Maybe don't full on bring it on because it will be a disaster, but... if anyone wants to learn how to make this not be quite such a huge problem, they can familiarize themselves with the hydrology concepts covered in the youtube channels of Andrew Millison, Brad Lancaster, John D. Liu, Geoff Lawton. There has been a ton of quality work already done, and it has been well documented.

tldr - megaflood can be prevented by building earthen berms throughout the landscape to catch, spread, and sink rainwater runoff into the ground, thereby recharging aquifers and preventing catastrophic flooding.