Exsurgence de Veyrières

Sump 1, with an average cross-section of 2 x 3 m, is lined with clay and has a bell halfway along. Sump 2, of large cross-section, has a typical "U" profile. Sump 5 consists of a succession of chambers occupied by clay dunes and punctuated by low passages. After a clay squeeze, a flat-out passage and a new squeeze between the ceiling and blocks, one emerges into a large chamber of 12 x 20 m. S6, not very spacious, becomes impassable after a clay flat-out passage because of a sand bank that touches the ceiling. In the North branch, one passes under a collapse and, shortly before the terminus, through a chamber 10 m in diameter.

In the North-West branch, a 2 m climb allows one to ascend 35 m up a large calcited scree slope to elevation +57 (ceiling at +77). Further on, one progresses through a meandering, decorated gallery.

The North-West branch has a tributary on the right bank, which is followed upstream for 240 m to S5 (515 m ; -30), preceded by two wet ceilings. Sump 5 passes a low point at -27 before gradually rising to -12, then finally plunging again to -30 in a narrower conduit. After S5, one passes a wet ceiling. In the North branch, the river rises by steps over 1250 m to an unclimbed waterfall estimated at 20 / 25 m, whose base is at +110 and 1945 m from the entrance.

North-West branch (from the exit of S4 to S6): about thirty metres after the exit of S4, a tributary appears on the right bank; it is followed upstream for 240 m to S5 (515 m ; -30). After S5, one passes a clay squeeze, a flat-out passage and a new squeeze between the ceiling and blocks to emerge into a large chamber (12 x 20 m) at 1707 m from the entrance. A 2 m climb allows one to ascend 35 m up a large calcited scree slope to elevation +57 (ceiling at +77). One then descends to rejoin the active stream. One passes a wet ceiling then progresses through a meandering, decorated gallery where one must climb twice in opposition to find the passage. After 183 m of progression from the exit of S5, one arrives at S6 (15 m ; -9), whose pool is located at 1900 m from the entrance. To the right of the pool (on the right bank), a start of a clay flat-out passage remains to be explored.

From the entrance to the exit of sump 4: the entrance, closed by a counterweighted metal door, gives access after 8 m to the pool of S1 (90 m ; -4). The exit of the sump is into a chamber that continues with 200 m of low river passage to S2 (25 m ; -6). The latter emerges into a fine chamber followed by 90 m of river interspersed with a 3 m waterfall and a chaos of blocks to climb. S3 (310 m ; -8) is followed by 20 m of dry galleries before plunging into S4 (360 m ; -25). At the exit of the latter, the system divides into two branches.

North branch (from the exit of S4 to the 20 m climb): this is the main branch. The river rises by steps over 1250 m to an unclimbed waterfall estimated at 20 / 25 m, whose base is at +110 and 1945 m from the entrance.