An essential ingredient to successful gardening is water. The best water for the garden is rainwater. Ever notice how the lawn and garden seems to have a sudden growth spurt after it rains and also looks much greener? This is because rainwater does not contain salts and minerals that are found in tap and well water. Plants absorb rainwater irrigation more efficiently compared to tap and well water. Thus rainwater irrigation can be stretched much farther because plants do not need as much rainwater as tap or well water.
Rainwater can be
collected
and stored by harvesting rainwater. Harvested
rainwater is great for gardens, lightens the load from your water supply, and
is free. Rainwater harvesting
requires that rainwater is collected and routed to a storage container.
The area used for rainwater collection is referred to as a catchment.
Catchments include roofs, patios, decks, concrete and paved areas such
as driveways, and even the ground. However,
some catchments are more effective at collecting water than others.
For example, a concrete driveway delivers more water than the ground
which is much more absorbent. Gutters,
downspouts, drains, and trenches route collected rainwater to storage units
such as tanks, barrels, and depressed ground-holding areas.
The home you live in comes
with a built in catchment, which is your roof.
To harvest rainwater, all you need now are gutters, downspouts, and
storage containers. When
installing gutters, the gutters should be at least 5 inches wide to capture
all of the rainwater and should be made from sturdy steel or aluminum.
Downspouts should be spaced apart 20 to 50 feet along the gutters,
depending on the collection area being covered by the downspout.
The size of the rain tank should be based on the collection area.
One square foot of catchment area will collect approximately 0.6
gallons per inch of rainfall. So
if you have a 1000 square foot catchment area, that is 600 gallons per inch of
rainfall! For pitched roofs, the
collection area is measured by the length and width of the collection area
edges parallel to the ground, not from edge to edge along the slope.
This is based on the assumption that rain will fall straight down from
the sky, not at an angle. Two or
more rain tanks can be linked together if one rain tank is not large enough to
store all the water delivered from a downspout. Gutters need to be kept free
of debris and leaves. Look for
rain tanks that have filters built in that are easy to clean. This will eliminate the need for screens and hard to reach
filters in the gutters and downspouts.
Rain tanks need to be child and animal safe, and mosquito resistant. Rain barrels and tanks without lids can be a hazard for pets and children. Decorative rain barrels can add an attractive element to your home and landscape. Overflows are essential on rain barrels to divert excess water to a linked companion tank or to a desired watering location. In areas were the temperatures fall below freezing, rain barrels that can withstand damage from frozen water can collect rain and snow runoff all winter and store it till the spring. Thus, plenty of rainwater will be available for gardening in the spring. Make sure you use a rain barrel that has not been used for storage of anything other than water. Then you won’t have to worry about contaminants spoiling your fresh rainwater. A spigot installed on a rain barrel will allow you to get the water out when it is time for watering the garden.
Rainwater is not only good for outdoor gardens, but can be used for indoor plants, water for pets and farm animals. Rainwater harvesting is also an effective means to conserve water.