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Ordinary High Water Mark

The ordinary high water mark (OHWM) as defined in the SMA is a biological vegetation mark. Ecology rules include a default tidal or fresh water elevation line where the OHWM cannot be found.

Ecology's official guidelines for making OHWM determinations in different situations are found in Chapter 173-22 WAC.

Definition

The ordinary high water mark is defined as:

• "that mark that will be found by examining the bed and banks and ascertaining where the presence and action of waters are so common and usual, and so long continued in all ordinary years, as to mark upon the soil a character distinct from that of the abutting upland, in respect to vegetation as that condition exists on June 1, 1971, as it may naturally change thereafter, or at it may change thereafter in accordance with permits issued by a local government or the Department of Ecology:
• Provided, that in any area where the ordinary high water mark cannot be found, the ordinary high water mark adjoining salt water shall be the line of mean higher high tide and the ordinary high water mark adjoining fresh water shall be the line of mean high water."

For more information

Law: 90.58.030(2(b)) (under Geographical Definitions)
Rule: WAC 173-22-030(11)

For assistance with ordinary high water mark determinations, contact the shoreline permit specialist assigned to your jurisdiction at Ecology's regional offices.

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