Building Blocks for Dyke Walls

A section of the riverbank on the Diligent River estuary. At this location the river flows through a salt marsh and here the riverbank is an exposed vertical cross-section of the Diligent River tidal wetland.This cross-section shows the typical root matrix that exists beneath the surface of a salt marsh. A salt marsh is not a layer of grass sitting on "marsh mud" To quote Sherman Bleakney:

"It would be more accurate to say that the roots bond well with themselves and that the marsh mud becomes trapped in that firm, wiry, entangled matrix¹."

It is from this firm, wiry, entangled matrix that the dyking spade was used to CUT sods to be used in the construction of dykes. These sods had a rigidity that allowed them to be shaped and to be regarded as a form of building blocks. Of the many plants found on a salt marsh only two were suitable for sods; “Salt Marsh Hay” (Spartina patens) and "Black Rush" (Juncus gerardii ).

An eroding bank on an undyked section of a salt marsh located on the Apple River clearly illustrates that the internal structure of a salt marsh has the rigidity that building blocks for dyke walls require.

¹ Bleakney, J. S. (2004). Sods, soil, and spades: the Acadians at Grand Pré and their dykeland legacy. Montreal: McGill-Queen's University Press. p. 24