Irrigation System Blow out

We spent yesterday blowing out the irrigation system for the winter.  The timing is based on our potential water needs and the onset of winter.  We were at a substantial deficit until the 4" of rain came last week. 
We use a very large compressor that sends a column of air through the system while we operate our control boxes and turn on a few heads at a time until only air comes out of the head and we then move on to the next set of heads.  The rain in the middle of the afternoon made for a miserable last couple of hours of work but what else can you do during a rain storm but blow out irrigation.  Final steps in winterizing the system will be to break down the pump station.  We have heat for the pump house but this is a preventative measure in case the heat would go out for an extended period of time due to a power outage or heater failure.  By program alone, we ran about 3.2 million gallons of water from October 1st until shutdown which is a lot of water for this time of year.  Our water budget for November took a pretty good hit due to the extra water requirments.  We had a couple tons of seed in our rough we were trying to keep alive, trees were pulling any available moisture from our rough and we were keeping some moisture to the zoysia as it was going into dormancy.