The kingdom of Urartu, in the south of Armenia, was a powerful rival of Assyria during the period from about 850 BC to 600 BC. Its capital was Tushpa, on the shores of the lake Van, whose water is too salty to be potable. Therefore this capital city’s thirst led to the development of a vast water management program in this mountainous region, developed in successive stages (Figure 2.18).
In about 800 BC, the king Menua brought water to the capital from a perennial and abundant spring located some thirty kilometers to the southeast. The 56-km canal — aqueduct built for this purpose carried at least 1.5 m3/sec, and was destined to be used
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Figure 2.18 Water supply for the two successive capitals of Urartu (Tushpa and Toprak Kale) in the 8th century BC — after Garbrecht (1980, 1988). |
for 2,500 years until it was partially renovated in 1950.
Later, probably about 670 BC, the king Rusa II[77] [78] moved the capital some ten kilometers to the north (Rusahinili, today Toprak-Kale). The two rivers that supply the two cities, the Engusner and the Doni, are intermittent. Therefore the sovereign created an artificial reservoir, the Rusa lake (today this is the lake Keshish Golti, whose water level is 10 m lower than at the time of king Rusa). The lake was created by damming two natural outlets of a mountain basin. The north dam has been measured at 15 m high and 75 m long, and the south dam at 7 m high and 62 m long.
This south dam has been well preserved (it is no longer in contact with water, for the lake is now 10m lower). It is constructed of two walls of dry stone, each 7 m thick, containing an earth fill of thickness 13 m. Water is conveyed from this south dam to a secondary dam-reservoir on the Doni Cayi, in part to provide for irrigation of the Tushpa region. Later, other dams are built downstream on the two rivers, to increase the storage capacity.
Thus we see that the water management system of lake Rusa includes several dams. Over the centuries, the north outlet of the lake has apparently been destroyed and rebuilt several times, which may explain the existence of a dam attributed to Roman times, downstream on the Engusner Cayi. Its most recent reconstruction, lower than its original height, dates from 1950. The dam-reservoirs upstream on the Doni Cayi are still in service today. These are probably the oldest dams still in use[79] in the entire world.
