The dam supplies drinking water, and supports industry, irrigation and fish farming.

[1] The reservoir covers parts of the municipalities of Alto Santo, Jaguaribara, Jaguaribe and Jaguaretama.

The river basin cover about 75,669 square kilometres (29,216 sq mi), over half the area of the state.

The idea of building the Castanhão Dam came from the Cunha family, who led the region's oligarchy at the time.

[2] The Castanhão Dam was one of the most important projects of DNOCS (National Department of Drought Works).

A new seat, Nova Jaguaribara, was built, but as of 2016 there were still outstanding claims for indemnification of lost land.

[2] The giant dam supplies water to the Metropolitan Region of Fortaleza and supports irrigation and the industries of Pecém.

It controls the level of the Jaguaribe River, preventing floods and ensuring a constant flow year round.

[7] At the end of 2012, the first year of low rainfall, the reservoir had 3,725,880 cubic metres (131,578,000 cu ft), or 55.61% of its capacity.

[4] By February 2016 the dam was releasing just 5 cubic metres (180 cu ft) per second, but water levels were dropping 1 centimetre (0.39 in) per day due to evaporation and consumption.

[5] By mid-2016, following low rainfall and high consumption, the reservoir was down to just over 550,000 cubic metres (19,000,000 cu ft).