Under the shelter of my porch, I watched as a gray squirrel corralled her three babies up a maple tree. The expression “like herding cats” came to mind, and I smiled at mama’s dedication and instinctual commitment to protect her young.
Within minutes, they scrambled up high into the maple’s branches and the family disappeared into the clump of leaves that served as their nest.
It was just in time. Seconds later, a thunderstorm crashed through releasing colossal quantities of water onto the unsuspecting woodlot. Yet the squirrel family stayed safe and dry beneath the green umbrella of the maple tree’s canopy.
Retain the rain
At some time in our lives, most of us have also retreated to the trees for the protection of their leaves and branches, attempting to dodge the drops when rain showers took us by surprise.
Indeed the canopy created by trees is incredibly effective at slowing the rate of rainfall, stopping drops “in their tracks,” and reducing the impacts of a hard rain.
While we appreciate trees for their shelter and their shade (among countless other benefits), rarely do we quantify the value that trees give us in this capacity. Often overlooked is the fact that trees also ensure cleaner water! More and more, however, the critical role of trees in storm water management (and municipal budgets) is soaking in.
Trees: At your service
Aside from keeping you dry in a sudden downpour, the collective action of tree leaves, branches, bark, and roots retains large volumes of water and provides amazing services. The tree’s “magic” works in the following ways:
• The leaves intercept and slow rainfall and also store and release water into the atmosphere through evapotranspiration.
• The roots increase infiltration and storage, reduce erosion by holding soil in place, and take up nutrients and pollutants from the soil and water.
• The leaf litter builds healthy soil, increases the soil’s water-holding capacity, and helps replenish groundwater.
Show me the money
While it is easy to place a monetary value on tree products, calculating the environmental benefits and ecosystem services that trees provide is much more challenging.
Fortunately, the U.S. Forest Service and many major partners have developed a state-of-the-art software suite that quantifies the structure of community trees and their environmental services.
Known as i-Tree, these tools enable users to easily and accurately find the dollar value of the benefits provided by urban trees and offer research-based guidance.
The i-Tree tools provide calculations on a species basis with consideration to many variables including seasonal conditions, storm durations, and geography.
To determine the annual benefits and storm water gallons retained by one of your trees, just enter the tree species, zip code, and diameter into the benefits calculator (see www.treebenefits.com/calculator/).
Depending on the tree species and size, a single tree can store 100 gallons of rainfall or more, until it becomes saturated after a one to two inch rain event.
That sugar maple tree where the squirrels live, for example, has a diameter of only 12 inches but can intercept as much as 1,100 gallons of storm water every year. Now zoom out from that single tree and multiply all of the trees in a community… and the amount of rainwater captured and filtered increases significantly.
In fact, an urban forest can reduce annual runoff by an estimated 2-7%. Studies have shown that when trees are combined with other natural landscaping like native plants, the amount of storm water runoff in residential developments decreases by 65%.
Drop by drop retention amounts to significant dollar savings when trees are incorporated into community storm water management. The reduction of water running through our storm drains and ditches after a storm results in less expensive infrastructure needed in our communities and ultimately cleaner water reaching our rivers and lakes.
Make this your year to “branch out” by learning more about the trees in your yard and around you. The Geauga Soil and Water Conservation District (SWCD) along with five other districts in northeast Ohio are “Taking Root for Clean Water!”
This initiative promotes the use of trees and native plants for storm water management, nutrient reduction, and improved water quality throughout seven contiguous counties.
As part of the Northeast Ohio Public Involvement and Public Education (NEO PIPE) work group and with the help of a grant through ODNR Division of Soil and Water Resources, this project will include tree plantings, publications, and a special regional event from 5:30 p.m. – 8 p.m. Sept. 26 at the West Creek Reservation in Parma.
All are invited to Cleveland Metroparks’ brand new facility showcasing urban watershed stewardship techniques.
Participants will learn about countless benefits of native plants and trees and how communities are incorporating trees into storm water management. Explore tree species on a guided hike and see how this living laboratory demonstrates real-world solutions for storm water and pollution control.
You can also join Geauga SWCD and Geauga County Master Gardeners to learn about a variety of tree topics from backyard landscaping to tree maintenance by attending More Trees, Please from 10 a.m. – 12:30 p.m. Oct. 12 at the West Woods Nature Center in Novelty.
For more information on any of these programs, visit www.geaugaswcd.com or call 440-834-1122 ext. 2.