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Shoreline Master Programs

Task 2.2.1: Characterize ecosystem-wide processes

See SMP Handbook: Chapter 7 for more guidance on shoreline inventory and characterization.

Ecology's Shoreline Master Program (SMP) Guidelines recognize that shorelines cannot be properly managed in isolation from activities taking place upstream, updrift or on adjacent land. It’s important to understand ecosystem processes and how they affect ecological functions of the shoreline.

Ecosystem or watershed processes occur over larger landscapes that include both the shoreline and watershed features draining to the shoreline. Processes determine both the type and level of performance of shoreline functions. These processes occur at many geographic scales, from watersheds (100’s to 1000’s of square miles), to smaller sub- watersheds (10’s to 100’s of square miles), to shoreline reaches (parts of a mile to miles).

The flow of water, sediment, nutrients and materials into and through shorelines are the driving processes that determine the health of the overall system. Modifying or interrupting these ecosystem-wide processes may affect local processes (such as bank storage, hyporheic and overbank flows) and ecologic functions that occur within shoreline jurisdiction.

The following table helps to explain the relationship between processes and functions. Ecology recommends that you use a table format during the analysis to guide you in identifying ecosystem wide processes, ecological functions and their relationship to one another.

Ecosystem-wide process

Ecological function group

Ecological Function

Hydrologic – movement of surface and subsurface water

Water quantity functions

Storage of surface water in floodplains and depressional wetlands 

Movement of sediment, toxics, nutrients and pathogens

Water quality functions

Removal of sediment, toxics, nutrients and pathogens (fresh water and tidal floodplains & depressional wetlands)

Movement of water, sediment and large woody debris

Habitat functions

Aquatic habitat for invertebrates, native fish, amphibians, birds and mammals.

Recommended steps for conducting the characterization include the following:

  1. Determine contributing watersheds and shoreline reaches.

    Determining the watersheds that influence the shoreline is the easier of these two tasks. These watersheds are likely already mapped. Review existing watershed, WRIA or drainage plans for watershed maps. Or, you can determine watershed boundaries by using topographic maps (Instructions on how to do this).

    Reaches are specific segments of the shoreline and should be the basis for in-depth discussion of shoreline functions. Sometimes called “management areas,” reaches are typically distinguished by the relative intensity of land use development patterns, the physical landscape or critical biological processes. See SMP Handbook: Chapter 7 for more guidance on shoreline inventory and characterization.
  2. Conduct the analysis in order to characterize shoreline processes and functions.

    The SMP Guidelines outline three approaches to characterize shoreline processes and functions:
  • Conduct the characterization within the framework of an existing regional plan or use the data provided in the plan.
  • Use available scientific and technical information.
  • Pursue a characterization of greater scope and complexity.

When deciding what approach to use, consider the geographic size of your jurisdiction, number of drainages, variety of shorelines and number of ecosystem-wide processes that are present. The analysis for a county with many miles of marine, river and lake shorelines will be more complex than that for a city with one-half mile of river shoreline.

Use existing information and data gathered during the inventory. Use inventory information to help you answer questions about the level of impairment to shoreline processes and functions. Inventory data such as amount of armoring or impervious surface are examples of impairments.

Think about the cause and effect relationships between the stressors of the natural environment and existing shoreline conditions. Levies, dikes, channelization, or channel incision (often caused by increased surface water runoff) can cause floodplains to be disconnected from streams and estuaries. With a disconnected floodplain, the shoreline suffers a loss of wetlands, loss of floodplain storage, loss of opportunity for nutrient cycling, and loss of sediment storage.

For more information

See SMP Handbook: Chapter 7 for more guidance on shoreline inventory and characterization.

Contact Ecology’s regional shoreline planner serving your town, city, or county for your town, city or county.


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