dollarton highway realignment project
DESCRIPTION
Dollarton Highway Realignment Project. District of North Vancouver. May 12, 2006. Project Area. Maplewood Mudflats. Maplewood Mud Flats Conservation Area. New Dollarton ROW. Environmentally Sensitive Area. Maplewood Mudflats Conservation Area. - PowerPoint PPT PresentationTRANSCRIPT
Dollarton Highway Dollarton Highway Realignment ProjectRealignment Project
District of North VancouverDistrict of North Vancouver
May 12, 2006
Project Area
Maplewood MudflatsMaplewood Mudflats
Maplewood Mud Flats
Conservation Area
New Dollarton ROW
Environmentally Sensitive AreaEnvironmentally Sensitive Area
Protect a rare & vital Burrard Inlet ecosystem
Groundwater dependencies.
Water Quality.
Maplewood Mudflats Conservation Area.
Wildlife habitat & migration corridors.
Scope of the ProjectScope of the Project
New Roads Constructed.
Dollarton Highway Realignment – 1.1 km major arterial, 4 lane divided
Riverside Drive East – 0.3 km major collector, 4 lane undivided.
Other roads – 0.9 km local commercial/industrial, 2 lane undivided.
Carried out in 5 phases starting in 1999 and completed in 2003
Total cost of project approx $8 Million
Project Catchment Area – 40.6 Ha.Project Catchment Area – 40.6 Ha.
Technical RequirementsTechnical Requirements
Drainage Design
Must service the entire drainage area.
Safe disposal of storm water.
Groundwater recharge
Minimize post-development flow impacts.
Provide overflows to storm sewer for large storms
Storm Sewer SystemStorm Sewer System
Existing Site ConditionsExisting Site Conditions
Native soils - well graded sandy gravel / gravelly sand
High water table (anywhere from 1.0m to 5m below surface
Measured hydraulic conductivity 1x10-3 to 4x10-3 m/s (medium permeability)
Flat terrain – road grades from 0.5% to 3.7%
Design ConsiderationsDesign Considerations
Used dispersal drains for 49 of the 69 catch basins installed.
Incorporate groundwater recharge into the design .
Use gasketed joints for storm sewers to avoid groundwater table draw down.
Include trench dams to prevent groundwater from following trench lines to the outfall.
Typical Road Cross SectionTypical Road Cross Section
Infiltrating CB system
Catch Basin Dispersal DrainsCatch Basin Dispersal Drains
Infiltrating CB system
Dispersal Drain Plan ViewDispersal Drain Plan View
Dispersal Drain Detail
Dispersal Drain SectionDispersal Drain Section
Dispersal Drain Detail
Marine OutfallMarine Outfall
Adapted O&G Chamber design based on previous research & experience.
Design low flow bypass in sewer main to divert water into chamber when most needed.
Better treatment (TSS removal) and less frequent maintenance, virtually no re-suspension of entrained sediment.
Marine OutfallMarine Outfall
Oil & Grit Interceptor
Marine OutfallMarine Outfall
Riparian planting plan for rip rap slope between elevations 2.5 and the top of the slope
Ecopockets planted @ 1 plant per 1.5 m2 or as directed by the environmental monitor
Riparian planting stock
•Red osier dogwood
•Black Hawthorn
•Pacific WIllow
Low flow diversion weir
Oil & Grit Interceptor
Treated water outfall
Dollarton Highway west of Dollarton Highway west of Riverside DriveRiverside Drive
Dollarton Highway east of Riverside Dollarton Highway east of Riverside DriveDrive
What Have We learnedWhat Have We learned