Why Collect Rainwater?
Individuals and businesses may collect rainwater to supplement the water they access through taps from their municipal system. Whether the motivation is to reduce their environmental footprint or to save on their water bills, homeowners and small business owners may use the water they’ve collected to irrigate landscaping, wash vehicles, keep dust under control, etc. They may also use good quality rainwater indoors to flush toilets or do laundry. Rainwater can also be filtered and disinfected for use in potable applications like cooking or drinking.
Is it Illegal to Harvest Rainwater?
Despite many rumors to the contrary, the Federal Government does not restrict rainwater harvesting in any way and most states not only permit rainwater harvesting, but most actively encourage it. A few more (including Florida, Delaware, and Rhode Island) even offer incentives such as tax credits to encourage rainwater capture. In some states, harvested rainwater is approved only for non-potable or outdoor uses, while others limit the amount that can be stored. Both Arkansas and Illinois have specific construction and permitting statutes that must be followed, but there is no state in the US where it’s entirely illegal to collect rainwater.
If you’re considering setting up a rainwater collection system, odds are that you’re in a good situation. Do some research on your state and county, or even call up your local county extension agent. Chances are, you’ll get helpful information, useful tips, a list of best practices, and maybe even some information about tax credits and rebates for equipment you purchase.
Is it Possible to Harvest Rainwater in Freezing Weather?
Yes, but just like your plumbing, some components of a rainwater harvesting system such as pumps and pipes, are vulnerable if water is allowed to freeze in them. If you live year-round in an area with long, cold winters, the best solution is to install your system below ground (and below the frost line). At that depth, freezing temperatures won’t cause problems to your system.
If you’re expecting an unusually cold winter but your system is above ground, there are still a few measures you can take to keep your system operating. First, add an aerator to your tank. The flow of bubbles will keep your water moving constantly so it doesn’t have a chance to freeze.
Next, use a heat pump to circulate hot water through your system to keep the pipes from freezing. Make sure there is no standing water in any of your pipes and be sure that both the heat pump and its supply line are always kept above freezing.
What’s the Best Way to Harvest Rainwater?
The simplest and cheapest way to start harvesting rainwater is to set up a purpose-made rain barrel or two. If you don’t want to purchase an actual rain barrel from the local home improvement store, 55-gallon plastic drums are inexpensive and easy to find. If there’s any chance that you’ll be using your harvested rainwater to provide drinking water for pets or livestock, it’s worth picking up a food grade or, even better, a potable grade drum. If you’re converting a regular drum, there are rain barrel conversion kits you can use to install a spigot, secure connections to your downspout, a diverter, etc.
Unless you’re using a very small barrel to collect water, you’ll need to build a solid, stable base for the barrel to stand on - one that will prevent your container from sinking into the ground or tipping over. The platform can also be used to raise your barrel above ground level, giving you enough water pressure to easily fill small containers.
Once your rain barrel is situated and connected, it’s time to check the weather for your next rainy day. The rain you collect is suitable for use to water your lawn and landscaping, wash your car or your pets, or flush your toilets if you have a graywater system. Any uses that involve drinking, cooking, or even washing fresh produce will need to be filtered and disinfected before it’s considered safe.
What Are the Benefits Of Rainwater Harvesting?
- Once your system is set up, rainwater can be a great source of free, relatively clean water that you can use to supplement, or replace your dependency on municipal water.
- If you live in a city with water restrictions, your carefully harvested rainwater could mean the survival of your prizewinning lawn.
- Rainwater harvesting is a great green effort to boast about to your environmentally and socially conscious neighbors.
- Since rainwater isn’t chlorinated, it’s often healthier for gardens and landscape plants.
- Capturing the rainwater that runs off your roof can solve drainage problems on your property.
- The rainwater you capture is removed from the flow of municipal stormwater which can severely damage local surface waters. Your favorite fishing spot will thank you.
- When rain shows up in the forecast, you can celebrate a bountiful harvest rather than being bummed by the gray weather.
Is Rainwater Safe to Drink?
Rainwater is widely considered one of the safest and cleanest sources of water around, but it’s impossible to say with any certainty whether your rainwater is safe to drink. It’s important to consider where the rainwater was collected from. Some roofs are made of or contain toxic materials (asbestos shingles, lead roofs, etc.). In urban environments, your roof may be covered with tiny particles from smog and other heavy pollution that could include heavy metals, chemicals, and oil and gas residue. Even in rural environments, your roof may have bird droppings, feces from squirrels and other rodents, and various dead insects or other bugs.
If you manage to collect rain directly as it falls before it contacts any surface, you’re in pretty good shape, but then you need to consider how long it has sat there. Water that’s exposed to the open air over time is going to pick up whatever types of contaminants settle on the surface or splash into it. Fairly pristine rain barrels can host colonies of mosquito larvae or algae - and those are just the organisms you can recognize. Who knows what else could have moved in?
How Do I Provide Pressure for My Rainwater?
Rainwater systems can take advantage of gravity to provide pressure for water delivery within your system. It’s the same principle as those tall water towers that provide water pressure even in large cities. The higher your storage tank (rain barrel, cistern) sits, the more pressure it will provide. If you know how much PSI you need for a specific application (like a filtration mechanism), you can run a quick calculation: for every foot of elevation of your water, you increase your water pressure by a factor of 0.43 PSI. If your water tank is 1 foot above ground, you’ll have 0.43 PSI. A 5-foot elevation will give you 0.86 PSI and so on. This doesn’t mean you should go overboard, though. If you place your cistern above the lowest level of your roof collection area, you won’t be collecting any rainwater, since gravity doesn’t make water flow uphill.
If site logistics or the layout of your home do require you to move water uphill, or if you need extra oomph to operate a lawn sprinkler or to push water through a UV filtration & disinfection system, for example, that requires adding a pump to your storage tank. You can choose a submersible or surface pump, but the size depends on how much PSI you’re shooting for. A friendly conversation with a knowledgeable salesperson at your local farm and tractor supply or home improvement store should help you find what you need.
