Surface runoff can be a cause for concern in many urban areas as it can contribute pollution to streams , wetlands , rivers , lakes , and oceans . During precipitation events , some portion of the precipitation is intercepted by vegetation ( trees and shrubs ) while the other portion reaches the ground . The portion of the precipitation that reaches the ground and does not infiltrate into the soil becomes surface runoff ( Hirabayashi 2012 ). In urban areas , the large extent of impervious surfaces increases the amount of surface runoff .
Urban trees and shrubs , however , are beneficial in reducing surface runoff . Trees and shrubs intercept precipitation , while their root systems promote infiltration and storage in the soil . The trees and shrubs of Mount Auburn Cemetery Sample Plots help to reduce runoff by an estimated 21 thousand cubic feet a year with an associated value of $ 1.4 thousand ( see Appendix I for more details ). Avoided runoff is estimated based on local weather from the user-designated weather station . In Mount Auburn Cemetery Sample Plots , the total annual precipitation in 2016 was 33.8 inches .
I-Tree Report of Ecosystem Analysis at Mount Auburn Cemetery Insert to the Climate Action and Sustainability Plan
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