The flood in the valley of the Rio Colorado; Chapter 3 in Arthur Coleman's book.
The illustrations and their captions have been omitted from this translation to speed the loading of the page.
ON EMPTYING AN ANDEAN LAKE A GREAT FLOOD WAS CREATED
On talking about the Bahía Blanca to Neuquén railway in another chapter, I explained about the regime which dictates the floods in the Andean rivers, in particular the Limay and the Neuquén, which together form the great Río Negro, and how the creation of Lago Pellegrini in the low lying area, Cuenca de Vidal, has been used to control the floods and prevent the periodic flooding of the valley.
The other big river which crosses this line, the Colorado, has not had its flow controlled up till now, and its valley has not achieved the importance of that of the Río Negro. It is only recently that it has had disastrous floods. One of them, perhaps the most severe, affected me personally in 1914, and I will describe the unusual causes of it.
On Sunday 29th December 1914, I received a telegram from the Governor of Neuquén [territory], seeking my permission to allow him to take his motor car across the railway bridge over the Neuquén [river], moreover adding that he had received news that the Río Colorado had high flows. A few hours later another message came, this time from the Governor of Río Negro [territory] asking for the immediate assistance of the Southern Railway to give help to the inhabitants of Río Colorado [town], confirming that they were expecting a furious flood, but without giving any details about the truth or otherwise of this rumour.
With a view to gaining time, and preferring as was my wont, to sin through taking precautions before lamenting my indolence, I made arrangements to run a relief train, made up of twenty bogie vans and two open wagons on which, as a precaution, were loaded four rowing boats. We left Bahía Blanca at two in the afternoon heading for Río Colorado station. [end of page 241]
On passing through Buena Parada, a small village of some two hundred inhabitants, some 3 kilometres from Río Colorado station, and located near the metal bridge across the river, I had the train stop, and invited everyone to get on to the wagons. The police saw the need in certain cases of reluctance to act energetically without wasting time. Many old inhabitants, knowing the district and how the Colorado rises and falls, ridiculed the idea, which they thought fantastic, that the river might overflow its banks here and put lives and homes at risk. They never remembered the river rising so high as to constitute a threat to them. Nevertheless through conviction, or by force, we managed to get all the inhabitants on to the wagons with some of their possessions. We continued our journey to Río Colorado station, the highest point in the area, where we left the wagons with the folk. It was now about nine at night.
The timetabled train, which should have left for its destination, Neuquén, had been held at Río Colorado for some hours, because it had not been possible to get either telegraphic or telephonic information from Juan de Garay, Pichi Mahuida and Fortín Uno stations, where the line runs almost alongside the river.
From the previous night, the river had risen very slowly, without giving rise to any suspicions of real danger, but at ten in the evening of Sunday, the Station Master at Pichi Mahuida, had reported by telephone that he was in his office with the water up to his waist and that he was about to abandon the station. It was already time for him to do that to save himself, after having stayed at his post until the last moment, as does a railwayman conscious of his responsibility. [end of page 242]
Prudently, I had ordered the passenger train held at Río Colorado to return to Gaviotas station for greater safety, by getting further away from the river, without paying heed to the protests aired by the passengers, who were opposed to such an order.
At four thirty on the following morning, Monday, we continued our journey with three official coaches and one wagon with two of the boats loaded at Bahía Blanca, leaving the others at Río Colorado, They were later used in courageous rescues. [end of page 243]
After running some 25 kilometres, we saw on the horizon a sort of mirage which resulted from, as we had feared, water. Continuing the journey for a further stretch we reached the edge of the flood. I arranged that we should retreat slowly for about a kilometre, and then decided that we should return to Río Colorado station to await the events which were approaching.
On going back some three kilometres, we established that the lower part of the line behind us had been invaded by the flood and, on attempting to restart the retreat, found that we had been completely surrounded by water, that the embankment had subsided and that the train was leaning to one side. Not being able to advance or retreat, we resolved without loss of time to adopt the measures necessary for our safety.
Sailing in a boat over the fences.
We prepared the two boats and loaded them with those things which we could accommodate, an action which was very opportunely taken, for half an hour later, the water reached the windows of the first coach which had remained on the line in an almost normal position.
We cast-off the boats and started to sail, crossing a metre over the top of the lineside fencing, heading towards a piece of ground [end of page 245], a sort of hillock, about two kilometres away. Our shipwrecked group was made up of thirteen persons, including the engine driver, the fireman, the train guard and the brakeman.
The thing which drew our attention the most, as we were rowing, was the enormous quantity of animals, horses, cattle, goats, sheep, ostriches and the rest which were fighting for their lives on being caught by the current. The small living world was represented on the bubbling surface by thousands of snakes, tarantulas, monstrous spiders, mice, guinea pigs and an infinity of insects which gave the water a curious look as they jumped and moved, seeking their salvation in some dry spot. The water appeared extremely muddy of a deep chocolate colour.
About nine, it appeared to us that the level of the water was stationary, we then pulled ourselves together and landed on the high ground. Using theoars to support blankets, with which we were well provided, as awnings, we raised a roomy shelter in the best way we knew. It served us as our abode, I'll not say convenient, but certainly efficient, for the week in which we remained completely isolated, without being able to tell of our whereabouts by any means.
During our enforced isolation, various expeditions we sent out by the railway company to search for us, but could not get near to where we were. When the water went down, neither could we get immediate help from the east side because of the 20 to 30 centimetres of thick red mud which the water had left; on the west we were hedged in by dense spiny thickets of natural scrubland. Despite everything, [end of pages 246 & 247] we were not disquieted nor hungry, as having explored the country, we had found a flock of sheep in a hollow some five kilometres from our improvised camp site, and in consequence, we had an ample supply of meat. It's logical to think that we didn't preoccupy ourselves over much about the brand on the animals and the name of their owner in those special circumstances.
The flooding of the town of Río Colorado.
On our return to Río Colorado after our enforced summer holiday on the hill, I knew that, had I not insisted that the inhabitants of Buena Parada take refuge on the wagons, all would have perished in the uncontainable current. In the seven days that they stayed at the station, they lived having clambered on to the roofs of the wagons, of the locomotive shed and the station building. The inhabitants of the town in their turn had to shelter on the roofs of the houses built of burnt brick, as those made of adobe or other materials had collapsed under the weight of water.
The boats which had previously been left in Río Colorado, provided important services, ferrying many people in danger to a safe place. The waters reached the top of the boiler of our train, which for thirty days could not be moved because of the damage to the line and the time it took the ground to dry out.
To give some idea of the height to which the waters reached, it is sufficient to say that the butcher of Señor Duhau's estancia, reached our camp on horseback, swimming it over the railway's telegraph lines. The workers of that estancia drove a cart to a nearby hillock with ten people, women and children who remained on the vehicle from the morning of Monday, day and night, with hardly any food, until the afternoon of Friday, suffering the mid-summer January sun. [end of page 248]
Beyond Río Colorado the regular train service along the Neuquén line was out of action for something more than a month.
Given the precautions taken, and despite the terrible flood, the loss of life was not as great as might have been expected. Nevertheless, a small village called Veinte Cinco de Mayo, located on the banks of the Colorado, was totally swept away by the waters, drowning many of its inhabitants.
The cause of the overflow.
The cause of the sudden unexpected flood was identified as a geological phenomenon, very rarely seen along the courses of the rivers, which flow in to the Atlantic Ocean to the south of Bahía Blanca.
Near the birth place of the Colorado [river], in the Andes, some 480 kilometres from the railway, flows the Barranco [river], a tributary of the Colorado. Lago Carri Lauquén was located on the course of the Barranco. This feature, which disappeared suddenly, was some 32 kilometres long, with a width varying between three and twelve kilometres. It had formed hundreds of years ago because the exit from a valley boxing in the Barranco had been closed by a volcanic eruption which had largely obstructed the outlet with enormous rocks [end of page 249] leaving a small outlet for the lake.
With such a constrained outlet, Lago Carri Lauquén acted as a natural regulator for the Barranco, for though more water might enter the lake, the rate going out remained the same due to the rocky sluice.
Lago Carri Lauquén had the capacity to store all the water which could land on its catchment, be it from melting snow in the Andes, or from heavy rain, without its overflowing or filling up to capacity. On the 27th or 28th of December 1914, the Andean receptacle was very full, and the extraordinary pressure of the liquid, or perhaps some seismic movement, caused the plug, which blocked the outlet, to come apart by moving the volcanic rocks which sealed the gap. The lake emptied rapidly with the results referred to.
Later, I was able to confirm this during an inspection carried out by Señor Blencowe, an engineer with the Southern Railway, that the mud laid down on the sides of the lake indicated that its depth in its centre when it burst was 110 metres and at its edges 85.
The volume of water which the lake suddenly discharged into the Barranco, and in its turn into the Colorado, was estimated to be not less than 2, 8, , tons or cubic metres. This quantity of liquid explained the unexpected flood and was why the inhabitants of Buena Parada could not have saved themselves had they not abandoned their homes just in time.
With the destruction of Lago Carri Lauquén, the main controlling factor against the dangers of flooding of the Colorado, be it from rapid thaws or intense rain in the Andes, had been removed. Now rises in the Colorado are possible to the extent that it may overtop its banks. [end of page 250]
The BAGSR's route to Neuquén