Evaluate the preparedness of the Tehran (capital of Iran) WDS. Because of the aging water distribution infrastructure of Tehran, the water pipe breaks are a common problem in this city. As there is not any rehabilitation program of aging pipes in this city, this problem is getting more severe over the time. The total length of pipes in the Tehran WDS is about 9,323 km and an informal figure of 700 pipe breaks in a day is quoted. This results in a break rate of about 8/100 km of pipes per day, which causes considerable water losses during a day. Furthermore, a lack of emergency teams in the nearby posts (say within 10-minute response time) has resulted in oscillating adverse factors of disengagements. So evaluation of system preparedness in dealing with this problem and developing strategies for increasing the system readiness are essential for the Tehran WDS.

The considered part of Tehran water distribution supplies water for 120,000 residents in an area of about 450 ha (1 ha = 10,000 m2). Maximum daily water consumption in this system is about 60,000 m³. The simulated part of the WDS of Tehran has been shown in Figure 11.7 . There are 35 main demand nodes with the total demand of about 0.51 cm and 78 water mains. The characteristics of the network are shown in Table 11.3 . The minimum and desirable pressures for this water

distribution network are 5 and 20 m, respectively.

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TABLE 11.3 Characteristics of Water Mains in the Simulated WDS Diameter (mm) 200 250 300 350 400 >400 Number of Pipes 30 18 11 1559 Total Length (m) 9,458 4,960 2,931 690 1,585 3,197