How much do humans impact floods and droughts?

We know climate change leads to more floods and droughts. We also know that humans can change the flow of streams and rivers. But what happens when we put these two things together?

Singh and Basu (2022) investigated seasonal flow in natural and managed watersheds in the US and Canada. A watershed is an area of land where precipitation (snow and rain) drains into a common water body like a lake or river. What they found was that things like pavement, dams, and canals significantly alter the natural flows leading to more flooding and or more drought compared to their natural neighbours. In addition, managed watersheds had lower biodiversity.

So what does this mean? Not only are humans the major cause of climate change, but the impacts of humans on areas like watersheds also amplify the impacts of climate change making them more extreme. This has the potential to be a reinforcing feedback loop in our current system. Greater impacts lead to greater modification which increases the impacts and possibly also increases climate change depending on how those modifications are developed.

I just finished reading The Ministry for the Future by Kim Stanley Robinson. One of the scenes is a description of flooding that basically puts a large amount of California under water. Reading it was a very surreal experience because it was somehow unfathomable and completely realistic seeming at the same time. It is not a fundamental human characteristic to try to control nature. There are extensive examples throughout history of people working with nature but it requires systemic change for Western culture. It requires thinking of humans as part of nature rather than as separate and above. To which I wonder if we have the capacity to change that much?