Civil Engineers with Experience Using the Colebrook Equation?

[C.Ret]

Hello everyone

What is missing here a good numerical example so that we can check assumptions or simply correctness of our computations.

Yesterday rain has fall all the day along. To avoid overflow in the installations, I had to open the valve and let charged water (sea water with decomposed biologic depots and organic mood) to flow through the canalization line (diam. 120 mm old iron coated with concrete) into the second main emergency retention basin. After 3 hours, I close the valve and notice that nearly 150 m3 of moody water stand now in the reservoir.

From your formulae, I calculate that the friction factor of the canalization is about 0.59
Is this correct ? May I suggest to my company head director to change the canalization and have easier or faster flow rate ?