Flooding In Downtown From Hurricane Harvey

[cspwal]

Boston also places restrictions on increasing density for the same reason; their housing problem isn't as bad just because they have more land to spread out in (there's no bay between the city and the rest of the state)

[ADCS]

3 hours ago, HoustonIsHome said:

Who said that high density development would be worse? 

 It's the miles and miles of low density developments that are making it harder for the city to deal with excess water. 

 

And surface lots do not help drainage. They just pass water through. 

 

Concentrating development in a small area would leave  surrounding areas open for surface absorption and having a smaller area to with with means that the area requiring drains would not be miles and miles. 

Much easier to build drains for 610 area than the entire grand parkway catchment area

You're dead on, but the idea of cheap, low density development is too close to the heart of why a lot of people prefer living in Houston compared to other areas. It's a tough nut to crack.

[IronTiger]

43 minutes ago, HoustonIsHome said:

 

And surface lots do not help drainage. They just pass water through. 

 

 

It's the drainage below that makes the difference. I'm proposing something like this--right now I'm at work so I can't show you "before", but this used to be a Burger King surrounded entirely by parking lot with no real drainage. Today, it's a retention pond with no development, while still providing parking for the area. That's what there should be more of (a lot more of). It still "fits" in with development, isn't super-expensive, and adds far more benefits than drawbacks for reasons listed earlier in this thread.

https://www.google.com/maps/place/Almeda+Rd,+Houston,+TX/@29.7303881,-95.377226,89m/data=!3m1!1e3!4m5!3m4!1s0x8640eab710ba6797:0x665638146e08a4e5!8m2!3d29.6585817!4d-95.4016789

[samagon]

They were still pumping as of Saturday when I was out riding. I assume they are still pumping. There's a lot of water in the underground parking.

 

It'd be great if surface parking lots over a certain size were build below surface level, at least 3-4 feet so they could act as retention ponds.

 

I do get so disappointed by all these news agencies from other towns writing stories about how Houston development has caused this. the flooding is not an affect of development, it's an affect of the amount of rain. Here's an article with some great photos of an event that happened in 1978 in Alvin... 48" yeah, guess what, it flooded then too.

 

http://www.chron.com/news/houston-texas/texas/article/After-35-years-Alvin-still-holds-U-S-record-for-5644837.php#photo-6640233

 

these photos are remarkably similar to what we saw just a few days ago.

 

the flooding we saw was not a result of development, maybe, MAYBE we can build smartly (or rebuild smartly) so that when Houston floods again there's less damage to homes and businesses. But the rain we saw was simply what it was, intense amounts of rain that overwhelmed the areas it fell in most heavily.

[ADCS]

1 hour ago, samagon said:

They were still pumping as of Saturday when I was out riding. I assume they are still pumping. There's a lot of water in the underground parking.

 

It'd be great if surface parking lots over a certain size were build below surface level, at least 3-4 feet so they could act as retention ponds.

 

I do get so disappointed by all these news agencies from other towns writing stories about how Houston development has caused this. the flooding is not an affect of development, it's an affect of the amount of rain. Here's an article with some great photos of an event that happened in 1978 in Alvin... 48" yeah, guess what, it flooded then too.

 

http://www.chron.com/news/houston-texas/texas/article/After-35-years-Alvin-still-holds-U-S-record-for-5644837.php#photo-6640233

 

these photos are remarkably similar to what we saw just a few days ago.

 

the flooding we saw was not a result of development, maybe, MAYBE we can build smartly (or rebuild smartly) so that when Houston floods again there's less damage to homes and businesses. But the rain we saw was simply what it was, intense amounts of rain that overwhelmed the areas it fell in most heavily.

 

We still built where we knew it was going to flood. That's a direct result of development policy.

[Nate99]

For a 1/500 chance, most people mentally igore it or, just figure the mitigation will suck, but they will deal with it at that time.

 

Here we are. It will be interesting to try and see if planning can come up with something that is worth the tradeoffs.  

[IronTiger]

1 hour ago, ADCS said:

 

We still built where we knew it was going to flood. That's a direct result of development policy.

I hope you're talking about specific areas like Canyon Gate, which was built below the Addicks Reservoir level and no real way to drain out, but I don't think you are. Pointing to development that was flooded and saying that it was "development policy" is very broad strokes. Steps can be taken to alleviate that flooding, but shrugging and just blaming the flood plain is like saying Amsterdam, which is often cited as "ideal" urbanism, should be leveled because it's below sea level and thus liable to flood. However, Amsterdam has built ways to prevent it from becoming flooded, so no demolition is necessary. Houston is above sea level, so that's even better as far as flood control goes.

[Ross]

34 minutes ago, IronTiger said:

I hope you're talking about specific areas like Canyon Gate, which was built below the Addicks Reservoir level and no real way to drain out, but I don't think you are. Pointing to development that was flooded and saying that it was "development policy" is very broad strokes. Steps can be taken to alleviate that flooding, but shrugging and just blaming the flood plain is like saying Amsterdam, which is often cited as "ideal" urbanism, should be leveled because it's below sea level and thus liable to flood. However, Amsterdam has built ways to prevent it from becoming flooded, so no demolition is necessary. Houston is above sea level, so that's even better as far as flood control goes.

Canyon Gate was built in the Barker Dam, not Addicks. That's the result of a developer being willing to pay too much for land, more than the CoE could pay to expand the area of the reservoir.

[HoustonIsHome]

7 hours ago, ADCS said:

You're dead on, but the idea of cheap, low density development is too close to the heart of why a lot of people prefer living in Houston compared to other areas. It's a tough nut to crack.

I was not arguing for denser development, I was arguing against the assertion that sprawl mitigates flooding.

 

The poster I responded to stated that it was good that we are so spread out Because it would have been worse if we were compact. I am asserting the opposite.

Reducing the area of surface absorption and increase concrete area just increases water levels down stream.

 

I bet you many shopping strips with seas of parking was once natural retention ponds. With all of these areas paved over the water just pools and drifts to the south. 

 

Neither sprawl not high density areas improve the flooding conditions of an area, but sprawl sure does make it worse.

[IronTiger]

13 minutes ago, HoustonIsHome said:

I was not arguing for denser development, I was arguing against the assertion that sprawl mitigates flooding.

 

The poster I responded to stated that it was good that we are so spread out Because it would have been worse if we were compact. I am asserting the opposite.

Reducing the area of surface absorption and increase concrete area just increases water levels down stream.

 

I bet you many shopping strips with seas of parking was once natural retention ponds. With all of these areas paved over the water just pools and drifts to the south. 

 

Neither sprawl not high density areas improve the flooding conditions of an area, but sprawl sure does make it worse.

But if we were talking about retention ponds, it's irrelevant if it's sprawl or high density.

 

College Station, Texas doesn't tend to flood due to higher elevation and less rainfall in general. But it does get rainfall from time to time. At some point in the not-too-distant past (roughly 2004-ish but after the 1990s), they began requiring detention ponds for all development. A lot of the older shopping centers and buildings will have wet parking lots for days after a rainfall, while the ones with large detention ponds (like the one that was built in the middle of the Walmart parking lot during a redevelopment of the building, replacing a storm drain) dry off very quickly. Even larger developments have retention ponds, and many neighborhood parks are built around these ponds (as a component, not as the main park). College Station is a sprawl-oriented town, single family homes stretch for miles with nary a building higher than two stories in sight save for the occasional large hospital, hotel, or apartment complex.

 

Houston still has a lot of sprawl but it has none of the retention ponds that development (of any type) needs to not flood. Again, I suppose you could blame development for not having it these years, but it's something that can be corrected retroactively without significantly changing the exist cityscape. Oh, and that little parking lot and greenspace I showed you earlier?

 

Here's what it looked like circa 2001. By this point, the 1970s-era Burger King had closed and redevelopment was just a few years away, but you get the idea. A building sitting on an entirely paved lot with what looks like a giant puddle formed in the corner because there's practically no drainage. That's bad. That's what we want to avoid.

 

Instituting that new development have retention ponds while rehabbing grayfields into attractive little green space will make the city less suspect to flooding while making things a little greener.

[BeerNut]

What's the opinion on permeable parking lots?

[Houston19514]

On 9/5/2017 at 6:47 PM, IronTiger said:

But if we were talking about retention ponds, it's irrelevant if it's sprawl or high density.

 

College Station, Texas doesn't tend to flood due to higher elevation and less rainfall in general. But it does get rainfall from time to time. At some point in the not-too-distant past (roughly 2004-ish but after the 1990s), they began requiring detention ponds for all development. A lot of the older shopping centers and buildings will have wet parking lots for days after a rainfall, while the ones with large detention ponds (like the one that was built in the middle of the Walmart parking lot during a redevelopment of the building, replacing a storm drain) dry off very quickly. Even larger developments have retention ponds, and many neighborhood parks are built around these ponds (as a component, not as the main park). College Station is a sprawl-oriented town, single family homes stretch for miles with nary a building higher than two stories in sight save for the occasional large hospital, hotel, or apartment complex.

 

Houston still has a lot of sprawl but it has none of the retention ponds that development (of any type) needs to not flood. Again, I suppose you could blame development for not having it these years, but it's something that can be corrected retroactively without significantly changing the exist cityscape. Oh, and that little parking lot and greenspace I showed you earlier?

 

Here's what it looked like circa 2001. By this point, the 1970s-era Burger King had closed and redevelopment was just a few years away, but you get the idea. A building sitting on an entirely paved lot with what looks like a giant puddle formed in the corner because there's practically no drainage. That's bad. That's what we want to avoid.

 

Instituting that new development have retention ponds while rehabbing grayfields into attractive little green space will make the city less suspect to flooding while making things a little greener.

 

FWIW, I'm pretty sure we do require new developments to have detention, and have for some time.

[mollusk]

Much of the development to the west and northwest occurred on former rice fields - which flood as part of growing rice.  They flooded to only a foot or so of depth, but it's still a form of detention (and good bird hunting) we no longer have.

[Joke]

On ‎9‎/‎5‎/‎2017 at 6:47 PM, IronTiger said:

Houston still has a lot of sprawl but it has none of the retention ponds that development (of any type) needs to not flood. Again, I suppose you could blame development for not having it these years, but it's something that can be corrected retroactively without significantly changing the exist cityscape. Oh, and that little parking lot and greenspace I showed you earlier?

 

Here's what it looked like circa 2001. By this point, the 1970s-era Burger King had closed and redevelopment was just a few years away, but you get the idea. A building sitting on an entirely paved lot with what looks like a giant puddle formed in the corner because there's practically no drainage. That's bad. That's what we want to avoid.

 

Instituting that new development have retention ponds while rehabbing grayfields into attractive little green space will make the city less suspect to flooding while making things a little greener.

 

I'm no engineer, but I think these retention ponds would've done nothing to mitigate the effects of Harvey.

 

Yes, it would be helpful for a small rain event in an are that's susceptible to local flooding. But you're likely looking at just keeping a few inches of water off the streets. And I think projects like the big culvert they're building at the edge of Midtown/Montrose (I think Taft and Fairview area) are more likely to be the solution to that sort of local flooding problem.

[IronTiger]

3 hours ago, Joke said:

 

I'm no engineer, but I think these retention ponds would've done nothing to mitigate the effects of Harvey.

 

Yes, it would be helpful for a small rain event in an are that's susceptible to local flooding. But you're likely looking at just keeping a few inches of water off the streets. And I think projects like the big culvert they're building at the edge of Midtown/Montrose (I think Taft and Fairview area) are more likely to be the solution to that sort of local flooding problem.

I don't think any FEMA flood maps have been released, but there are areas in Houston more susceptible to flooding than others. Obviously, a retention pond in Midtown won't save Meyerland, but as a whole, they should reduce the effects of flooding, and even a "few inches" can make a big difference in house flooding, and even roads.

 

From what I saw in maps what was flooded and what had dried off, Interstate 10 east of 610 West had dried off quickly because retention ponds had been built (I seem to recall reading that when the Tax Day Floods happened last year). Southwest Freeway near University Place also seemed to dry as well because it was a modern highway built with systems in place to prevent catastrophic flooding (it too, was dealt with post-Allison). But Beltway 8 near Town & Country Village wasn't afforded those same sorts of benefits, being years older, and filled up with water. From driving it (before it flooded, obviously), there are small roadside drains that can drain off in a normal rainstorm but are completely inadequate to drain off huge floodwaters in a major rain event. Now, there were a few retention ponds in related to the Katy Freeway rebuild, but that was for the Katy Freeway...allegedly, before the rebuild, the frontage road intersections (which were a full level underground, not sure about that now) would get quite wet even during a significant rainfall.

 

[phillip_white]

I'm not sure if this is part of the plan, but wouldn't the current re-design of 45 being below grade through downtown double as a massive detention pond? They could actually use the underground culvert idea to push water into it once the bayou elevation reached critical flood stage. That amount of water being moved would most definitely curb the damage in downtown, but I guess you have to look at the cost/benefit for flooding vs shutting down a major interstate artery.

[cspwal]

45 is currently already shutdown in downtown because of the Dallas Dip - though without that dip you'd still have flooding from white oak

 

edit: I meant during a bad storm not right now

[UtterlyUrban]

4 hours ago, phillip_white said:

I'm not sure if this is part of the plan, but wouldn't the current re-design of 45 being below grade through downtown double as a massive detention pond? They could actually use the underground culvert idea to push water into it once the bayou elevation reached critical flood stage. That amount of water being moved would most definitely curb the damage in downtown, but I guess you have to look at the cost/benefit for flooding vs shutting down a major interstate artery.

Interesting......

 

why nut nut dig a HUGE cistern below this new freeway?  Yes, I know that it would costa fortune but.......other than that, why not?  Make it like 10 stories deep..... huge.... concrete it in...... would hold a lot of water...... wow.  Will never be funded but, wow.

[Ross]

8 hours ago, phillip_white said:

I'm not sure if this is part of the plan, but wouldn't the current re-design of 45 being below grade through downtown double as a massive detention pond? They could actually use the underground culvert idea to push water into it once the bayou elevation reached critical flood stage. That amount of water being moved would most definitely curb the damage in downtown, but I guess you have to look at the cost/benefit for flooding vs shutting down a major interstate artery.

My rough estimate is the depressed portion of the freeway would cover about 27 acres of horizontal space, so 20 feet of depth would provide 540 acre feet of detention, 23.5 million cubic feet. That's 28 minutes of the 14,000 cfs flow from Addicks and Barker. That's just to give an image of the water volumes, not to say there's anything wrong with the concept. To put it another way, that's less than the runoff from 12 inches of rain on Midtown.

 

The reality is that an event like Harvey can only be partially mitigated, as we probably cannot afford to design for 36+ inches of rain in two days. at least not without Houston as we know it disappearing.

[UtterlyUrban]

On 9/9/2017 at 1:54 AM, Ross said:

My rough estimate is the depressed portion of the freeway would cover about 27 acres of horizontal space, so 20 feet of depth would provide 540 acre feet of detention, 23.5 million cubic feet. That's 28 minutes of the 14,000 cfs flow from Addicks and Barker. That's just to give an image of the water volumes, not to say there's anything wrong with the concept. To put it another way, that's less than the runoff from 12 inches of rain on Midtown.

 

The reality is that an event like Harvey can only be partially mitigated, as we probably cannot afford to design for 36+ inches of rain in two days. at least not without Houston as we know it disappearing.

Thais is great info!  Thank you!

[HoustonMidtown]

A few "after" pics from today"

 

[H-Town Man]

Wow thats a lot of dirt.

[Triton]

2 hours ago, H-Town Man said:

Wow thats a lot of dirt.

 

Indeed.

 

 

Omni Hotel north of the Galleria by Marc longoria, on Flickr

[H-Town Man]

Wow thats a lot of dirt.

[samagon]

good opportunity to make Galveston island bigger

[corbs315]

I guess a lot of garages are still closed. I went to hobby center today to buy tickets (screw ticketmaster fees) and usually just have to park on 2...had to park on 6 today.

[UtterlyUrban]

I am being told that the wortham center is closed for flood related repairs until next summer.

[UtterlyUrban]

I am being told that the wortham center is closed for flood related repairs until next summer.

[Nate99]

On ‎9‎/‎17‎/‎2017 at 8:55 PM, H-Town Man said:

Wow thats a lot of dirt.

 

Brings up a whole set of questions, amazing.

 

I'm wondering how much silt has built up in Lake Houston since the last time it was dredged (if ever).

[H-Town Man]

7 minutes ago, Nate99 said:

 

Brings up a whole set of questions, amazing.

 

I'm wondering how much silt has built up in Lake Houston since the last time it was dredged (if ever).

 

I also recall reading in my trusty copy of "Houston: A History" by David G. McComb that after the 1935 flood, the ship channel was so laden with silt that it took months to re-dredge. I can only imagine that is the case today.