Collecting rainwater Westen Washiington (Vancouver, Shoreline: rental, houses, transfer)

[WestGuest]

Does anyone have a catchment system? If so how large a tank, what do you use it for and are you happy with it?


More specifically I'm interested in SW Washington where it rains 90" a year, so supply should not be a problem.
My understanding is the water is purer and of better quality for drinking and irrigation than traditional water sources.




Would a 5000 gallon tank be enough for a two- person family and two thirsty dogs as well as for irrigation for two acres? Summer rain is only about 1.5 inches a month.

[notnamed]

Where in SW WA do you get 90" a year? Vancouver WA averages 42". Coast I presume?

Is there an official definition of SW WA? See some that list it just as Skamania, Clark, Cowlitz, and Wahkiakum counties but some also include Pacific county.

Only legal to collect what falls on your rooftop. I would not say roof water is purer than what comes out of the tap.
https://www.sightline.org/2011/07/14...r-rain-barrel/
https://homeguides.sfgate.com/can-wa...ink-78356.html

[WestGuest]

Skamokawa- Cathlamet area. I think I could collect what's on another building as long as it had some other purpose- greenhouse -storage shed etc


Even at 50" a year it would be a lot of rain collection on say a 900 sq ft roof.

[notnamed]

Yeah I know people who have rain barrels but just use it for irrigation through the summer, not for drinking.

[Diana Holbrook]

I guess if it's a catchment system, it's cleanliness depends on the cleanliness of the roof!

Trouble with our rainfall is we get it all during nine months of the year, and very little in the hottest months, when water usage and irrigation would be at their highest. Surviving the summer would be the challenge.

As easy as it is (usually, relatively speaking) to find well water here, I'm not sure it's worth doing except maybe as an emergency backup supply for power outages.

Remarkably enough for Washington, governments don't like people collecting water and you may actually need permission to have a 'legal' catchment system.

[StealthRabbit]

Legal and encouraged in WA.
https://ecology.wa.gov/Water-Shoreli...ter-collection
https://www.quora.com/Is-it-illegal-...-state-and-why

You can get a video from Library on building an underground tank, I was considering a 20,000 - 30,000 gal.

Basically;

1. Dig a basement,
2. stick in a sheet of 'pond-liner',
3. stack it full of plastic milk crates (or aqua-blocks' designed for underground tank construction)
4. Add a submersible pump
5. Wrap blocks up like a Christmas Gift
6. Back-fill (hopefully before your neighbors get home from work)

https://www.youtube.com/watch?v=YdwKDVzh1cs

I will probably do one on my adjoining props in TX and in WA. (Each have huge shops and barns and house, so qty of surface area / water is no problem). I get 40" annual rain in TX and 100"+ in SWWA (16 miles from PDX, but over 2x the rainfall, Neighbor has a reporting station for NOAA)

Will add 'gray water system' in TX (cuz I have a bunch of RV sites for friends.)

There is a very innovative water filtration / recovery supply company in Portland who makes commercial filtering systems for parking lots and will have stuff to work for RW collection. Or the engineering to do your own.

https://www.waterworld.com/municipal...ypes-of-runoff
https://stormwater.pca.state.mn.us/i..._of_filtration

BioSTORM® Stormwater Treatment Systems • BioMicrobics Inc.

For irrigation, you will only want to do drip from a recovery system, WAY too much volume required for sprinklers. Can't do that effectively, even with a BIG tank!

[Hemlock140]

With a 5,000 gallon tank, at the typical city water 5/8" hose volume of 17 gallons/minute, your water would last 294 minutes when irrigating. That's only about 5 hours, not nearly enough to get through July and August. Home catchment systems are good for watering small vegetable/flower gardens and that's about it. In our climate with your 50" of rain (we get 60") it doesn't seem worth the effort for such a short watering season. This summer I only watered the lawn twice and it's never been more green.

[catz&dogz]

Originally Posted by WestGuest

Does anyone have a catchment system?
If so how large a tank, what do you use it for and are you happy with it?
My understanding is the water is purer and of better quality for drinking and irrigation than traditional water sources.
Would a 5000 gallon tank be enough for a two- person family and two thirsty dogs as well as for irrigation for two acres?
Summer rain is only about 1.5 inches a month.

Does anyone have a catchment system?
Yes.

If so how large a tank
7500 underground concrete and 2200 ipool.

What do you use it for?
To ... Store ... Water?

Are you happy with it?
Yea sure, drinking water tanks are not really something you have to think about.

My understanding is the water is purer and of better quality for drinking and irrigation than traditional water sources.
Maybe, our ground water is contaminated with e-coli from septic systems so rain is 100.

Would a 5000 gallon tank be enough for a two person family and two thirsty dogs.
Yes, plenty of household water for 1 month. There are handbooks at your extension, FEMA, Red Cross, about water harvesting.

As well as for irrigation for two acres?
Two acres can use a lot of irrigation and that would usually be done with a small water well.
Is it greenhouses or field?

If it is open field its a lot easier and cheaper, only the cost of a backhoe rental and pond liner.
Remember you have rain so you would probably want to dig an irrigation pond and pump back pond on each end of your field.

It doesnt have to be the panama canal.
It can usually be done with a small backhoe on a weekend rental.
If your field is a rectangle you are in luck.
A two acre field is 87120 sq ft so using the rainwater harvesting formula of square foot xtimesx inches of rain xtimesx 0.623 equals 54,275 gallons per inch of rain.
The dirt will absorb most of that but any excess will make its way to the lowest end of the field and into your pump back pond.
Head pond is at the highest end and pump back pond is at the lowest end.
On a 2 acre rectangle where the length (416' feet) is twice the width (208' feet) i'd figure on a 10' foot wide pond on each end. The depth is up to the soil perc or the width of the pond liner you use but a 10' x 208' x 7' deep pond will hold 100,000 gallons and you will have two, but usually only partially full. Once you dig the ponds you will need to fill them and thats a good time to use the cheapest plastic HD has. Put it down in the fields during the rainy season and if you get 5" inches of rain that will be a little more 200,000 gallons about enough to fill both ponds at once. Once the ponds are full roll up the plastic and put it away. Get a gas powered transfer pump to start and move the water where you need it. Most people do aquaculture, fish, crayfish, snail, frog, turtle, etc., and grow water plants too, duckweed, cattail, bamboo, and floating baskets.
A small plot managed properly can produce more food than maybe 10 families can eat, imo.
It sounds complicated but its super easy once you get the hang.

Summer rain is only about 1.5 inches a month.
For house water get a nice 5,000 gallon tank. Use same formula to calculate roof runoff. Climate change means there will be more water evaporation and that means more water in the atmospheric rivers and that means bigger storms that dump more rain during one event. If you havn't installed gutters get the biggest you can find because you will likely fill them to the brim in the near future. We are already overflowing our 4" inch'ers.
We use above ground pools during the rainy season to catch every drop, put up more as we fill them and then take them down as we use the water.


Sq Ft x inches x 0.623

[Arktikos]

What would you be irrigating? Perhaps you could have two tanks as suggested above, one for home use and one for the farm. If conservative with water you'd have left over from home tank for irrigating in the summer, if necessary.

Looks like there's a bit of summer rain there. https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa1205

[StealthRabbit]

A friend in Eastern WA was just explaining how he goes through 80,000 gal of water / day irrigating ~5 acres. (Not possible to achieve or sustain using rain catchment ).

Drip will suit you.
You can add an elevated tank high on your property or use a low volume low pressure jet pump.

I found a windmill that has a vacuum pump for low flow / low pressure irrigation.