• Reduces  the water volume processed by community storm water systems
• Decreases the water borne pollution entering local streams and rivers
• Reduces soil moisture in contact with the home’s foundation
• Provides oxygenated, un-chlorinated water for garden plants  (Rain Barrel Source.com)

Two ways to capture water are through the use of Rain Barrels and underground storage tanks.    I want to begin the discussion with Rain Barrels.  They are the easier of the two storage options to install.  Rain Barrels are relatively inexpensive, ranging in price from $199 to $299.  Rain Barrels are simply set around the house under your existing downspouts.  Rain water from your gutters flows into the rain barrels and fills them for use at a later time.  The Rain Barrel has a spigot and valve that is located at the bottom of the barrel that controls the release of the water.  

The simplest method for releasing the water from a Rain Barrel is through gravity.  As long as the barrel is higher than the area to be watered or close to the same height, the pressure of the water in the barrel along with gravity will cause it to flow.  Once the water is flowing, the siphon effect will cause it to continue until you close the spigot.  The flow of water can also be increased by placing the Rain Barrels on elevated platforms or tables.  Make sure that the surface that you set your Rain Barrel on is strong and solid.  A rain barrel can contain as much as 65 gallons with a weight of over 540 pounds.  An unstable or weak supporting surface can be dangerous and messy if the Rain Barrel shifts or falls.

Modification of your existing downspouts is required to divert the water into the rain barrels, but the process can be performed with relative ease.  Several companies manufacture diverters.   One type of diverter fits neatly into a standard 3x4 downspout and has an overflow float that will stop water from going to the Rain Barrel once it is full (Gardeners.com).   A second type of diverter acts like a simple trap door.  When opened manually, it will divert water into the rain barrel.  Most rain barrels have an overflow relief of some kind that will allow excess water to flow out of the Rain Barrel and continue on to the path of the downspouts (Composters.com ).   You will find many versions and improvements on the diverter system as you investigate.  One company that makes a barrel that appears to be well thought out is (Aqualbarrel.com ).  The added benefit to their barrel is that they are recycled from discarded barrels used in the syrup and food concentrate industry.

Larger storage tanks can also be employed for the containment of rain water.  Large storage tanks will require the assistance of a landscape contractor for installation.  They must be dug into the ground and then tied into the gutter drainage system.  Underground storage tanks also require an overflow that allows excess water to continue on into the storm sewer system.  “For every 1,000 square feet of catchment area, you can expect to collect, in total, approximately 600 gallons of rain water for every inch of rain that falls” (Rain Barrel Source.com ). By burying a large 1000 or 2000 gallon storage tank and diverting the water from downspouts to it, a sizable amount of rain water can be contained for future use.  If underground storage tanks are used, they will require the use of some sort of electric pump to extract the water.  These pumps can also be used to aid in the dispersion of water from Rain Barrels (Rain Barrel Source.com ).  You will need to make sure that the pump is sized to accommodate your particular tank and situation.

Many people falsely assume that they can use rainwater to irrigate their lawns.   I spoke to my landscape contractor (Basile Landscaping.com) regarding the amount of rainwater that is necessary to irrigate a lawn, and it is a staggering amount.  The lawn and landscaping in your yard needs an average of one inch per week.  For every square foot of lawn area, multiply by .62 and this will give you gallons of water required to give you 1 inch of coverage over the yard per week.  The average lawn of 7500 square feet requires 4650 gallons of water per week.  As you can see, this is far beyond what you will collect with even a large 1000 gallon storage tank.  The best use for collected water is to supplement the watering of gardens, flowers and residential landscaping.  These smaller areas will not produce the same demand for water that your lawn requires but can still benefit from your collected rainwater.  For example, a 6 foot bed in front of your house that is 50 feet long is a total of 300 square feet.  This bed will require 186 gallons of water per week to maintain the required 1 inch of water.  This is much more attainable with the systems that we are discussing.  Remember, that every gallon of water that you collect and use is one less gallon that needs to be collected, purified and pumped from your municipal water system.