Rainwater harvesting

By Admin | Heating
08 May 2016

to establish their own rainwater collection system will have to spend just one weekend.And the collected water can be used for watering gardens, washing cars and other needs.Remember that such water is unsuitable for drinking or cooking.

collecting water


Before you go to the hardware store, you need to do a little calculation.To begin with we define the material of construction of the roof of your home, the amount of water that will flow down the roof, the volume of water that needs to be collected on the basis of their calculation of daily water consumption and annual precipitation.

  • Not suitable roof covered with tar, gravel and asbestos.This coating will leave in the water collected unwanted chemicals.

  • Measure the perimeter of the roof, and then calculate the area, excluding the slopes and cornices.Living area is at least 80% of the total area.This parameter depends on the roof surface.To calculate the approximate volume of water collected in the year using the following formula:

V = (S * A * k) / 1000 liters where:

V - the volume of water collected
S - the total roof area in m2
A - the annual amountrainfall in mm
k - coefficient of efficiency of collection of water, k = 0,8

size tank for water collection is chosen on the basis of the volume of water consumed daily by all the inhabitants of the house.The general formula: consumption of water per person per day & amp; 規 number of people & amp; 規 = number of days required volume of water.

Another option - the duration of the rainy season.Divide the rainy season months, the average monthly rainfall record, you subtract the required amount of water per month.The result is the amount of unused water, which can be transferred to the next month.

And remember: if you have a round tank to collect water, its volume is calculated as follows: surface area & amp; 規 tank height.

Purchase materials

  • barrel / tank: free -?(You can look around).
  • Polypropylene barrel - 0.35- $ 1.00 / gallon (very easy, unlike other)
  • Metal Barrel - 0.40 - 0.60 dollars / gallon (can not be used for storage of drinking water if there are no special pads).
  • Gutters - 0.30 dollars - 30.5 cm - you can make yourself.
  • pipes leading to and from the tank to collect water: about $ 10 for 3 meters (pipe diameter depends on the size of the area collecting water)
  • Knee PVC - $ 2 per piece.
  • Cement - $ 5.
  • materials for flat and stable surface, for example, a special support / mattress -6 dollars.
  • enclosure for the reservoir around the perimeter of -10 dollars.
  • Coverage for track - 20 dollars.
  • 1 bag of Portland cement -30 dollars.
  • tank can be stably set, digging beneath the deepening of a few centimeters.However, it is not suitable for all soil types.

collecting water

Note: in order to gutters are clean, you can set the grid to collect leaves, mesh filter or funnel.


1. The opening of the tank should be positioned a few centimeters below the funnel drain.

2. It is desirable that the tank has been masked by the trees.

3. The tank should be on a flat, stable surface (on the substrate / mattress).Make a small fence around the reservoir.Fenced land fill a special coating for roads - it is cheap and compact.Then put a small layer of Portland cement.Loosen, make sure that the surface is smooth, cover with water.Allow to dry.

4. When attaching the gutters need to remember:

- Measure the length of the eaves in order to determine the lengths of gutters.
- gutters should be fastened at intervals of 10-15 meters along the entire length of the trough.
- Count the number of drains - increase the number doubled to get the required number of elbows.Count the number of turns on the 900 and 450, to acquire the necessary number of the tribes of the desired shape.
- Count the number of fasteners required, flexible clamps and plugs.
- Brackets should be placed on the ledge with the periodicity in the 9th or on the head of each of the rafters.
- Gutters recommended to have a slope of 0.6 - 1.2 cm towards the drainpipe every 3 meters. To do this, measure the perimeter of the house.

To gutters are not clogged, set the grid to collect leaves, mesh filter or funnel.Nets are set to collect the leaves at the beginning of the gutter, and the filter mesh and funnel - at the junction of water in the gutters.

General rules: 15m2 collecting surface of the roof drainpipe diameter = 7.5 cm on kazhdye15m length of gutter connected to a PVC pipe with a diameter of 10 cm, at which water enters the tank.

5. For smaller surfaces drainpipe diameter of 5 cm for every 12 m length of gutter connected to a PVC pipe with a diameter of 7.5 cm.

6. When connecting PVC pipes with cement, rotate them a quarter turn to and fro,that the coupling element is uniformly dispersed.If the tube formed around small balls, you did everything right - pipes will not leak.Also, do not forget to leave a little slack when cutting pipes - about 7.5 cm (for connections).

7. Install the tank should be at the highest point, as the water pressure is 453 g / 2.54 cm 2 for every 70cm in height.