How Trees Prevent Urban Flooding & Runoff

Recent climate changes have made it clear that no community is free from the threat of severe weather. In high-density urban communities, storm damage like flooding can be particularly problematic. While there are many tactics that can be used to address urban flooding and runoff, one important but often overlooked solution is strategic tree placement.

How Do Trees Prevent Flooding and Runoff in Urban Communities?

Trees have compelling advantages for urban environments, including increased shade and noise control. Of course, tree-lined avenues also add beauty and visual interest to communities, helping to restore a natural element that balances out heavily developed areas. Beyond these perks, however, trees can also offer some “re-leaf” during heavy rains.

In natural watersheds, streams and rivers offer a place for runoff water to go, which helps to control flooding. Yet, most urban communities lack these natural features and instead rely on drains, gutters, sewer pipes, and other manmade infrastructure. While these features can redirect storm water to some degree, heavy rains can overwhelm these systems and lead to urban flooding. This is complicated by the fact that concrete and asphalt prohibit the ground from soaking up water.

Trees can be an effective and economical solution for cities looking to control rainfall, as their canopies and root systems can manage runoff in several ways. For one, their leaves capture falling rain, creating a surface area where water can land and then evaporate. In fact, their canopies can intercept as much as 50 to 60% of rainwater (thousands of gallons a year), helping to prevent the flash flooding effect that often takes place in urban communities.

Tree roots also soak up water that enters the ground, keeping soil in place and reducing erosion. Both tree roots and the soil surrounding them have a sponge-like effect, allowing water to slowly seep into permeable surfaces and minimize the demand on storm water drains.

What’s the Best Approach to Using Trees to Control Flooding in Urban Communities?

Using trees for flood prevention does require some careful planning. There are several factors to consider, including:

  • Soil composition
  • USDA hardiness zone
  • Tree species
  • Space limitations
  • Maintenance needs
  • Exposure to pollutants like chemicals and salt
  • Access to shade and sunlight

While finding the perfect trees calls for attention to detail, for urban planners, the payoff may be well worth the initial effort. From amending the soil to strategically choosing the right tree species and placement, navigating these steps properly could yield meaningful results — including up to an 80% greater reduction in surface water runoff compared to asphalt alone. As always, native trees will have the best chances of thriving. The American Sycamore and Eastern Cottonwood are some of the trees in Georgia which can help with drainage. But there are a variety of other species which your local tree expert can help you select.

Of course, prolonged exposure to standing water can also take its toll on trees. Dealing with dead or downed trees isn’t ideal in urban environments either, so while trees may help to prevent flooding, they shouldn’t be planted directly in the heart of flood zones. The right tree placement can make all the difference in helping urban trees thrive.

Tree planting and maintenance don’t have to be complicated, but they can be made easier with some professional help. Whether you have a problem tree or you’re planning a new project, consult Premier Tree Solutions for assistance. Learn more about our services or call 404.252.6448 to get in touch.a

Controlled Burning and Trees

Too many recent news stories have shown us just how devastating forest fires can be. From our neighbors to the north who have seen wildfires spread across millions of acres of Canadian land, to Maui’s heartbreaking loss of life and property, the force of these natural disasters is all too familiar. In an effort to maintain the safety of at-risk forests, controlled burning is sometimes used as a fire prevention method.

What Is Controlled Burning?

Also sometimes referred to as prescribed burns, controlled burning is a planned, low-intensity fire that aims to remove hazardous fuel such as low-growing vegetation. In doing so, these fires can help stimulate regrowth and reduce the risk of high-intensity, high-heat fires that might otherwise devastate landscapes.

There are two types of prescribed burns commonly used:

  • Broadcast burns, which involve lighting fires across a designated space
  • Pile burning, which entails the individual burning of multiple stacks of vegetation in a specific area

Pile burning is often used when broadcast burns are considered unsafe due to risky conditions, such as drought. In this approach, debris is cut, accumulated, and prepared for safe burning when weather permits. Oftentimes, dead trees and fallen branches are also used as materials to assist in the process. While prescribed burning can possibly kill shrubs and small seedlings, most mature trees can withstand the impact of these controlled fires.

How Is Controlled Burning Performed?

Before a controlled burn is initiated, a detailed plan is put together. This outlines the overall size of the fire, what it will burn, and what will be accomplished. Weather and environmental factors are included, as well as meticulous contingency plans should any areas of the fire need to be extinguished. Details also include how the fire will be set and managed, including smoke control, and how and when the public will be alerted.

Prescribed burns are performed all across the U.S., with thousands taking place every year. More than 99% are performed successfully, but naturally, all fires come with inherent risks. That’s why it’s critically important for everyone involved with controlled burns to follow protocols precisely.

In rural areas such as Georgia’s forests, prescribed burns can be an effective way to prevent uncontrollable fires. Yet, even when performed on your own land, you’ll still need to acquire a burn permit from the Georgia Forestry Commission before performing a controlled burn. You’ll also want to familiarize yourself with the best practices for performing controlled burns in southern ecosystems from the U.S. Department of Agriculture. This will help you when developing your written burn plan, which should include:

  • The burn unit’s boundaries
  • Information about the adjacent land parcels and their owners
  • Topographical details
  • Control lines
  • Anticipated direction of the smoke
  • Smoke management strategies
  • Weather factors
  • Burning techniques and fuels
  • Smoke sensitive areas

There are several other important factors to consider when formulating a prescribed burn plan, including vegetation, soil, wildlife, human welfare, and air and water quality. Weather conditions are one of the most critical aspects to monitor. Ambient air temperatures should be 60 degrees or lower for wintertime burning, or 80 degrees or higher for burns performed during growing seasons, and relative humidity should be between 30 to 55 percent. Winds that are low in speed and consistent in direction are also important for ensuring the fire remains controlled.

With so many variables to consider, many land owners turn to experts from the Georgia Forestry Commission when pursuing a controlled burn. While these professionals can’t actually ignite the fire themselves, they can consult with you on every aspect of the controlled burn to mitigate risks to the greatest possible degree.

Minimizing the risk of forest fires is an important aspect of being a responsible land owner, and caretaker of our environment and community. Removing dead or at-risk trees can also help to keep your property safe. Premier Tree Solutions can help you with every aspect of tree care, from root to bud. Contact us by calling 404.252.6448 or by sending us a message online.