Rainwater usage update & analysis

At the beginning of October I reset my flow meter to zero.  I wanted to measure exactly how much rainwater I used in one month.

The result?  I used 607.7 gallons. That was for flushing a toilet, washing cars, and watering the lawn.  I wanted to use up what I had in the barrels.  Good thing I did too, because it went below freezing in the first week of November.

My sophisticated gauge showed that my barrels were empty on November 2.  I used a shop vac to remove the inch or two of water that was left in the bottom of each barrel.  Then I disconnected the hoses from the pump and briefly ran it to get any remaining water out.

So what are the results? 

I've been saving my water bills for the last few months.  I think the results are inconclusive.  The bills range from 28 to 34 days so I can't compare total gallons used.  Thankfully the water company is kind enough to list the average daily usage.  They even include a handy-dandy graph.

My average daily water use for my August bill (July 08 to August 05) was 125 gallons.  I ran rain water to my toilet on August 13.  I expected to see a drop in water usage on the next bill.  But it hardly made a difference.  My average daily usage for my September bill (August 05 to September 08) was 123 gallons.  My usage dropped only 2 gallons per day!

The October bill is where things got interesting.  It ran from September 08 to October 07.  My daily average usage for it was 100 gallons.  That was a big drop.  I have no explanation as to why.  My most recent bill (October 07 to November 07) average usage was 119 gallons.  That was with the toilet back on the house water for the last 5 days of that billing cycle. 

I don't know what to make of these results.  I was expecting to see fairly significant (5-10 or more gallons per day) drops in my water usage, and I only saw that during one month.  It hardly made a difference in the other months.  I can say that my bills would have been higher without the rainwater.  I'll certainly keeping an eye on this next year.  It'll be interesting to compare those graphs year-to-year.