2007-02-06 5-C Power PointPresentation to
City Council
City of Alameda
February 6, 2007
Comprehensive Sidewalk
Replacement Program
City of Alameda
City of Alameda has:
• 260 miles of sidewalk
• 260 miles of curb and gutter
• 20,000 trees
E ,4 1 i!
•
Tree roots uplifting improvements
Existing Program
Pilot Projects — Gibbons Drive
Pilot Project No. 1 (Keep tree)
Remove sidewalk and expose roots
Note: Tree roots gravitate towards lawn where
water and nutrients are plentiful
Pruning structural roots in sidewalk space reduces
tree's stability — evaluate the risk
Must maintain sufficient sidewalk space so meander on to
private property may be required for large tree trunks
Pilot Project No. 2 (Remove Tree)
• Note conflict with driveway and electric pole
• Is there potential ponding in the street that requires gutter
modifications ?
• Minimum planter strip space minimizes tree species options
Structural tree root much greater than 3 inches — cannot
cut or shave
• Electrical pole relocation
• Property owner to hand water tree until established
• Irrigation on private lawn to be modified
Sidewalk Repair Options
• Trim roots and replace sidewalk (baseline option,
no change)
• Trim roots and use herbicidal geofabric under
new concrete sidewalk
• Trim roots, use aggregate layer +filter fabric
under new concrete sidewalk (and in street if
needed, also may use structural soil)
• Airspading, then use aggregate layer + filter fabric
(for trees with large diameter and
minimally invasive)
• Rubberized Sidewalk (under grant program)
• Remove tree (as last resort), then replace sidewalk
using baseline option and plant new tree
Cost Comparison of Sidewalk Options
• currently, about $10 per square foot of
sidewalk repair
• new approach, estimated costs are:
- Herbicidal geofabric under new sidewalk at about
$15 per sq. ft.
- Agg. layer + filter fabric under new sidewalk at
about $20 per sq. ft.
- Airspading at about $2,500 per location
- Tree removal + stump grinding at about $1,200
per location
- Rubberized Sidewalk at about $30 per sq. ft.
Proposed New Tree Planting Program
• Establish planting criteria
- current criteria: > 5 ft from driveway, no
conflict with utilities and drainage
• Update Master Tree Plan — select best species for site
and provide replacement plan
• Use new planting standards
• Provide PVC sleeves under new sidewalk
• Maximize width of planter strip
- may require removal of impermeable area
and replacement with rock or soil
Impermeable planter strip - concrete
Permeable planter strip — soil / grass
Modify Tree Maintenance Program
• Early structural branch pruning program
• Root pruning program
• Watering standards for public landscape
strip and private properties
EBMUD water conservation assistance
www.ebmud.com
• Trees maintenance around power lines
New Tracking program
• Develop a database to track repairs
• Record inventory of trees and site
conditions in City
• Monitor effectiveness of
different methods
• Develop long term maintenance schedule