Today, the husband and I attended a free rainwater harvesting workshop held at a local garden center. We wanted to learn more about this conservation method, since our last couple winters have been unusually warm and dry. If we purchase tanks this weekend, we’d get a 15% discount! Bruce, from Bushman, was presenting the information. He said when designing a system, it’s important to remember the four C’s – Catchment, Conveyance, Containment, and Consumption. Thankfully, he went into detail about each “C”. I took notes to help us design our system, and now I’m sharing them with you!

Catchment

Every 1 inch of rain on a 1000 square foot roof can collect around 600 gallons of water. That’s a lot of water! To determine how much you can collect per year, take the area of your roof and multiple it by .6 and multiply that by the average amount of rainfall in your area.

Here’s an example of how much water a home with a 1500 square foot, in a location that gets 20 inches of rain per year can collect.

1500 multiplied by .6 multiplied by 20 = a maximum of 18,000 gallons

The goal is to design a system to collect half of your maximum amount, so this “example” house could collect 9000 gallons!

Conveyance

He recommended any non-slim tanks should use a first flush diverter.  It conveys water from the gutter to the diverter, which keeps debris from going into the larger tanks, and that’s important because the tanks are so big they can’t be easily cleaned. At the end of the rainy season, you need to clean out each tank not using a diverter, and clean out any diverters on the larger tanks.

Containment

The size of tank to get is up to you. This decision is usually based on the amount of space available, and your budget. Keeping small, 60 gallon barrels near a deck or porch allows you to easily use that water for smaller, decorative plants. Slimline tanks are designed to fit under the eaves of your house and take up less space than large, round tanks. They need to be secured to a stable, permanent structure, similar to how water heaters are secured. Any of the tanks can be setup to run on drip systems. All tanks will need to be placed on a level surface with 3-4 inches of gravel to rest on. This keeps them from losing their shape while they are full of water. If you have sandy soil, concrete may need to be used instead of gravel. Tanks can be linked together to allow for more water storage from the same location. All Bushman tanks are for above ground use only. None hold over 5000 gallons, because anything bigger requires a permit in California. It’s important to check your states permit requirements before installing any rainwater tanks. Other manufacturers typically have a 3 to-6 year warranty on their tanks. Bushman offers a 10 year warranty.  They are made of a plastic that is UV resistant; however, they shouldn’t be kept in direct sun because they will deteriorate more quickly.

Consumption

Placement is important. If possible, try to have it near a source you wish to irrigate. If your tank is placed higher on your property, this makes a drip system an easier option. New fruit trees are an example of something  that consumes a lot of water, about 100 gallons every couple weeks! We have at least 12 established trees that need water, hopefully they don’t need that much water! There are two types of pumps: electric and solar. The solar pump can pump about 100 gallons at a time.

Maintenance

Gutters must be kept clean. The debris basket on the top of the tank needs to be emptied once a year. The first flush diverter should be rinsed every 4-5 years, and should be checked once a year. Their tanks have a stainless steel 20×20 mesh on inlets and overflows to prevent mosquitos and other pests from getting into the tanks. Once smaller tanks are is empty, it should be rinsed out. There should be no smell inside the tank at any time, whether it’s full or empty. If there a smell, something is wrong and it’s important to remedy the problem.

After hearing all this, we were pretty gung ho to get tanks! The discount was only good for the weekend, so we had to design our system quickly, and place our order by Sunday. My husband got right to work designing everything and came up with a great system. We placed an order for eight various sized slimline tanks, one 865 gallon round tank, and two 60 gallon barrels.  We even got an additional 5% discount because of our large order! Soon the fun of installing it will begin! Hopefully it will be ready before our first rain of the season!

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How do you conserve water?  Share your tips with me!