Açude Aires de Souza, also widely known as Açude Jaibaras, is a reservoir in the northern part of the state of Ceará, constructed on the course of the Rio Jaibaras. It spans the municipalities of Sobral and Cariré, with coordinates placing it at approximately 3°47'S, 40°31'W. Built and completed in 1936 by DNOCS (the federal agency responsible for water infrastructure in the Brazilian Northeast), the reservoir has a total storage capacity of 104.43 million cubic meters, making it a substantial body of water for the region.

The reservoir is situated near the district of Jaibaras, which falls within the municipality of Sobral. When water levels are high and the reservoir reaches or approaches its maximum capacity, the area draws increased numbers of visitors, suggesting that access to the waterfront is feasible at high water. A deactivated small hydroelectric plant exists at the site, which paddlers should be aware of as a structural feature in the vicinity of the dam.

Water levels in this semi-arid region are subject to significant seasonal variation tied to the Northeast Brazilian rainy season, which typically runs from roughly January through May. During drier periods, the reservoir can drop considerably below its maximum capacity, which would affect the extent of navigable water and access conditions. Planning a visit during or shortly after the rainy season offers the best chance of encountering fuller water levels.

The reservoir supports fish farming (piscicultura), indicating the presence of aquatic life and some level of ongoing water use management by local stakeholders.