As strange as it might sound to talk about rainwater collection in San Diego, our arid climate is precisely why the subject is so important. Every drop counts, especially during “boom times” like El Niño. Whether you use collected rainwater for emergency storage or gardening, here’s a handy guide about how you can be water smart with few modifications.
Calculating Roof Runoff
The most efficient way to collect rainwater is from your roof. You probably already have rain gutters installed, which can be easily connected to rain barrels or water storage tanks. A single inch of rain on 1 square foot of roof area produces about 0.62 gallons of water. To find out how much rainwater you can feasibly collect in a year, you’ll also need local rainfall data. An easy resource that does the math for you is Appropriate Technology Projects’ Rainwater Collection Calculator.
You can collect rainwater from roofs made of nearly any material, including metal, asphalt shingles, clay tiles, and even cedar shingles. Gutters and downspouts can be made from aluminum or plastic, and they should be in good condition and fitted with screens to prevent large debris from entering the storage tanks. For roof collection areas up to 1,000 feet, a 5-inch-wide gutter and 3-inch-wide downspout are adequate, but larger roofs will need wider gutters and downspouts.
As for storage, the tank you choose will depend on average rainfall and what you plan to do with the collected water. Rain barrels come in either 50- or 65-gallon sizes and are great for gardening use. They are also typically available in a variety of colors and styles, including some available at San Diego Drums & Totes that look like terracotta pots and wine barrels. Many rain barrels also come with a reversible lid that can be used as a planter for herbs or flowers, adding beauty and functionality to their existing usefulness.
For emergency water storage, you will need something larger (at San Diego Drums & Totes, we have water storage tanks ranging from to 130 to 5,050 gallons). In the event of a natural disaster, large storage tanks can provide water if municipal supplies are affected. And considering San Diego County’s recent history with wildfires, anyone living in rural areas where firefighters don’t have ready access to water should invest in storage tanks that can be outfitted with pumps to spray down the roof and a protection zone around the house.
Other Uses for Collected Water
Aside from gardening and emergency storage, collected rainwater can be used for watering lawns, washing cars, pressure washing, deck cleaning, and refilling a hot tub. Another way to collect water is reclaiming greywater (all the water used in your household—except from the toilet—including sinks, showers, and washing machines). However, experts say that reclaimed greywater should be piped directly outside for use in gardens and lawns, and stored for no longer than 24 hours, after which time nutrients will begin to break down and create unpleasant odors.
Not sure which storage tank is right for you?
At San Diego Drums & Totes, we offer a full line of water storage tanks and accessories, as well as experienced professionals who can answer your questions and help you choose the right tank for your home. We even have equipment for greywater collection, so you can fight the drought by squeezing use out of every last drop of water. Give us a call or drop by one of our two locations, in Lemon Grove and San Marcos.