Green Streets Proposed Amendmentfor the Montgomery County Road

Code

Montgomery County StormwaterPartners

3/07

Our Streets and Roads are a SignificantPart of the Stormwater Problem…

• Boiling Brook Parkway

They Can Now Become Part of theSolution….

• The Road Code bill should be amended tomandate that a minimum quantity ofstormwater be retained and treated on-site,within the road right-of-way, preferablyusing vegetation-based stormwatermanagement techniques.

Key Components

1) Numeric performance standards in inches ofrain to be treated within the road ROW.

2) Toolbox of stormwater techniques withpreference for vegetation-based bioretention.

3) Specifications to be developed by DPWT w/DPS and DEP.

Green Streets Methods

Stormwater Planters

Street Tree Stormwater Units

Bioretention Medians & Curb Extensions

Bioswales

Open Section Roads with Trees

Permeable Pavement

Stormwater Planters

Street Tree Stormwater Units

Street Tree Stormwater Management:Continuous Trench Technique

Bioretention Medians

Bioretention Curb Extensions

Permeable Pavement

Bioswales

Seattle SEA Street Project(Street Edge Alternatives)

Open Section Roads

Open Section Roads With Trees are keyto maintaining rural character.

• The late Michael T. Rose employed this principle at hisNorthridge Development: “This rural character of acommunity is mirrored best through the community’srural lanes. Flanked by mature vegetation and grasseddrainage swales, these rural lanes impose only a gentleimpact…Rather than subduing and pushing backnature, nature softens the lanes and becomes a part oftheir character.”

Benefits of Green Streets Techniques• They increase pedestrian and traffic safety by reducing average auto speeds.

• They improve water quality and help protect our streams from further damage.

• They beautify our neighborhoods, re-introducing native plants.

• Natural systems projects involve neighbors in the planning and implementation.

• Rather than deteriorating over time like piped systems, natural systems become more effective asplants and trees grow. Total life-cycle costs are reduced with natural systems.

Source: Seattle Public Utilities’ Natural Drainage System web page at:www.seattle.gov/util/About_SPU/Drainage_&_Sewer_System/Natural_Drainage_Systems

What are the drawbacks & needs?

More time to plan, design, and construct

More community outreach and involvement

Cost impacts will vary, yielding a savings or acost increase depending on the project and site-specific factors.

Maintenance, cold weather issues.

Conclusions

1) Require that new and reconstructed roads bedesigned to absorb and treat at least somestormwater on-site.

2) Preserve rural and rustic roads and theiradjacent trees and woodlands.

3) Minimize impervious surfaces as much aspossible, once pedestrian, bicycling and othertransportation needs are served.