I recall a few years ago an appraiser making fun of my listing. He thought it was absurd a farmer would install sprinklers that spouted underground or some such way. He was pretty derogatory about this description.
He did not understand what the word meant, and I imagine many city people moving to the country to enjoy the rural lifestyle also do not understand that term. It is both cause for rejoicing and cause for concern.
What causes sub-irrigation? Typically, this results from an impervious layer of rock or clay fairly close to the surface. Ground water flows to the bottom of the ground then hits this layer and can go no further, or seeps downward very slowly. This results in the ground being “irrigated” from this collected water when normally, it would have dried out. In much of Williams Valley which is just west of Deer Park in Eastern Washington, you can dig a hole in the ground in late August and within ten feet hit water.
So, what is good about this? Obviously, you can really grow a lot of grass and other agricultural crops. Again, check to be sure what you grow is compatible with the water level in the ground. That is a good subject for another discussion and I am not going to go there now. But, if you are driving around a rural area in the late summer and there has been no rain for a month or two, look for nice, lush green growth. You have probably located a sub-irrigated field.
So, What is bad about this? Two things come to mind.
Basements. You may want to think twice about putting a basement in your home or be very careful if buying an existing home with a basement. If the home does not have a sump pump, you may need to install one later. Expect drainage issues. A killer? No, just be aware and learn how to work with it. Especially if you are building. Make sure to factor this issue into the construction equation.
Septics. Septic systems work on two equations, drainaige and evaporation. In our area, we need about six feet of drainable land before hitting an impervious layer. When your six foot deep perk holes rapidly fill with water, you have a problem. Again, not a killer, just plan to spend extra money on your septic system. If you are buying raw land and it is very green in the very late summer, you better include a perk test as part of the contingency. Know what you are dealing with. That is the key to success.
Sub-irrigation is a real state and like most things in life, it has both good and bad wrapped up in the equation. Also, like most things in life, do your research before you buy, not afterward.
Call Dave Atherton to Buy or Sell or talk real estate. (509) 216-4985. DavidWAtherton@gmail.com MyCountryhomes.com