 DRY MONTHS
From my data of Melbourne a water  efficient household uses 750- 1200L of water per person per week
water usage data

Lets allow 1000L per person per week over 13 dry weeks.
1000L x 4 people x 13 weeks gives a required stored water volume of 52,000 L

MY EXAMPLE EARLIER IS INCORRECT.
HAVING BEEN ASKED TO EXPLAIN, I WENT THROUGH MY NOTES AND REALISED I HAD EXCLUDED SHOWERING AND KITCHEN USE.
I AM WORKING AT NIGHT HERE, PERHAPS I RUSHED I AM SORRY.
BUT I CANNOT YET EDIT THE OLD POST.
SO 52,000L needs to be stored not 26,000L

John C Daley wrote:Another set of calculations
Rainfall is about 25mm per week across 12 months
So you have about 80 sq m of roof [ 780 sq ft ] x 10 weeks x 25mm
= 80 x 250mm
= 80 x .25M
Total volume captured over 10 weeks is
= 20 cubic M which is 20,000 Litres or about 5000 gals.


My source of data for water consumption is water consumption
Essentially from that data an efficient house would use 1000L per person in a very water efficient house per week.

Just wanted to give a quick thank you for sharing your water consumption resource.

Rainwater is back on my mind after a short break now that we're discussing construction- and we'll need water for the construction sight even before the roof goes up. We'll have to truck in water until we can collect.

Good.
Perhaps purchase a 20,000L tank, install it where it would be required, get a pressure pump and set up a small water pipe system.
Its moving forward and giving you experience at the same time.
What are you building the house from?
Can you get a roof near the tank quickly?

John C Daley wrote:Good.
Perhaps purchase a 20,000L tank, install it where it would be required, get a pressure pump and set up a small water pipe system.
Its moving forward and giving you experience at the same time.
What are you building the house from?
Can you get a roof near the tank quickly?

We’re planning on doing aerated concrete ICF blocks.

My husband did mention something about getting some kind of cheaper roof over head for shade during construction... perhaps we’ll get a carport put up first for this purpose. It would also help to have that extra roof for rainwater needs as my recent calculations were pushing it. (My calculations did not include carport or garage)

Something extra I encourage in Australia, put good quality insulation under the carport roof.
It will stop condensation and stop heat pouring through the roof in summer.

INFORMATION ABOUT LEGALITY OR REGULATION OF RAINFALL CATCHMENT
USA - legal mechanisms if any in the USA about rainfall collection

Judging by questions I am getting, this post is provoking thought.

I really appreciate all the information you've posted on this. We collect some water off our roof, but we don't have any system in place or much storage. We need to deal with freezing in the winter and it's a big project that's just not as high priority as other things. I'm definitely going to refer back to this thread in the future, though.

Can you store water in a basement?
I have seen it stored inside Barns with walls. And one had a small heater
In basements it is possible to get flexible water bags down there for storage.

I will look for some ideas around the world.

Tips to Reduce a water storage tank from freezing
Best action is to insulate the tank
One of the best—and cheapest—ways to limit the risk of freezing is to insulate the tank. This involves wrapping the top and sides with blankets made from fiberglass, mineral wool, ceramic fiber, or some other cushioning material. These wraps are also layered with sheets of aluminum to further reflect heat as it escapes the tank. Not all insulation wraps are alike, however, as some are pricier and have higher temperature thresholds. How much and what type of insulation you should use depends on the climate of the storage tank: The lower the average temperatures in winter the more robust and protective the insulation system needs to be.

If you can’t afford either insulation or a heating system, or if your tank is in a climate with minimal risk of freezing, there are some steps you can take to reduce the chance of your water freezing up.

1.) Get as big a tank as you can – Small volumes of water freeze faster than large volumes. Use this basic law of nature to your advantage and get a tank that is slightly larger than you think you might need.

2.) Avoid square or rectangular tanks – For the same reason that larger tanks take longer to freeze, rounded tanks insulate better than similar sized rectangular tanks. Why? Because they have smaller surface areas and, thus, less room for heat to escape.

3.) Monitor the tank for cracks or leaks – This applies to the network of pipes running to and from the water tank as well. Any leaks that form will accelerate the pace of heat loss and quicken the freezing process. You want to make sure your water system is all buttoned up before the first frost arrives.

4.) Avoid flat tank covers – Don’t give your tank the chance for ice to form anywhere around it. A flat cover dramatically increases the likelihood of ice forming because rain, snow, or overflow that accumulates on the surface has nowhere to go. If the cover is sloped, the water will just slide off to freeze somewhere else.

5.) Bury your tank – This isn’t always an option but underground tanks enjoy more stable, consistent temperatures, even through winter. They’re harder to access, pricier to install, and more difficult to maintain, but they’ll get you most of the way there in terms of frost-prevention. Underground tanks need to be made stronger to resist the earth pressure collapsing the tank .

6.) Buy a plastic tank – There’s no signifiant difference in the rate of heat loss between a plastic and metal tank. But in the event that water does freeze, plastic can better withstand the force of expansion. Metal, on the other hand, is more likely to crack when water turns to ice. Also, because plastic is cheaper and more malleable, you have more options for choosing the right shape and size to suit a water storage system that can survive the winter.

6.) Keep water moving – Moving water is more energetic and, thus, requires colder temperatures to freeze. Preventing frost can be a simple matter of jostling the tank from side to side on particularly cold days, installing some sort of flow system to keep water agitated and moving, or periodically flushing or plumbing system. if the tank is hooked up to a pressurized water line you can run the taps to keep water moving through the pipes.

From Research about rainfall collection

Highlights from Dr Coombes’s research
Unlike water catchment systems such as dams, which are subject to large losses of water, rainwater tanks harvest water efficiently during drought, thus reducing demand on water supply reservoirs
There is more rainfall in urban areas and minimal water is lost form the roof to the tank
Rainwater tanks complement mains water supply infrastructure. They’re underutilised if water is only used for irrigation.
Maximum benefit occurs when rainwater is used indoors and outdoors
Rainwater quality is ensured by a natural treatment chain in the tank that reduces the presence of bacterial and metal contaminants.
Bacteria, organic compounds and chemicals form flocks that become biofilms on surfaces or settle to the bottom of the tank to the sludge.
The processes of flocculation, settlement and biofilms in tanks act to improve the quality of rainwater. The majority of bacteria in rainwater tanks are harmless and from the environment
Water quality monitoring has shown effective pasteurisation of rainwater to remove bacteria in hot water systems.
Rainwater used in hot water systems set at >52 degrees Celsius was compliant with Australian drinking water standards
Separation of the first “flush” of rainwater from the roof and gutters improves tank water quality

Rainwater tanks reduce stormwater volumetric discharges by 39%
Cost of rainwater varies from $0.30 kL to a benefit of 0.39 kL – considerably less than mains water
Extensive analysis of literature and research has revealed that health concerns about rainwater tanks are significantly overstated. You are more likely to contract illness from drinking mains water compared to rainwater.  

Other research
Roof-collected rainwater can be made safe and potable so that it complies with strict international drinking water standards (Waller & Inman, 1982; Gould & McPherson, 1987). This is especially true when measures such as tank cleaning and the use of first flush diverters and coarse rainwater filters are undertaken.

In South Australia, 42% of residents mostly drink rainwater in preference to mains water without any apparent effect on the incidence of gastrointestinal illness (Heyworth et al. 1998).  

To investigate the relationship between tank rainwater consumption and gastroenteritis in South Australia, a prevalence survey of 9,500 four year-old children was undertaken and this was followed up with a longitudinal cohort study of gastroenteritis among 1000 four to six-year-old children, selected on the basis of their tank rainwater consumption (Heyworth, 2001). This study found that in South Australia, children drinking tank rainwater were not at a greater risk of gastroenteritis than children drinking public mains water. In fact, the data suggest that those children drinking treated public mains water were at an increased risk of gastroenteritis.

Maelstrom On-Tank’s ultra-fine secondary filter
Maelstrom On-Tank’s ultra-fine secondary filter

Get cleaner water in your tank
Maelstrom On-Tank’s ultra-fine secondary filter removes particles down to 180 microns – 5 times finer than standard rain heads and pre-tank filters. This gives you cleaner, better quality water and lowers the volume of sediment putting pressure on your tank pumps and post-tank filters.

These units may be the bees knees in terms of water quality.
They are about 6 times the cost of a cheaper unit. But they are clever in the way they work as a secondary filter system after leaves etc.

Maelstrom web site

Interesting thread!  We purchased a 2500 gallon tank as part of our preparedness for our rural home (that wants to be a homestead) and water was definitely an issue.... I feel much better having this no-brainer resource here in the Pacific Northwest USA (Washington state) where we are known for chronic rainfall during the fall/winter and spring.

I'm interested to know more about methods to pump it out and if there is a way to have water pressure.

What is Chronic rainfall? Too much or too little.
Pumps are straight forward, research "constant pressure pumps".
They come 12V, 24V, 110 V. Some are better with an expansion tank.
Getting the water clean before it enters the tank isw a good idea.

Was just reading "Essential Rainwater Harvesting" (the authors are from Canada), and mention that one of the author's mom grew up in a house where the rain tank was essentially a room in their house (attached to the house via putting the tank inside a room in the house, the room attached to the house). So they incorporated heating the tank in the winter into heating the house.

Makes sense. I assume they had a reliable heating source (what if the electricity goes out the winter? Which it will), but they didn't say what it as.

I think I have talked about a bloke with a barn, into which the tank was set within a room. That room had a small wood heater to keep the room at about 5 degrees C.
Thus preventing freezing.

The Australian Government has published papers on rainfall collection, and potential problems;
Things to think about when collecting rainfall off a roof

The paper talks about being aware of matters which can have an effect, most can be dealt with.

look at this site for roofing material comments
roofing-materials-for-rainwater-harvesting/

@Rebecca Blake

Yearly Water Needs = Days  X  People X Rate
Yearly Water Needs = 365days X 4ppl X 50gal/day/person
Yearly Water Needs = 365 X 200
Yearly Water Needs = 73,000gallon
(the avg american actually uses 80gal/day not just 50gal/day as used in the calculation
It's possible that your family size will grow in the future, maybe an additional 2 people)

Yearly Water Catchment = Roof Size  X  Rainfall Amount  X 0.623
Yearly Water Catchment = 2000sqft X 36inch X 0.623
Yearly Water Catchment = 45,000gallon
(Due to 1st flush and other system losses you will actually catch 20% less water)

Catchment is less than Usage
You are not catching enough water, you will need to double your roof, from 2000sqft to 4,000sqft (barn/workshop/2nd house/etc)


Tank Size = Days  X  People X Rate
Tank Size = 100days X 4ppl X 50gal/day/person
Tank Size = 20,000 gallon (~76,000L)

Rainwater System
$10,000 Barn Roof (2,000sqft barn to catch the additional water)
$1,100 Gutter ($3/linear foot, assuming a 4,000sqft roof size)
$400 First Flush Filter ($50/each)
$250 Pipe
$20,000 Tank (about $1 per gallon)
$4,000 Tank Foundation
$250 Pump
$500 Pressure Tank (maybe get two smaller separate ones for $250/each)

I just had a crazy idea.
Instead of spending $24,000 for a tank, what if you just made a 45,000gallon pond(L=40ft, W=20ft, H=8ft) and filled it with sand. It would be able to store the 20,000gallon of water. We could even cover the top of it with the same pond liner, then a few inch of sand on top of it. Then we could just drop a pump into this "pond".  This is based off a sand dam.

The concerns would be:
Microbe filled water, so we would have to add a sediment filter + UV/Ozone filter.
But sand by itself is also good https://www.cdc.gov/safewater/sand-filtration.html

Now I have gone off topic.

The dam you speak of may work.
But I have found that tanks do work.
Water in a tank cleans itself, and you can see how much you have.
I will admit a preference for tanks.
Mind you a 20,000L tank costs about $2500.
I hope you had your tounge in your cheek when you wrote these costings

Rainwater System
$10,000 Barn Roof (2,000sqft barn to catch the additional water)
$1,100 Gutter ($3/linear foot, assuming a 4,000 sqft roof size)
$400 First Flush Filter ($50/each)
$250 Pipe
$20,000 Tank (about $1 per gallon)
$4,000 Tank Foundation
$250 Pump
$500 Pressure Tank (maybe get two smaller separate ones for $250/each)

- You cannot count a barn as part of your costs
- 8 first flush units are a large number to have
- you dont need to store all the water in one hit, the water volume syred goes up and down.
- a 20,000L may suit
-  a single pressure tank is ok, you dont need 2.
FINALLY, people tend to use less water when they are on tanks.

-Cheaper water tanks
-Desert/Drought 3week vs 3month Buffer Tank
-Yearly Catchment Size Problem
-System Redundancy and Social Permaculture

On average water tank cost $1/gallon vs the price that you quote that is half of that, esp after delivery is factored into it. But I was able to find one that is closer to your price before delivery. Do you have any tips on how to get cheap water tanks? I wonder what price others have bought their tanks for and where. https://www.ntotank.com/20000gallon-steel-water-tank-x1654367

S Bengi wrote:
Tank Size = Days  X  People X Rate
Tank Size = 100days X 4ppl X 50gal/day/person
Tank Size = 20,000 gallon (~76,000L) (maybe not all of the tank will be useable due to sludge/filter/equipment/etc)

20,000gallon(76,000L) equals to 3months of water buffer
5,300gallons(20,000L) equals to 26days of water buffer

5300gallon = 26days x 4ppl x 50gal/day/person
5300gallon = 26 x 200
Do you recommend a tank with 3weeks of usage or one with 3months of usage buffer? Given the wet summer(Hurricane)/dry winter ...monsoon like climate, and drought. And that the family might expand with children or relatives that stay for month+.

In the wetter month when we have 6in+ of rain with a properly size roof(4,000sqft) there will be 15,000gal of rain in just one month. If the tank is too small it would have just wasted two months worth of rain, which we will not have for the dry season. Unfortunately Texas does not have even rain distribution. If we use the dry season 2inch/month of rain as our baseline we could go with a smaller 5,000gallon tank if you increase our roof to 6100sqft
Monthly Usag =  Monthly Catchment = Tank Size
Days x People x Rate                            =      Roof X Rainfall X Factor X Efficiency
30days x 4ppl x 50gal/day/person      =      6100sqft x 2in x 0.623 x 80%  
30 x 200                                                 =     12,200 x 0.623 x 0.8
6000gallon = 6000gallon (~ Tank Size) (but what about the 6100sqft roof cost

S Bengi wrote:
Yearly Water Needs = 365days X 4ppl X 50gal/day/person
Yearly Water Needs = 73,000gallon

Yearly Water Catchment = 2000sqft X 36inch/year X 0.623
Yearly Water Catchment = 45,000gallon (36,000gal at the usual 80% efficiency)

Catchment is less than Usage
You are not catching enough water, you will need to double your roof, from 2000sqft to 4,000sqft (barn/workshop/2nd house/etc)

How do you propose that we fix this lack of water catchment problem other than building an unwanted $10,000 roof to catch the water that is needed? It is true that the roof will provide additional benefits other than just catch water. But it would be something that has to be done in year 1 vs a regular barn/pavilion that someone might not do until year 7. But I agree we could discount at least some of this roof cost. We could even discount all of the cost of the roof if the house was going to be say 8000sqft vs just a 2000sqft house.

Maybe I am mistaken and this part of Texas gets 72inch of rain per year (to work with a 2000sqft roof) and get even monthly rain distribution of 6inch of rain in the dry season (5,000gallon tank size). But I think that is not the case for central Texas so we will probable have to increase the tank size and the roof both by a bit.

I like the idea of having redundancy and freedom built into the system. So having two pump/pressure tank and even water tank to go along with the most likely two separate houses/roofs. Sound like a good idea to me. One could always lean on the other one in case there is a failure/issue/maintenance, with reduce capacity vs total system failure. The purchase price will also be the same. I think that the houses are going to be 250ft+ apart so it makes sense to keep as much things as possible separate, so that it is easier to troubleshoot and easier to see who is using all the water and make changes, esp when living with in-laws.

I actually have 8 first flush because I envision 2 sites that is separated by some distance (250ft+)
Site A is 2000sqft with a house+garage
Site B is 2000sqft with a cabin/house+barn/etc

I prefer a regular tank too. I was just throwing out the crazy sand filled cistern/pond idea because it hit me suddenly in the night.

I am really liking the idea of having 6,000sqft of roof, with a 5,000gallon tank  + Misc(pump/etc)

Tank + Misc = $5000 to $7000
Roof = $10,000 (Barn1-2000sqft) + $10,000(Barn2/Workshop-2000sqft) + $0(House-2000sqft)
So the total cost would only be $25,000, which is cheaper than a well and you get two barns out of the deal.
And you could always upgrade later and get another tank (5000gal) and you would be able to capture the rainy season water and support 6ppl vs just 4ppl per year.  

I will respond to the larger comments a bit later.
BUT, I am delighted you have made the connection between a rainwater catchment system and its lower cost compared with some well systems.
That is a point I have been hoping others would also see.

S Bengi wrote these points and I hope to explain some thoughts
-Cheaper water tanks
-Desert/Drought 3week vs 3month Buffer Tank
-Yearly Catchment Size Problem
-System Redundancy and Social Permaculture

Cheap is not always good, plan for tanks to last 25 years at least and cost them per litre or gallon per year
you will be amazed at the figures
Buffer time The longer your carryover time is the better.
The longer time allows more settlement of fine suspended solids and time for the water to self clean.
It also means you dont run out of water between rainfall events.
Local knowledge helps here.
Yearly Catchment Size Problem I am not sure what the issue is here.
System Redundancy  Remember its a household system animals etc may not rely on it for life beyond a couple of hours.
Apart from good quality underground pipes and great quality tanks, the remainder of the equipment is not critical.
Having backup pumps, pressure tanks etc are not necessary if you are located close to a purchase point.
If you are remote, I would suggest keeping spares in the barn.
If you have 2 households 2 pumps are essential.

The advantage of the larger 20,000 gallon tanks is the price per litre captured and the longer buffer and settlement times.
One enormous tank is much better value than the equivalent same volume with 5 oir 6 tanks. If you can afford the upfront higher cost.

Which of the systems do you recommend.
Option 1 = $33,000 (This system would struggle on a yearly basis if someone visits or the family grows, due to catchment area)
$10,000 Roof (Yearly use=yearly catchment demand an extra 2000sqft of roof for a total of 4000sqft x 36inch of rain)
$20,000 Tank + Foundation (3month buffer, based on a family of 4, and saving monsoon rain for dry winter)
$3,000 Misc (Gutter, Pump, etc)

Option 2 = $33,000 (This system could still serve the family if it expands or someone visits)
$20,000 Roof (extra 4,000sqft of roof-barn, required to match catchment to usage in the month with the least rain, and 3x water in the wet month)
$10,000 Tank + Foundation (1.6x month buffer, based on a family of 4. no need to save monsoon rain for the dry months )
$3,000 Misc (Gutter, Pump, etc)

Option 3 = $33,000
A well system. It uses more alot more electricity to operate. Well have been running dry, and getting salty/contaminated. When the pump fails it is a $7,000+ bill. The cost does not come with a side benefit of a 2,000sqft - 4,000sqft barn/workshop. Or a backup source of water even if the pump fails or I lose electricity. But in theory it gives me alot more water.

I will study the options and get back.
There are no need for  expensive foundations for water tanks.

Any tank just needs a flat surface, covered with sand 3 inches deep. I dont think that would be the $4000 you listed somewhere.

As a matter of interest the $2500 I quoted for a 20,000L tank came from a tank company in Texas, USA.

Generally the bigger tank option is better. In option 1 the larger roof area can be delayed and water even carted in if need be.
And then additional catchment can be created as cash and need arises.

Once again, there maybe local knowledge about. I found one tank supply company taht was right onto what I was talking about.

You guys sure are a wealth of knowledge... and you made me realize I need to get serious in designing our rainwater system now that we gave our floor plan over to an architect to draw up!

One thing that you seem to be bending over backwards for is having 4 people under just a 2000 sqft roof. We’re building two homes and my parent’s home I believe will be much larger than our own. We have discussed attaching their system to ours since their 2 person home won’t need as much as our 3+ person home... and they’ll have more roof- say 3,000 sqft.

Of course it is impractical to have our home with less roof space since we’ll be the ones with more people but we’re the ones who are young and poor...

I think the reality is that we’ll be starting with 1600 sqft of roof and maybe only 10,000 gallons in tank (two 5,000 gallon tanks). At first it will just be us young and poor ones (2 adults, 1 toddler) so no second house to steal rainwater from and no funds for random roofs lying around. We’re planning on trucking in water when needed at first... we do plan on expanding our home so that will add more roof... and if we need the roof for more water sooner we’ll put preference for a carport over the second building.

Biggest hurdle is the bank... if we can get a mortgage there’s no problem. But we’re not sure we can get a mortgage due to the rainwater system and wanting to be owner builders.

Also most recently we were discussing forgoing the septic tank and just do greywater filtration and an incinerator toilet (hubs was not open to compost toilet but he loves this fancy incinerator a friend told us about lol). Guess I need to check with the county on that first, though...

In a perfect world we’d build without a mortgage so we can do whatever the hell we want and however slow we want without someone staring down our back but a tiny home wasn’t in the books for my husband so... we’ll see what happens!

Rebecca, please dont freeze your brain over building with a permit. They have a place in society, but your plans need to be detailed and not changed.
Most home owners want changes and each change can coist $1000 plus cost of doing the work.
Instead of 2 x 5000 gal tanks. why not a single 10,000 I am sure it will cost less.
I think we talked about a tank joint near you?

lets look at the other issues;

But we’re not sure we can get a mortgage due to the rainwater system and wanting to be owner builders.

What is the detail with this?

Yearly Water Needs = Days x People X Rate
Yearly Water Needs =  365days x 3ppl x 50gal/day/person
Yearly Water Needs = 55,000gallon (or 73k if you have another kid)

Yearly Water Catchment = Roof x Rainfall X 0.623
Yearly Water Catchment = 1600sqft x 36in/year x 0.623
Yearly Water Catchment = 36,000gallon

Water Deficit is about 20,000 gallon, which you will have to haul in.
Do you know how much it cost to haul 5,000gallon? Maybe $50-$100
So 4 trips costing $200-$400 per year. Thats minimal compared to electric/gas/car/food/shoes bill.

John C Daley wrote:Rebecca, please dont freeze your brain over building with a permit. They have a place in society, but your plans need to be detailed and not changed.

I'm not freezing my brain with that... we're not even getting a permit because it's not required here- why would we?

I just wanted some more official document to take to the bank so our rainwater system and owner-builder aspect of it is less scary to them. My husband also wanted it for his own commercial construction minded brain- he likes plans. We're only being charged like $1,200 for the whole thing and we already drew up all the changes and whatever we wanted before we sent it over so... we're doing it the smart way.

Just need a permit for septic.

In terms of the mortgage issues, we've heard people having difficulties getting funding because of their rainwater system. This is because the banks are idiots and can't figure out the value of a house with a rainwater system due to there not being many on the market. It really is silly but that's how the world runs.

I'm not sure it will actually be an issue, but we haven't spoken extensively with any banks yet

Maybe dont even mention where the water supply is coming from.
Afterall the issue really is,' is water available to the house', yes or no?

I found this good video about making a filter system for your collected rainfall
Build your own water filter system

It seems to be a practical concept using 4 blue 200L drums filled with different media, and passing the water through each.
Just like real filters, but much bigger..

floating-water-intake-tankster-for-best-tank-water/

Images of other floating discharge ideas

Cleanqable disc filters are great here are some

This is an easy explanation of how to size the tank storage system you may use.
I prefer a single larger tank, for reasons explained earlier, BUT this system may be useful to others
https://www.bluebarrelsystems.com/diy/size-your-system/

John C Daley wrote:Look under Rain Harvesting, that may open your world to stuff

I know this thread is a few years old but I'm also in Oz, Sunshine Coast QLD where it is currently raining mid summer.  We lucked it when we purchased our acreage home 6 years ago, that the previous owner had the foresight to install 2 x 15,000 Litre (4,000 gallons) Water tanks which supply the house, and a Well on the opposite side of the house which supplies the outdoor taps for gardens etc, but with the flick of a tap, and turning off the rainwater tank pump, when we run dry we can flick it over to the well to provide the house water.  Even with the 30,000 Litres, we run dry yearly for maybe a month or two.  We have recently had our tanks cleaned of sediment and had our well water tested which they stated was pristine and better than our tank water!  We are surrounded by Strawberry farms and forest and were told there was limestone underground which acts as a natural filter.  Not sure how true this is as the neighbours on 16 acres behind us had trouble drilling for a bore and could not find an extra water source to what they already had.  The only filters we have installed are carbon under the kitchen sink for our drinking water - this is usually a standard set up here in Oz for drinking water as it helps to screen out some of the nasties from rainwater, and helps screen out some of the chemicals from council supplied treated water.  

We have a lot of rainfall when it does rain... and we really need more tanks installed!!

My re-newed interest in permaculture is the fact that I have inherited 1100 acres in NSW that has been pretty much classified as useless by all the neighbours.  Running Stock is the norm in the surrounding areas but the two hills in my parcel of land are steep in areas (I like to call this undulating), very shrubby, very rocky, and only has a seasonal creek which runs through the valley of the hills.  We have not seen this land in person yet, only going from 15yo photos and Google Earth, but when the local farmers/neighbours are not interested in buying it, it's kinda saying something.

We are going to take a week or so for a visit most likely in Feb (end of our summer season), to look at what fences need repairing, and how we can set up some kind of water collection.  The property is also land locked, so we have to look into sorting legal access.  I am one of those people who likes to  look outside the box, and where the land may not be viable for 'living off/feeding the masses' (and of course that just depends on 'how' you live), then what else can it be used for?  We could live a hermit lifestyle... or the neighbours have described it as 'extreme', so extreme everything comes to mind... hiking/walking trails, camping, escape to nature - the views from the top are 360 degrees of spectacular (great for artists, writers or anyone just needing alone/chill time).  I have found a property in Mudgee NSW that is a little tin shack at the top of a hill with amazing views. The bottom tin walls on 3 sides open upward to create little verandas, and the top section houses the loft bedroom.  It is simple but well designed and the only way to get there is on horse back (from what I have read), but I digress as I imagine living in that style of shack on top of my own hill!  

But back to the water collection, I am assuming (sigt unseen) that we can utilise/shift the rocks into the seasonal creek to make extra catchment areas to make water flow slower and hopefully create a few extra water holes along the way. My late mother told me that the creek would hold water for 6-9mths of the year, and that it could snow through Winter.  Or maybe we can set up a few 'lean to's (Skillion roofed shelters) with rainwater tanks in various locations around the property.  The problems that we may encounter is getting any heavy machinery on site if we need to create any tracks, dig bores etc - so until we actually get 'on site' to see what we actually have ahead of us... then I am learning as much as I can about permaculture, homesteading, living off the land, bush tucker etc and may even be able to look at the WWOOF'ers movement to get help with fixing fencing, building, setting up for chooks, a few veges etc.  Natural disaster wise we are possibly looking at bush fires and high winds.   But the options are always endless... so it's just being able to come across the right people, and find the right groups that have had the experience before us!!

Anyways, nothing to really contribute just yet - but wishing everyone a Happy New Year, and lets see what 2022 brings!!!

#AlwaysTheDreamer

In Central WI, we don't have the same problems, but having clean water is still problematic.
One benefit that I do not see mentioned much in harvesting water is avoiding contaminated groundwater. I live 10 miles from the closest town and my area is very sandy, which allows nitrogen from dairy cows and the crops necessary to sustain them to flow everywhere under their neighbors' properties. Corn, potatoes and dairy is our Big Ag's economy. All need copious amounts of fertilizer, unfortunately.
This is here a typical, annual  irrigated, planted rows economy. It is easy to dig but it may freeze deeper in a cold winter.
Hmmm. Just looked it up. Our frost line is only 4 ft. actually. Our first water here is at 10 ft. [Yep, I can almost hear you salivating and wondering what I'm doing here complaining about water!]  Dairy farmers and CAFOs dig down to 130-140 ft., which means that in drier years, everyone is pulling on groundwater and shallower wells may be left high and dry, literally! [Most private wells are at around 28ft. Some lakes run dry. The concerns are with quality as well as quantity in dry years. My water is still excellent at 0.4ppm of nitrogen, but we started at 0.01 in 1970. I also have 2 sand points for irrigation.
It should be possible to install deep buried tanks, do you think? Could they heave/ collapse?
Water catchment from a roof would be a lot cleaner. Also, considering that we are relatively water-rich with 36" of rainwater/snow on average yearly, it might be $$ conscious to harvest this God Given water.
How would creating a water catchment  system in zone 4b [yes, we get 20-40 below zero most winters] work for folks whose water has gone bad through excessive nitrogen [that often cannot be "remedied" by reverse osmosis [> 44 ppm of nitrates]  drinkable water is 10 ppm maximum. or by digging another, DEEPER well [which, by the way, may also be contaminated]. [A deeper well does not always solve water woes as we have bogs on the other side of the Wisconsin river: A deeper well will yield brackish water for them.]
A commercial well driller will easily fetch $8,000, just for a 30 ft. cased well.
The farmers [who cause 90+% of our water pollution] are well protected in Madison in the name of "helping farmers" and "saving our Dairy industry]. They get generous yearly subsidies too. In return, they are some of the biggest donors to politicians who support them. When they pollute, it is usually the taxpayers who pick up the tab of 'remediation'. There is even a farm near Green Bay that has severely contaminated the water all round them and they are appealing to our DNR to more than double their dairy cow herd! and it looks like they might get their way!
The Farmers' solution has been to give bottled water [of course not enough] to the injured parties. The Courts are not much help either. They fix to the minimum the amount of water "needed".
Our lakes often has toxic algae bloom and beaches get closed every summer.
It is becoming a nightmare.
So how much do you think it might take for folks to get clean water with a buried tank /several buried tanks? Is it even possible? [we have concrete septic tanks and they don't freeze, so...?
Help. What do you think?

Cecile, please remember the topic is about "RAINFALL HARVESTING" nothing else, polluted water is not often a problem unless you have polluted dust around.
BUT, answering you concerns as best I can.
Polluting farmers must be stopped and that is a long fight, and you need to get the community on side.
There must be a group somewhere near that has started a fight.
Otherwise start a 'letter to the editor' scheme detailing one or two points at a time, get everybody aware and annoyed, avoid libel, but go in hard.
IE Community deserves clean water, action needs to be taken to assist poulters to save the out flow of nutrients for their own use.
I have led such campaigns and worked in the field as well, its thankless and can be dangerous, but somebody has to start.

UNDERGROUND tanks are available and expensive.

So what are you needs and for what purpose, that may be a good place to start a conversation.