Associated wetlands and river deltas are features that have developed in association with other shoreline features, such as streams, lakes, or marine shorelines.

Deltas, like the Nooksack River delta, are landforms that are created at the mouth of a river or stream where it enters a larger, slower moving body of water. As water from rivers or streams enter a marine waterbody, the velocity of streamflow decreases and the stream loses capacity to carry most of the sediments and debris that were being transported in the stream load. These sediments then settle out and create a delta deposit at the mouth of the river or stream.
Associated wetlands are generally created and maintained by the controlling factors characteristic of the associated shoreline feature.

Backshore, or tidal wetlands, are located along marine shorelines or rivers flowing into marine waters. These are primarily influenced and maintained by tidal action.

Riverine wetlands are located in association with river and stream systems and are generally products of flood processes.

Lake Associations
Wetlands associated with lakes are generally located along the shallow, outer fringe and are controlled by the wind, currents, or seasonal water fluctuations that affect the associated lake body.