Risley Moss peat accumulation filled the depression, allowing colonisation by bog mosses such as the "Sphagnum" varieties, thus giving rise to the name "moss". Risley Moss is one of only two mosses in Cheshire where the water level has been deliberately raised in an attempt to encourage the regeneration of an active bog surface. The long-term restoration project to re-wet the moss began in 1978 and was completed in 2002. This scheme was undertaken to create a series of scrapes and bunds to retain water and recreate the perfect conditions for bog flora such as cotton grass and sphagnum mosses to re-colonise
Portlethen Moss saturated organic layers could actually rupture, spilling large volumes of mud and organic debris to surrounding fields, thus enabling a bed for further spatial expansion of the entire bog. Ultimately the colour of the moss waters became blood red in colour, from the successive organic decay and stagnation. Only in times associated with cattle grazing and significant human presence (probably the late Iron Age), would this process reverse and the bog reduce in size. A wide variety of sphagnum, sedges, rushes and other characteristic bog species inhabit Portlethen Moss. Sometimes insectivorous plants reside in mosses, since the soils are generally