It isnt an outlier - its a reality that every developer literally deals with and engineers/builds around. The need/complexity of those requirements is a fact of private property rights. See how the "rights" dont quite end on the property line?
I used an extreme example - because extreme examples of bring logic to its conclusion and filter it to reality that i keep trying to describe for you. Generally - you have to be legally responsible for the flood you create on your neighbors property - if someone can reasonably prove that you caused it. Further - why i wanted an extreme example, i didnt want to argue the semantics of science/physics with you.
Regulations requiring engineers to maintain pre-existing flow rates is preservation of property rights - not destruction. The guy upstream still maintains his right to develop, but he must put in controls (detention ponds for example) to stop additional flow on to your property.
Ok. Extreme real example-
Head over to the ambler's thread here. Then, come back here. You can practice all your theory, and when you enter reality, we can discuss again.
Otherwise, you're real extreme examples do nothing but serve your point, hence the need to go extreme.
And yes, the parking lot happens all the time...and people complain. All the time. Most of those complaints NEVER come to actual fruition. The few that do actually don't go to court, the ones that do usually wind up with 'well prove to me your foundation, your waterproofing are all adequately, competently installed Because just proving whatever I did that did not interrupt water flowing downhill to you, doesn't mean your structure is good to begin with
Enter more costs for downhill Harry homeowner. And it's valid. And it's what would occur. Then-after all that discovery and cost, we'll meet again, where downhill will be asked again- simply building a AHJ APPROVED, PERMITTED, INSPECTED AND VERIFIED (ie- ahj now owns liability and culpability), something that AHJ deemed safe and applicable....etc etc legalities and insurance.....more money...
Your Insurance is paying more than likely, unless you didn't inform them prior to suit, then 50/50 they pay.. More than likely not mine without you going uphill legally against the AHJ itself and me and winning....
So now, You're at least on a bad day 2:1 outspending me on legal fees, insurance will probably not cover your flood damage as A-act of God, B- you didn't provide insurance enough time prior to suit notification, and your choice, is sit and spend for 12 months minimum, regardless verdict.
At the end, win lose or draw on the deal I'm covered multiple ways, as is the city, you've spent thousands and at least a year in court, I've spent a few thousand that'll go against my burden on taxes and, probably, was already factored into the project as legal fees, and if there's some left over...bonuses.
So, your theoretical extreme vs my old everyday reality. Which do you think will win? Which is proven? The theory you stand behind at its extremes, or the realities of everyday life?
And a victory in court is not in the verdict but the quit. A win is a win is a win. And attrition gets an A for effort.