Rainwater collection, often known as rainwater harvesting, is an excellent means to offset some of your irrigation water usage from other sources. It’s also a simple way to collect and keep chlorine-free water to have on hand in case of restricted access to clean drinking water due to drought, a natural disaster or contamination.
The idea is straightforward: take rainwater from a downspout and use it for gardening, domestic water and other uses. However, not all harvesting systems are the same, nor do they suit every climate or purpose. Before you begin collecting rainwater, you should consider several factors to be sure you construct the best system for your purposes.
What is Rainwater Harvesting and Why is it Becoming More Popular?
Rainwater harvesting is the process of collecting rainwater runoff from roofs or other impervious surfaces for later use. The rainwater can then be used for various purposes such as watering plants, flushing toilets and even drinking.
One reason rainwater harvesting is becoming more popular is that it’s an easy way to conserve water. If you use rainwater for tasks that don’t require potable water like watering a garden, washing the car or other similar tasks you can reduce your water bill and be prepared with a backup water supply in the event of a drought. Additionally, rainwater is often cleaner and more natural than tap water since it doesn’t contain chlorine or other chemicals.
Are There Legal Requirements for Rainwater Harvesting?
There are no federal laws regulating rainwater harvesting, but there are some state and local laws that may apply. Some homeowners associations also prohibit rainwater collection due to the aesthetic of the tank conflicting with that of the neighborhood. In most cases, rainwater harvesting is allowed as long as the runoff is not contaminated with pollutants. It’s important to check with your local authorities to ensure you are in compliance with all applicable laws and regulations.
If you can believe it, California prohibited rainwater harvesting prior to 2021, but now the state allows it. The only caveat is that a license is required if the water is used for landscaping purposes. Most states encourage the practice and offer tax benefits for those who install a system.
Different Rainwater Collection Methods
Rainwater harvesting systems are available in various shapes and sizes, from basic rain barrels to more complex installations with pumps, tanks and purification methods. Which one you choose depends upon your setup, purpose for the water and how much water you want to collect. There are three main types of rainwater harvesting systems: roof-catchment, surface-runoff and subsurface-drainage.
Roof-catchment systems are the simplest and most common type of system. They collect rainwater from a roof using gutters and downspouts and then store the rainwater in a cistern or tank.
Surface-runoff systems collect rainwater from hard surfaces, such as driveways, sidewalks or parking lots using a system of pipes and filters.
Subsurface-drainage systems collect rainwater from soil using perforated pipes or trenches that channel the water to a storage tank or infiltration basin.
How Do I Know Which Rainwater Harvesting Method is Right for Me?
The best way to determine which method is right for you is to consult with a supplier that has experience designing rainwater harvesting systems for various applications, and can help you select the system that best meets your needs.
How Much Rainwater Can I Collect?
The amount of rainwater collected depends on several factors including climate, location and size of the catchment area. Generally speaking, you can expect to collect between 0.5″ – 2″ of rainfall per square foot of catchment area per hour. Since we are talking about home use, the catchment area is the square footage of your roof.
What Size Rainwater Collection Tank Do I Need?
The size of the rainwater collection tank you’ll need depends on the amount of rainwater you want to collect, the size of your catchment area and the rainfall intensity in your area. To calculate the size of the rainwater collection tank you’ll need, first determine the square footage of your roof, and then multiply that by the rainfall intensity (in inches per hour). For example, if you have a 1,000 square feet of roof area and the rainfall intensity in your area is 1″, you’ll need a rainwater collection tank that can hold 1,000 gallons of water.
Pros and Cons of Rainwater Harvesting
There are both pros and cons to rainwater harvesting. Some pros include water conservation, reduced water bills and a backup water supply. Some cons include the initial cost of installation and the need for regular maintenance in some cases. If you are handy with a few tools and can get up on a ladder without fear, then an above ground system could easily be a DIY project. Otherwise, you may need to hire a contractor.
Are Rainwater Harvesting Kits Available?
Yes, rainwater harvesting kits are available and can be a DIY project if you’re handy. These kits typically include all the components you’ll need to install a rainwater harvesting system, including a rain barrel, spigots, filters, diverter and a rainwater collection tank.
What is the Initial Cost of Rainwater Harvesting?
The initial cost of rainwater harvesting will vary depending on the size and complexity of the system. Simple above ground systems can cost as little as $298.00, while more complex systems, including the barrel(s), can cost upwards of $1,700.00. If you need to bury the storage tank, the costs would need to be adjusted for the excavation and additional plumbing required.
Ongoing Costs of Rainwater Harvesting
The ongoing costs of rainwater harvesting are much lower than the initial cost. The main ongoing cost is regular maintenance, which will vary depending on the size and complexity of the system. Accessories like spigots, adapters and filters may need to be replaced occasionally, but normal maintenance will usually involve a simple cleaning of the tanks, filters and diverter.
Tank Depot is the Premier Online Retailer of Rainwater Harvesting Tanks and Accessories
Tank Depot offers a wide variety of rainwater tanks and rainwater harvesting accessories, including rain barrels, rainwater pumps, rainwater filters and rainwater diverters. Contact us today for more information on rainwater harvesting kits and other water storage solutions.