Rainwater Harvesting Beyond the Rain Barrel
When 55 gallons are just not enough or when you have more than 8 pots to water, a cistern may be in order. A cistern is a really BIG Water Butt and provides a little more flexibility than just being able to water pots. However, cisterns bring on a whole new set of problems like: aesthetics, neighbor’s opinions and loss of municipal revenues. When placed above ground they can make quite the architectural statement or in the opinion of the neighbors, be quite the eyesore.
Rainwater for Flushing Toilets
Here is a great green idea…let’s use water from the cistern to flush the toilets. Cool idea! Why use water fit for drinking for peeing and what not, but first the general public’s health must be protected. The water must be dyed blue so the public knows not to drink the water. (True story from a “green” grocery store in North Carolina, but who knows maybe they have an issue in the home of NASCAR with people drinking from the toilet).
Whew, now that the public health is safe what about the government’s welfare? Since sewer fees are based on consumption of potable water, the city is missing out on revenues! Solution: submeter the rainwater harvesting cistern to determine the amount of water flushed down the toilet so the city can collect the sewer fee and turn the rainwater clear again. As the saying goes, “No good deed goes unpunished.”
Rainwater for Irrigation
For larger sites where rainwater is used for irrigation, a subterranean tank is needed to store 1000’s of gallons of water so the irrigation system can be still be used in time of mild drought. An moderately sized irrigation zone uses approximately 200 – 400 gallons per cycle so an irrigation system with 12 zones sprinkles 2400 – 4800 gallons each day it runs. If the system runs 3 days a week, you can understand how large the tanks need to be to run the irrigation system just for a single week.
Alternatives to Cisterns for Rainwater Harvesting
New to the rainwater harvesting market is an item called a Rainwater Pillow (thanks Twitter @RainwaterPillow). While I have no personal experience with the product it appears to be pretty cool. Instead of using a traditional metal or wood cistern to store water the Rainwater Pillow is a large rubber bladder that can be placed under decks or in crawl spaces. There are several standard sizes available, but they can also be customized. They come complete with a filter and a pump. Again the ROI for rain collection does not make sense except in times of drought. During a drought harvested rainwater is not only free, it’s priceless.
What is your favorite rainwater harvesting solution?