Rain barrels are widely utilized tools for water conservation, capturing rainwater runoff from a roof for later use in the garden or landscape. Moving this stored water efficiently requires a connection method that works with a standard garden hose. Depending on the distance and pressure required for the watering task, various methods—from simple gravity to mechanical assistance—can be employed to transfer the water from the barrel.
Using the Built-in Spigot for Gravity Flow
The most straightforward method involves connecting a garden hose directly to the barrel’s built-in spigot or drain valve. This approach relies entirely on gravity, where the weight of the water above the spigot creates the flow. The pressure generated is directly proportional to the vertical height difference between the water surface and the hose’s exit point.
For every foot of vertical elevation, this method generates approximately 0.43 pounds per square inch (PSI) of pressure. Since most rain barrels are only elevated a few feet, the resulting pressure is very low, often falling between 1 and 2 PSI. This minimal pressure is insufficient for operating a standard oscillating sprinkler or spraying water over a long distance. Gravity flow is best suited for filling a watering can, running a very short soaker hose, or supplying a low-pressure drip irrigation system.
Creating a Siphon with the Hose
A siphon provides a non-mechanical way to move water when the destination point is lower than the water level inside the barrel. This process works by atmospheric pressure pushing down on the water surface and gravity pulling the water down the hose’s slope. For the siphon to function, the entire hose must be filled with water, creating a continuous column free of air bubbles.
To begin the siphon, one end of the hose must be placed fully submerged in the rain barrel. To prime the hose, submerge the entire length in the barrel until it is filled. Alternatively, the hose can be attached to a tap, filled until water flows from the other end, and then quickly capped or plugged.
Once primed, the submerged end must remain below the water line, and the other end must be quickly lowered to a point well below the barrel’s base. The difference in height between the water level and the hose’s outflow end determines the flow rate. The continuous column of water maintains the siphonic action.
The flow will stop immediately if the intake end rises above the water surface or if the discharge end is raised to a height equal to or above the water level in the barrel.
Maximizing Flow with a Submersible Pump
When a greater volume of water needs to be moved quickly, or if the water must be delivered uphill or over a long distance, a small submersible utility pump is the solution. These pumps sit directly inside the rain barrel and generate significantly higher pressure than gravity alone. Most utility pumps are equipped with a standard garden hose adapter, allowing for a direct connection to the discharge port.
A submersible pump can generate enough pressure to run a standard garden hose nozzle or sprinkler system effectively. These units are commonly powered by a standard 115-volt electrical outlet, though battery-powered options are available. To operate, the pump is lowered into the water, the hose is attached, and the unit is plugged in or switched on. The pump will continue to move water until the level drops below the pump’s intake, providing a reliable, high-pressure flow.