Here in Reno, Nevada, we get under 7" of rain per year. Can we collect enough rain water in a rain barrel or barrels to make a dent in the average 136,000 gallons per year that a metered user like our household uses? Admittedly about 70 per cent of the yard is lawn--around 3000 square feet of it.
Olivia L. ~ Reno, Nevada
Hi Olivia, You might be surprised at how much water you can collect in rain barrels from just 7 inches of rainfall each year. Much of it is going to depend on how much roof area your home has and any other detached buildings you may have on your property.
You can figure the approximate area of your roof by measuring the outer perimeter of your home and adding for any roof overhangs you may have. If your home is a rectangle and happens to be 50 feet long and 40 feet deep with a 12 inch roof overhang all the way around, then you would multiply 52 feet by 42 feet to arrive at a roof area of about 2814 square feet.
Most homes aren't a perfect rectangle so you may have to do a little adjusting to come up with your particular roof area. Studies have shown that for every inch of rain on 1000 square feet about 600 gallons of water can be collected. Using the house in the example that would mean that for each inch of rain 1680 gallons of water could be collected and with 7 inches of rain 11,760 gallons of water could be recycled.
You don't mention if you have any idea how much of your 136,000 gallons of annual water usage goes for watering your lawn, but I would think that with only 7 inches of annual rain if you want a green lawn in Reno, Nevada, you have to do a lot of watering. The amount of water you can collect in rain barrels may not sound like much when compared with your annual water usage, but think of the water savings if each of your neighbors started doing the same thing. If 12 houses were about the same size as the example, they could collect enough water each year to make up for one home's total water usage for that year.
Rain barrels are similar in concept to the cisterns many old houses used, and still use, to conserve on the amount of water that had to be used from the home's well and as we endure more long periods of drought I think cisterns and rain barrels are almost going to become a necessity, especially in the southwest.
Another solution you may want to consider is doing a little more desert landscaping that might not require as much water during the hot summer months. You might keep parts of your front and backyards green with grass and plants, but use gravel or other materials that don't require water in some of the other areas and there are also some plants that do well in a dry environment.
Most recycling doesn't seem like much when only one person or family is doing it, but when many people join in it can add up quickly.