The Represa De Ilha Solteira is a large reservoir formed by the Usina Hidrelétrica de Ilha Solteira on the Rio Paraná, marking the boundary between the states of São Paulo and Mato Grosso do Sul. On the Mato Grosso do Sul side, the reservoir borders the municipality of Selvíria, while the opposite bank lies within Ilha Solteira (SP). The dam itself is crossed by highway MS-444, which connects the two municipalities and serves as a significant regional transport link.

The reservoir is substantial in scale, with an average depth of 8 to 12 meters and a maximum depth of 65 meters. The underwater and shoreline structure is varied, featuring submerged trees (galhadas), sandy beaches, and steep embankments — characteristics that give the water body a diverse physical character and create notable depth changes in certain areas that paddlers should be aware of.

Water temperatures range from 24 to 28°C during the most favorable period for activity on the reservoir, which runs from March through July. This autumn and winter window corresponds to cooler, drier conditions in the region.

On the Mato Grosso do Sul side, there is an Área De Lazer, Camping E Picnic, which provides a point for reaching the water along with camping facilities. The Marina e Praia Catarina, located near the dam area, offers free public access, parking, and quiosques. The presence of the hydroelectric dam and its associated infrastructure means paddlers should remain well clear of the dam structure and be attentive to any operational activity in that zone.