The Paraguay River reached its lowest level ever measured, according to the Brazilian Geological Survey (SGB), reaching 62 centimeters below the reference level. The series of measurements was initiated by the Navy in 1900, at the Ladário post, near the city of Corumbá (MS), on the border with Porto Quijarro (Bolivia). The previous minimum, recorded in 1964, was 61 centimeters below the level.
The standard level is 5 meters (m) of average depth, according to the Mato Grosso do Sul Environmental Institute (Imasul), which had already issued a warning about the river’s lowest historical level last Wednesday (9). , based on own measurements. The station serves as a reference for the Navy in analyzing navigation conditions and defining restriction measures.
The Paraguay River flows through the states of Mato Grosso, where it originates, and Mato Grosso do Sul, from where it goes to Paraguay and Argentina. Its springs are fed by waters that come from the Amazon, such as the Rio Negro. The region is also experiencing historic drought. According to the National Water Agency (ANA), the Paraguayan Hydrographic Region occupies 4.3% of the Brazilian territory, covering part of the states of Mato Grosso and Mato Grosso do Sul, which includes most of the Pantanal of Mato Grosso, the largest area continuous humid climate on the planet.
For the SGB, the situation had been expected since February, when researchers warned about the possibility of reaching a historic low in the region. “This drought has been observed due to below-normal rainfall throughout the rainy season, since October 2023. Therefore, we have been warning about this process that was taking place in the basin”, explains researcher Marcus Suassuna in the institution’s note.
According to Imasul, the drop in Paraguay’s level has direct implications for the economy and the environment, affecting tourism and fishing, in addition to the supply of riverside communities. ˜Experts associate this drastic reduction with climate variability and the lack of rainfall in the river basin. The Pantanal, one of the most fragile and important biomes on the planet, is particularly vulnerable to these changes, which affect both biodiversity and human communities”, highlights the institute in a note.
Slow recovery
According to SGB projections, the recovery of levels in the Paraguay River Basin will be slow. The level in Ladário (MS) should remain below the quota until the second half of November. “We observed that the river’s rate of descent has decreased considerably and was stabilized since last Monday (7) due to these first rains of the rainy season. Rainfall is expected to continue, but not at a very strong rate that will contribute to rapid rises in this section and throughout the basin”, analyzes Suassuna in the note.
The decade has been marked by insufficient rainy seasons for the reserves to recover. According to the SGB, during the rainy season starting in October 2023, an accumulated deficit of 395 (millimeters) mm of rainfall was recorded. The estimated total was 702 mm, while the expected average would be 1,097 mm. In the decade, considering the accumulated period from 2020 to 2024, the deficit was approximately 1,020 mm, a value equivalent to the total of one hydrological year.
Also according to the SGB report, last week, the Paraguay River Basin recorded a volume of rain of 3 mm. The rivers in the region have levels below normal for this period of the year, with the exception of the Cuiabá River, which has a level within expectations. The situation on the Cuiabá River, however, is due to the regularization of flows caused by the operation of the Manso Hydroelectric Plant.
In Barra do Bugres and Porto Murtinho, the Paraguay River reached the lowest level in the history of the entire station monitoring series. The study explains that the projections used indicate rainfall accumulations of 27 mm in the coming weeks, leading to the beginning of recovery in levels in Cáceres, Ladário, Forte Coimbra and Porto Murtinho, in addition to stabilization in other locations.
According to the National Electric System Operator (ONS), considering the estimate for Affluent Natural Energy (ENA), the South Region should reach 86% of the Long Term Average (MLT). The measure indicates the capacity of hydroelectric generation systems. For the other regions, the rates are as follows: North, with 49% of MLT; Southeast/Central-West, with 45%; and Northeast, with 34%.
Navigation risks
The Navy maintains a series of alerts for the Paraguay River, most of which indicate worsening navigation conditions. In one of them, it states the need for safety precautions. “Due to the rigid drought regime observed on the Paraguay River and the consequent outcrop of sandbanks and rocks, navigators must double their attention, making use of the nautical chart in force, paying attention to the markings and maintaining a safe speed.”
Furthermore, before starting navigation, you should consult the daily nautical radio warning bulletin available on the website from the Oeste Hydrography and Navigation Centerin order to check the difference between the river level and the reference level on the nautical chart (nr), possible changes in the marking and other warnings for the safety of the navigator.
The region has had constant boat traffic since at least the 18th century, establishing an important integration corridor with neighboring countries. Today it is one of the six waterways whose bidding for concession to the private sector is established as a priority by the National Waterway Transport Agency (Antaq), along with the Madeira, Tapajós, Tocantins, Lagoa Mirim and Barra Norte waterways. The project aims to accelerate the transport of cargo, especially agricultural and mineral production, for processing and export, which should favor the increase in the exploration of these items in the region, activities that lead to increased water consumption.
