What is rain water harvesting?

Basically, rain water harvesting is using the existing roof of a home (Capture point), using the existing gutters and downspouts (Collection point) and connecting to the bottom of them and diverting the water by a series of pipes to a storage tank.  The water is then run through a pump and out a hose bib and/or into an irrigation system.  This can be done above or below ground level.

How does it work?

In the case of an underground system:  A storage tank is buried beneath the surface of the ground and the pump system is inside of the tank. All of the drainage system from the downspouts is also buried below the surface and all directed to the tank.  Once everything is installed and buried, it is unseen to the homeowner except the lid to the tank itself.  It can also be hooked up to an irrigation system and run through that along with hose bibs.  The homeowner notices no difference in efficiency when compared to being hooked up to the City water system other than a smaller water bill and the ability to water even when there are restrictions because of drought.  A sign is installed at the front of the property indicating rain water in use.

In the case of an above ground system:  A storage tank is leveled above ground and concealed by plants, trees, under a deck or a fence.  Everything else is the same.

How much water are we talking about?

2,000 sq. ft. roof X 1” of rain = 1,200 gallons of water

Average rain fall in our area is 42.8” per year

This adds up to 51,360 gallons of water a year collected.

Bigger homes, bigger roofs, more water collected.

What are the benefits of harvesting rain water?

To the homeowner:

• Ability to water and keep landscaping alive during a drought.
• Rain water is much better for plants and lawn and gardens.
• Saves money on water bill and in some situations where the sewer bill is related to the water usage there is additional savings.  This depends on the size of the yard and how much watering the homeowner wants to do or has done in the past.
• Saves on the cost of replacing landscaping after a drought and the restrictions keep you from watering (if you don’t water with rain water).

To the environment:

• It is being more responsible with what we are given and helps with the water treatment.  Our treated drinking water is not being used on the landscaping.
• Creates a better quality of ground water because it slows down the run off that causes erosion to our lakes and streams.
• Reduces the water demand.

This is such a common question.  The reality of the question is much bigger than just collecting rain water for personal use around the home.  If it doesn’t rain, then our entire area is in trouble.  Our lakes, our rivers and our bigger water supply.  What if our water supplying agencies who rely on it raining somewhere to get the water they supply to the people of the city thought the same way and chose to not spend the money on pipes and filters and pumps to get us our water?  We would all be in trouble.

Firstly, it does rain some or we would be living in a desert, so we need to be prepared for the couple of hours it does rain and collect as much as we can.  We need to address our own water usage and conserve.  We need to be wise in our landscaping choices and choose plants and grasses that are drought tolerant.  We can also look for every way to collect water.  We can collect water from our washing machines.  A front loading washer uses between 30-40 gallons of water per load (you need to use environmentally friendly soap).  You can collect water from your air conditioning condensate (in the summer months this can contribute 5 gallons a day).

So, the question really is what can I do to be prepared for when it does rain?  What can I do to increase my conservation of water and what is my part? 

Other pro-active solutions besides Rain Water Harvesting

• Drought tolerant grasses and plants (require less water which increases the efficiency of the system).
• www.townofcary.org/depts/pwdept/water/waterconservation/landscaping.htm#choosegrass
• Collect washer water and air conditioning condensate.
• Plumb home to use rainwater to flush toilets

Ultimate Vision

Whole subdivisions that collect all rain water and gutter run off of every home and then divert it to a recycling system and re-use it again in the homes.  This recycled rain water is used in each home to flush toilets, wash clothes, water lawns, wash cars and fill pools.  The washer water, shower water and sink waters are also drained into the recycled plant.  This is already being done in Australia, why not here…