2023-07-13 23:30:00
June 2, 2022
June 13, 2023
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The water supply for millions of inhabitants in and around the Uruguayan capital of Montevideo reached critically low levels in the fall and winter of 2023 in the southern hemisphere. The shortage has come as two main freshwater reservoirs serving the region, Canelón Grande and Paso Severino, have almost completely dried up.
As of June 28, the larger of the two, the Paso Severino reservoir was estimated to contain only 2.4 percent of its 67 million cubic meter capacity. Increasingly salty water was coming out of household taps, and the government implemented emergency actions to provide citizens with drinking water.
The image above, acquired by the Operational Earth Imager 2 (OLI) aboard the Landsat 9 satellite, shows the reservoir on June 13, 2023, about a week before the Uruguayan government declared a water crisis. . The image below shows the reservoir almost a year earlier, on June 2, 2022. This image was acquired by the OLI aboard the Landsat 8 satellite.
The images have added color to make it easier to distinguish the water, which in 2023 registered the largest decrease in volume in its history. With this band combination (6-5-3), the water appears dark blue and the vegetation appears light green. In fact, ground-level observations match some of the stark differences between the two scenes, finding that grass grows where there used to be water.
The region is in the midst of a multi-year drought, the consequences of which have been highlighted in recent months. In late April, anticipating short-term water shortages, the water supply company began rendering the supply by mixing it with brackish water from the Río de la Plata estuary.
Shortly after, in early May, the country raised the limit for allowable levels of sodium in the water system to 440 milligrams per liter (mg/L). As points of comparison, many US state and federal agencies recommend a maximum level of 20 mg/L for very low sodium diets and 270 mg/L for moderate sodium restricted diets. While the Uruguayan government declared the utility’s water potable, it advised people who are pregnant, have high blood pressure, or have kidney disease to limit or avoid drinking tap water.
On June 19, a state of emergency came into effect in the Montevideo metropolitan area. With the measure, the government guaranteed the supply of drinking water to hospitals and other critical institutions; it also eliminated taxes on bottled water. In addition, it will provide hundreds of thousands of Montevideo residents with funds to buy bottled water, according to press reports.
The country has recently invested in water infrastructure projects, including the development of a new drinking water source. In the meantime, however, relief will have to come in the form of rain.
NASA Earth Observatory images by Wanmei Liang, using Landsat data from the US Geological Survey. Reporting by Lindsey Doermann.
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