Depollution of Urban Rivers

[north 42]

The Detroit River has been so cleaned up, river otters have returned to the area after an absence of over 100 years.

https://www.greatlakesnow.org/2022/0...detroit-river/

[Yuri]

Originally Posted by north 42

The Detroit River has been so cleaned up, river otters have returned to the area after an absence of over 100 years.

https://www.greatlakesnow.org/2022/0...detroit-river/

I follow some Detroit pics Instagram profiles, and I saw this pic of the Riverwalk and the water was crystal clear. It's surprising as it's rare in wide rivers.

How bad Detroit River was in the past?

[muertecaza]

Originally Posted by north 42

The Detroit River has been so cleaned up, river otters have returned to the area after an absence of over 100 years.

https://www.greatlakesnow.org/2022/0...detroit-river/

Awesome.

Unfortunately for Phoenix, the Salt River is unlikely to be restored any time soon. I suppose it's a different sort of "pollution" we'd have to deal with--even if the river could flow freely (which it won't in my lifetime, given the upstream dams, the water needs of a growing population and a decades-long drought), the mostly dry river bed would have to be restored from its long use as a gravel pit and the infestation of invasive plant species.

The best we could potentially do is to fund the 'Rio Reimagined' project, which John McCain made his pet project before he passed away. The proposal was to reinvigorate in various ways the ~60 miles of river that run through metro Phoenix. Unfortunately, after making some waves in local news a couple years ago, the project doesn't seem to have much momentum.

[The North One]

Originally Posted by Yuri

I follow some Detroit pics Instagram profiles, and I saw this pic of the Riverwalk and the water was crystal clear. It's surprising as it's rare in wide rivers.

How bad Detroit River was in the past?

Because it's not actually a river, it's a strait and it acts more like a lake.

But also pretty much all waterways in the great lakes system have crystal blue water.

[Yuri]

Originally Posted by The North One

Because it's not actually a river, it's a strait and it acts more like a lake.

But also pretty much all waterways in the great lakes system have crystal blue water.

Yeah, it's indeed not a river. In the pics it has a shape of a large river though and it's different to see such clear waters.

[Klippenstein]

Originally Posted by The North One

But also pretty much all waterways in the great lakes system have crystal blue water.

Isn't that mostly because of the invasive zebra and quagga mussels?

[The North One]

Originally Posted by Klippenstein

Isn't that mostly because of the invasive zebra and quagga mussels?

Not sure but if that's true why isn't every lake in America clear? Zebra mussels are pretty much everywhere.

They're also in the Mississippi.

[Yuri]

Are there pics of Detroit River dirty?

[woodrow]

Originally Posted by Klippenstein

Isn't that mostly because of the invasive zebra and quagga mussels?

In a word, yes.

Prior to the introduction/invasion of them the lakes were significantly less clear. The two mussels are very efficient at filtering plankton and other plant material from the water. The lakes are clearer but the ecosystem of the great lakes has been turned upside down.

https://oceanactionagenda.org/story/...food%20source.

https://www.greatlakesnow.org/2020/0...pact-good-bad/

Good article about the new normal in the Great Lakes -
https://www.greatlakesnow.org/2021/0...d-great-lakes/

[biguc]

This is a great thread topic.

At risk of getting reamed out by some random lurker for talking about a city I know, like, and care about--the one I live in--I'll post about Berlin. (I love your posts, muppet. Never change)


Berlin has had a reasonably well-publicized project underway for a while now to make one branch of the Spree along Museum Insel swimmable: Fluss Bad Berlin


https://berliner-abendblatt.de/2021/...net-im-sommer/

I don't know if that article is correct that it will open this summer.

Anyway, the plan is here:
https://www.stadtentwicklung.berlin....berlin-neu.jpg

There are already locks at the upstream end of Museum Insel to control water levels for shipping. To make this stretch clean, they'd add a marsh area at the upstream end, and divert a combined sewer that dumps sewage into the river during heavy rain.

I think Berlin has similar problems to London in that the old sewers will almost inevitably pollute the river when there's heavy rain. I understand there are further problems upstream with coal mining pollution, but I don't know if that affects the river by the time it reaches the city. Whatever the case, there's a lot of boat and barge traffic on the Spree and it's generally kind of nasty, in a city river way. I wouldn't wade it and expect to not step on something gross or sharp.

There are plenty of clean lakes around Berlin so it's not as though we need to swim in any given part of the Spree.

Cleaning up the Landwehr canal, on the other hand, would be wonderful. During covid summers, tour boat operation on the canal ceased, and everyone in Kreuzberg bought an inflatable boat and took the space back.



https://www.world-today-news.com/ber...andwehr-canal/

Dinghy parties on the Landwehr are really fun. But the canal is really gross. That doesn't stop everyone form getting in the water. People don't swim laps or anything, but I've seen people floating around in inflatable rings, with their junk in the water, or swimming to shore to buy beer. Seems like an invitation for a UTI.

Another Berlin waterway I'd like to see clean is the Panke, a pleasant small river in the north east.


https://www.tip-berlin.de/stadtleben...nim-bis-spree/

The Panke runs through a chain of lovely parks and some of those classic Berlin spots under train tracks where cultural spaces have emerged. It's never deep enough to be swimmable, but it seems like it would be a nice wading creek on hot days. I don't know how dirty it really is, but it probably picks up some agricultural effluents at its headwaters, and the usual storm sewer overflow here and there along the way. Whatever the case, nobody goes in the water. It would be nice if, at least in parts, it were deliberately cleaned and manicured for wading.

The Panke ends up in a culvert in the city centre, before it emerges again and dumps into Nordhafen. Were it clean, something like the Nordhafen Vorbecken would make a fun little swimming spot.


http://m.dein-plan.de/poi/53524_Sell...Berlin-Wedding

[acklac7]

The Scioto near Columbus, Ohio has been cleaned up quite nicely. Removed a Dam and redeveloped the area into a park called the "Scioto Mile":

Before:


After:

[iheartthed]

Originally Posted by Yuri

I follow some Detroit pics Instagram profiles, and I saw this pic of the Riverwalk and the water was crystal clear. It's surprising as it's rare in wide rivers.

How bad Detroit River was in the past?

It's not clear, but it is very blue. It is much bluer now than when I was a kid.

[muppet]

Those Berlin pics remind me of the Netherlands.


I visited Utrecht last month, just south of Amsterdam and a much prettier, cleaner version. It has a ring of canals that the entire city gravitates around, the sides lined with businesses, cafes, restaurants
and boathouses, with the waters used by canoeists, rowers, paddleboarders, picnic boats and party boats. It's one big parade as you eat al fresco on the sides. Lots of people also just sit on the cobbles
and have a few quaffs of beer or wine too.




The city centre is rammed with businesses that have converted the former below-street warehouses, every door a new restaurant or bar:






The local celebrations often use it - their Pride is fantastic as the floats literally do that:






I found Amsterdam to be dirty and chaotic, and often a tourist circus with more visitors than the national population (avoid main streets, dive down to parrallel ones). Utrecht is a nice antidote.

[Northern Light]

In 1969, a mock funeral was held for Toronto's Don River, which lies just east of the downtown area, and flows into Lake Ontario.

Here is CBC's digital archive of that event:

https://www.cbc.ca/player/play/1517591107745

The River has improved in health over the years with Beavers now often making their home along its banks; and a variety of other wildlife too.

I took this photo back in early June of this year, of a Double-Crested Cormorant in the River:



Today two more significant projects are under way.

One which will recreate a natural river mouth, and the associated nature, instead of the concrete channel where the river currently makes a hard-right into the Lake.

This render (one of many) reflects an idea of the hope for finished product:



You can see the new river valley being constructed in this photo. Its due for completion in early 2024:



In addition to that, a massive new storage and diversion tunnel is being built to divert all the combine sewer overflows which pollute this river (lower portion of River only for now); to holding tanks, whereafter the sewage would be pumped over the treatment plant, when conditions permit.

The outline of that project can be seen here:



This is one of the giant new holding tanks:

[nito]

Originally Posted by shadyunltd

I live in London, and I don't know anyone who would be willing to drink from or swim in the Thames, no matter how clean it is.

In the 1950’s – like most urban rivers – the Thames was biologically dead. Since then, a lot of investment has gone into cleaning up the Thames, such that there is now a diverse aquatic population including seals, sharks, whales, dolphins, seahorses and other marine life. The work isn’t yet complete; during extreme downpours there are discharges of untreated sewage which are hazardous to all life. The solution – for at least the next 100 years or until London reaches a population of 16mn – combined with green roofs and more porous urban environments is the Thames Tideway Tunnel, a 25km combined sewer tunnel which bisects existing sewers and follows the route of the Thames which should open in 2025.

• Video Link

Even with these investments, drinking from the Thames would possibly not be advisable due to non-sewage contamination such as animal effluence, fertiliser runoff, etc… further upstream.

Swimming is another matter and safe in most areas – I’ve swam in the Royal Victoria Dock – the biggest risk is from river traffic and the tidal nature of the river.

[mrnyc]

Originally Posted by woodrow

In a word, yes.

Prior to the introduction/invasion of them the lakes were significantly less clear. The two mussels are very efficient at filtering plankton and other plant material from the water. The lakes are clearer but the ecosystem of the great lakes has been turned upside down.

https://oceanactionagenda.org/story/...food%20source.

https://www.greatlakesnow.org/2020/0...pact-good-bad/

Good article about the new normal in the Great Lakes -
https://www.greatlakesnow.org/2021/0...d-great-lakes/

yes that is very true for lake erie, which is the shallowest great lake and often not clear water, albeit mostly due to churning water. the zebra mussels did a lot to make it clear, especially at first, but with the good comes the bad as they wreck the ecosystem, for example algae blooms and there are fish affected.

and speaking of lake erie, that leads to another great way to clear up waters, which is to get rid of industrial pollution. that is at least one good thing to be thankful for with the loss of big industry in the former rustbelt region.

[north 42]

Originally Posted by iheartthed

It's not clear, but it is very blue. It is much bluer now than when I was a kid.

It is much more blue now, but it is also much clearer, especially in late winter and early spring.

[Yuri]

Video about the rehabilitation of Los Angeles River:

• Video Link

From 2:20, there are plenty of images showing how the restored banks, vegetation and wildlife will be like.

It's obviously a great initiative, but I guess they could keep the current shape near Downtown. It's so Los Angeles.