Rainwater harvesting is the collection of rainwater, storing, and using the water for various purposes.People have been using this method of providing water for their crops, animals and homes for thousands of years.
In many arid areas and underdeveloped countries, this is the primary water source.
Turneffe Island Resort uses rainwater harvesting for all the water supply.
The drought that devasted Georgia in 2007 drove home the idea that water is a valuable resource. Lakes dropped to record lows, water for home use was in danger of being restricted. ALL watering for landscaping, gardens and flower beds was prohibited. Yards withered and many trees suffered damage so severe they died. Businesses suffered, jobs were lost and a feeling of unrest settled over the state as everyone sought to answer the question: Where are we going to get sufficient water to sustain us?
Lakes receded so that many docks & boats were left high and dry. Recreation and property values suffered
The advantages of using rainwater are simple:
If you use municipal water for your landscaping, you pay both water AND sewer fees. Sources say that approximately 60% of residential water consumed is used for landscaping.
Rainwater is a source of virtually mineral free water
Rainwater Harvesting preserves the groundwater. As more & more homeowners attempt to maintain their landscaping through private wells, the groundwater becomes depleted. Rainwater Harvesting reduces runoff into storm drains and can ease urban flooding.
Rainwater Harvesting allows you to water your plants no matter what restrictions are in force. Treated rainwater can be used exactly like the municipal or well water you now use. Untreated rainwater can be used for a wide variety of tasks that don’t require purified water.
Auto & Equipment Washing
Filling Fountains or Pools
Watering Livestock or Poultry
The next logical question is: Can I collect enough rainwater to make the cost of a rainwater collection system worthwhile?
Below is a method to calculate the rainwater collected from your roof:
First you need to know the size of your roof.
Measure in feet the width (W) and length (L) of your roof. (A close approximation is good enough for this exercise) Since a collection system is not a curb appeal feature, we will use only the back of your home
Multiply W X L = R (square feet for ½ your total roof)
Now we add in a known constant to our calculations: .624 gallons of water are collected off every square foot of roof during a 1” rain.
For a house with a roof width of 20 ft and a length of 50 ft, 20 X 50 = 1000 sq ft. roof area for rainwater collection.
In a 1” rain so 1000 X .624 = 624 gallons rainwater collected from your roof. Griffin, GA receives an average of 50 inches of rain per year. That 1000 sq ft roof collects 31,200 gallons of rainwater!
The next question that most people ask: How much water do I need?
- What is planted in your yard?
- How big is your yard?
- How often does it rain?
In landscaping it is best to locate plants having similar water and light requirements close together so that they have the best growing environment. A cactus takes little water and full sun. Impatiens need daily water in high temperatures and afternoon shade. Don’t plant them side by side and expect good results if you treat them as equals. With water at a premium, xeriscaping, use of native plants and watering BMP’s will give you best results.
So the answer that is the most accurate: The largest tank you can accommodate. You’ll be glad you did.
Here are some generalizations on water requirements by climate type. It will help you put your water requirements in perspective.
Inches of Water per Week
Stored Water Requirements
.3 gal / sq ft
.6 gal / sq ft
.9 gal / sq ft
Georgia is a temperate climate. In order to flourish, a vegetable garden will require at least 1″ of water per week.
A garden that is 10 ft wide X 20 ft long contains 200 sq ft. An inch of water a week means you would need 120 gallons per week to keep your garden healthy. Calculated: .6 gal/sq ft X 200 sq ft = 120 gallons A dry spell lasting 3 weeks would require 360 gallons of water to keep your garden flourishing.
ONE NCI Rainwater Harvesting Kit holding 305 gallons rainwate
FOUR competitor rain barrels holding 200 gallons rainwater
- Which kit works the best? NCI kit has a black poly tank with resins rated for potable water, secure filter, single spigot, single overflow and holds 50% more water than other barrel kits looped together
- Which kit looks the best? NCI kit has a single black tank that takes less space that multiple barrels
- Which kit costs the least per gallon of water? NCI complete kit comes to $.91 per gallon! Compare the prices. Multiples of their product will be much more than one of ours!
SAFETY WARNING!! A full water tank is heavy!
Often people balance a barrel on concrete blocks or bricks in order to get the water out of storage. Water weighs 8.34 pounds per gallon. Do NOT put a barrel or tank where it could be tipped over or is not fully supported. The 305 gallon tank weighs 2,544 pounds! Each 50 gallon rain barrel weighs 417 pounds.