A Safe and Beautiful Right-of-Way. Part 2.
This post is the second in a two-part series, where we explore the important role right-of-ways can play in supporting community, native species, and growing a healthy urban forest.
If your daily commute involves standing on a hot sidewalk waiting for the bus or Link, or walking several blocks without shade, you are probably glad that the hot summer days are ending. Unshaded sidewalks, where temperatures can be 10-20 degrees hotter than on shaded sidewalks, are a health hazard–and they are very common in Tacoma. This is due to the city’s low tree canopy coverage, the lowest in Western Washington. Tacoma’s low tree canopy is due, in part, to lacking public plantable space.
Our work at TTF is informed by the 2018 urban tree canopy report, an analysis of the city’s plantable spaces. As of 2018, there are 6406 acres of existing urban tree canopy, 16344 acres of impervious (non water absorbing) surface, and 4064 acres of possible planting space. The majority of the plantable 4604 acres are on single-family residential properties, which means that property owners play a critical role in Tacoma’s goal of reaching 30% tree canopy coverage by 2030. Trees planted in any location, private or public, are important for moving us towards our goal. But planting street trees–trees along the sides of roads or on sidewalks–increases public access to green space: street trees mean more residents can access the health benefits of trees.
Street trees are critical in achieving tree equity across the greater Tacoma area, but planting them comes with special challenges.
Ensuring our street trees live long and healthy lives in urban areas involves considering planting restrictions due to under and above-ground utilities, the size of available planting space, soil health and compaction.
What is the right-of-way and why does it matter?
The space where street trees are most commonly planted is called the right-of-way or ROW. In simple terms, the ROW includes the impervious surfaces–street, sidewalk, compacted gravel–and grassy areas that sit between the road and private property. All trees considered street trees are planted in the ROW. However, the exact boundaries of the ROW are more nuanced than this. The word “easement” is often used to define the ROW. The legal definition of easement is “a right to make limited use of, or enjoy a specific benefit from, a piece of land belonging to another.” It is also defined as “something that provides ease, comfort, benefit, or assistance.” In sum, the ROW or easement exists as part of the space allotted to the public for travel around the city. And it is also there for the public’s comfort and benefit.
Where exactly the ROW begins and ends can be confusing. The City of Tacoma defines the public ROW as an easement over the land of the adjacent property owner that includes:
the traveled portion of public streets and alleys
sidewalks
planting strips
traffic circles
medians
The City defines the boundaries as “streets and alleys extending from the owner's property lines out to the curbs or edges of pavement […] and out to the centerlines (see Figure 1 below). The centerlines are the lines or pavement that divide traffic lanes moving in opposite directions.
Figure 1: City of Tacoma, Urban Forestry Program, ROW Example.
Generally, these public ROW spaces which are not sidewalk, driveway, or street can be utilized by property owners to: plant vegetable gardens with raised beds, rose gardens, trees, or parking.
While there are a lot of open ROW spaces in Tacoma, usually only a small section of the ROW is plantable. The size of the ROW, and utilities such as overhead power lines and underground piping create planting restrictions. Despite the restrictions and considerations that are required for street tree planting in the ROW, ROWs where planting space is maximized are critical for making Tacoma a more equitable place. Because the plantable ROW space is scarce in Tacoma, it is especially important to use it to the fullest.
Right Tree, Right Place
Maximizing ROW space for planting means utilizing all available space while considering utility restrictions. To do so, it is critical to use the right-tree-right-place principle. This principle involves choosing tree species according to their growth habits while ensuring that f utilities have been marked, and that planting follows the appropriate space restrictions and considerations:
It is not safe to plant a tree within 5 feet of most underground pipes.
It is not safe to plant a tree within 25 feet of a utility pole.
Trees planted under power lines should have an average mature height of no more than 25 feet (trees taller than this are likely to be cut back by utilities so that they can maintain power lines).
Space for roots. Trees rely on small pockets in the soil called pores which allow water, nutrients, and oxygen to access the roots. Without these pockets, trees can become stunted or suffocated by soil compaction.
Comfortable, safe, and beautiful ROWs are possible.
In an effort to bring attention to the ROW’s function as an easement, or place of comfort, especially in our changing climate, Luke Vannice, TTF Board Vice President and landscape architect, created this art installation in Hilltop.
Photo: Luke Vannice.
To illustrate the benefits of planting trees in ROW spaces, Luke painted colorful dots radiating out from dead and live trees in a Hilltop neighborhood ROW. Green dots indicated the cooler temperatures provided by the living tree; red dots illustrated the hotter temperatures around the dead, leafless tree.
For neighborhoods that lack street trees, heat builds in the summer, making average temperatures 10-20 degrees hotter, a phenomenon that we call the urban heat island effect. Residents who live in urban heat islands have higher rates of illness and health issues, both due to the heat and the air and water pollution that existing trees mitigate.
Photo Credit: Luke Vannice.
Maximizing the ROW in creative ways can go a long way to creating a comfortable and convivial easement for everyone in your neighborhood. As we recently highlighted, Luke has cultivated a prairie right-of-way where three Garry oaks grow alongside dozens of native plants. It is a great example of how ROW space can reach its full potential. With multiple trees, shrubs, grasses, and flowers, it is a space Luke, his neighbors, and a number of insects and birds can enjoy. See below for a list of native meadow flowers that you can plant for spring!
You too, can maximize the space in your own right-of-way using our guide to planting in the ROW:.
Locate your right of way. If you live in the City of Tacoma, this map is a helpful tool for understanding the boundaries of your right-of-way. Open the data menu at the top (the first icon at the top right), and make sure to enable “Right-of-Way-Easement” to view ROW boundaries.
Apply for a planting permit for a street tree if you live in the City of Tacoma through their permitting website. Permits are free!
Call 811 to have your utilities marked before planning to plant on your ROW.
Take note of any overhead power lines.
Measure your ROW space and determine whether or not the soil in your ROW is compacted. If the soil is compacted, it will need to be decompacted and potentially amended. The Depave Puget Sound project may be able to support you! Structural soil cells are another tool to consider that can help preserve space for root systems and prevent soil compaction that can kill or harm trees. Considering your utilities and the size of your ROW, start researching the kinds of plants that would be suitable for your space. This may be a tree, or it may not. Remember to maximize your space! The City of Tacoma offers 3 lists of trees suitable for street tree planting: small, medium, and large tree lists. Note: Planting compacted soils with herbaceous perennials and grasses with deep tap roots (such as prairie species) is a great way to decompact soils over time too.
Plant your ROW!
Enjoy the beautiful new green space you have created.
Resources:
City of Tacoma Right-of-Way guidelines.
Download our Native Pollinator Meadow Plants Guide (below)
Become a Tree Steward (learn more here)
Take our Fruit Tree Pruning Workshop (check our calendar)
Take our Structural Pruning Workshop (check our calendar)
For a fun way to learn more about planting while considering utility restrictions, find TTF at an event to play our Right-Tree-Right-Place game!
Many thanks to Luke Vannice for collaborating with us on this series, including previous and upcoming reels that you can find on Instagram and Facebook. Give us a follow! Photos included in this post that are not captioned are credited to Eden Standley or Julia Wolf. Please email us if you would like to use them.