The lake lies in the vast Balqash-Alaköl basin at 1,122 feet (342 m) above sea level and is situated 600 miles (966 km) east of the Aral Sea. It is 376 miles (605 km) long from west to east. Its area varies within significant limits, depending on the water balance. In years in which there is an abundance of water (as at the beginning of the 20th century and in the decade 1958–69), the lake's area reaches 6,900–7,300 square miles (18,000–19,000 square km).