Açude Poço Branco is the fourth largest reservoir in Rio Grande do Norte, with a storage capacity of 136 million cubic meters. It sits on the rio Ceará-Mirim in the Agreste potiguar region, approximately 62 to 64 kilometers from Natal. The dam was inaugurated in 1969, constructed in response to a devastating flood in 1964 that destroyed the original settlement of Poço Branco, and it remains central to the municipality's water supply, irrigated agriculture, and recreational life.

The reservoir supports a registered fishing community of around 160 fishermen, and irrigated farmland extends roughly 16 kilometers along its margins, benefiting more than 400 families. These working uses of the water are worth keeping in mind when planning a paddling trip, as boat and fishing activity can be expected. The municipality has hosted nautical events on the reservoir, including a recurring Encontro Náutico, indicating that the water body is actively used for recreational boating.

The climate is semi-arid, with temperatures ranging from around 19°C at night to 36°C during the day. Rainfall is concentrated between March and July, which is the period most likely to bring the reservoir to higher levels. The dam overflowed in June 2024 for the first time in 15 years, reaching full capacity, which illustrates how variable water levels can be across years in this drought-prone region. During drier years, the reservoir may sit well below capacity.

A balneário known as the Balneário da Casinha is located in the area, and there is open space near the dam structure used for recreational purposes. The water that exits the reservoir flows down the rio Ceará-Mirim toward the coast at Extremoz. The surrounding landscape is caatinga vegetation, typical of the northeastern Brazilian semi-arid interior.