Phoenix averages 8 inches / 200mm of rain per year. It is extremely erratic. Some years we get very much more, and some years very much less. About 60% falls in thunderstorms during the summer monsoon; the remainder as gentle winter rains that blow here a day after southern California gets them.
I collected almost 300 gallons / 1135 liters in the one storm at my house so far this summer. Usually we have 4-6 summer storms, but not this year. I collected rain from two of four runoff points from my roof.
It looked as though it would rain last week so I put stock tanks under all 4 runoff points. No luck.
In a good storm I can collect 900 gallons of rain in 10-15 minutes. It sometimes comes down so hard you can't drive a car because the wipers can't keep the windshield/windscreen clear.
I have about 20 gallons left from the winter rain I collected. Most of the other barrels are full of summer rain, or empty. I clean each barrel with soapy water as I empty it, and set it ready to fill when we do have more rain. Whatever rain I collect in excess of that needed to fill all the barrels goes into the outdoor pond to reduce the salinity.
The photo faces south along one of three entries to my neighborhood. The road dips into a normally dry desert wash. This was taken in September 2014 about 3 hours after the rain stopped. If you enlarge the photo you will notice the water was above the crown of the road on the far side of the wash, and the place I stood to take this was also under water.
Linear Mode
