Vulnerability Assessment Overview

The San Diego Bay Vulnerability Assessment evaluates where and when sea level rise impacts may occur, as well as the extent to which exposed community assets would be impaired by an impact and whether they may be able to cope or adapt on their own.

The assessment was conducted through a combination of modeling, mapping, and intensive consultation with the project’s Technical Advisory committee. For full details of the assessment, download the complete report. Key findings include:

• In the next few decades, the greatest cause for concern will be an increase in the kind of flooding that the region already experiences due to waves, storm surge, El Nino events, and very high tides. When planning for this period, an emphasis should be placed on preparing for more common and more severe extreme events.
  
• Starting around mid‐century, the Bay may become more vulnerable to regularly occurring inundation of certain locations and assets, some of which are being planned
  and built today. As a result, this longer‐term risk of inundation should be a
  consideration in today’s decision‐making.
  
• The most vulnerable sectors in the community include stormwater management, wastewater collection, shoreline parks and public access, transportation facilities, commercial buildings, and ecosystems.

Vulnerabilities by Sector

Ecosystems and Critical Species

• Bay ecosystems, which provide habitat for many endangered and threatened species, are extremely vulnerable to inundation that is expected to result in habitat shift. These shifts could cause the loss of irreplaceable habitats for critical species in many areas.
• Upland areas are vulnerable to erosion, and subtidal ecosystems are threatened by erosion of upland areas when it results in degraded water quality.

Contaminated Sites

• Hazardous waste sites are highly vulnerable to flooding and inundation as storage tanks in the area could be opened or moved, or motors and pumps could be impaired thus releasing contamination into flood waters or area soils.

Stormwater Management

• In all scenarios, storm sewers are highly vulnerable to flooding and inundation in the Bay due to higher sea levels, a condition that would result in localized flooding in very low‐lying inland areas.

Wastewater

• Sanitary sewers in low‐lying locations will be vulnerable to floodwater inflow which could exceed their capacity, potentially resulting in discharge of wastewater to the Bay.
• The entire wastewater collection system in the planning area will be vulnerable to inundation impacts.

Potable Water

• Above‐ground water distribution components such as valves, meters, and service points will be vulnerable to flooding and inundation.

Energy Facilities

• Above‐ground electricity transmission and distribution in limited areas will be vulnerable to erosion, particularly after 2050 and during major storm events. Erosion could undermine infrastructure, causing outages or safety issues.
• Above‐ground electricity transmission and distribution will be moderately vulnerable to flooding and inundation, particularly in the 2100 timeframe when more components are likely to be exposed to regularly occurring flood events.

Local Transportation Facilities

• Access provided by local transportation facilities will be vulnerable to flooding and inundation, particularly in the 2100 timeframe when more components are likely to be exposed to regularly occurring inundation.
• Roads and other facilities could also be vulnerable to flooding and inundation due to saturated soils and impacts on road substructure and pavement degradation.

Building Stock

• Residential buildings have a low vulnerability to flooding in the 2050 scenario due to limited exposure.
• They are highly‐vulnerable to flooding and inundation in the 2100 scenarios as exposure expands to large portions of residential neighborhoods and major commercial facilities.

Emergency Response Facilities

• Fire stations in San Diego and Coronado are moderately vulnerable to flooding in the 2100 Extreme Event scenario.

Parks, Recreation, and Public Access

• Shoreline parks and recreational facilities are extremely vulnerable to regular inundation due to extensive exposure around the Bay and high sensitivity to inundation impacts.
• The system is highly vulnerable to flooding because of extensive exposure and high sensitivity, but adaptive capacity to cope with flooding is higher than for most other systems.

Regional Airport Operations

• Parts of the Airport site will be vulnerable to localized flooding from blocked storm outfalls in the Bay.
• In the 2100 scenarios, Airport operations will be extremely vulnerable to Bay flooding and inundation, particularly from impacts on access roads, future terminal areas, and portions of the runway/airfield.

Vulnerable Populations

• Many groups that are currently vulnerable – such as low‐income residents, the homeless, elderly, and ethnic minorities – will face even greater threats from future flooding, particularly in the 2100 time frame.
• Residents that work in sectors that could be adversely impacted by future flooding are also a key vulnerability for the region.