Laboratory measurements of the vertical and horizontal permeability of samples of Bothkennar clay have been made in controlled flow tests and values have been estimated from interpretation of consolidation tests. The permeability anisotropy that has been observed can be linked with different clay facies that have been identified in parallel engineering geological studies.
Little, J. A., Muir Wood, D., Paul, M. A., & Bouazza, A. (1992). Some laboratory measurements of permeability of Bothkennar clay in relation to soil fabric. Géotechnique, 42(2), 355-361. https://doi.org/10.1680/geot.1922.214.171.1245