>>512021656
Another factor in western hydrology is flash flooding. Flash flooding can occur in both winter and summer (everywhere except CA usually because the monsoons stop at the eastern side of CA mountain ranges typically). The variable nature of the flows makes it difficult to use for humans, but the natural ecology is well adapted to flooding. The main use humans have for flash flooding is to quickly refill reservoirs. If you build reservoirs in sequence, you can possibly significantly extend the total flow of a flash flooding event or season, making it last through the dry season even in giga shithole deserts. The downside is huge dams can destroy native fish populations by interrupting seasonal migration and breeding, making the water temperature much cooler and less turbid downstream, and withholding sediment action downstream which adversely effects plants living in the flood zones and on banks. Typically the best place to put dams ecologically would be in tight canyons where banks are tiny or almost non-existent.

Full dams differ from rocks dams by the fact that rock dams only slow down flow but still allow sediment to pass through after it builds up first. Rock dams also allow fish to pass through. Rock dams are not ideal on the larger rivers or creeks, but can be ideal on smaller perennial or intermittent creeks. As they build sediment, increase soil moisture and raise water levels, and allow for plant growth on banks, and they somewhat stabilize extreme floods by slowing the water down and keeping it around longer.

Pic related is a monsoon flooded river, it doesn't look it but it's actually more than 12 feet deep in the middle, probably closer to 15-20 ft.