Opened in May 2013, the Poxim-Açu River Dam, located in Povoado Timbó, in São Cristóvão, was planned to reinforce water security in the metropolitan region of Aracaju for 20 years. But, just over 13 years after its inauguration, the reservoir reached 20.5% of its useful volume, amid the drought associated with the El Niño phenomenon, according to data from the weather report released by the government of Sergipe this Friday (13).
El Niño is a climate phenomenon characterized by the abnormal warming of surface waters in the Equatorial Pacific, capable of altering rainfall and temperature patterns in different regions of the world.
According to information from the State Secretariat for the Environment, Sustainability and Climate Actions (Semac), the reduction in volume is related to the decrease in rainfall and the increase in evaporation caused by higher temperatures.
The percentage of 20.5% places the dam in the alert range of the state water safety classification. Between May and August 2026, Greater Aracaju recorded 565 millimeters of rain, a volume 35.9% lower than the 881 millimeters expected for the period. Starting next Monday (16), there will be water rationing in neighborhoods of Aracaju, São Cristóvão and Nossa Senhora do Socorro.
Construction of the dam began in 2001 and received an investment of R$85 million, in a partnership between the state and federal governments. It has the capacity to store more than 32 billion liters of water, measuring 15 meters high and 1,125 meters long.
The function of the structure is to reserve the waters of the Poxim-Mirim and Poxim-Açu rivers, important tributaries of the Poxim River. Currently, the reservoir is responsible for approximately 30% of Aracaju's supply. The other 70% comes from the São Francisco Water Pipeline.
The current crisis is attributed to the severe decrease in rainfall: the volume of precipitation was 68% below the historical average in 2026.
The dam's storage capacity is more than 32 billion liters of water. Normal consumption is around 1.4 billion liters per week.
With the soil dry and without rain, the entry of new water into the reservoir dropped by almost 70%. As weekly consumption remained at normal levels, but natural replenishment practically stopped, the dam has been losing around 2% of its reserves each week.
The government of Sergipe uses four classifications to monitor the water safety of reservoirs: normal, attention, alert and emergency.
The classification considers the percentage of the useful volume of water stored:
Normal: above 50%;
Attention: between 30% and 50%;
Alert: below 30%;
Emergency: below 10%.
With 20.5% of the useful volume, the Poxim Dam is in the alert range. The classification allows monitoring the conditions of reservoirs and guiding the necessary measures to address the reduction in water availability.
In the bulletin released on November 13, the government also reported that the Jacarecica I Dam, in Itabaiana, had 44.9% of its useful volume, remaining in the attention range. The other four reservoirs monitored by the state were classified as normal.
There is a possibility that the dam will reach the so-called 'dead volume' between the end of December 2026 and the beginning of January 2027, if the reduction in the level continues.
The usual water collection in the dam occurs by gravity, through a vertical tube equipped with two passage windows. The dead volume is the water reserve that is stored below the lowest window of this tube.
To be able to use this emergency reserve if the level continues to fall, Deso is investing around R$3.5 million. The plan envisages the installation of two floating rafts equipped with motor pumps, which will pull water from the bottom of the dam.
Actions are divided between immediate restrictions and engineering preparations:
Rationing: temporary blockage of water flow from November 16th, from 10pm to 7am, in neighborhoods of Aracaju, São Cristóvão and Nossa Senhora do Socorro.
Emergency capture: assembly of the floating raft structure to access the dead volume.
New disciplinary measures: if the dam reaches dead volume, Deso and the state government do not rule out the adoption of even stricter restrictions on consumption.
Other coping actions, such as the reactivation of the Poxim II system, which will help reduce water withdrawal from the dam, the operation of the São Francisco 1 and 2 pipelines, which are already working at maximum capacity, in addition to the drilling of seven new wells.
The situation also led to the cancellation of New Year's Eve in Aracaju and summer festivals, with the aim of redirecting resources from parties to reduce the impacts of shortages. The values of the resources have not yet been announced.
The rational use of water by the population is essential to avoid more severe measures during the hottest months of the year. Reducing time in the shower, suspending the washing of sidewalks and cars and combating internal leaks are fundamental attitudes to contribute to the longevity of the system.
Although 16 municipalities are in an emergency situation due to the drought, as of this Friday (13), according to Civil Defense, there is no provision for rationing in the conventional network at this first moment.
To supply the population in the areas most affected by the drought, 210 water trucks are in operation in the impacted locations.
In the municipality of Poço Redondo, 184 km from the capital of Sergipe, producers report the impact of the lack of water and the prolonged drought that hits the region.
