By Randy Johnson, Jamestown S’Klallam Tribe Habitat Program
For a variety of reasons, humans are deeply attached to and highly value accretionary shoreforms, i.e. sand and gravel beaches, spits, and other low-angle, non-rocky shoreline features. These have also been referred to as “drift babies” because they are products of drifting sediment and, in geologic terms, they can never grow old.
Drift babies cannot persist in their natural condition without a steady supply of nourishment from the sediment source within their drift cell. On the northeastern Olympic Peninsula, these sediment sources consist primarily of eroding coastal bluffs, although larger rivers, such as the Elwha, can also be significant sediment sources for accretionary shoreforms. Major threats to drift babies include bulkheads built along the toe of feeder bluffs, which reduce or stop the recruitment of sediment into the drift cell.
Figure 1. Curvilinear Spits on the Northeastern Olympic Peninsula.
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Figure 2. Cuspate Spits on the Northeastern Olympic Peninsula.
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Ediz Hook, which forms Port Angeles Harbor and is occupied by industrial facilities and a Coast Guard station, provides an excellent case history on the effects of reducing a drift cell’s sediment supply. There, bulkheading of the drift cell’s most active feeder bluffs in the 1920’s and 30’s contributed to sudden, catastrophic erosion of Ediz Hook. Since the 1950’s, many millions of dollars have been spent on wooden and then rip rap bulkheads, steel sheet pile, and beach nourishment to prevent Ediz Hook from eroding away. Every few years a major spit maintenance project is performed at the Hook.
Figure 3. Ediz Hook, a Curvilinear Spit in Port Angeles.
Increasingly, resource managers recognize the importance of conserving sediment sources in drift cells, particularly where the drift cell includes an especially significant accretionary shoreform, such as Dungeness Spit. In some cases, land use regulations appear to ensure that feeder bluffs will be protected from human impacts. However, permit exemptions, grandfather clauses, conditional use permits, and other loopholes can render local, state, and federal shorelines regulations ineffectual at preventing shoreline armoring of these precious features.
The long term conservation of drift cells cannot be entrusted solely to land use regulations. Property acquisitions and the use of conservation easements are essential tools to ensure the permanent conservation of Washington’s magnificent drift babies.
Located in the Strait of Juan de Fuca near Sequim are the 5-mile long Dungeness Spit and its associated 5-square mile Dungeness Bay. These provide crucial habitat for fish, shellfish, and wildlife that are extremely important to the Jamestown S’Klallam Tribe. Since the 1980’s the Tribe has worked to conserve shorelines, protect water quality, and restore habitat forming processes in local rivers and bays, especially the Dungeness River, Jimmycomelately Creek, Dungeness Bay, Washington Harbor, and Sequim Bay. A part of this work is focused on ensuring the continued existence and health of the area’s natural spits and has included the drafting of a conservation strategy for the Dungeness Drift Cell.
