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.
advantages of rainwater:
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 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 municipal or well water. Untreated rainwater can be used for a wide variety of tasks that don’t require purified water.
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:
- Know roof size
- Measure in feet the width (W) and length (L) of your roof. (A close approximation is good enough for this exercise) Most collection system only use the backside roof of your home.
- Multiply W X L = R (square feet for ½ your total roof)
- Known constant: 0.624 gallons of water are collected off every square foot of roof during a 1” rain.
For a house with a roof width of 20′ and a length of 50′ then 20 X 50 = 1000 sq ft. roof area for rainwater collection. Therefore, a rain of 1” you would calculate: 1000 sq ft. X 0.624 = 624 gallons rainwater collected from your roof. Griffin, GA receives an average of 50 inches of rain per year. Therefore in an average year of rainfall, your 1000 sq ft roof collects 31,200 gallons of rainwater!
How much water do I need?
- What is planted in your yard?
- How big is your yard?
- How often dry if your home’s climate?
Usually, our tank experts suggest the largest tank you can accommodate in your space. You’ll be glad you did.
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′ wide X 20′ 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.