Rain Water Harvesting

Usable and/or potable water.

What is your intended method?

It could be store and use runoff water from any roof.

It could also be seeding the clouds to change natural precipitation patterns.

or a variety of methods.

Lots of houses in my town use this system. Gutters at the roof eaves are formed of galvanized sheet steel, aluminum, or a plastic such as PVC. They collect the rain and drain via slip-joint pipe of similar material to one or more tanks. My house has two tanks about 20 m³ each, made of corrugated galvanized sheet. Polypropylene is another popular material.

or you can try Google!

I found this: http://www.google.com/search?q=rain+barrel&sourceid=ie7&rls=com.microsoft:en-us:IE-SearchBox&ie=&oe=

The best way is to see what you have available to you now and calculate to see if you need to make adjustment. So here are the pieces of the puzzle for you to consider.

Contact the Department of Agriculture for your area. They can help you get the basic information you need, or tell you where to get it:

• The average rain fall for your area that accrues during the growing season. Don't forget to get the percent of variances from year to year factored in.
• Water requirements of the plants you intend to grow in your garden.
• Soil conditions need to be evaluated for it's draining properties. Added in for the frequency of watering.
• Growing season temperatures for evaporation adjustment.
• You do not need to determine losses to runoff due to the slope of the garden area. If the slope becomes a factor pick a new garden location.

A value you need to know is that there is 231 cubic inches, or 0.133680555 cubic feet, in one gallon of water.

Let's just say you are going to use your garage roof, a peak type roof, as a rain collector. You have to calculate the effective collection area of this roof.

Here you will use "c" to represent 1/2 of it's width, sloped sides.

Calculate for "a". If the scarecrow can do this (a²+b²=c²⁾ in "The Wizard of Oz" so can you. This resulting value, times 2, is the actual rain collection width of the roof.

Multiply this width, by the roofs length, will give you the effective collection area.

Now you have all the pieces of the puzzle. Make sure you put all values in like terms and calculate how much water your roof will collect over the growing season. This is the water you will have in reserve.

Go get the containers and piping necessary to assemble this reserve. There are may videos on You-Tube that will help.

Now you can compare you requirements to the reserve. You will have to take into consideration the garden will naturally get rain fall for the growing season, so you can subtract that from your requirements.

If you need more reserve, turn your house into a collection system as well. Or you can turn a hill side into a collection system. Use you imagination.

The reason I left off "the out of growing season rain fall" is due to the winter months freezing up your system, and snow will blow off the collection system. No real measurements to consider.

This will give you a great start in one of the best ways in watering your garden. Have fun with it. What? You were hoping for all the answers and even some examples?

Oh, I do not care if you drive in a dirty car.

Thanks rcf-jr

The info was very usefull

The effective area should not make a difference. What you gain on the one side will be lost on the other. m A steeper pitch wont increase the volume.

Calculate on the footprint space.

Look again young man. Your statements makes no sense as applied to my answer. If you take a 4'x8' piece of plywood and lay it flat on the ground there will be an area of 4'x8' exposed to the rain fall. Now raise the long end up by 4'. Now you have decreased the amount of area collecting the rain, the true area actually collecting the rain (effective area), that is why the calculations are necessary.

Using my example, on a peaked roof there are two sides that are raised. Each side collects the rain. You only need the pitch to direct the water, any angle will do. Nothing is lost. I did not even mention a steeper pitch to increase the volume, why would I, for it makes no sense.

I like giving answers that challeng the mind yet explain the theory, no easy way out. I know that no matter how complicated the roof might be, the effective area is the buildings basic foot print.

Engineers do not just give answers, they explain.

Hi rcf-jr

Maybe I misunderstood you but :=

At my age I don't get on roofs anymore (to measure C)

I don't get into the roof anymore - almost impossible to measure b in any case.

2xA I can measure directly.

Use a piece of brandering and a spirit level and mark the sides on mother earth and use a tape to measure to any degree of accuracy.

Even I can do that with no possibility of landing in hospital.

And I don't even have to remember what I did with all 5 (or 6) pocket calculators.

I somewhere had an prisms type of range-finder (like on a old camera) with which I could measure 2xA quickly. Rainfall is very variable and a few inches either way would not be a train smash.

A few years back I was asked to assist an indoor grower in designing a water collection system. The owner questioned me on why I was using the greenhouse footprint and not the surface area in my calculations. Now you know why the long version. Have a great day!

Thanks rcf-jr

I come from a rain forest area (Malaysia) and it rains practical every other day

where rain water goes to waste, I am planning this for the future so that a tank can be placed at the second floor of a house so that distribution will be gravity all the way.

The present gobal warming will take its toll in the future in my region so I am preparing to incorporating water harvesting tanks for homes

You have been a great help

Hi - I grew up in an arid area and never had to contend with surplus water.

What you seem to need is a way of having the water available for convenient use.

You have to guard against overspending - that is having the water cost you more than from a water service provider.

Any plan need to be subject to the structural strength of your home.

Consider putting the tank on the highest level possible - On the ceiling of the top floor.

then construct a lightweight funnel type of catchment above the roof.

Provide for an overflow in the tank.

-

Your second concern is to size the tank correctly.

Estimate your needs and take it from there - Just remember that water weighs in at about 1 kg / liter.

Thanks Hendrik

your comments will be noted during my design

If you could, come back with some photos. We all would like to see them.

Ok

Its presently in the design stage

will get somw pics when they are being constructed

Have a nice day

Our very own CR4 Guru "Cwarner" is probably the best one to ask about rainwater collection systems....