Houston spent massively on new stadiums, not its aging dams. As Harvey proved, that was a very bad choice.

[SZonian]

Two Januarys ago, the City of Houston, after a delay of at least seven years, finally started a critical long-term project. It was patchwork on two dams constructed during the post-World War II era to protect the city from catastrophic flood and deemed by the U.S. Army Corps of Engineers to have fallen into as dangerous state of disrepair as possible. The cost: $72 million in federal funds.

Two decades ago, Houston found itself without a professional football team for the first time in seemingly forever. There was no holdup. There was no skimping.

The city immediately sought an expansion franchise from the NFL, won one, and within just three years was breaking ground for a new eighth wonder of the world, as its old Astrodome was called. It built the NFL’s first retractable-roof stadium. The cost: $449 million, including $193 million from the public.

[excerpted]
https://www.washingtonpost.com/sports/houston-spent-massively-on-new-stadiums-not-its-aging-dams-as-harvey-proved-that-was-a-very-bad-choice/2017/09/05/94d006de-923a-11e7-aace-04b862b2b3f3_story.html?utm_term=.c3df213a8203#comments

Houston's Mayors for the past 35 years...
Sylvester Turner D
Annise Parker D
Bill White D
Lee P. Brown D
Bob Lanier D
Kathryn J. Whitmire D

[thackney]

Two Januarys ago, the City of Houston, after a delay of at least seven years, finally started a critical long-term project. It was patchwork on two dams constructed during the post-World War II era to protect the city from catastrophic flood and deemed by the U.S. Army Corps of Engineers to have fallen into as dangerous state of disrepair as possible. The cost: $72 million in federal funds.

Two decades ago, Houston found itself without a professional football team for the first time in seemingly forever. There was no holdup. There was no skimping.

The city immediately sought an expansion franchise from the NFL, won one, and within just three years was breaking ground for a new eighth wonder of the world, as its old Astrodome was called. It built the NFL’s first retractable-roof stadium. The cost: $449 million, including $193 million from the public.

[excerpted]
https://www.washingtonpost.com/sports/houston-spent-massively-on-new-stadiums-not-its-aging-dams-as-harvey-proved-that-was-a-very-bad-choice/2017/09/05/94d006de-923a-11e7-aace-04b862b2b3f3_story.html?utm_term=.c3df213a8203#comments

Those dams are not city property.  They are owned and maintained by the feds.

[Bigun]

Those dams are not city property.  They are owned and maintained by the feds.

But it was Houston government that agreed to allow the construction of housing in the flood plain below those damns against the strong advice of that same Corp of Engineers. Albeit that was a long time ago.

[thackney]

But it was Houston government that agreed to allow the construction of housing in the flood plain below those damns against the strong advice of that same Corp of Engineers. Albeit that was a long time ago.

I would like to see the info for that advice.  So would those with homes in that area.

[the_doc]

@RoosGirl

But it was Houston government that agreed to allow the construction of housing in the flood plain below those damns against the strong advice of that same Corp of Engineers. Albeit that was a long time ago.

I would guess that it would take about half-a-trillion dollars, maybe even more than that, to make Houston safe from another storm as bad as Harvey.  It's probably more feasible to stop all of the cow farts.

[Bigun]

I would like to see the info for that advice.  So would those with homes in that area.

If I hadn't lost my main computer during the storm I would dig it up for you.  As it is I'm reduced to the use of this danged tablet on which I can accomplish little.

[Bigun]

@RoosGirl
I would guess that it would take about half-a-trillion dollars, maybe even more than that, to make Houston safe from another storm as bad as Harvey.  It's probably more feasible to stop all of the cow farts.

Which is worse?  Doing that or continuing to deal with the flooding that happens there all the time?

[RoosGirl]

I am not at all familiar with how Houston was developed, but I can tell you with 100% certainty, that you cannot design for the storm even they had there.  I mean, you *could*, but it's just not economically feasible to design for a 1000 year storm.
@the_doc

[SZonian]

The Latest: Engineers 20 years ago warned of flooding risk

A report released two decades ago about the Harris County reservoir system predicted with alarming accuracy the catastrophic flooding that would besiege the Houston area if changes weren't made in the face of rapid development.

The report released in 1996 by engineers with the Harris County Flood Control District says the Addicks and Barker reservoirs were adequate when built in the 1940s.

But it notes that as entire neighborhoods sprouted over the years around the reservoirs in western Harris County, as many as 25,000 homes and businesses at the time were exposed to the kind of flooding Harvey has now brought.

Engineers proposed in the report, obtained by The Dallas Morning News , a $400 million solution that involved building a massive underground conduit that would more quickly carry water out of the reservoirs and into the Houston Ship Channel.

Arthur Storey, who in 1996 was director of the flood control district, says he's embarrassed that he "was not smart enough, bold enough to fight the system" and implement an action plan to prevent the damages of Harvey from occurring.


http://www.sfgate.com/news/texas/article/The-Latest-Inmates-are-moving-back-to-12173465.php

[thackney]

The Latest: Engineers 20 years ago warned of flooding risk

A report released two decades ago about the Harris County reservoir system predicted with alarming accuracy the catastrophic flooding that would besiege the Houston area if changes weren't made in the face of rapid development.

The report released in 1996 by engineers with the Harris County Flood Control District says the Addicks and Barker reservoirs were adequate when built in the 1940s.

But it notes that as entire neighborhoods sprouted over the years around the reservoirs in western Harris County, as many as 25,000 homes and businesses at the time were exposed to the kind of flooding Harvey has now brought.

Engineers proposed in the report, obtained by The Dallas Morning News , a $400 million solution that involved building a massive underground conduit that would more quickly carry water out of the reservoirs and into the Houston Ship Channel.

Arthur Storey, who in 1996 was director of the flood control district, says he's embarrassed that he "was not smart enough, bold enough to fight the system" and implement an action plan to prevent the damages of Harvey from occurring.


http://www.sfgate.com/news/texas/article/The-Latest-Inmates-are-moving-back-to-12173465.php

Thank you for that, it would be $623 million in today's dollars.

[thackney]

Found a good graphic to help others understand the topic.



https://www.dallasnews.com/news/harvey/2017/09/05/houston-grew-officials-ignored-lifetime-chance-spare-thousands-flooding

[SZonian]

Thanks for the graphic, very informative.

That remark in the upper left about the neighborhoods flooded along both reservoirs...

I can't help but wonder what happened there with regards to building permits issued for those areas.

[thackney]

Thanks for the graphic, very informative.

That remark in the upper left about the neighborhoods flooded along both reservoirs...

I can't help but wonder what happened there with regards to building permits issued for those areas.

The are above the flood plain.  Just like homes near me but outside the flood plain still flooded.  The draw a line at the 1% chance and at the 0.2% chance.  While flooding can and did happen outside those bounds, most people accept the risk.  Well, most people probably don't understand the risk.

[Bigun]

Thanks for the graphic, very informative.

That remark in the upper left about the neighborhoods flooded along both reservoirs...

I can't help but wonder what happened there with regards to building permits issued for those areas.

They were issued despite the strong warnings of the Corp of Engineers not to do so.

[SZonian]

The are above the flood plain.  Just like homes near me but outside the flood plain still flooded.  The draw a line at the 1% chance and at the 0.2% chance.  While flooding can and did happen outside those bounds, most people accept the risk.  Well, most people probably don't understand the risk.

Thanks for the explanation, makes sense now.

I hope I chose correctly when I looked at the flood plain maps carefully before we bought our home in the desert here in CA...but if a 1000 year storm hits, all bets are off.

[SZonian]

They were issued despite the strong warnings of the Corp of Engineers not to do so.

No bueno...

[thackney]

Thanks for the explanation, makes sense now.

I hope I chose correctly when I looked at the flood plain maps carefully before we bought our home in the desert here in CA...but if a 1000 year storm hits, all bets are off.

I think, if you buy a home using a title company, they may have to disclose if you are in a flood plain.  I know the mortgage company is going to require flood insurance if you are in the flood plain.

But if you are outside a 0.2% recognized chance of flooding, it is hard to predict.  Nearly impossible predict with a storm like Harvey, 52" of rain???  How would you plan for that, and similar chances of other events?

[SZonian]

I think, if you buy a home using a title company, they may have to disclose if you are in a flood plain.  I know the mortgage company is going to require flood insurance if you are in the flood plain.

But if you are outside a 0.2% recognized chance of flooding, it is hard to predict.  Nearly impossible predict with a storm like Harvey, 52" of rain???  How would you plan for that, and similar chances of other events?

No flood insurance required, so under "normal" circumstances, we should be ok. 

Yeah...52+" of rain...just load up the family/pets/camping gear/valuables and vamoose to higher ground, which fortunately we have a lot of close by. 

I've always said if things get bad enough in CA I'd just toss the keys under the doormat and leave...nothing here worth dying over and it's not our "forever" home.

[RoosGirl]

They were issued despite the strong warnings of the Corp of Engineers not to do so.

In Florida the final permitting entity, usually a county or city, will require documentation from ACOE if you're developing within a flood plain.  They will not issue a permit without write off from ACOE.

But, again, you cannot design for 52" of rain over 72 hours.  That's close to our rainfall totals for the year.

[the_doc]

I am not at all familiar with how Houston was developed, but I can tell you with 100% certainty, that you cannot design for the storm even they had there.  I mean, you *could*, but it's just not economically feasible to design for a 1000 year storm.
@the_doc

You bet. 

The area of Houston is more than 600 square miles, and it is on or near the drainage path for areas vastly more than that.  Worst of all, the whole area of Houston is flat, so gravity-based drainage systems are slow.  And when nearby watercourses are overloaded, the situation is a bona fide disaster.  Not much can be done about it.

One of the other threads said that Harvey dumped something like 20 trillion gallons (over 4 days?).  I could not tell whether that amount was dumped on Houston alone (but I assume that it was being quoted for the City of Houston alone--since 20 trillion gallons is not that much for a city of 600 square miles). 

To illustrate the mess Houston encounters when the ground is completely saturated and when normal gravity systems are overloaded by torrential rainfall elsewhere in the watershed, let's assume that a mere trillion gallons has to be pumped away from Houston over four days' time.  A pumping station handling on the order of 200 million gpm would be required.  If my calculations are correct, a single 40-ft-diameter rainwater disposal pipeline back to the Gulf of Mexico could carry, at most, only 4000 cu feet per second, or only 1.8 million gpm.  On top of all of this, the wastewater collection infrastructure within the city for handling the load would be ridiculously expensive.

In short, without gravity drainage being available, there are some storms that a big city simply cannot handle.  But this has never happened to Houston before, because the inland areas of the watershed had never been drenched this badly.

     

[endicom]

The are above the flood plain.  Just like homes near me but outside the flood plain still flooded.  The draw a line at the 1% chance and at the 0.2% chance.  While flooding can and did happen outside those bounds, most people accept the risk.  Well, most people probably don't understand the risk.

Do a search on houston subsidence and that should show that the general area has sunk by as much as ten feet.

[Bigun]

You bet. 

The area of Houston is more than 600 square miles, and it is on or near the drainage path for areas vastly more than that.  Worst of all, the whole area of Houston is flat, so gravity-based drainage systems are slow.  And when nearby watercourses are overloaded, the situation is a bona fide disaster.  Not much can be done about it.

One of the other threads said that Harvey dumped something like 20 trillion gallons (over 4 days?).  I could not tell whether that amount was dumped on Houston alone (but I assume that it was being quoted for the City of Houston alone--since 20 trillion gallons is not that much for a city of 600 square miles). 

To illustrate the mess Houston encounters when the ground is completely saturated and when normal gravity systems are overloaded by torrential rainfall elsewhere in the watershed, let's assume that a mere trillion gallons has to be pumped away from Houston over four days' time.  A pumping station handling on the order of 200 million gpm would be required.  If my calculations are correct, a single 40-ft-diameter rainwater disposal pipeline back to the Gulf of Mexico could carry, at most, only 4000 cu feet per second, or only 1.8 million gpm.  On top of all of this, the wastewater collection infrastructure within the city for handling the load would be ridiculously expensive.

In short, without gravity drainage being available, there are some storms that a big city simply cannot handle.  But this has never happened to Houston before, because the inland areas of the watershed had never been drenched this badly.

   

Your post raises another important factor in the overall equation.  Almost all of the land along Buffalo bayou was raw land back when Addicks and Barker were constructed and coul absorb lots of water in that state whereas today much of that land has been paved over and thus cannot absorb anything.

[the_doc]

Your post raises another important factor in the overall equation.  Almost all of the land along Buffalo bayou was raw land back when Addicks and Barker were constructed and coul absorb lots of water in that state whereas today much of that land has been paved over and thus cannot absorb anything.

Right.  I just don't know how much (and how fast) that now impervious cover could have absorbed in a storm before it was paved over.  (Harvey was a big, bad storm over a huge watershed--and there is a limit to the capacitance effect of unpaved ground--especially when the upper aquifer is so shallow as I believe it is in the Houston area.)

[Bigun]

Right.  I just don't know how much (and how fast) that now impervious cover could have absorbed in a storm before it was paved over.  (Harvey was a big, bad storm over a huge watershed--and there is a limit to the capacitance effect of unpaved ground--especially when the upper aquifer is so shallow as I believe it is in the Houston area.)

I doubt that it made much difference in Harvey but flooding occurs there all the time and that paved over ground is a big factor in how sever the flooding becomes in those lesser events.

[Elderberry]

Do a search on houston subsidence and that should show that the general area has sunk by as much as ten feet.

Only a few isolated areas have shown that much(10ft) subsidence. Half that over a sizeable area.

http://hgsubsidence.org/wp-content/uploads/2013/07/SubsidenceMap1906-2000.pdf