Ecotone Levee
Type of Development
Restoration, New Development, Reconnection
Topography
Baylands
Longevity
Long Term
Environment
Natural Habitat
Maintenance
Low
Cost
More cost effective than levees that are used against flooding and sea level rise.
Overview
Rather than traditional vertical levees which create a short-term sea wall to block waves, horizontal ecotone levees are sloped embankments of plants designed to slow wave velocity, reduce sea level rise impacts, and restore tidal marsh ecosystems. Ecotone levees are gentle slopes or ramps located bayward of flood management levees and landward of tidal marshes, that provide wetland-upland transition zones. Ecotone levees are most useful when properly vegetated with native clonal grasses, rushes, and sedges.
Function
Ecotone levees connect habitats and hydrologic systems, attenuate waves, provide high tide refuge for marsh wildlife, and allow marshes to migrate in response to sea level rise.
Benefit
Ecotone levees connect habitats, allowing nutrients to flow through ecosystems and animals to travel through landscapes safely. Furthermore, ecotone levees dampen wave velocity by providing a sturdy structure for strong native vegetation to take root. Decreasing wave velocity reduces erosion risks, reduces sea level rise effects, and decreases flooding impacts.
Dependency
Hydrologic System, adjacent ecosystems
Development Considerations
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Environmental Considerations
Consider how to effectively leverage levee connections beyond the project area to maximize benefits.
Maintenance Consideration
There is little to no maintenance required as long as the hydrologic system is adequately restored and there is a regular sediment flow. However without that restoration there is a need to continue a sediment supply until the ecosystem can sustain itself. While other maintenance is not required, tracking of progress is valuable for future projects.
Cost Considerations
More cost effective than levees that are used against flooding and sea level rise.