watersym2.gms:

References:

• GAMS Development, Reformulation of Models from GAMS Library.
• Brooke, A, Drud, A S, and Meeraus, A, Modeling Systems and Nonlinear Programming in a Research Environment. In Ragavan, R, and Rohde, S M, Eds, Computers in Engineering, Vol. III. ACME, 1985.
• Drud, A S, and Rosenborg, A, Dimensioning Water Distribution Networks. Masters thesis, Institute of Mathematical Statistics and Operations Research, Technical University of Denmark, 1973. (in Danish)
• Original source: GAMS model waterx.gms from Gams Model Library

Points: p1  p2 
Best known point (p2): Solution value 940.92 (global optimum?, SCIP certificate)