Monsoon season brings much-needed moisture to our Arizona deserts. Yet when rain falls on the roof or impervious paved ground, 80-95 percent of the water is lost as runoff flow, diverting a precious resource. Fortunately at Sun Lakes, our developers designed the roadside drainage so that our runoff feeds into our lakes where it can be gradually absorbed into the ground, sometimes flooding onto the golf greens if needed.
An abundance of desert adapted plants in your landscape helps to retain rain water, otherwise the runoff can be 80 percent for bare earth or clayey soil. You can minimize the loss of rain water from your yard by creating trenches, slopes and swales to guide the flow of water into landscaped areas. Retain any excess water by building berms around your trees or landscaped areas so that water will slowly seep down into the soil around your plants.
The roofs of our homes are an untapped resource in harvesting rain. For a house with a 1,500 square-foot roof, a half inch of rain will result in around 500 gallons of water flowing down from the roof! Thus, in a year’s time, this house could collect 7,000 gallons of water, assuming Phoenix’s annual rainfall to be around 7 inches. To assess your potential to harvest rain water, spend some time outside observing how the water flows from your roof during a rain storm. The simplest and least expensive way to harvest the rain water is to direct the roof water to flow toward your landscaped areas. If your roof has gutters, you can simply guide the downspout runoff to landscaped areas or to a storage tank for future irrigation.
Any rain storage tank should be capped to keep out mosquitoes, birds and animals and it should be kept in darkness to prevent algae growth. You can explore many creative options by doing an internet search. Even a large bucket or plastic drum strategically placed under the roof can collect enough water to wash your car or water a few plants by hand.
Brad Lancaster in Tucson, who has spearheaded an effort to harvest rain and transform his arid surroundings, provides extensive resources on his website at www.harvestingrainwater.com. Using cleverly designed storage tanks for rainwater, his group has transformed their community into a shadier environment that has cooled their neighborhood, produced native agricultural products and attracted different species of birds. Brad sets an inspiring example of how to work with our environment to create sustainable beauty and comfort.
Remember, for each half inch of rain that falls in your yard, you can skip one cycle of irrigation with your piped water. As a result your plants will grow better and you will save water from our aquifers.