The maximum geodetic height difference in the system is about 93m (average 78m). Also the entire supply is
gravity driven due to the high elevation differences (see Fig. 1a). There are high demand variations throughout the
year. The factor for the highest observed peak flow of maximum day is 2.0 (regulative a peak factor of 1.7 would be
required [7]). That peak value only occurred one time in 10 years. Sorting the obtain values and evaluating the rank
of the events gives estimation of the return periods of the different peak days. The second highest observed value was
1.9 (return period 5years) and with a return period of 1years a factor of 1.87 occurred. For the hourly peak demand, a
maximum value of 7.15 was observed (only one time in 10 years) and the second highest value was 5.66. For a return
period of 1 year, a value of 4.71 was observed (regulative requirements are 2.64 [7]). For the peak hour on the
maximum day, the demand is more than 14 times (2.0 x 7.15) the average water demand. But also for these conditions,
the water can be supplied in the system with a minimal pressure of 16metres. With the regulative required peaking
factors (total factor of 1.7 x 2.64 = 4.5) a minimal pressure of 38metres was calculated with the Epanet2 model.