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Shoreline Sensitivity Rankings List

The following table is a complete list of shoreline classifications for Environmental Sensitivity Index (ESI) maps for three types of environmental settings:

  • Estuarine: River-mouth; salt- or brackish-water.
  • Lacustrine: Related to lakes.
  • Riverine: Related to rivers, particularly large rivers.

Lower rankings represent shorelines that are less susceptible to damage by oiling; higher rankings become more likely to experience damage by oiling.

Visit our photo collection, ESI Shoreline Types, to see photos of many of the shoreline types.

ESI Rank Estuarine Lacustrine Riverine
1A Exposed rocky shores Exposed rocky shores Exposed rocky banks
1B Exposed, solid man-made structures Exposed, solid man-made structures Exposed, solid man-made structures
1C Exposed rocky cliffs with boulder talus base Exposed rocky cliffs with boulder talus base Exposed rocky cliffs with boulder talus base
2A Exposed wave-cut platforms in bedrock, mud, or clay Shelving bedrock shores Rocky shoals, bedrock ledges
2B Exposed scarps and steep slopes in clay
3A Fine to medium-grained sand beaches
3B Scarps and steep slopes in sand Eroding scarps in unconsolidated sediment Exposed, eroding banks in unconsolidated sediments
3C Tundra cliffs
4 Coarse-grained sand beaches Sand beaches Sandy bars and gently sloping banks
5 Mixed sand and gravel beaches Mixed sand and gravel beaches Mixed sand and gravel bars and gently sloping banks
6A Gravel beaches
Gravel beaches (granules and pebbles)*
Gravel beaches Gravel bars and gently sloping banks
6B Riprap
Gravel beaches (cobbles and boulders)*
Riprap Riprap
6C* Riprap
7 Exposed tidal flats Exposed tidal flats
8A Sheltered scarps in bedrock, mud, or clay
Sheltered rocky shores (impermeable)*
Sheltered scarps in bedrock, mud, or clay
8B Sheltered, solid man-made structures
Sheltered rocky shores (permeable)*
Sheltered, solid man-made structures Sheltered, solid man-made structures
8C Sheltered riprap Sheltered riprap Sheltered riprap
8D Sheltered rocky rubble shores
8E Peat shorelines
8F Vegetated, steeply-sloping bluffs
9A Sheltered tidal flats Sheltered sand/mud flats
9B Vegetated low banks Vegetated low banks Vegetated low banks
9 Hypersaline tidal flats
10A Salt- and brackish-water marshes
10B Freshwater marshes Freshwater marshes Freshwater marshes
10C Swamps Swamps Swamps
10D Scrub-shrub wetlands; Mangroves** Scrub-shrub wetlands Scrub-shrub wetlands
10E Inundated low-lying tundra
* A category or definition that applies only in Southeast Alaska.
** In tropical climates, 10D indicates areas of dominant mangrove vegetation.
More Information about ESI Maps

Anatomy of ESI Maps: Learn about the basic elements of ESI maps, including the types of information that are mapped.

Last updated Thursday, June 6, 2019 11:48pm PDT