Roadways
This study area includes sections of low-lying roads across the park that have been identified for protection based on flood risk. The roadway focus areas extend across the Island, both within and outside of other identified study areas. Nearly 5.5 km of roads across the park have been identified as focus areas for flood protection. Roadway flood protection generally involves raising the roads to a higher elevation.
Roadways Existing Conditions
During the flooding in 2017 and 2019, flooded roadways restricted access and mobility around the park, impacting emergency services, residents, and businesses. As part of the 2020 emergency works, over 500 m of roadway was raised along Lakeshore Avenue and Cibola Avenue to maintain emergency vehicle access while the Class EA is completed.
Concept 1
Clay Cap
Concept design alternatives for the roadways involve raising identified road segments above the 100-year flood level. All road raising alternatives include an impermeable layer that effectively creates a flood barrier within the road itself.
Concept 1 involves raising the roadways above the 100-year flood level and capping the shoulder of the road with a clay layer to reduce permeability and create a flood barrier.
- Lower cost solution compared to other alternatives and uses more readily available materials
- Has been previously implemented and proof tested as part of emergency works
- No notable disadvantages compared to other concepts
OVERALL RANKING: HIGH
Concept 2
Concrete Core
Concept 2 involves raising the roadways above the 100-year flood level and using a concrete core in the center of the road base to lower permeability and create a flood barrier.
- Moderate cost solution compared to other alternatives
- Design has not been proof tested on the Islands
OVERALL RANKING: MEDIUM
Concept 3
Concrete Curb
Concept 3 involves raising the roadways above the 100-year flood level and installing a concrete curb along the shoulder to reduce permeability and create a flood barrier.
- No notable advantages compared to other concepts
- Design has not been proof tested on the Islands
- Highest cost solution compared to other alternatives
OVERALL RANKING: LOW
Concept 4
Crusher Run Limestone
Concept 4 involves raising the roadways above the 100-year flood level and using low permeable material for the base itself to reduce permeability and create a flood barrier.
- Moderate cost solution compared to other alternatives
- Design has not been proof tested on the Islands
OVERALL RANKING: MEDIUM