Açude Arrojado Lisboa, widely known as Açude Banabuiú, is a large reservoir in the sertão central of Ceará, built on the rio Banabuiú — the principal tributary of the rio Jaguaribe — within the municipality of Banabuiú. Construction was carried out by the Departamento Nacional de Obras Contra a Seca (DNOCS), with works completed in 1966. The reservoir holds approximately 1.7 billion cubic meters at full capacity, making it the third largest in Ceará and the largest within the rio Banabuiú sub-basin. Its coordinates place it at roughly 5°20'S, 39°00'W, about 240 km from Fortaleza — approximately 3.5 hours by car via the BR-122 toward Quixadá, then the CE-138 toward Banabuiú, with paved road all the way to the town center and the dam roughly 4 km beyond.

The reservoir's water level fluctuates considerably. It has overflowed its spillway only twice in its history — in February 2004 and May 2009 — and reached a critical low of just 0.39% capacity in February 2017. As of April 2024 it stood at approximately 42% of capacity. Paddlers should check current levels before planning a trip, as low water can significantly alter the character of the reservoir and access conditions.

The reservoir is well regarded for sport fishing, particularly for tilápia — with specimens above 3 kg recorded regularly — and tucunaré, which have established themselves well over the years. Boat rentals are available in the town of Banabuiú, and local fishermen familiar with the water can be hired as guides, which is advisable given the reservoir's large size. Accommodation options exist in Banabuiú, Quixadá, and Senador Pompeu.

Given the sertão location, sun exposure is intense and paddlers should carry ample water, electrolytes, and sun protection. Early morning departures are recommended to take advantage of cooler temperatures and calmer conditions before midday heat sets in. The reservoir's primary designated purpose is water resource management — supplying human consumption, supporting irrigation, and controlling flooding — so paddlers should be aware that operational releases of water can occur and that the reservoir serves a critical regional function.