How close to an earth fissure can I build a home? State Geologist Lee Allison says even a mile away is too close because there’s no way to tell when a tiny fissure will open into a big gulley, or how long that gulley will spread.
His advice to home buyers:
- Find out if the property you own or the land you’re thinking about buying contains a fissure. Go to the Web site of the Arizona Geological Survey’s Earth Fissure Center (http://www.azgs.az.gov/EFC.shtml). You’ll find maps there that show where some of the state’s fissures are located. The Arizona Geographic Information Council (http://www.agic.az.gov/) soon will post an updated map that shows every known fissure in Maricopa, Pinal, Pima and Cochise counties.
- If you want to buy a home, study the seller’s real estate disclosure form before signing a contract. The owner has to reveal whether there are fissures on the property. If the owner doesn’t know, have a soils expert inspect the property before you buy.
- Avoid building or buying a home on a fissure, even if it looks like only the slightest crack in the earth. There’s no way to tell when or even if it eventually will open up and swallow whatever is sitting on it.
- Build or buy your home as far away from a known fissure as possible. Even if the obvious signs of a fissure are a mile away, that crack could extend underground for a long way. If a monsoon downpour caused it to grow from a crack to a gully, it could open up on the property around it.
- If there is a fissure on your property, keep it dry. Water is the catalyst that turns tiny cracks into huge gullies. Don’t irrigate your lawn. Direct the runoff from downspouts in another direction.
