Rain Water Collection and Storage

[Steve Spence]

Water, the essence of live. Clean, abundant water is not to be taken for
granted in many areas of the world, and is getting more scarce. I've put
together a number of tips for rain water catchment, water filtering, and
cistern construction at http://webconx.green-trust.org/cistern.htm

 

[Harry Chickpea]

Water, the essence of live. Clean, abundant water is not to be taken for
granted in many areas of the world, and is getting more scarce. I've put
together a number of tips for rain water catchment, water filtering, and
cistern construction at http://webconx.green-trust.org/cistern.htm

Also, the current issue of Mother Earth News has some info on catchment.

 

[John Hall]

Goundwater is abundant almost everywhere and pumping water from wells
costs only pennies per day on the grid.

Perhaps you have not yet, or recently, experienced "almost
everywhere".

 

[JNJ]

Visited your site, nice numbers, but I have to ask... why?

Goundwater is abundant almost everywhere and pumping water from wells
costs only pennies per day on the grid. The total runtime for pumps is
just a few minutes per day and they can be powered by an inexpensive
solar/wind electric generation setup for those off the grid.

Rainwater is horribly polluted in urban/industrial areas and subject to
the whims of the weather. If it's cached, it must be sterilized and
filtered. It cold climates, it's not an option at all.

Not everyone can tap into groundwater -- for example, where I live it is
flat out against the law to have a well if city water is available. In
fact, if you have a well and city water becomes available you have to tie
into the city's system and shut down the well.

James

 

[William P.N. Smith]

cistern construction at http://webconx.green-trust.org/cistern.htm

Maybe it's just me, but I'm getting connection refused at port
8383(?)...

 

[William P.N. Smith]

Water, the essence of live.

With a flexible water tank, it can be an addition to a restful
lifestyle: http://compusmiths.com/TomPronal.jpg or a fun one:
http://compusmiths.com/WaterTrampoline.jpg

8*)

If you can use it in your application, they are a lot less expensive
than a 'hard' cistern. The one in the pictures above is about 10K
gallons, and costs around (Euro)2255 plus shipping (another couple
hundred Euros), FWIW.

 

[Harry Chickpea]

Dean,
Take a look at Colorado's groundwater laws.
Same for wells, Someone already owns the water, even if it's in a stream
passing through the property you own. Many people where I live have to buy
water from the city and dump it into their cisterns to have household water.

Don't bother responding to Dean. Judging from the last post, Dean has made it
abundantly clear that he never heard of places like Love Canal or the burning
rivers, likes to take poorly aimed potshots at "armchair environmentalists",
hasn't figured out that municipal water bills are often overpriced to subsidize
increased sewerage costs from businesses, industry, and governmental
discharges, and has never had a small property where just "digging deeper"
wouldn't hit decent water. Since trolls live under bridges, their chances of
finding water are much greater than that of the average person on usenet.

FWIW, much of the potable water on the islands in the Carribean comes from
catchment systems. On a larger scale, continual use of underground water
supplies in So Florida has caused salt water intrusion that has rendered ground
water unusable around the coast. Dropping water tables in central Florida are
a prime cause of sinkholes. There are plenty of situations where ground water
is not the cheapest or best solution. It just takes a mind that is a little
more open than Dean's to find them.

 

[SpiderG]

When I accessed this site my firewall complained about the unusual TCP port
(8383). I had to explicitly allow the connections, you may have a similar
problem if you are using a firewall or proxy server.

HTH
SpiderG

 

[Fred B. McGalliard]

Michael,

There is as much water here as there was 3.5 billion years ago. The same
amount will always exist on this planet. That's a fact. People like you
who chant "you must conserve... the water is running out!" are generally
ignored. Nothing personal, but I've lived long enough to hear this water
conservation argument come up every 10-15 years (since the '60's) and
then it quietly fades away. As it should. You see, 40 years have passed
and we still have lots of water. Holler "wolf" one too many times and no
one listens to you!

You can't mean that? Folks are fighting wars over water. Most large cities
are sucking up all the available fresh water inside several hundred miles,
and many are fighting tooth and nail over who gets to dump their sewage and
run off and how much they have to treat it so the folks down stream can
afford to treat the water with less than full distillation. In Washington
state we have farmers taking up arms to demand a share of the water the west
siders want to spill over the dam to provide power, and the fishing industry
wants spilled to provide enough water for the salmon. The LA megalopolis and
the vast desert farms around it suck water in such vast amounts that their
needs, wants, a bit extra for a million pools, determine who gets enough to
grow food crops. If Mexico were closer to par with us in military force the
straws now sucking the Colorado dry would likely be cut off in large numbers
so Mexican farmers could continue to thrive. Water is not running out, it
has run out (in many areas) and it's availability is determining which
cities, even which countries will continue to thrive. You know that. Perhaps
you were imagining we would just suck up ocean water to provide California's
water needs (this would work fine if we has a few hundred square miles of
solar distillation plants)? Or we could all move to the rain belt and try to
grow our food where it rains all the time.

 

[Harry Chickpea]

The problem isn't that there are "environmentalists" claiming something that
isn't true - the problem is that there are people like you that are in denial!

You can't win over a troll with logic. He is more interested in getting a
response out of you than having a fair debate. Don't feed the trolls.

 

[clare @ snyder.on .ca]

Fred,

Like I said, the amount of water on the planet remains the same. That's
a fact.

You do bring up an excellent point with which I fully agree. Water, both
fresh and salt, covers 80% of the planet. We don't pump gas out of the
ground in Texas/Oklahoma for use exclusively in those states. We move it
around. It's a commodity. Water is the same deal. For those who insist
on living in places where water is too expensive to obtain locally, they
will be able to buy it on an open market. Desalination plants are being
used on seawater on a small scale for exactly this purpose. Someday it
will be pumped underground, like gas is today, to homes and businesses
all over the country. Is this a good thing? I don't know. But it will
happen. The government will then tax it like they do gas, and those of
us silly enough to live where water was once judged to be too expensive
to pump out of the ground will be paying $1.85 a gallon for it just like
gas. And guess what? There will be plenty of water to go around, just
like there is plenty of $1.85 gallon gas to go around. See a pattern?

And those of us who choose to live where water can be had for $.001
gallon will be rolling around on the ground laughing. That is, until we
realize we can sell the stuff at an enormous profit to city slickers by
stuffing it in the pipeline, just like we now do with electricity. Gee,
does anybody know if my water pump will run backwards like my electric
meter does?

Dean

Fred B. McGalliard wrote:

I currently live in the Grand River watershed area of Ontario Canada.
Kitchener/Waterloo/Cambridge is the largest urban area totally
dependent on groundwater. Several of our major wells have gone dry,
and a couple others have gone bad. A few years ago the region built a
large aquifer recharge system, which pumps water out of the Grand,
pre-treats it, and pumps it down recharge wells. The water is then
pulled from other wells, is re-treated, and put in the distribution
system.

Not that very far from here is the municipality of Walkerton. If you
listen to anything more than hometown USA news, you will have heard of
Walkerton because there was a serious E-Coli issue there a couple
years ago. Quite a few deaths, and a lot more seriously ill people,
some still suffering the effects. Problem? Contaminated ground water.

My home town of Elmira has had to be coupled to the regional system
and it's wells taken off-line because of chemical contamination from
what has, for the last several decades, been UniRoyal Chemicals - and
before that was Naugatuck Chemicals. They produced Agent Orange and
other defoliants and weed killers since the forties. The groundwater
is now being treated and returned, trying to flush the aquifer.
Millions and Millions of dollars per year are being spent on
remediation, trying to clean up the source of the chemicals - buried
drums and tar pits etc.

Growing up, I'd have laughed at the idea that WATER would cost more
than gasoline. Bottled water is about $1 for 1/2 liter - regular gas
is from $0.65 to $0.72 per liter today.

 

[William P.N. Smith]

http://webconx.green-trust.org/cistern.htm

BTW, if you have detailed rainfall data, you can fairly easily
calculate how much cistern you need to get through the driest period
in your dataset:

[in Perl, but pretty self-explanitory, Global_Negative_Cistern starts
out at zero, and PersonUnitRoof is how much roof you need per person
for the long-term average]

# the global cistern size calculation happens on a daily basis, not in
# the global calculation section below...

# now figure out how much cistern capacity we need per person.
# Subtract some gallons from the unit cistern for that one person and
# add the amount of rain that fell on the PersonUnitRoof during that
# day.
$Global_Negative_Cistern -= GallonsPerPersonPerDay;
$Global_Negative_Cistern +=
(($Daily_Rain_in_TOT/12.0)*PersonUnitRoof)*GallonsPerCubicFoot;
if ($Global_Negative_Cistern > 0.0)
{$Global_Negative_Cistern = 0.0;} # any
overflow is lost
if ($Global_Cistern_Min > $Global_Negative_Cistern)
{$Global_Cistern_Min =
$Global_Negative_Cistern;} # remember min size

 

[William P.N. Smith]

I haven't... 30 gallons per day?

I thought the North American Wasteful Standard was 100 gallons per
day, and I know the regional water authority just asked our town to
get us down to 65 gallons per day. Several people in the newsgroup
seem to live on a lot less, though they may move some of their water
use elsewhere. 8*)

You can read your water bill (or meter) and divide by the number of
people in your household to see what you are currently doing, or pick
a number in the 50-100GPD range.

Having read of the 10'x16' Manhatten "condo"
that recently sold for $135K (plus a $505/month maintenance fee), I've been
thinking it would be nice to build self-sufficient, solar-heated, water-
ballasted greenhouse structures on flat city roofs...

Because roof space is free? Cost of water is hardly going to be your
only utility...

(this is 200 cu. Ft. (6x6x6 ft.) and weighs 5.6 tons + weight of tank)

You better talk to your building engineer...

I didn't quite follow the algorithm you suggested, although I can imagine
something like "Start with no cistern volume. Add rainfall. Consume water.
If we are out of water, increase the cistern volume until, figuring backwards,
we wouldn't have run out of water."

Close, it's more like "Start with zero volume. Every day add rainfall
and subtract GallonsPerPersonPerDay. Discard any overflow above zero
and record the largest _negative_ number you see." Similar to having
a cistern that's too big and recording the level you use it down to...

Seems to me this would overestimate the
required volume if the data record began with a few dry days.

Yes, but either you assume some starting amount of water (maybe you
are going to fill your cistern with city water the first month?), or
you are going to end up in a similar situation to the real world,
where you build your house and start occupying it at some time which
may begin with a few dry days.

How do we determine the catchment area and the economic balance
between the collection and storage costs?

For catchment area take the long-term average daily rainfall and
GallonsPerPersonPerDay and calculate how many square feet of roof you
need to collect that much water. That's PersonUnitRoof in the code,
the amount of roof collection area one person needs (long-term).

Balance between collection and storage costs is an interesting
question, I suppose you'd have to iterate over the dataset several
times with PersonUnitRoof increasing from it's minimum value, but I
can't imagine letting your water cistern size effecting your house
size. IMHO it's always cheaper to build more cistern than more
house...

 

[Steve Spence]

all the water goes through a slow sand filter, and drinking/cooking water
through a reverse osmosis unit. the "waste" water from the osmosis unit goes
to irrigation, as does greywater. that info will be added to our rain water
article shortly.

http://www.howstuffworks.com/question29.htm
http://www.rvwaterfilterstore.com/ABRO.htm

http://www.agr.gc.ca/pfra/water/slowsnd_e.htm
http://www.globalwater.org/Slowsand.htm

 

[Steve Spence]

I had to use 8383 & 8484, as my ISP was blocking port 80.

--
Steve Spence
www.green-trust.org

When I accessed this site my firewall complained about the unusual TCP port
(8383). I had to explicitly allow the connections, you may have a similar
problem if you are using a firewall or proxy server.

HTH
SpiderG

 

[JNJ]

all the water goes through a slow sand filter, and drinking/cooking water

through a reverse osmosis unit. the "waste" water from the osmosis unit goes
to irrigation, as does greywater. that info will be added to our rain water
article shortly.

Thanks for the info, Steve -- I'll follow up with the links you've provided.

How effective are these filters at removing the various contaminants that
are common in urban environments (i.e., the air pollution that the rain
washes out)? What about biological contaminants?

Noc.

 

[Steve Spence]

slow sand filters are very effective at removing some type of contaminents,
see http://www.siwin.org/reviews/swr0004/swr0004b122.html

Colour 30% to 100% reduction
Turbidity Turbidity is generally reduced to less than 1 NTU
Faecal coliforms 95% to 100%, and often 99% to 100%, reduction in the
level of faecal coliforms
Cercariae Virtual removal of cercariae of schistosomes, cysts and ova
Viruses Virtually complete removal
Organic matter 60% to 75% reduction in COD
Iron and manganese Largely removed
Heavy metals 30% to 95% reduction

 

[Harry Chickpea]

That giant bladder looks like fun...

I think that is one of the more unusual statements I've seen on usenet, Gig.

 

[Steve Spence]

with no conservation, 2 adults and 3 kids, a washing machine that runs once
daily, and a dishwasher that runs once daily, we were hard pressed to use
more than 35 gallons / day / person. Now we use about 15 / person, and the
composting toilet will drop that even further.

 

[Nick Pine]

That giant bladder looks like fun...

You might fill a $62 100' roll of 30" round polyethylene film
greenhouse air duct with 4000 gallons of water...

Nick