Lake Texcoco was the largest of five interconnected lakes. Since it formed in an endorheic basin, Lake Texcoco was brackish. During the reign of Moctezuma I, the levee of Nezahualcoyotl was constructed, reputedly designed by Nezahualcoyotl. Estimated to be 12 to 16 kilometres (7.5 to 9.9xa0mi) in length, the levee was completed circa 1453. The levee kept fresh spring-fed water in the waters around Tenochtitlan and kept the brackish waters beyond the dike, to the east.