The result is really interesting suburban infrastructure that reducing demand on the storm sewer. The Walmart parking lot isn't 5 acres of asphalt -- they left trees in place and have soil buffers with grass or other landscaping. Curbs are designed to direct water flow to those buffers.
I live in upstate NY, and even in that very different environment, those types of techniques as well as things like retaining pounds can really improve the situation with respect to flooding. Otherwise, the only way to remediate the impact of the increasing number of high volume thunderstorms is to dig up streets and build cisterns to sudden inflows.
To be fair just <something low cost, but high externalized cost> is a cheap and immediate solution. Lots of companies don't have the money for <high cost, low externalized cost>
"Kicking the can down the road" should be called out and minimized. The HN hivemind usually frowns on regulations, but I don't see another practical solution for protecting the community from environmental hazards?
Sadly, SF has done a pretty bad job managing this:
SF's esponse to this problem has shaken my confidence in the city's governance. SF is going in the opposite direction from what is suggested in this article - we are paving over (with non-permeable surfacing) more than ever. The common practice of paving over your front year for extra parking is generally illegal, but like most quality of life issues in SF, enforcement is so rare that the city created an entitlement - and it has become the norm in some neighborhoods.
I know some people my chuckle that this particular issue would cause me to question SF's government, considering what is going on. But I think it's the straightforward nature of this - the clear engineering failure, the cause and effect between excessive paving and storm system overflow, the unenforced legislation to curtail it, the massive city budget and projects without adequate funding for critical infrastructure... it's the mundane failures that really drive home how badly SF's government is handling serious problems.
We have a great example in Maine of how well CSOs can be addressed and minimized in the twin-cities of Saco and Biddeford. These two municipalities face each other across the Saco River and have separate waste water systems. They both have historical issues with CSOs and have been working to address them.
Saco worked quickly, spent a ton of money, and raised a lot of fees to upgrade their sewer infrastructure to minimize CSOs into the Saco River. They are largely complete with that work and total CSOs has dropped to under 1 million gallons per year estimated, and only 600k gallons in 2016 (highly dependent on rainfall).
Biddeford has been slower off the block, to be honest I'm not sure what they've accomplished although I know they've made progress. I believe a recent large Main Street reconstruction included CSO work. Their CSO discharge rate sits around 20-40 million gallons year year.
One big difference is that Saco charges an CSO impact fee on new sewer volume, currently $11.27 per rated gallon. I'm pretty sure that Biddeford doesn't charge a CSO fee at all, at least it's not detailed on their wastewater permit application.
A community is a reflection of it's citizen values. Care about CSOs? Talk about them, build consensus, and raise money to deal with them. There will always be someone complaining about the municipal fees to build and live in a particular community, don't let those individuals dictate the narrative and thereby the world you live in.
It's easier to see your impact in a small community (like Saco, ME) as compared to a large community (like San Francisco, CA), I get that. Don't get discouraged, keep working.
While the concepts may not be difficult, the scale often is.
See the Milwaukee deep tunnel system, storing 521 million gallons in 28.5 miles of tunnel.
But it does work: https://urbanmilwaukee.com/2014/06/12/murphys-law-the-remark...
"Too Big, Will Fail" is a pretty common refrain from anti-infrastructure personalities, but when it comes to simple civil engineering projects it doesn't matter what the scale is if the mechanism is proven. Solving CSOs isn't the Hyperloop, it's just building a bathtub big enough in the right place and figuring out how to drain it appropriately when it fills up.
Milwaukee, Chicago - these are examples that prove that stormwater management is a solved problem. So let's apply that solution to places where the problem still exists.
Anyways, cool link, I didn't know about Milwaukee's system.
Chicago's blows that away. 17.5 billion gallons of storage, 110 miles of tunnels. I think it's the largest current public works project in the US.
The problem is where policy becomes enforcement. San Francisco, I believe, isn't good at translating intent into reality.
Pave overs are actually a good example. San Francisco has very specifically illegalized front yard pave-overs, and the board of supervisors voted to increase the fines. However, very little budget (in a massive, massive city budget for a city SF's size) is allocated to enforcement. They're also in a bind now, as they have allowed the practice to go on so long, with such light enforcement, that it's going to be difficult to roll it back.
Another experience I had was replacing my windows with energy efficient, double pane, insulated windows. The Bush administration (George W) created a tax credit for energy efficient home improvements. Gavin Newsom, SF's liberal mayor at the time, talked quite a bit about about the importance of "Green" San Francisco.
Gavin Newsom's San Francisco collected permit fees that more or less confiscated George W Bush's federal tax incentives to encourage energy efficiency. Savor that for a moment. Ironic, isn't it? But to me, this story, along with the pave-over debacle, kind of gets at how SF goes wrong on so many things.
The program provides partial funding and reduced permit fees if homeowners arrange for at least four houses on a block to remove the concrete. Citizens are encouraged to become “ambassadors” and knock on neighbors doors and try to convince them to remove it. If the citizen fails to get enough neighbors on board? No funding.
To me, this program takes an issue of permit enforcement of critical importance to the infrastructure and pushes it out to people with zero authority, and asks them to knock on doors, explain the law, and ask if they’ll please consider complying with permits.
The government gets to duck the awkward business of enforcing a law that turned into an entitlement, while pretending to do something ang getting a smiling feel good photo op (win win!)
Meanwhile, where I live, pave overs continue apace with no apparent enforcement at all. Houses flood with raw sewage. In one recent storm, a dog was electrocuted in the flooded garage. This area is one of the few parts of sf with a high percentage of children, including lower income children.
It turns out the government does need to establish and enforce sensible laws.
That said: it’s often that the Bay is more socially progressive than fiscally or infrastructurally.
Plus they’re just shit at getting things done (often due to NIMBYism).
In decades past they voted for Nixon.
Here's an Australian product: https://www.grassreinforcement.com.au/
Here's another one: https://www.bunnings.com.au/cirtex-surepave-plastic-pavers_p...
Also, pave-overs are illegal in San Francisco - the problem is that the law is generally unenforced. Enforcement is complaint driven, and there's a huge backlog.
(I sort of understand not being able to convert lawn to concrete parking space, but this seems much more draconian).
According to this, it also reduces the amount of salt needed 75% for deicing and the pavement doesn't seem to have been damaged from reading the abstract.
Trees, grass, wetlands, etc, do better in part because they are preventing the water from leaving. They pool water in small puddles, they absorb water, leaves have water sit on them, etc.
It cost 3 billion dollars and took 13 years to build.
I would like to see how these held up during the tsunami.
You get 1. drainage, 2. reduction of heated urban micro-climates, 3. elimination of emissions, 4. "driving automation" in the sense that you don't really need to steer something on rails.
Steel wheels on steel tracks are way more efficient than rubber on asphalt. There are many reasons this hasn't been done already.
Ancient cities in Mesopotamia flooded. Ancient Rome flooded. Cities flood because they are built on or near bodies of water and bodies of water flood. The reason cities are built on or near bodies of water: water is a necessary condition for any city. Water is also an economic engine: fisheries, agriculture, waste removal, transport, trade. This makes flooding a price of doing business.
It's not that mitigation is a bad idea. The bad idea is that a city will never flood. Though it is theoretically possible, it is practically unlikely.
Houston had a prime opportunity in 1996 to do something similar when I-10 W was rebuilt- and engineers recommended building a conduit under I-10 to carry flood water from the Barker and Addicks reservoirs to the ship channel. Alas, that proposal was ignored so West Houston flooded during Harvey.
October 30, 2017: http://www.channelnewsasia.com/news/asiapacific/kuala-lumpur...
September 2, 2017: https://www.nst.com.my/news/nation/2017/09/275610/evening-do...
> One way to deal with flooding is to build highways in a manner where they become channels in such events
That's exactly what Houston did. The problem with this is that it makes evacuations more difficult and risky - the main ways for people to leave the city during a hurricane or flood become the canals for draining the water!
The bad idea is building in a place that was specifically designed to flood.
It's easy to look at Port Arthur, TX and think "Yep, of course that's going to flood." It's hard to look at Houston and think the same thing. The difference is a matter of frequency and relative extent not possibility.
Bad policy makes the effects of floods more costly.But good policy does not prevent floods.
Houston is designed like this as well (the Addicks and Barker reservoirs). But they are designed based on a given rate of rain over a given area. That assumption wasn't actually violated that badly by Harvey, it was within the margin of error. What was violated in the Houston flood model was the amount of hardscape and where the homes were. The assumptions about the amount of hardscape affects how much of a given rain will reach the reservoir (a lot never does to to evaporation or local use) as well as the rate at which that water reaches the reservoir. That whole system is designed to rate limit the flow of water into the core of the city of Houston. The model and assumptions were built when the core of the city was the main part of the city and the suburbs were much smaller. The water has to go somewhere, and it wants to go into the gulf of mexico...but the rivers and canals in the city core have a limited discharge rate into the gulf. Therefore the goal was based on creating a system that tolerated the hardscape based reduction of the cities 'sponge' and a greater reliance on the sponges of the suburbs. This is all not to mention that they actually built homes INSIDE the reservoirs that are a lot of what we talk about when we talk about the Houston flooding...those homes flooding was the system working as designed, the only people out of the loop were homeowners (slightly more true: and realtors, developers, and local officials who aren't hydrological engineers) . They should have known better but they didn't, because people tend to not notice, understand, or take seriously these details of municipal planning. Then they are shocked when either it works as designed (as a net positive for society at potential costs to individuals) or when it fails because choices made from lack of knowledge have blithly broken a system that is designed for emergencies. Think of it this way, there were people in the Houston gov who knew exactly what was going to happen...do you think talking about a biblical level flood in Houston was going to be taken as a more powerful narrative than 'economic growth, jobs, housing, american dream' when deciding on zoning permits?
TL;DR any sponge can become saturated but the point is that you should not artificially reduce the size of your sponge. Cities know how big their sponge is, its the ground around them. They make predictions and plans on it...and then subdivisions and growth massively seal off parts of the sponge.
The test is whether the sponge can absorb rain as fast as it can fall for a long-enough time that other consequences of the rain become serious problems (e.g. deferred outdoor maintenance), while the sponge still isn't saturated.
Still, many people are pushing it because you get more plants not because it's cost effective.