How to get the most out of your rain barrel
By Amber Murray
Folks, it’s May. Just a few weeks before the famous, southern Alberta “monsoon June”, where we traditionally see the majority of our rainwater fall from the sky. Furthermore, the City of Lethbridge has launched its Environmental Incentive Program that includes a $100 rebate on rain barrels purchased this year. If you have been considering the installation of rainwater storage, there is no better time in Lethbridge to do so than right now. This article will help you consider placement, type of barrel, what you need to know about stored water, and some places in Lethbridge that you can find them.
Types of barrels
A Rain barrel can be made from pretty much any strong, watertight material (reinforced plastic, wood barrels, fiberglass) with a flat base. They can range in size from a couple hundred litres to several thousand litres and are meant for short-term storage of excess rainwater (from roofs and surfaces) during rain events for use in the landscape during dry periods instead of treated water. The City of Lethbridge has posted an article on how to build your own DIY rain barrel or check here for a list of Lethbridge suppliers.
Special considerations about DIY barrels
Many folks, myself included, use food-safe IBC (intermediate bulk container) totes to store rainwater (see photo below).
They are large, metal-reinforced, plastic containers with standard volumes of about 1000L. They are easy to place and raise due to their square shape and flat sides, come equipped with an overflow as well as an easily-adaptable base valve, and can sometimes still be found for free (ensure they are FOOD grade, however, as they are also used to store herbicides and other chemicals, which can’t be cleaned appropriately).
The trouble with these totes is that they are made with clear or slightly opaque plastic. This means sunlight will pass through into any stored water, which will cause the growth of algae (there will be organics in your rainwater) and increased water temperature. Furthermore, because they are made from plastic and are designed for bulk liquid transport and storage, they will break down in sunlight. For this reason, when they are used for rainwater harvesting, they should be covered (and ideally, placed in the shade). Heavy duty landscape fabric works and can be slid between the plastic container and its metal guard when the tanks are empty.
Tarps also work well as a cover but will break down in the sun. I’ve also seen them nicely covered with recycled wood boxes (and that is my plan with my own tanks). Once they are covered and kept cool, the water can be stored longer-term.
Placement of tanks
Again, placing tanks in the shade is ideal, because cooler water means you can store it longer. Heat and sun cause organics to grow and spoil in your tanks, which means that the water can damage your plants when you use it.
Tanks should be near a downspout and completely level. Water weighs 1 kg/L, which means even a small tank can be 200 kgs (nearly 450 lbs) when full. A tank placed on an uneven surface can tip and damage plants and structures and spill its considerable amount of water into a foundation. For this reason, the tank must be on a stable and firm base, hardscape, or at the very least, hard ground.
If you only have downspouts in constant sunshine, it’s wise to construct a little hut for shade, or know that that stored water should be used quickly.
Colour of tanks
Modern rain barrels come in all shapes and colours, so you can match them with your home or blend them into your environment. White tanks are great in sunny locations for reflection, but again, any tank sitting in the sun will grow algae and heat the water. Do not use dark colours in sunny spots, even for short-term storage. If the tank is constantly in the shade, it can be any colour and not really affect the water inside (note that even in the shade, clear plastic or light-coloured plastic/fibreglass tanks will grow algae).
Capture and overflow
There are many techniques for removing debris from rain water, including screens and first-flush diverters. Both require regular cleaning to function properly. You can allow everything to flow into your barrel, but the debris may block your outflow, which is always situated at the base of the tank (and where particles will settle). There are differing opinions as to whether you need to clean your tank annually (you’ll definitely want to if it starts to grow algae or has a blocked valve), but it helps to keep maintenance down if you remove macro-debris before it enters the tank.
Overflow diversion is extremely important to protect both the stability of your tank and building foundations (as tanks are usually adjacently situated). If tanks overflow, the water can degrade concrete/wood/soil bases, which can lead to tipping, and that water will head right into the foundation of nearby structures. There are backflow valves that can be installed into a downspout (on a closed system), but a small outflow at the top of the tank with a hose attached is the simplest way to divert excess water during a rain event. Simply ensure the hose is long enough so that the outflow is directed away from buildings or gardens (best place would be the base of a large tree).
If you are in the market for a brand new tank, Flexahopper Plastics is a Lethbridge company that has made attractive “Spacesaver” 189L (50gal) rain barrels in grey and sandstone especially for this initiative. You can order them directly from the company by calling 403-328-8146. Remember to keep your receipt if you do purchase a new tank and take several pictures of it to send to the City for your $100 rebate. Happy Rain Harvesting!
