Collecting your own rainwater is an excellent way to conserve this precious resource. A basic rainwater collection system catches rainwater from your roof or other surface and channels it into a container for storage. Rainwater itself is generally clean, but it can pick up microorganisms, pollutants and debris when it hits your roof. This is why systems for rainwater use inside your home often include filtration or other treatments for safety.
Outdoor rainwater collection systems don’t need as much treatment because the water is typically used outside. One of the easiest rain collectors to make is a repurposed old garbage can. Whereas, you can install a rainwater cistern if you want a larger system. There are many different uses for collected rainwater no matter what type of rainwater harvesting system you have.
1. Drinking and cooking
Rainwater can actually be very high-quality water for human consumption. It’s relatively pure and doesn’t contain any chlorine or other chemicals, which are often used to sanitize city tap water. The problem starts when rainwater is collected from roofs or other dirty surfaces. You can make rainwater safe to drink by installing a filtration system, boiling or distilling the water. Some systems can also directly collect clean rainwater to use for drinking.
2. Bathing and laundry
Washing clothes accounts for about 22 percent of indoor water use in the United States. Showers take 17 percent, and baths 2 percent. If you used harvested rainwater for all of these, you could reduce your municipal water use by over 40 percent. Depending on how clean you want your washing water, you could use either treated or untreated rainwater. SFGate has some suggestions on how you can treat rainwater to use for showering.
3. Flushing toilets
This is another huge water drain. Toilets use almost 27 percent of water in your home. To use collected rainwater instead, try keeping a bucket of it next to your toilet. When you need to flush, pour the rainwater straight into the bowl of the toilet. This will automatically flush your toilet. Make sure your bucket can hold the amount of your toilet’s tank. For instance, if you have a toilet with a 6 gallon (22.7 liter) tank, use at least a 6 gallon bucket of water
Another option is to plumb a pipe for rainwater directly into your house and connect it to your toilet for flushing. Check out a very low-tech method to do this.
4. Watering lawns, gardens and houseplants
Rainwater is naturally designed to water plants, and it can easily be used for your indoor and outdoor gardens. You can use rainwater in watering cans to water plants by hand. You can also attach any rainwater storage tanks directly to an automatic irrigation system.
Passive systems to conserve and collect water in your soil are also helpful. Plant garden beds along the edges of your driveway, or at the bottom of a hill, to take advantage of water’s natural movement. Also, try planting a raingarden at the ends of your eavestroughs to catch any excess runoff.
Water is essential for proper decomposition of your compost pile. Make sure you water your compost with the rest of your garden. Harvested rainwater is also good for compost tea. Home Composting Made Easy describes a simple way to make compost tea.
6. Water for wildlife, pets or livestock
You can use recycled rainwater for birdbaths, troughs, or other containers for wildlife to visit. Rainwater is also typically safe for pets or livestock to drink or wash in, especially if you have a method to collect clean rainwater directly.
7. Outdoor ponds and water features
Rainwater can be filtered for use in fountains or other water features with pumps that could get clogged. Otherwise, you can fill outdoor ponds and pools with any type of collected rainwater.
8. Rinsing vegetables
Dirty rainwater is great for rinsing vegetables straight from your garden, especially root vegetables. Try filling a large bucket with rainwater, adding some carrots, potatoes, beets or other hard vegetables, and swish them together to knock the soil off.
9. Washing vehicles and equipment
Washing outdoor items is another excellent use for untreated rainwater. Cars, garden tools, lawnmowers, tractors and even the driveway and sides of your house are all perfect candidates.
10. Fire protection
A rainwater catchment system with a large storage tank could give you some extra protection if you live in an area prone to wildfires. Make sure you also install a good pump so you can access the water quickly if needed.