07/02/2025
We’re excited to tell you about the sustainable landscape design for Sixth Avenue from Russel to Craig Road.
The project calls for roadside bio-infiltration swales. A swale is similar to a channel, with the low point helping gather and, in this case, treat stormwater to remove oils and other chemicals from vehicles, which collect in rain and snow on the roadway. Traditional stormwater drainage calls for a series of underground pipes and storage containers. Ardurra Landscape Architecture Manager Jaime Snyder praised the project's sustainability and the city's forward-thinking approach.
“The swales have a treatment soil in them as well as the plant material,” Jaime said. “The combination of those two items helps to filter the water as it drains through and improves the water quality as it works through the system.”
At their most basic, the roadway curb inlets channel water into a landscape feature that mimics nature to help improve water quality near where it is collected. Jaime explained that this stormwater management approach, known as Low-Impact Development landscape, is designed to be close to self-sustainable and will require less maintenance, including less fertilizer or pesticides, than traditional sodded swales.
Vegetation will be drought-resistant, keeping with state-mandated drought resiliency requirements that the city must include in its 2026 Comprehensive Plan. The plants that were selected along the roadway are suitable for warmer temperatures, less precipitation, and are more tolerant of the winds in Airway Heights. For instance, evergreen junipers will make up some ground cover. The trees selected include trees donated under a grant to the Lands Council and Spokane Conservation District. The trees selected for the Airway Heights dry and windy environment are part of this grant’s goals of increasing trees in communities with low-income households. Trees create shade and reduce the heat generated from paved surfaces. Ornamental grasses, shrubs, and perennials will be used throughout the swales, with pops of yellow and calming colors like blue and purple. Not only will the plant material provide aesthetic apply, it will also help improve the quality of stormwater. However, it will take time to establish the plants before lowering the amount of irrigation water used.
"It's important for the community to realize that if they see sprinklers on, we're using the renewable water system out there,” Jaime said. “It’s separate from the drinking water and freshwater that the city relies on.” The renewable water system is fed from the City’s reclaimed water treatment plant. Using reclaimed water, rather than potable (drinking) water, the costs for irrigation the plantings are lower than purchasing water from the City of Spokane. The City of Airway Heights has been purchasing water from Spokane since 2017 after notification of the contamination of the City’s wells by PFOA/PFOSA.
Jaime praised the project for helping manage our finite water resources and creating value for stormwater. To her, it makes the perfect recipe for responsible stewardship. “The big thing of this project is to highlight its sustainability, both of the plant palette, how it’s watered, and how they're treating stormwater. Those three things together go a long way for the environment in the future.”
