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Report from Hamnsmølnelva and Vallerdalgrotta

We recently received a report from Mark Dougherty on his exploration in Hamnsmølnelva and Vallerdalgrotta. Hamnsmølnelva  requires some dry caving, and they have been diving in two small sumps. It is too tight/difficult to proceed, so the exploration in Hamnsmølnelva  is considered to be finished since 2008. During 2010 and 2011 Mark and othes have been exploring Vallerdalgrotta in Røyrvik. Read on for the whole report and survey maps.

Just to quickly report on the status of my ”offical” project in Hämnmölnselva River Cave.

This site involves 120m of easy caving to reach the sump 1. The sump is in fact static; the water pours into the sump pool from a tiny passage to the right, with the water then flowing directly out of the pool and thence out of the cave.

Sump 1 proved to be just 12m long. Beyond was an interesting little labyrinth of passages and the stream was regained. It flows downstream into a minute passage (which presumably drains to the inlet just above sump 1). Upstream led quickly to sump 2 (2-3m), which was freedived without equipment. Beyond the second sump two short crawls both lead to a wide, low and very wet area. A very constricted duck/sump is the only way forward and it was not pushed because of a number of very sharp projections. Further progress here would be quite difficult and the project can therefore be considered finished. A survey is attached.

Meanwhile I have been actively exploring another cave: Vallerdalgrottan in Lybekksdalen, Röyrvik, Nord Tröndlag. I attach an article which will appear in the next issue of Grottan and also a survey of the cave. This project is ongoing and I would like to register it in the list of active projects. If any divers from Norway would like to join us on a trip there in the future, they are very welcome to contact me. I know there have been some cave diving activities in that valley in the past.

Vallerdalgrotta Expedition 2011

In Grottan 4-2005 Trevor Faulkner reported the existence of an interesting cave in the upper reaches of the dry valley above Marmorgrottan. Vallerdalgrotta is just on the Norwegian side of the border, but is within the same limestone bed as Korallgrottan. The main downstream passage of the cave flows into a sump.

In August 2010 Mark Dougherty and Kristian Lyberg made a lightweight attempt on this sump, carrying two small cylinders and wearing wetsuits. Kristian won the coin toss and took the lead. He returned after about 20 minutes with the news that the sump was short (35m) and easy and that a fine continuation of the streamway lay beyond. Mark put on the diving gear and swam through for a quick look but it was decided to leave further exploration for another trip, since solo caving beyond a sump involves some risks. With only one set of diving equipment it was of course impossible for both divers to go through the sump at the same time.

The team therefore returned in August 2011 reinforced by a third diver, Stefan Barth. Since all three divers planned to go through the sump, day one of the trip was spent carrying all the equipment to the cave. Unfortunately on the second day of the trip it rained heavily and this prevented diving.  Day three was fine, but water levels were still high, so the divers went for a walk in Bjurälven to assess the prospects for cave diving in some of the other dolines. A single cylinder, a mask and a torch were carried and Stefan took his wetsuit. Various pools and dolines in the area over the end of the known underwater cave were looked at without success. Lunch was taken at Dolinsjön and to great amusement a line reel which had been lost the previous winter was found half buried in the sand!

On the way home we looked at a collection of dolines marked on the surface map of Bjurälven as “Den Åtta”. Here Stefan was able to report that prospects for future cave diving look good, with easily large enough passages for diving underwater. The current was strong, but not impossible to make progress against. Note that permission from Länsstyrelsen is required for cave diving in Bjurälven so it was not possible to explore this lead further at the time (our interpretation of the rules was that diving in the pools didn’t count as “cave diving”, but clearly a return with full equipment and actually entering the underwater caves would).

Day four was the big day! The team was up early and walked to Vallerdalgrotta in good weather. We then had to transport three sets of diving gear to the sump. This was something of a struggle in the crawls, but eventually all divers were at the sump and ready to kit up. The line from 2010 was found to still be in good condition and all three divers dived through without problem. After dropping off and securing the diving gear, survey work started. About 60m of wonderful streamway reached a choke. This was easily passed at floor level, but beyond the passage carrying the flow of water became smaller and smaller (and the speed of the water flowing correspondingly faster) until it was decided it was unsafe to continue.  After a dry period it would probably be possible to explore further.

Just beyond the choke a dry continuation was spotted and a further 100m of quite awkward narrow rift passage was explored. This eventually broke out into a fine breakdown chamber with water flowing out at floor level. The continuing passage was wide and low and the divers soon arrived at a second sump. Just before sump 2 an inlet passage was followed into a second breakdown chamber. After finishing the survey work and taking some pictures, the divers dived back out. Day five was spent carrying the gear back from the cave. The team then participated in a rescue practice in Korallgrottan before travelling home. A total of 237m of cave passages were mapped.

The water in Vallerdalgrotta is assumed to flow all the way under the valley to the risings near Marmorgrottan, a distance of about 3,5km. The vertical drop is not that much (of the order of 20m from sump 1), thus significant lengths of underwater passage can be expected. However, the cave seems to be developed on more than one level , thus opening up the possibility of drier passages bypassing eventual sumped sections. No bypass to sump 2 was discovered though, and this will be the goal for a future exploration trip.

Both of the dives in Vallerdalgrotta were done without any support from “sherpas”. This proved to be reasonably feasible, but if the cave continues in the same fashion, the logistical challenge of transporting the equipment will become greater. Leaving a depot of some equipment (lead weights, harnesses, fins, etc.) in the cave will be an option worth considering.


Safe diving,
Mark Dougherty, viceordförande, Sveriges Speleologförfund


Survey of Hamnsmølnelva: MarkD.HRC.2008
Survey of Vallerdalgrotta: MarkD.Vallerdalgrotta.survey.2011

One Response

  1. Georg Stauch

    Hello, I am Georg Stauch from Germany. I will stay my holiday in august 2013 in Norway and Sweden. I am a cavediver. In Norway I dove Plura and Bubbel’n (a karstic well near Bognelvdalen / Alta). I visited the area around Korallgrottan, and I am interested in al of the karst there. Is a report about Bjurälven existing?
    In the moment, it is not sure if I can dive or not during my holiday (open wounds after surgical treatment) but I hope the best.
    Is there any expedition in august, so i can contact you?
    Greetings from Germany
    Georg Stauch