Where will you land? Right on the water surface of the lake? In Bolivia, or in Peru? Just more than half of the lake surface belongs to Bolivia. Or in the catchment area of the lake? It is almost impossible to miss the catchment area of Lake Titicaca with its size of almost 60,000 km². In comparison, the area of Austria is about 84,000 km². The surface of the lake itself comes to one-seventh of the entire catchment area and is about 15 times the size of Lake Constance. 15 times! The chances of a direct dip into the lake are not bad.
Splash! You landed. In the middle of the highest commercially navigable lake in the world at more than 3800 m above sea level! You look around, turn around. You can see many other water drops smirking friendly. You decide to ask them about their journey and their experiences at a later occasion. First of all, you want to further explore your surroundings.
You can see a fish on your left. You approach him and ask him shyly who he is. He tells you that his name is Charles, that he is a trout, and that many friends of his kind live here in the lake. However, his former relatives live in Canada, a distant land he would like to visit one day. Charles introduces you to his friends. You recognize immediately that among them are other fish - catfish! You leave Charles alone and join a happy-looking catfish. From him you learn that all his ancestors lived here in Lake Titicaca - he would not know where else to live. After spending a while together with the colorful school of fish, you move on past an unknown underwater world.
You meet with an excitedly babbling drop of water. From his tirades, you can deduce that he has already traveled over a long distance, landed somewhere in the catchment, saw grazing lamas and alpacas, watched farmers at work, and then, for some time, examined the highlands from the inside: he infiltrated into the ground. Probably moving as interflow for some time, he reached a river. You imagine how beautiful the journey must have been in the river - surrounded by a unique Altiplano landscape.
Your new friend then landed in the larger and deeper part of the lake - the Lago Grande with an average depth of 125 m. This is almost as deep as St. Stephen's Cathedral in Vienna is high! You imagine what it would be like, so far down in the deep. You ask yourself which living beings would exist there, and if you could see something down there. You are very excited and want to know more about each other's journey. He tells how he travelled through the Straits of Tiquina to the smaller part of the lake and finally met you here. You ask him if he knows exactly where you are. "Sure!" He replies in astonishment, "in the Lago Menor, just before the Río Desaguadero."
You wonder if you would have liked to land somewhere in the catchment and to have a long trip all the way to the lake - yes, definitely! Half of the rain drops - like you - fall directly on the lake surface, whereas the other half, like your friend, enters the lake through tributaries. The major meeting point for all water drops in the catchment area is exactly here - in Lake Titicaca! You are happy to have so many friends around you! You wonder if there is the same number of water drops in the lake all year round and decide to find an answer to this question.
You are approaching the shore, hoping for human help on this issue. On the way there you pass many fishing boats, fish, aquatic plants, and other living beings. From some distance, you can see a group of young people, presumably students, listening attentively to the words of a man who repeatedly points to the lake in your direction. You see your chance to learn more about the exciting waters and head straight for it!
You were right! The man is talking about the water balance of the lake. "Over the year, the water level varies by about one meter on average. In some years it can also vary by up to ten meters. This is strongly related to a weather phenomenon known as El Niño". Oh wow! Up to ten meters! Even a meter of difference all over the lake surface would be a huge amount of water. You try to imagine how many water drops could fit into this volume. Unimaginably many! Suddenly you feel very small, compared to this big lake.
You hope that you can learn more and decide to stay here for a while. "More than 90 per cent of the lake water goes away through evaporation", the man explains. Oh gosh, it's probably going straight back up to the clouds. You decide to hope for the remaining 10 per cent so that you can continue your journey on the surface of the earth. "What happens to the remaining water?" a young lady asks. Yes, this you would like to know! "They flow into Río Desaguadero and continue to Poopó Lake. In periods after heavy rainfall, the journey of some of the water continues all the way towards the salt deserts of southwestern Bolivia", the professor explains. "The rainy season brings about 80 per cent of the annual rainfall to the Altiplano. This concerns the months of December to February, the summer here in the southern hemisphere." You are very impressed by all these new pieces of information you have just received. You think about which time of the year it could now be. You are calculating, thinking about the various conversations, and finally coming to the conclusion that it must be March, shortly after the rainy season. This means that the water level of the lake must be rather high and the chances of traveling to Lake Poopó would be not so bad. What a joy! So your adventure here in Bolivia can go on! There is still so much to discover.
Despite your euphoria about the new possibilities, you can still hear how the professor explains that the lake is very important for the climate and therefore for the farming and growing of potatoes, corn, barley, oca and quinoa around the lake. It thus acts as a climate regulator. What would it look like without the lake? A barren landscape? You are even more excited about the beautiful environment and that it is the way it is.
As you slowly move away from the student group to make your way to Río Desaguadero, the voices fade away in the middle of the explanation that the lake was probably created tectonically, this means by plate movement and resulting uplift and subsidence. A girl tells that she has heard from a tourist guide that there would be fossils providing evidence of sea water. But now you are too far away to understand more words. The wind is blowing softly and you are moving away from the shore.
You look forward to the upcoming adventures in the Río Desaguadero and enjoy the sunset. What will the coming days bring?
