117 Los Boyones
Secadura VN55859955 Alt. 50m Length 100m

Updated 13 February 1998; 19th Febrary 1999; 2nd May 1999; 5th November 2005

The water found in Cueva de Carcavuezo (81), Cueva Llueva (114), Cueva Hoyuca (107) and part of Cueva de Riaño 1 (105) - the whole of the Four Valleys System (line survey)- resurges in the Secadura valley. In wet weather the water emerges from a number of openings along a 200m long front but in normal conditions the water resurges at Los Boyones. Major building and piping works were started in the mid nineties and an elevated walkway now passes the "resurgence front" and ends over the main resurgence pool where water is extracted and past over the hill to Moncallian. Information gleaned from the Dirección General de Obras Hidráulicas y Ciclo Integral del Agua in 2005 shows an average water flow from the resurgence over the previous 20 or so years of 650 litres per second. (The Fuente Aguanaz resuregence emits 951 litres per second on average. Unlike the 4 Valleys System, there are currently no known feeders or caves which drain to the Nacimiento de Aguanaz).

The small, excavated cave entrance is 5m above the normal resurgence and located just behind a large embankment of boulders which form part of the pumping station complex. The hole usually emits a strong draught.

A 5m pitch leads to a hole down into the boulder choke (which is unstable in places). The draught can then be followed between the boulders to the river at the base of a steep mud slope.

Various climbs at the top of the slope close down and the draught is lost.

In 1997 a pool of standing water leads to a way on upstream with deep water - not pushed.

Nearby, to the west, is Cueva 77A (site 154) which is all part of the difficult to explore resurgence complex.

References: anon., 1974b (logbook); Kendal Caving Club and Manchester University Speleological Society, 1975; Cope J et al, 1976; anon., 1977b (logbook); Corrin J et al, 1978; Manchester University Speleological Society, 1982; Mills L D J and Waltham A C, 1981 (survey); Corrin J S and Smith P, 1981; anon., 1981 (logbook); material in file; anon., 1989 (logbook); Corrin J, 1992b (survey); Corrin J, 1994b (survey); anon., 1996a (Easter logbook); Corrin Juan, 1997a; Corrin Juan, 1997b; anon., 1997b (logbook); Corrin Juan, 1997c; anon., 2005c (autumn logbook)
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