The value of protecting a sprinkler system from freezing
Freezing weather will damage certain parts inside the backflow device on your sprinkler system. (The back flow is the pipe like apparatus located on the side or rear of your house) Those parts are designed to give way when the water in the backflow freezes, which protects the metal housing from rupturing and adding to the repair costs.
When those parts are exposed to light freezing conditions, they may not fail at the time, but they are weakened. Slow leaking from the backflow is a good indication the parts have been compromised. Once those parts are compromised by light freezing events, they are candidates for failure at the least suspected times.
I had the occasion to complete a repair where this was the case. The parts had been previously weakened by freezing and finally failed in September. When the parts fail, the result is an unbridled flow of water at the backflow.
If the homeowner is away when it occurs the water lost can be significant—something like ten gallons per minute. If there is a window well nearby, the water will flood the basement. Nothing good happens when water flows unchecked.
Denver can have freezing weather on any night in October. The first average freeze is October 7; however, in 2005 the first freeze occurred on October 5.
A homeowner can prevent these events by deactivating the system prior to the first freeze. If one wishes to extend the watering season, then the backflow should be wrapped with a towel for insulation and covered with a plastic bag. Use duct tape to seal and secure the bag to the backflow.
Do not extend beyond the first week of November or the system will likely be damaged and require expensive repairs.
Some may be concerned about the lawn receiving adequate water if the system is shut down early in the month. Because the days are shorter and the nights cooler the evaporation rate is low, and lawns require much less water as compared to the summer months. A lawn will do simply fine without the sprinkler system in October.
Be prudent and deactivate early or wrap the exposed pipes until the system is shut down.
|Earliest Date of First Freeze|
|September 8, 1962|
|Latest Date of First Freeze|
|November 15, 1944
|Average Date of First Freeze|
|First Freeze Recent Years|