The second case study is also a real problem, in the city of Itororó, Brazil. Figure 2 presents the WDN topology, with 1 reservoir, 20 pipes linking 17 demand nodes, 3 loops, and a hydraulic pump with a water catchment level of 222 m, responsible to pump water to the reservoir. Table 6 presents the nodes and pipes characteristic. Available set of seven distinct commercial diameters are presented in Table 7, with the respective costs. In this case, the costs in R$were converted from USD (USD 1 = R$ 4). The water velocity must be bounded between 0.2 and 3.5 m/s and the minimum required pressure is 15 m for all demand nodes. The Darcy–Weisbach equation is used and a roughness coefficient equal to m for all pipes was considered. The water kinematic viscosity at 20 °C is m2/s. The pump efficiency is 75% and 7,300 h/year is considered as the operation time. The energy cost is 0.134 $/kWh and the annual interest rate is 10%. The lifetime considered is 25 years and the annual increase in the energy is 6%. Table 6 Nodes elevation and demands and pipe lengths Node/PipeElevation (m)Demand (L/s)Pipe length (m) 220.5 5.05 324 215.6 1.91 124 210.4 3.81 184 210.5 1.40 206 209.5 4.35 103 213.2 3.51 202 218.5 3.44 134 230.7 2.48 227 211.5 3.06 167 10 213.5 1.85 166 11 205.5 2.86 152 12 208.8 6.11 168 13 215.5 5.09 177 14 212.6 4.06 225 15 207.5 8.05 254 16 219.4 4.26 263 17 220.5 1.21 133 18 321 19 105 20 169 Node/PipeElevation (m)Demand (L/s)Pipe length (m) 220.5 5.05 324 215.6 1.91 124 210.4 3.81 184 210.5 1.40 206 209.5 4.35 103 213.2 3.51 202 218.5 3.44 134 230.7 2.48 227 211.5 3.06 167 10 213.5 1.85 166 11 205.5 2.86 152 12 208.8 6.11 168 13 215.5 5.09 177 14 212.6 4.06 225 15 207.5 8.05 254 16 219.4 4.26 263 17 220.5 1.21 133 18 321 19 105 20 169 Table 7 Costs for the commercial available diameters for the Itororó WDN Diameter (m)Cost ($/m)Diameter (m)Cost ($/m) 0.0534 24.16 0.2042 87.62 0.0756 32.12 0.2520 118.59 0.1084 47.09 0.2998 152.24 0.1564 63.80 Diameter (m)Cost ($/m)Diameter (m)Cost (\$/m)
0.0534 24.16 0.2042 87.62
0.0756 32.12 0.2520 118.59
0.1084 47.09 0.2998 152.24
0.1564 63.80
Figure 2

Itororó WDN.

Figure 2

Itororó WDN.

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