As can clearly be seen,the site is unlike a "conventional" motte and bailey site.No part of the ditches have any depth of water;a few places are squelchy,but walkable.Most of the ditches are dry.
see http://www.castleuk.net/castle_lists_midlands/138/corfhamcastle.htm
see http://www.pastscape.org/hob.aspx?hob_id=111237
see http://homepage.mac.com/philipdavis/English%20sites/3098.html
see http://www.ecastles.co.uk/corfham.html