The R9 water distribution network is a medium-size municipal network in Joao Pessoa city – Brazil, implanted by urban water company in 1982, which consists of 53 nodes connected via 72 pipes and a reservoir. Table 2 provides the available diameters, Darcy-Weisbach coefficients and unitary prices for pipe investment. The minimum pressure requirement at nodes 1, 2, 3, 4, 5 and 6 is 25 m and the others nodes is 15 m.

TABLE
Pipeline data and costs

Diameter (mm) Darcy-Weisbach Coefficient Unit Cost (Cr$/m)*
100 0.01 1 629
150 0.01 4 054
200 0.01 5 769
250 0.01 7 718
300 0.10 9 237
350 0.10 11 012
400 0.10 12 397
450 0.10 15 501
500 0.10 17 686
600 0.10 23 132
* Current Brazilian currency in 1982 (Cr$ 90.60 = USD 1.00)

R-9 Network (file .inp)