One of the characteristics of the Caroní's water is the dark color, caused by the high amount of humic acids due to the incomplete decomposition of the phenol content of the vegetation.

In the late 1940s diamonds were found in the Caroní basin near the famous Lost World Region which then was accessible only by aircraft and four wheel drive vehicles.

Because of its high discharge rate, with a yearly average of 4,850 cubic metres per second (171,000 cu ft/s) and a steep slope, the Caroni ideally suited for the generation of hydroelectric energy with four plants along its course (Macagua I, II and III), near its mouth, the Caruachi, some 30 kilometres (19 mi) aback, and lastly the plant of Guri, in the middle of Necoima or Necuima, some 80 kilometres (50 mi) from Puerto Ordaz.

This plant has its reservoir, with an area of 4,000 square kilometres (1,500 sq mi), in the middle of the river, and has a power of 10,000 MW, and is now the third biggest in the world, after the Three Gorges dam in China (22,500 MW) and the Itaipu Dam in Paraguay and Brazil (14,000 MW) In the high basin of the rivers that form the Caroni (Aponguao, Cuquenán and Yuruaní) the Gran Sabana is spread out, partly belonging to the Canaima National Park.

Besides the devastating effects of logging and deforestation to clear the site for the mines, the far greater danger is the use of mercury which poisons the Caroní river, its fauna and inhabitants living along its shore.