Bioswales?

[NineOfClubs]

So are there many of these where you live?

Portland is constructing hundreds, if not thousands, of these bioswales to prevent runoff reaching the river through storm drains.

They come in all shapes and sizes, with varying vegetation.

 

[NineOfClubs]

Here's another. Newly constructed with starter plants.

 

[Corny]

I am not sure what distinguishes them from usual "plant filled green patches along the road"? Are those special plants for the job?

 

[NineOfClubs]

Many seem to have "drains" deep beneath the surface to take filtered water to the sewage system.

Others seem to just absorb all the runoff from sidewalks and roads and return it to the earth.

I thought the genesis of this was European and expected guys from there to say "we've had these for decades".

 

[Corny]

yes, we have had those for decades basically on every street here. but i never heard that they were there for this purpose. that's why I am asking

In some towns you can get official permission to add plants to them if they look too boring in front of your home

But I am not entirely sure if it is the same thing. They certainly do take dirt out of the rainwater and filter it. I do not know if some of them are connected to the drains.

 

[NineOfClubs]

yes, we have had those for decades basically on every street here. but i never heard that they were there for this purpose. that's why I am asking

In some towns you can get official permission to add plants to them if they look too boring in front of your home

But I am not entirely sure if it is the same thing. They certainly do take dirt out of the rainwater and filter it. I do not know if some of them are connected to the drains.

They replace drains. On corners with bioswales there are no storm drains.

 

[blackbeltninja]

^I'm probably being dense, here, but if there are no drains and you have say twenty minutes of heavy rain which could really cause trouble how do they get water off the roads quickly? The bioswales seem to have banked sides and it looks like water won't just flow in there like it does down a gutter in those pictures.

Or are there still drains in the road but just not on the walkways?

-d-

 

[NineOfClubs]

^I'm probably being dense, here, but if there are no drains and you have say twenty minutes of heavy rain which could really cause trouble how do they get water off the roads quickly? The bioswales seem to have banked sides and it looks like water won't just flow in there like it does down a gutter in those pictures.

Or are there still drains in the road but just not on the walkways?

-d-

All runoff, roads and sidewalks, is directed to them.

The bioswales are sunken. Lower. And seem to be able to take on a lot of water.

My question is that if there were ever heavy summer rains, couldn't they become a breeding ground for mosquitos, etc.?

P.S. I'd like to show you more pictures but there are few on the internet. I see dozens every day, no two alike.

 

[Corny]

They replace drains. On corners with bioswales there are no storm drains.

in the first pic it looks like there is a drain right next to it?

 

[NineOfClubs]

I'm not seeing it.

 

[blackbeltninja]

^The yellow drain, sort of almost at 9 o'clock in the first pic.

-d-

 

[NineOfClubs]

^The yellow drain, sort of almost at 9 o'clock in the first pic.

-d-

The "yellow" thing is a speed bump for the blind and disabled.

All our new intersections have them. They're building many more with "stimulus" money.

 

[Corny]

aah my mistake. kinda looks like our drains
those speedbumps are called "tactile paving" or "stripes" here and they are adding them virtually everywhere in the bigger cities now. i think it's a good thing

 

[pat grimshaw]

They are now being introduced in Australian cities to allow stormwater to seep into the ground and reduce the amount running into the ageing underground pipes.

I am not sure what distinguishes them from usual "plant filled green patches along the road"? Are those special plants for the job?

Australia's seem to be like the Portland pictures in that they are being planted with plain 'Prairie Grasses' like Lomandra, Dianella and South African Dietetes.

 

[Harke the Boeotarch]

So are there many of these where you live?

No. Not in central Amsterdam. Can you guess why?

 

[T-Rexx]

Many seem to have "drains" deep beneath the surface to take filtered water to the sewage system.

I suspect that none of them actually drain to the sanitary sewage system. That would be rather old-fashioned design.

At one time, combined storm and sewage drainage was routine in the USA. Today, most cities have separated the storm sewers from the sanitary systems. The problem is that sanitary sewers drain to a treatment plant (or, at least, that's the idea ). Such plants cannot accommodate the sudden increase in water volume that comes with even a routine rainfall. That forces them to "bypass", which means they dump raw, untreated sewage into the nearest open waterway. Obviously not preferred.

A number of cities (notoriously Cincinnati, OH) continue to maintain ancient (>100 year old) combined storm and sanitary drainage systems. Cincinnati long ago reached a point where even the lowest flow levels in their system were too much for their treatment plants to accommodate. They therefore treat only a fraction of the city's sewage at the best of times, dumping much of it into the Ohio River as raw, untreated waste. When it rains, Cincinnati treats almost none of its sewage.

The solution to the problem is to monitor levels of E. coli bacteria (from the human gastrointestinal tract) within the Ohio River and issue warnings to the population to stay away from the river when the bacteria levels are too high.

 

[pat grimshaw]

I'm not getting how runoff water makes it into those medians. ?…

The Sydney ones are definitely below the normal street level. The two Portland pictures show breaks in the kerb for water to drain into.

 

[fetaby]

couldn't they become a breeding ground for mosquitos, etc.?

Mosquitos only breed on still/stagnant water. If the water isn't draining away, the design of these features is busted.

 

[pat grimshaw]

I like how interesting words are coming into use like 'swales' and 'gabions'

 

[NineOfClubs]

The Sydney ones are definitely below the normal street level. The two Portland pictures show breaks in the kerb for water to drain into.

Exactly.

There are gaps on both the street side and the sidewalk side designed to catch water.