Protect Your Rainwater System
by Doug Pushard
There is nothing worse than spending time and money planning and installing a valuable asset and then having it destroyed or break due to lack of maintenance. Kind of like going to the dentist and having a tooth pulled because you didn’t floss.
In an earlier article I discussed tanks freezing and what can be done to prevent this from occurring. In this article, I will discuss the other elements of a system and what can be done to prevent them from freezing.
In Northern New Mexico and many parts of the upper states, above ground cisterns and any exposed parts are very susceptible to freezing. This needs to be part of the consideration when you are planning or maintaining your system. What parts could potentially freeze during a hard freeze and what can be done to prevent this? Metal parts are going to freeze more quickly than plastic parts. Additionally, metal is less flexible than plastic so is more likely to get damaged by freezing.
When planning your system, minimize the amount of exposed metal. With pumps an easy way to do this is to make the pump easily removable. This makes it possible to be taken out of the system in the winter. Alternatively use a submersible pump which in the water is not likely to freeze in larger above ground or below ground systems. If it is a small above ground tank (i.e. less than 1,000 gallons) and located on the north or shady side of the building, the tank will need to be drained. Removing the submersible pump from an empty tank is always a good precaution.
The second most common item that freezes is the backflow preventer. These devices are required by plumbing code if the system is going to be connected to a potable water system. These devices are metal and need to be drained and exposed to air during periods of hard freeze. If not all the water is drained out of these devices they are highly susceptible to freezing and cracking.
Lastly exposed piping from your tank either to your irrigation system or from the tank to the pumps or valves that should be deeply buried. If it is not possible then these connections should also be drained in the winter.
Insulation will work in milder years to slow down freezing, but will not prevent it. Heat strip tape, sold at most plumbing and hardware stores, are an alternative if it is not possible to fully bury or drain exposed parts. Make sure to buy only heat tape that can be exposed and that turn on when the temperature falls below about 40 degrees so not to waste energy when not required. With many of the outdoor heat tapes it is possible to wrap the exposed parts and then insulate over the tape. These tapes are plugged into a standard outdoor GFI-protected outlet.
If year-round water is required, it is best to plan the system with an underground cistern and as many components indoors or sufficiently underground to minimize freezing. Deeply buried will not always work. In years experiencing really cold periods or hard freezing lasting for extended periods even municipal water meters will freeze and these are buried and insulated at greater than 3 feet. If not sure on how deep to bury your tank, find out the Air Freezing Index (AFI) in your area from your local building officials or get it from the HarvestH2o Site Analyzer.
Heat tape or temperature triggered heaters are a great precaution if year-round water access is required. If year round water access in not needed, winterize your system. – Draining what can be drained and covering the rest, these are prudent actions to take. You have invested in rainwater system, so maintaining it properly will ensure your system is not harmed. Don’t pay for something you could have avoided!