“An oyster, that marvel of delicacy, that concentration of sapid excellence, that mouthful before all other mouthfuls, who first had faith to believe it, and courage to execute? The exterior is not persuasive.”
― Henry Ward Beecher
Tidelands can include those lands between the low and high tide lines, the so-called, “intertidal lands,” and lands beyond the low tide line, or “sub-tidal lands”. These are pretty general definitions, by the way. Any discussion of tidelands gets you pretty quickly into very specific legal definitions beyond the scope of this discussion. For example “Mean Low Tide” is defined as, “The average of all daily low tides over a period of 18.6 years.”  Private ownership of tidelands is limited to tidelands sold by the State of Washington prior to 1971. Sales of tidelands by the State to private parties have been prohibited since 1971. Tidelands may be leased, either from the state or from private parties.
Now why would anyone want to own or lease land that’s under water some or all of the time? Easy answer – that’s where oysters grow. No matter how you feel about oysters, they’re big business in Washington. And so are mussels and clams. According to the most recent Census data, 125 aquaculture operations in Washington produced shellfish sales of $149 million in 2013, up from only $64 million in 2005, an increase of over 130%. Washington was by far the biggest producer of farmed shellfish in the US, with over 45% of national production in terms of sales value. Getting back to oysters, they accounted for some $81 million of shellfish sales from Washington aquaculture operations in 2013, over 54% of the total. All of this shellfish production came from over 15,000 acres of tidelands in 2013, of which only 2,100 acres is from state leased aquatic lands.
Being local to Washington state, PVI has had the pleasure of valuing quite a few tidelands around the area. We have valued several parcels of combined tidelands and vacant land located in Blaine, Washington, as well as many individual parcels, residential and commercial that also hold tidelands.
Appraising tidelands presents a special challenge. In coastal jurisdictions, some difficulty arises in regards to swamp and overflow patents, and in distinguishing between tideland from swampland. Additionally, tidelands that can produce a stream of income from aquaculture may be very valuable. On the other hand, tidelands that are simply associated with adjoining uplands and which are not suited for aquaculture may have only nominal value. Other factors to consider are:
Property rights conveyed of the tideland (tideland claimed on the property)
State’s claim on the tideland property
Water frontage to acreage ratio
Zoning, typography, density, and utility differences
As we say so often in this business, “it all depends.”
 Waterfront Titles in the State of Washington, George N. Peters Jr.; Chicago Title Insurance Company, 2008
 2012 Census of Agriculture, Census of Aquaculture (2013), Volume 3. Special Studies, Part 2; USDA National Agricultural Statistical Service, 2014