Abstract Title

Session S-04H: Technical Tools to Support Sea Level Rise Adaptation in the Salish Sea

Keywords

Shorelines

Location

Room 607

Start Date

1-5-2014 8:30 AM

End Date

1-5-2014 10:00 AM

Description

Historically, the main causes of coastal flooding have been due to astronomical (tides) and meteorological factors (storms). Estimation of the associated flood hazard from tides and storms typically has been predicated on the assumption of a stationary mean sea level. However, information from the global community of scientists and scientific agencies indicates sea level rise (SLR) is already occurring, and is expected to continue for some time. Furthermore, it is anticipated that the rate of sea level rise will increase in the future. As the sea level rises, it poses an increased risk of flooding to coastal communities, and also poses a challenge for local governments in terms of land development planning.Coastal Flood Construction Levels can be estimated as the sum of the following components:§ the higher high water level tide (HHWLT) elevation;§ an allowance for future sea level rise (SLR), tied to a particular time horizon, such as 2100;§ the estimated storm surge associated with the selected design storm;§ the estimated wave effect associated with the design storm; and§ freeboard.This report and presentation is intended to provide a technically-sound basis for local governments to develop coastal floodplain maps, including an estimation of Flood Construction Levels based upon best mapping and engineering practices. In light of rising sea levels, coastal floodplain maps will also allow local governments to define sea level rise planning zones, which will facilitate land use planning and development decisions.

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May 1st, 8:30 AM May 1st, 10:00 AM

Sea Level Rise and Coastal Floodplain Mapping Guidelines

Room 607

Historically, the main causes of coastal flooding have been due to astronomical (tides) and meteorological factors (storms). Estimation of the associated flood hazard from tides and storms typically has been predicated on the assumption of a stationary mean sea level. However, information from the global community of scientists and scientific agencies indicates sea level rise (SLR) is already occurring, and is expected to continue for some time. Furthermore, it is anticipated that the rate of sea level rise will increase in the future. As the sea level rises, it poses an increased risk of flooding to coastal communities, and also poses a challenge for local governments in terms of land development planning.Coastal Flood Construction Levels can be estimated as the sum of the following components:§ the higher high water level tide (HHWLT) elevation;§ an allowance for future sea level rise (SLR), tied to a particular time horizon, such as 2100;§ the estimated storm surge associated with the selected design storm;§ the estimated wave effect associated with the design storm; and§ freeboard.This report and presentation is intended to provide a technically-sound basis for local governments to develop coastal floodplain maps, including an estimation of Flood Construction Levels based upon best mapping and engineering practices. In light of rising sea levels, coastal floodplain maps will also allow local governments to define sea level rise planning zones, which will facilitate land use planning and development decisions.