Purpose:

Use vegetation to reduce water volume, sediment and other pollutants of stormwater in the watershed, thereby protecting and improving surface and groundwater and natural resources.

Justification:

Scientific research is increasingly demonstrating the value of trees and vegetation in reducing the negative impacts of urbanization on water and air quality, habitat, energy use, public health and quality of life (Cappiella, 2005)*. The strategic use of vegetation reduces the amount and cumulative impact of impervious surfaces. Structurally, vegetation also provides layers of opportunities (e.g. canopy, ground cover, roots in the ground) to intercept, use and infiltrate stormwater before it becomes runoff. Moreover, using vegetation to mitigate urban effects is often less costly than structural engineering solutions. This program provides opportunities and incentives to integrate better building and landscape design into land use decisions and policies and to pilot new approaches to solving resource problems.

• Reduce the volume, slow the rate and treat runoff leaving the land by using plants to:
• Reduce the amount and continuity of impervious surfaces
• Mitigate erosion
• Conserve and reuse water
• Increase capacity of the watershed to intercept precipitation and infiltrate and store water
• Lower temperatures and reduce water loss and heat stress associated with drought
• Pilot innovative ideas and techniques for local conditions
• Improve techniques, refine standards and identify limitations
• Create highly visible demonstration sites to inform and educate the watershed community
• Advance the development of water quality standards for landscape and building design
• Learn from and work with other groups and efforts
• Modify ordinances and variances
• Identify research questions
• Restore and protect habitat, native plant and animal communities
• Protect, enhance and restore natural areas by planting native species
• Actively seek opportunities to vegetate urban landscape and link green spaces

*Cappiella, K, T. Schueler and T. Wright. 2005. Urban Watershed Forestry Manual: Part 1 of a 3-Part Manual Series on Using Trees to Protect and Restore Urban Watersheds. USDA Forest Service. 118 pages + appendixes.