Rainwater harvesting

[Emmalina]

We made this as it doubles up as gallows and has 800w of solar on top works a treat !

[SY Kelpie]

Thanks for the replies, a lot of food for thought there.
I really like the idea of a dual-purpose awning and rain catching device. Pull it down to catch rain, pull it up the rest of the time. Plus a bucket with a through-hull in the side for the hose, so any debris can settle out. The same bucket could double up as a rain catcher at the gooseneck when under way.

On our previous boat, we had a solid toe-rail and deck drains, and yes I did once or twice rig this up to collect rainwater directly into the deck-mounted tank filler. But on the new boat, we have a performated aluminium toe-rail, and rainwater runs off pretty much everywhere, so I can't see a feasible way of blocking off the holes in the rail.

I think it will be much easier to keep a tarp clean than a deck, as well...

[chouliha]

Originally Posted by Erik de Jong

We use the deck as a water collection system. The toerail is mostly closed and is about 4" high above the deck. All we need to do to collect rain is to push a towel in a couple of scupper holes, open the deck fill and with decent rain we have 100 gallon collected in as little as 20 minutes. We usually need to let it rain for about half an hour before we open the tank fill so that the salt and other contaminants wash off the deck.

We have been using this method for years with excellent results. Amazing how much water you can collect in a short time using the decks as a collector

[Q Xopa]

Originally Posted by Cheechako

If you can build the bimini panel with a mini gutter all around seems it would work great! But yeah, you'd have to wash it I suppose.

Most house rain water collection systems, ie from the gutters off the roof use a 'first flush diverter'.

Google em, but the simple description is fills up a verticle pipe with a tennis ball in it. Water comes in the top. When the pipe fills the tennis ball floats to the top and blocks the drain tube, diverting all the cleaner subsequent water to the tank.

The theory is the amount of water it takes to fill the verticle pipe should have sluced off all the bird poo etc.

By the way, all those squimish about drinking bird poop, you might not want to look too closely at your regular Municipal water reservoir. You might be shocked to see birds have access to it. Dont even start to think about what fish do.

Of course its all a question of the 'dilution' factor.

Ideally you have some water treatment/ filtration at the use end.

A water maker membrane takes out particle sizes smaller than any nasty Giadia etc critters.

[Manateeman]

Collecting rainwater on a boat really is not an engineering problem and the method will greatly depend on the vessel design. What you do with that water is a biological and chemical question. So too is the storage issue. In almost every developed country part of the public health system is a group of scientists who monitor drinking water. Where it’s stored, during distribution, and at the final use. 99% of the population has never set foot in their laboratories. To state that it’s ok to drink collected rainwater because public water is also contaminated is a fallacy of logic. It also tries to equate guesswork with science. Witch doctors are helpful in some societies but if I’m ill, I’ll see someone with an MD.
So it’s raining on my tarp, deck, whatever. I wait some period of time. Based on what? My RO meter? Smell? Looks OK?
Next I dump it in my drinking water tank. Let it just sit. No I’m going to add some chlorine and I know exactly how much because I know how much rain fell.
Run it through a particulate filter then a carbon filter then your water maker...
and send it to a seperate tank..I have no problem with this because you are now removing a lot of deadly chemicals and biological.
But that’s not what is going to happen when Ken, Barbie and their cat sail off and start filming their blog which encourages more Ken, Barbie, cat, adventures.
Find a copy of And The Sea Will Tell by Vincent Bugliosi. Because when Ken and Barbie finish off the cat, they’ll be a might thirsty and you’ll have all that rain water and they won’t be too fussy about quality.
The wind is free. Poop in the sea. It’s all about me.
Happy trails to you.
Captain Mark and his beer drinking manatees

[Mike OReilly]

Always interesting to read how people have rigged various systems. I've collected lots of water from my upturned dinghy at times, but I haven't yet dumped it into the main tank due to lack of any filter. I do use it for washing and for showering though.

When we sailed Lake Superior I did, on occasion, dump lake water directly into our boat tank. Superior is as clean as open water can be (away from the few urban areas). I'd have no qualms using rain water, but I'd want to run it through some basic filter just to weed out any debris.

[Erik de Jong]

Originally Posted by Manateeman

99% of the population has never set foot in their laboratories. To state that it’s ok to drink collected rainwater because public water is also contaminated is a fallacy of logic. It also tries to equate guesswork with science.

I'm a scientist myself and know how science works. I also have my boat-water regularly tested in a lab because I use my boat commercially. I often get rain water, but also often water from streams and have done so for 35+ years. Never in my cruising life have I ran into an issue with water, other than water that was provided by villages along the way. I'll take care of my own water, you can get your popcorn ready and lean back.

[cal40john]

Originally Posted by Manateeman

Collecting rainwater on a boat really is not an engineering problem and the method will greatly depend on the vessel design. What you do with that water is a biological and chemical question. So too is the storage issue. In almost every developed country part of the public health system is a group of scientists who monitor drinking water. Where it’s stored, during distribution, and at the final use. 99% of the population has never set foot in their laboratories. To state that it’s ok to drink collected rainwater because public water is also contaminated is a fallacy of logic. It also tries to equate guesswork with science. Witch doctors are helpful in some societies but if I’m ill, I’ll see someone with an MD.
So it’s raining on my tarp, deck, whatever. I wait some period of time. Based on what? My RO meter? Smell? Looks OK?
Next I dump it in my drinking water tank. Let it just sit. No I’m going to add some chlorine and I know exactly how much because I know how much rain fell.
Run it through a particulate filter then a carbon filter then your water maker...
and send it to a seperate tank..I have no problem with this because you are now removing a lot of deadly chemicals and biological.
But that’s not what is going to happen when Ken, Barbie and their cat sail off and start filming their blog which encourages more Ken, Barbie, cat, adventures.
Find a copy of And The Sea Will Tell by Vincent Bugliosi. Because when Ken and Barbie finish off the cat, they’ll be a might thirsty and you’ll have all that rain water and they won’t be too fussy about quality.
The wind is free. Poop in the sea. It’s all about me.
Happy trails to you.
Captain Mark and his beer drinking manatees

A previous thread pointed out that many rural areas in the world use cisterns, collecting rainwater, water from streams, etc. Australia was mentioned by people that lived that life. I came across links by the Alberta Canadian government that advise people how to safely use their cisterns that can be filled by natural means.

Could the water be contaminated, sure. Crazy thing that only whack job sailors do? Not so much.

[Q Xopa]

Originally Posted by Erik de Jong

I'm a scientist myself and know how science works. I also have my boat-water regularly tested in a lab because I use my boat commercially. I often get rain water, but also often water from streams and have done so for 35+ years. Never in my cruising life have I ran into an issue with water, other than water that was provided by villages along the way. I'll take care of my own water, you can get your popcorn ready and lean back.

Exactly, in IMNSHO in the true yachtie self reliant spirit take care of your own water quality.

Treat it with filters, carbon, chlorine, UV whatever you feel comfortable with.

Test it EC meters, Lab test l, not at all or what ever you feel comfortable with.

Its not rocket science, although feel free to turn it into bleeding edge science if you feel so inclined.

[Q Xopa]

Originally Posted by cal40john

A previous thread pointed out that many rural areas in the world use cisterns, collecting rainwater, water from streams, etc. Australia was mentioned by people that lived that life. I came across links by the Alberta Canadian government that advise people how to safely use their cisterns that can be filled by natural means.

Could the water be contaminated, sure. Crazy thing that only whack job sailors do? Not so much.

Yes, being Australian and old enough, I remember all the rainwater tanks in everyones back yards.

I reckon they are great. Indeed modern plastic versions have had somewhat of a resurgence with current water shortages.

The old ones were galvanised corrugated iron verticle types. Galvanising is heavy metal leaching. I guess life expectancy wasnt so high back then.

But they did take some maintenance. They would periodically silt up. Which meant emptying and scrubing. The other favorite was the drowned possums. They went for a drink and couldnt climb out.

[thinwater]

Originally Posted by Manateeman

Bird poo, bat poo, what you going to do.
Drink it?
This is the start of the best ..no science allowed..thread ever.
Lot funnier than running a water maker in toilet harbor.
Ready on the set. Clapper. Action.
Mark and his popcorn ready manatees

In fact, there is a good bit of science on rainwater collection. It has been well studied by the health authorities and in common practice in the islands, Australia, and parts of Texas. Google it, read the studies and policies, and then comment based on the science.


Several factors to consider:
* Birds don't roost on occupied boats much, so this is non-problem when cruising.
* Fiberglass tops are easy to keep clean (solar can complicated this a little). They are also self-sterilizing in the sun.
* Treat the water (filter and bleach). Obviously.
* This has been proven for... centuries.

[thinwater]

Originally Posted by Q Xopa

... Galvanising is heavy metal leaching. I guess life expectancy wasn't so high back then....

* Galvanized is zinc. Some people take zinc pills. No problem.
* Lead (tern) was a problem a more than a century ago, but not in resent memory.


Zinc is toxic to marine life, but not to people.

[Q Xopa]

Originally Posted by thinwater

* Galvanized is zinc. Some people take zinc pills. No problem.
* Lead (tern) was a problem a more than a century ago, but not in resent memory.


Zinc is toxic to marine life, but not to people.

Yes you are correct , galvanizing is Zinc. And Zinc, in trace quantities is supposed to be good for you. Arguably, there is mounting weight of opinion its meant to be good for Covid? Time will tell on that one. But I digress.

However the seams were usually rivited and lead soldered.

[AKA-None]

Originally Posted by thinwater

* Galvanized is zinc. Some people take zinc pills. No problem.
* Lead (tern) was a problem a more than a century ago, but not in resent memory.


Zinc is toxic to marine life, but not to people.

Really? Zinc nontoxic to people?at what concentration? I’ve been zinc poisoned, it’s neither pleasant nor fun.

[SY Kelpie]

Well this discussion took a rather strange turn, didn't it?
My father spent his career as an engineer working in municipal water treatment and distribution. I will be completely happy taking his opinion on how to ensure our supply is safe.
(What we currently do is to dose the tanks with the recommended dilution of Milton solution; it's also very important to minimise any particulate matter in the water because the chlorine binds to it, reducing its efficacy).