[steve_adams_86]

Even here in wet Vancouver Island, British Columbia we have heaps of streams that are mostly gone by July. They are rain fed, the rain goes away, it’s just how some systems work.

I’m not saying everything is fine with the environment. Just, this is to be expected with a large number of streams in the world. Maybe it’s not alarming in each case.

[shotta]

I’m pretty sure the Mississippi River use to seasonally dry up in spots prior to the building of the lock and dam system.

[vmh1928]

In 2012 it was so low barge traffic came to a halt.

https://nation.time.com/2012/08/23/the-big-dry-up-where-the-... and https://stateclimatologist.web.illinois.edu/2012/11/27/why-t...

[positr0n]

Wow really? That is hard to believe given half the US drains through it. I can't find anything on Google on the subject though maybe I am using the wrong search terms.

[tjr225]

Or maybe you have no idea what you are talking about and are spreading misinformation?

[katbyte]

Are you sure you don’t mean snow fed? Lots of roaring rivers while it’s melting and then once the melt is done many shrink/nearly dry up.

Thou we have a ton of snowpack this year on the coast still

[steve_adams_86]

There are both, but we have many lower mountains that rarely get snow, let alone snow pack, but they have seasonal streams that can be quite large at the bottom of the water shed.

A decent example would be the French creek watershed by Nanaimo. I think it’s estimated that only 15% of the flow is from snow, with most of that portion flowing during spring. The rest is rain, mostly from higher up in the watershed.

This watershed doesn’t dry up entirely, but it naturally reduces dramatically by July with many of its tributaries vanishing completely. There are many like it without that 15% melt water, some of which mostly vanish under the bed rock and gravel depositions along the creek beds.

Unfortunately that’s also increasingly true, and it’s causing all kinds of species to die in watersheds that previously even supported multiple seasons of salmon runs. The last paper I read on French Creek suggested even swamps in the watershed were drying too much, killing insects and amphibians. Many streams have lost entire salmon runs due to drying too much, too often. It’s a fragile system. It seems like deforestation plays a major role in these watersheds drying out.