Trees & Underground Utility Lines
Hidden away beneath the soil, roots quietly go about doing their job. They anchor immense trees firmly against the wind, serve up vital water, and pry loose essential elements from the soil.
Most of a tree’s roots lie less than 8 to 12 inches below the surface, and they can grow outward to a distance one to two times the height of the tree.
Unfortunately, when trees grow in cities and towns, they must also share limited space with underground utility lines. In these crowded conditions, they live under constant threat of disturbance from utility installation or repairs, new lawn sprinkler systems, and any other activity that requires digging.
Why Tunneling and Careful Trenching Can Save Trees
Trenching near a tree can kill as much as 40 to 50 percent of the tree’s roots. This will almost certainly lead to stress, poor tree health, lack of firmness against wind, or outright death. A tunnel in the same place can preserve the tree’s roots, with no resulting damage to the tree.
When tunneling is not an alternative, the route of a trench can be altered to miss tree roots, or avoid as many of them as possible.
Homeowners should call “blue stakes” or “diggers hotlines” when digging in the vicinity of underground utilities.
Know Where Roots Really Grow
Roots spead where soil conditions allow access to soil nutrients, air and moisture. This results in about 85% of a tree’s roots being in the top 18 inches of soil, with the majority within one foot of the surface.