With a rainwater harvesting system, once you have filtered water in the storage tank, there are three ways to get it out—with a hand pump, electric pump, or gravity.
Most of the rainwater storage tanks available to homeowners come equipped with a standard garden spigot near the bottom of the tank where you can quickly hook up a garden hose (this is the option that takes advantage of gravity to provide the necessary pressure for watering).
But for larger irrigation systems or systems where most water is stored below grade, a pump—either hand or electrical—is generally required to get the water out of the storage tank.
A hand pump saves on energy (except for the human kind), while an electric pump include costs for materials, installation, and operation. On the other hand, an electric pump will enable you to water plants in a raised or hanging location without a struggle.
For standard roof-collecting systems, gutters are the first part of the conveyance stage. Almost all residential systems rely on gravity to move the water. This means that from the point where the rain lands on the collection surface to where it is deposited in the storage tank, the water must flow downhill.
The most common place to tap into a conventional gutter system is at the downspouts. From there, water can be diverted directly into a rain barrel or storage container. You can either cut the existing downspout and attach it directly to a filtering device or install downspout diverters that allow for more flexible rain barrel placement.
Once the barrel is full, excess water must be directed down and away from the house, so the system must accommodate this. A helpful product for this job is a rain barrel diverter spigot that is designed to divert excess water when the container is full.
How do you clean the debris out of rainwater that you want to use for watering your lawn or garden? Even though rainwater is relatively free of chemicals and toxins when it leaves the clouds, it can be plenty dirty by the time it gets to a rainwater storage container.
Any dust, leaves, bird droppings, or bugs on your roof will likely be washed into your conveyance system (the gutters and downspouts) with the first strong storm. Keeping your storage tank free of this gunk is critical if you want to maximize water pressure and the longevity of the rainwater system.
A simple metal mesh screen is ideal for filtering out larger debris, and a second fine screen at the mouth of the storage tank will help keep critters out of your watering supply. Be sure that the filtering screens are readily accessible to make cleaning and maintenance easy.