A thousand-person crew swept the streets of this city daily and collected biodegradable trash to be incinerated for lighting. This city's thorough waste management system used canoes to collect human urine to use as a mordant in fabric dying as well as (-5[1])excrement for fertilizer, creating zero toxic waste. The residents of this (-5[1])city built a 10-mile-long dike to separate a neighboring saltwater lake from its (*) namesake freshwater lake. (-5[1])This city was supplied with water (10[1])by a dual-pipe (10[1])aqueduct (10[1])made (10[1])of clay that was rebuilt (-5[1])in stone after it was washed away by a flood. Lake Xochimilco (10[2])still contains examples (10[1])of the structures upon (10[2])which this city was built (10[1])in neighboring Lake Texcoco. (10[2]-5[2])For (10[1])10 (10[1])points, name this city built on artificial islands called chinampas, the capital of the Aztec empire. ■END■ (10[5])