In the spring of 2012 we installed three 500-gallon cisterns on our property. For the recap read Starting with Cisterns and Installing Cisterns. The goal of this project was rain water collection for use outdoors.
In the figure below you can see that our city water use is typically low in the winter and rises during the summer months as it stops raining and we draw more water for our extensive gardens (grey bars).
Every summer in the Pacific Northwest is the same in that it rains infrequently. And every summer is unique in the particular pattern of that drought. In 2012, summer did not arrive until July, but then we had 83 days without any (appreciable) rain. One day with 0.01″ rain and 82 days with no rain.
So how did we fare? We did not finish installing the cisterns until May, so we started the summer with approximately 1000 gallons of stored rainwater. That water exclusively fed the gardens during June, July, and August. In September we ran out of stored water. But it was not raining yet and the garden still needed to be fed. Thus city water usage rose in September.
Now, you can’t help but notice the October water use is high. Like really high. That may be explained by house guests. We had them in the spring and then sequential 24-7s in September and Oct. The Oct guest was visiting for several weeks from the tropics. You know what that means – many showers, both for custom and warmth.
Take Home Message: I am pleased that our summer city water use reflects the use of cisterns until September! In 2013 the cisterns will be full when summer starts, so they should take us further into the summer. And we’ll try to keep those house guests to a minimum to get a more ‘normal’ water use history for comparison!