Açude Piracuruca is a large reservoir located in the municipality of Piracuruca in northern Piauí, Brazil, situated on the Rio Piracuruca within the Longá-Parnaíba basin. The dam was completed in 1997 and is operated by the state government of Piauí. With a maximum storage capacity of 250 million cubic meters (250 hm³) and a useful volume of approximately 235.93 hm³, it ranks among the larger reservoirs in the Parnaíba basin. The drainage area feeding the reservoir totals over 5,000 km². The main dam is an earthen zoned structure, 360 meters long and approximately 22.5 meters high above its foundation, with a maximum operational water level of 71.30 meters and a minimum operational level of 61.30 meters — a range of 10 meters that can significantly affect accessible shoreline and water depth depending on the season.

The Rio Piracuruca originates in the Serra da Ibiapaba at an altitude of around 650 meters, with its headwaters between the Serrote do Angical and the Serra dos Borges. The reservoir serves multiple purposes including public water supply for the city of Piracuruca and São José do Divino, irrigation, aquaculture, and animal watering. Pisciculture operations in excavated tanks exist in the reservoir's surroundings, which paddlers may encounter along the shoreline.

The Parnaíba basin holds recognized potential for water-based recreation such as boating, canoeing, and other nautical activities. Açude Piracuruca currently lacks designated paddling infrastructure or formal access points. Water allocation at the reservoir is managed through a formal commission involving state agencies including IDEPI and SEMAR-PI, reflecting active regulatory oversight of water use. Paddlers should be aware that the reservoir's water levels fluctuate seasonally and are subject to management decisions by state authorities, which can affect conditions on the water.