Trees

Green Infrastructure: Trees can be an important tool for retention and detention of stormwater runoff. Trees provide additional benefits, including cleaner air, reduction of heat island effects, carbon sequestration, reduced noise pollution, reduced pavement maintenance needs, and cooler cars in shaded parking lots.

Information: Tree trenches and tree boxes are bioretention practices. However, because of differences in design, construction and maintenance, we have created a separate section for trees.

Tree BMPs on Marquette Avenue, Minneapolis Minnesota. Photo courtesy of the Kestrel Design Group, Inc.

Use of trees to manage stormwater runoff encompasses several practices. Tree trenches and tree boxes (collectively called tree BMPs), the most commonly implemented tree BMPs, can be incorporated anywhere in the stormwater treatment train but are most often located in upland areas of the treatment train.

Tree BMPs are one component of urban forestry. Urban forestry is a broad term that applies to all publicly and privately owned trees within an urban area, including individual trees along streets and in backyards, as well as stands of remnant forest (Nowak et al. 2001).

The focus of this set of articles is on tree Best Management Practices rather than urban forestry. For more information on urban forestry, we suggest visiting the following websites.

• Urban and Community Forestry - USDA Forest Service
• Urban Forestry & Ecosystem Management - City of Philadelphia
• Watershed Forestry Resource Guide - Center for Watershed Protection and US Forest Service - Northeastern Area State & Private Forestry
• American Forests
• Urban Forestry - Virginia Tech University
• Stormwater to Street Trees: Engineering Urban Forests for Stormwater Management - U.S. EPA

Acknowledgements

• Overview for trees
• Types of tree BMPs
• Plant lists for trees
• Street sweeping for trees
• References for trees
• Supporting material for trees

Tree trenches and tree boxes

The following pages address incorporation of trees into stormwater management under paved surfaces. These pages may be viewed as a single article

• Design guidelines for tree quality and planting - tree trenches and tree boxes
• Design guidelines for soil characteristics - tree trenches and tree boxes
• Construction guidelines for tree trenches and tree boxes
• Protection of existing trees on construction sites
• Operation and maintenance of tree trenches and tree boxes
• Assessing the performance of tree trenches and tree boxes
• Calculating credits for tree trenches and tree boxes
• Case studies for tree trenches and tree boxes
• Soil amendments to enhance phosphorus sorption
• Fact sheet for tree trenches and tree boxes
• Requirements, recommendations and information for using trees as a BMP in the MIDS calculator
• Requirements, recommendations and information for using trees with an underdrain as a BMP in the MIDS calculator