Why do infrastructure projects always cause trouble, even in the Roman Empire?

From the Letters of Pliny   

Book X,  letter XXVII

 

Pliny to the Emperor Trajan

 

The citizens of Nicomedia, Sir, have spent 3,318,000 sesterces on an aqueduct which they abandoned before it was finished and finally demolished.  Then they made a grant of 200,000 sesterces towards another one, but this too was abandoned, so that even after squandering such enormous sums they must still spend more money if they are to have a water supply.

 

I have been myself to look at the spring which could supply pure water to be brought along an aqueduct, as originally intended, if the supply is not to be confined to the lower-lying parts of the town.  There are very few arches still standing, but others could be built out of the blocks of stone taken from the earlier construction, and I think some ought to be made of brick, which would be easier and cheaper.

 

But the first essential is for you to send out a water-engineer or an architect to prevent a third failure.  I will add only that the finished work will combine utility with beauty, and will be well worthy of your reign.

 

 

Letter XXXVIII

Trajan to Pliny

 

Steps must be taken to provide Nicomedia with a water supply, and I am sure you will apply yourself to the task in the right way.  But for goodness' sake apply yourself no less to finding out whose fault it is that Nicomedia has wasted so much money up to date.  It may be that people have profited by this starting and abandoning of aqueducts.  Let me know the result of your inquiry.