4.5 Trees

Trees provide a broad range of environmental, aesthetic, and economic benefits. McPherson et al. (2005) found that the benefits from trees, including energy conservation, air quality, carbon sequestration, increased property values, and stormwater management, significantly outweighed the costs of installation and maintenance.

Mature, healthy trees can play a significant role in reducing stormwater runoff by intercepting and storing precipitation, promoting evapotranspiration, and slowly releasing intercepted precipitation from foliage and branches to the surrounding soil. The root systems of trees also serve to penetrate soil, build soil structure, and provide conduits for infiltration.

Appendix D: Bioretention Plant List includes a list of trees appropriate for eastern Washington. Engaging qualified designers (landscape architects, certified arborists, or local extension services) at the early stages of design is important for success.

Figure 4.5.1
Illustration of a how a tree can intercept and infiltration stormwater. Source: AHBL, Inc.