Keeping Tree Root Intrusions Out With Geoscape Trees and Surface Cover Datasets

Trees are important in making a city attractive, healthy, and sustainable.

They benefit the environment by improving air quality, reducing stormwater runoff and reducing radiated heat from streets. However, as beneficial as trees are, when they invade water pipes, their roots can grow around and inside the pipes, causing damage and potentially leading to complete blockage. In fact, the most destructive problem encountered in a wastewater collection system is root intrusion into sewers. With the sewage system being one of the most important components of a city’s public health assets, this issue is extremely important.

Tree roots are a common cause of wastewater pipe damage, accounting for more than half of all blockages.

Why do tree roots intrude into the sewage system?

One of the primary reasons tree roots causes pipe damage is that sewer pipes and drains transport many sought-after “bio-rich” nutrients that fertilise and nourish the tree. When a food source is discovered, the tree instinctively searches for other leaks upstream and downstream from the initial break in the pipe or drain. Tree roots can enter small cracks in wastewater pipes in search of nutrients and then multiply. They take up more space as they grow, slowing drainage and contributing to overflows.

Sewer lines contain three essential elements for tree growth: water, nutrients, and oxygen. The extent of root invasion is determined by the sewer line’s condition, the type of tree, and the soil conditions in the root zone.

This causes ever-increasing damage, which is why it’s critical that the tell-tale signs of tree root damage in pipes are identified and addressed as soon as possible.

How to prevent tree root intrusions in sewer pipes?

To prevent tree root pipe intrusion, taking certain precautions, such as avoiding planting trees near sewer lines or underground pipes is important. To avoid further damage, trees that have already been planted near pipes may need to be removed or relocated.  If the tree is to be replaced, a species with a less vigorous root system is recommended.

In order to repair tree root-damaged pipes, extensive, inconvenient, and costly excavation may be required. Using a high-pressure jet or root-killing chemicals can be used to deal with tree root intrusion, however, care needs to be taken when using chemicals as they can be harmful to the environment.

The age and material of the pipes also play a role; older clay pipes are the most susceptible to root intrusion, but even newer materials such as reinforced concrete and plastic/PVC are not impenetrable. Critical factors include how well they were installed and how well the pipe segments are joined and sealed.

According to studies, service-connecting pipes typically have more root intrusions than main pipes, which have a lower sewer depth; however, roots in both connecting and main pipes were reported in nearly 50% of cases. Tree roots can enter services through leaking joints, deteriorated seals, and joints that have failed or become dislodged.

Result of tree root intrusions

Root intrusion into sewers is likely the most destructive problem encountered in a wastewater collection system, costing billions of dollars globally each year. Sewer stoppages and overflows, structural damage caused by growing roots, and septic pools behind root masses are all examples of root-related sewer problems.

Also, it is estimated that 15% of clean drinking water is lost through pipe cracks before it reaches households.

How Geoscape can help?

Geoscape’s Urban Trees solution provides the precise location of trees and with service pipe location data superimposed, the proximity of trees to pipes and the associated risk can be determined. In non-urban areas, Geoscape Surface Cover could be used instead of the Trees dataset.

Geoscape Trees is a national dataset representing tree cover and associated heights in Australia’s urban areas. It’s a raster dataset with a digital pixel representation of tree cover and heights at a two-meter resolution.

Geoscape Surface Cover represents different types of land cover in Australia. It’s a raster dataset with digital pixel representations of Australia’s various types of ground cover. The resolution is two metres in urban areas and thirty metres in non-urban areas.

For more information on Geoscape Surface Cover and Geoscape Trees visit here or contact our team.

Authored by – Stuart Hamilton​, Account Executive ‑ Data Solutions.