Using rainwater collected from your roof for the garden

[Kaleva]

Last edited Mon Aug 20, 2012, 10:35 PM - Edit history (2)

Been reading alot about gardening, indoor and out, and the steps people take to increase yield and cut costs.

If one lives in town like me and pay for your water, it might be worthwhile collecting the rainwater that falls on to the roof of your home and use that for the garden.

Below are a couple of links to sites that are quite informative. At the first link, you can find out what your average monthly rainfall is for where you live.

http://average-rainfall-cities.findthedata.org/

The next one has a link in the article to a rainfall harvest calculator. You enter the average rainfall per month which info you got from the first site and the square footage of your roof(s) and that will give you how many gallons you could collect.

http://www.gardeners.com/Rain-Barrel-How-To/5497,default,pg.html

The average amount of rainfall per month where I live is about 3 inches. The square footage of my home is 468 sq.feet plus 40 square feet for the front porch. I could collect, on average, about 953 gallons of rain water a month during the spring, summer and fall. 878 gallons off the roof of the house plus 75 gallons off the roof of the porch.

Now I'm on a tight budget but I could start out small and put in a rain gutter system (doing the work myself) on half of my roof at first. Looking at hardware and farm supply sites, a rough estimate for materials to put in a rain gutter on half the main roof would be a little over $200 and that includes a 100 gallon stock tank. There still may be old galvanized stock tanks at the family farm and if there is, that would save some money.

Edit: My single story garage is 24 X 22 and using the rainfall collection calculator, I could get about 990 gallons a month or 495 gallons if I use just one side. It'd be a heck of alot easier to put up rain gutters on the garage and to clean them or even take them down for the winter then on my small but two story house.

[HereSince1628]

1. This advice may be hazardous to one's freedom, such uses are often controlled west of the Missouri.

[Kaleva]

2. I know regulations are tight in Oregon but rainwater collected off roofs is exempted.

At least in that state.

[HereSince1628]

5. There was a recently a post on DU about a person in Colorado (?) who was found in violation

of that state's water laws by having rain barrels...which apparently interfere with the natural flow of water.

It's my impression that this isn't a water issue per se in the eastern US, although open rain barrels have gotten into trouble wth city ordinances written to eliminate potential breeding grounds for mosquitos.

[Curmudgeoness]

3. Rain barrels are great ideas.

If you already have gutters, all you need is a rain barrel (or one at each downspout of the gutter).

This is a cheap and easy way to make your own:

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They sell rain barrels, but since they have become so popular, they are rather pricey.

[Kaleva]

4. Great idea for a rain barrel!

Having worked as a plumber before, I already have the fittings on hand for the drain and over flow.

I may already have the barrel too as there was one such left here at this place by my ex wife's relative when she stayed at this house. I had set it up as a rain barrel for my ex but she never uses it as such as her garden is large and a distance going uphill from the house so it's much more convenient for her to use a hose . I could ask her for it back. I still have the cover for it in my garage and there's also a couple old screen windows in the garage that I can the screens from.

Putting the barrel on a couple of 8" cement blocks would increase its elevation in relation to the garden area and I could attach the hose to the drain valve on the barrel and then a soaker hose to that. Or I could just get a watering can from a yard sale or thrift store and walk back and forth many times. Or just buy a cheap plastic one from the local hardware store.

A person who has enough roof area that an average rainfall would over fill a 55 gallon barrel could get a second barrel and tie in the overflow of the 1st as a feed for the second barrel by using inexpensive 1 1/2" ABS or PVC pipe and fittings and cut the holes with a 1 1/2" spade bit (as shown in the video) or 1 1/2" hole saw bit.

[Kaleva]

6. After doing more research, it would not be cost effective for me to do this.

If I already had rain gutters installed, this would work for me but in figuring about how much water I'd need to supplement the average rainfall I do get in this area, the cost of installing the rain gutters would require a pay back of many, many years.

Replacing my over 20 year old top loading washing machine with a high efficient front loader would save every month about the amount of water I'd need for the garden. I'd be even further ahead investing in a fold-able clothes rack to dry my clothes indoors in the cold months and an outdoor clothesline to dry them in the warm months.

[Curmudgeoness]

7. Wow, I wasn't aware that there were houses without gutters.

You are right, this is costly if you don't already have gutters. Too bad, because this really can be done inexpensively if you don't have to do the gutter install. They are very popular here in W PA.

[Kaleva]

8. All the calculations I've done show it isn't worth the cost.

Most gardening sites I've read say a garden needs about an inch of water per week. I am preparing 160 square feet for a garden next year. The village charges $16.00 for 1,000 gallons and that includes the sewer charge ($10 for water and $6 for sewer for 1000 gallons).

Using the calculator at the below site, my weekly water bill for watering the future garden will be $1.59 and that's assuming it didn't rain that week. Monthly, the max bill would be $6.36.

http://www.dannylipford.com/calculating-lawn-irrigation-costs/

After doing some measurements on the house, I went to the Ace hardware site to get a rough estimate as to the cost of putting in a rain gutter system on just one side of my house. With tax, the estimate came to about $145.00 and that's with doing the installation work myself.

Now, if my basement got wet every timed it rained, I could justify putting up rain gutters for that reason and collect the runoff in barrels to water my garden with as a side benefit. But it doesn't.

I'd come out further ahead right away and with a much smaller initial investment by changing my clothes washing and drying methods and by making my own laundry detergent and fabric softener.

[Curmudgeoness]

11. God, are you lucky to have such low water/sewer costs.

For zero usage, we pay $21.00 for water and $45.00 for sewer monthly. The sewer rate doesn't change no matter what you use, but water goes to $25.00 for 1000 gallons. I know about the zero usage since they only measure in 1000 gallons, and about every 3 months, it rounds to zero since I use less than 1000 gallons monthly.

You are right, though, that for you, other options will work better.

[Kaleva]

9. Using the gray water from your washing machine to water the garden

Been reading sites where they talk about using the discharge water from their washing machine for watering gardens. This seems like a very interesting idea and I may do some playing around today as I have to wash a load today and I can find out how much water I can get. Some people stress to only use the water from the rinse cycle. Others use the wash water too but they stress using only environmentally friendly detergent(no bleach) or homemade detergent made with natural ingredients. And all have said not to use the water used to wash diapers. Not even the rinse water.

I wash a couple of loads a week and currently have a large capacity top loading washing machine. I'll update this later to let know how much water I get from the wash cycle, the rinse cycle and the total.

[Kaleva]

10. Well, my washing machine uses 48 gallons total

Emptied out an large plastic storage container and set it by the washer. Loaded up the washer with dirty clothes and put it going. When it went into the drain cycle, I held the drain hose and directed the water into the container. Shut off the washer and hauled the water up the stairs and outside and watered various plants and shrubs. This took many trips. I put the washer going again and repeated when the washer went into the drain and spin cycle. Hauled that water out too. So glad I took a shower before doing this as I'm now wet with sweat!

Measured the inside of the container (the container was just under full both times) and converted the cubic inches to gallons and came up with 24 gallons so it's 48 gallons total.

That's alot of water and as I do laundry about twice a week, that's 96 gallons of grey water a week going down the drain. Water I could be using on my garden next year. Looking at my water bill, my washer accounts for half of my water usage but I sure as frick am not going to be lugging that much water out of the basement and outside.

I'm in some pain right now so I'll take a quick shower and spend the rest of the day going over my budget to come up with the money to purchase a washing and drying method that uses much less water and is affordable to me.

[Curmudgeoness]

12. That does sound like too much work.

When I was living in drought periods, I always kept a large stock pot in the sink, and when I had to run water to get hot water or rinse dishes or wash my hands, I collected that water for the garden. I also took baths and collected the bath water to use. I still always use the dehumidifier water in the basement for garden or for the laundry. I never went as far as collecting the washer water, but mostly because I could not get to the discharge pipe.