Worse, it could cause flooding rather than prevent it. Sometimes it's easier to see what happens when people try to create complex systems and don't use systems engineering. Hubble was a recent, high-profile example. When the telescope was launched, it was discovered that the mirror had not been ground correctly. At least, that's what sound systems engineering would have proposed.
Piecemeal development treats each part of some eventual system as independent.
In the process, the developers of each separate part do their best, we might hope and expect, to produce the optimum part or product. This message is pretty obvious if you think about it. Imagine some surgeon-type deciding to optimize the human heart by creating a new mechanical replacement. Some students trying this as an exercise produced a fine mechanical heart. There are ways to optimize parts of a system.