Summary of site:
In dry conditions, the Sruh Croppa River usually drains into its own bed about 0.5km south of the Marlbank road, soon after crossing the north-west/south-east trending Cuilcagh Dyke which deflects the river to the south-east. In normal conditions, it sinks just south of the bridge on Marlbank where a cave gives access to a substantial passage trending along the former line of the river, now usually a dry valley. In periods of heavy rainfall, the river overruns this usual sink and flows into the dry valley north of the road where it drains into the ground at various points. In exceptional downpours, it runs the length of the dry valley and pours over the cliff into Catís Hole and beyond (see Marble Arch Karst: Catís Hole site record).
The waters of the Sruh Croppa have been proved by dye testing to enter the Marble Arch Caves system but there is no direct passable link.
The rivers feeding the Marble Arch Caves system show a variety of karst drainage strategies and the Sruh Croppa is a classic example of river bed drainage. It is easily accessed and appreciated from the Marlbank road.