Rainwater Harvesting: Why and How

Rainwater harvesting is the process of collecting water during rainfall and storing it for future use. You may be wondering if collecting rainwater is worth the trouble when you can already turn on your tap and have water in an instant. The collection of rainwater is all about saving: saving the planet, saving your money and saving your own store of usable water.

There are many benefits to collecting rainwater for both the harvester and the environment, and the process can be as easy as it is beneficial.

How it Helps the Environment

Collecting rainwater before it becomes groundwater and runoff helps to keep contaminants from our lawns and roads out of the rivers, lakes and water systems. Surface water can become contaminated with pesticides, fertilizers, metals and sediment. The more water run-off that flows from our properties into the water systems, the more contaminants travel with it, which can be a major source of water pollution in urban cities.

Using harvested rainwater also reduces the demand on our municipal water supply, thus reducing the amount of water that needs to be treated through the water treatment facilities, saving both water and energy. The decreased demand on the water supply is of particular importance in times or areas of drought when limits are imposed on domestic water use.

How it Helps You

Some studies show that up to 40% of water consumption is used on domestic irrigation. That means nearly half of the water used is not used for drinking, bathing or other household tasks but rather outdoor care and maintenance. By collecting rainwater for outdoor use, harvesters can expect to see savings on their utility bills by decreasing their use of municipal water. Additionally, harvesters in areas with water rates varying on peak usage times can further enjoy the savings by using their own water stores during these high rate times.

Collecting rainwater before it enters your home's water drainage systems also lessens the likelihood of property flooding and ground erosion.

Using water from the sky rather than the tap also means you won't be subject to use limitations brought on by either drought or emergencies. During times of drought, you won't need to watch your gardens wither away as you'll have your own water stores on hand. During emergencies you'll still have the supply you need to flush toilets, cook or filter for drinking.

Additionally, rainwater is actually better for watering your plants and vegetable gardens then the water from your hose, as this pure rainwater is free from additives and chemicals found in municipal water such as chlorine and fluoride that can be potentially damaging to your plants. Rainwater naturally contains the balance of nutrients that help plants grow.

How to Harvest

The most common way to collect rainwater is by redirecting the water from your roof's downspouts away from your yard or weeping tile and into containers for storage. This method allows for rainwater collection at just about any property or building, as long as there's a roof that can have eavestroughs. Depending on the size of the roof, it's likely you will need several collection basins placed at different downspouts. A building with a 40x20 foot roof sheds up to 600 gallons of water during each hour of moderate rainfall and rainwater harvesters can collect up to 80% of this water in their collection systems.

The type of basin you use is up to you as long as it is water-tight and will not erode or otherwise contaminate the water. Many styles and designs are available. However you can also make your own using plastic tubs, steel basins or even your standard home garbage can.

Even if you are just using your harvest for gardening and outdoor use, you'll want to ensure your barrels are fitted with filters to keep debris out of your supply. Eave guards can act as the first line of defense against leaves and other matter getting into your water stores. Store-bought barrels may come fitted with screens to filter out unwanted debris, and pea gravel can also be placed at the bottom of your barrel to further filter your water.

Collection from eaves into storage is the most common way rainwater is collected and makes it easy for even the most beginning DIYers. However, harvesters looking for alternative methods won't be disappointed. From standalone systems that effectively catch rain with a funnel, to fencewell tanks that combine water collection with privacy fencing, the options for harvesting are many.