I don't do photobucket. Is there a different way?Quote:
you can't figure out how to click a button to post a picture
Kingwood flooding doesn't pass the smell test
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Last: 5 yr ago by notheranymore
Host on imgur, upload to texags. Really simple.94chem said:I don't do photobucket. Is there a different way?Quote:
you can't figure out how to click a button to post a picture
I'm not sure what you are trying to prove with the Sand bar. There was tons of sand pushed downstream. Hell, they said that they are going to have to move more than 70,000 cubic yards of sand from Buffalo Bayou and that is much smaller than the San Jacinto river. That is what happens when everything everywhere gets flooded. Erosion is a thing.
Millions of cubic yards of sediment and sand were moved down stream with Harvey.
A new small sand bar in Lake Houston shouldn't be ground breaking to anyone.
What may be ground breaking, is that the USACE regulates that you have to get approval from them prior to ANY dredging activities, in order to be in compliance with the federal regulations.
A new small sand bar in Lake Houston shouldn't be ground breaking to anyone.
What may be ground breaking, is that the USACE regulates that you have to get approval from them prior to ANY dredging activities, in order to be in compliance with the federal regulations.
Those sand bars aren't small. Some of them are 10-15 feet high.
I don't think anyone doubts the enormity or the cost of the task ahead. But we already made this deal with nature by allowing unfettered development and mining all up and down our rivers and bayous. At this point, it's a question of do we want to spend millions and millions, to save billions and billions?
Just saying "to hell with it, there's nothing we can do and people should have known better", is not a responsible response. Houston has always lacked any semblance of real, responsible urban planning. We're just starting to really see a manifestation of that in a big way.
I don't think anyone doubts the enormity or the cost of the task ahead. But we already made this deal with nature by allowing unfettered development and mining all up and down our rivers and bayous. At this point, it's a question of do we want to spend millions and millions, to save billions and billions?
Just saying "to hell with it, there's nothing we can do and people should have known better", is not a responsible response. Houston has always lacked any semblance of real, responsible urban planning. We're just starting to really see a manifestation of that in a big way.
I didn't say "to hell with it". I'm just saying it should be surprising.
Let's just say it's 14 feet of material from top to bottom and covers half an acre (22,000 sq ft).
That's 11,000 CY of material.
In terms of material to be moved, it's a lot no doubt. In realative terms it isn't that much. The amount of material they are moving in Fort Bend County that sloughed off banks upstream is immense to say the least. The SAN JAC should have moved a lot more than what buffalo bayou did.
It needs to be addressed but it won't be a quick fix and will defintely take a while to complete.
Let's just say it's 14 feet of material from top to bottom and covers half an acre (22,000 sq ft).
That's 11,000 CY of material.
In terms of material to be moved, it's a lot no doubt. In realative terms it isn't that much. The amount of material they are moving in Fort Bend County that sloughed off banks upstream is immense to say the least. The SAN JAC should have moved a lot more than what buffalo bayou did.
It needs to be addressed but it won't be a quick fix and will defintely take a while to complete.
That sand bar has been there at least since 1998.
It's not new.
It was a great place to party with chicks and maybe later get some finger action.
It's not new.
It was a great place to party with chicks and maybe later get some finger action.
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that is where I perfected my finger koozie-ingScruffy said:
That sand bar has been there at least since 1998.
It's not new.
It was a great place to party with chicks and maybe later get some finger action.
Go back and look at GE historical images, the sand bar comes and goes. It was significantly bigger back in 1944, both upstream and downstream.Scruffy said:
That sand bar has been there at least since 1998.
It's not new.
It was a great place to party with chicks and maybe later get some finger action.
Are there any remotely sensible ideas being floated that would have prevented Lake Houston from getting that far out of its banks?
Maybe turning Cypress Creek, Spring Creek and the San Jac (both forks) into something akin to the LA River with big gates on the LH dam and everything downstream from there bought out and levee'd up would do it, but at some point the bay still meets you.
Maybe turning Cypress Creek, Spring Creek and the San Jac (both forks) into something akin to the LA River with big gates on the LH dam and everything downstream from there bought out and levee'd up would do it, but at some point the bay still meets you.
I was only a little bit serious. As in, "let's see pictures of the giant sandbar(s)".94chem said:Quote:
Pictures or it didn't happen.
Even if you were being serious, I don't know how to do that. Anyway, I wouldn't post pictures of my family here.
As far as not knowing how to do that, you have heard of Google haven't you?
Effective immediately the level of Lake Houston is being reduced from 42.5 feet to 40 feet. Once it reaches 40 feet, it is to remain at that level moving forward on a long term basis.
Lake Houston gaugeNomadicAggie said:
Effective immediately the level of Lake Houston is being reduced from 42.5 feet to 40 feet. Once it reaches 40 feet, it is to remain at that level moving forward on a long term basis.
I'm fine with that as long as they cut off all water supply to Kingwood during the next drought. We just flushed 9.6 billion gallons into the ocean. Would be interesting to see if residents would still want the lake lowered to prevent repairable flooding when their houses are on fire and not repairable.
The general reply on this forum to any action or suggestion to address flooding that occurred in the Kingwood area is essentially..."go f*&k yourself, you're stupid".
It's actually quite humorous. I guess you can be that way when you're home and possessions weren't destroyed. Aggie spirit indeed.
It's actually quite humorous. I guess you can be that way when you're home and possessions weren't destroyed. Aggie spirit indeed.
NomadicAggie said:
The general reply on this forum to any action or suggestion to address flooding that occurred in the Kingwood area is essentially..."go f*&k yourself, you're stupid".
It's actually quite humorous. I guess you can be that way when you're home and possessions weren't destroyed. Aggie spirit indeed.
Most of us are quite sympathetic to the people who's lives were destroyed. The issue arises when, contrary to all evidence, people default to some nefarious malfeasance rather than the watershed trying to absorb 50+ inches of rain in about 48 hours.
With a quickly increasing population, restrictions on ground water usage, an issue that affects the entire county and a drought recurrence about every 10 years, I firmly believe running out of water is a much bigger threat than preventing flooding from a 10,000-year storm on the San Jacinto River that affects a small portion of the county with normal lake levels. My Aggie spirit prioritizes ALL Aggies every decade, not just the ones that live in Kingwood once every 10,000 years.
I bought a house that doesn't flood, but has poor schools. Doesn't mean I think that other school districts' previous good decisions and hard work should be nullified or taken away so that my schools can be improved. I knew what I was getting into, and I choose not to blame others for my decisions. If we were flushing 9.6 billion gallons into the ocean because there's a massive tropical storm in the gulf headed this way, I'd fully support it. And I believe that was a mistake that was made last time. But doing this now is a monumental waste.
Incorrect.NomadicAggie said:
The general reply on this forum to any action or suggestion to address flooding that occurred in the Kingwood area is essentially..."go f*&k yourself, you're stupid".
It's actually quite humorous. I guess you can be that way when you're home and possessions weren't destroyed. Aggie spirit indeed.
The general reply to stupid suggestions that get brought up multiple times and have been shot down handily (with a whole lot of backup data explaining why) is "go f*&k yourself, you're stupid". Same goes with the implication that there is some conspiracy amongst various .gov entities to put it to Kingwood for one reason or another. It's just silly, and stupid.
Two and a half feet in the lake is worth how much at the level where housing starts? Something much less than that given the wider footprint, right?
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schmellba99 said:Incorrect.NomadicAggie said:
The general reply on this forum to any action or suggestion to address flooding that occurred in the Kingwood area is essentially..."go f*&k yourself, you're stupid".
It's actually quite humorous. I guess you can be that way when you're home and possessions weren't destroyed. Aggie spirit indeed.
The general reply to stupid suggestions that get brought up multiple times and have been shot down handily (with a whole lot of backup data explaining why) is "go f*&k yourself, you're stupid". Same goes with the implication that there is some conspiracy amongst various .gov entities to put it to Kingwood for one reason or another. It's just silly, and stupid.
The first 3-4 pages of this thread are full of factual information on why Kingwood flooded, yet not one of the conspiracy theorist want to address them.
So per the Lake Houston capacity curves here (https://waterdatafortexas.org/reservoirs/individual/houston/rating-curve/twdb/2011-12-01), the decrease in surface elevation increased the storage by 24,992.59 acre ft.
The peak flow rates of 400,000 cfs during the storm have already been well established here: (https://texags.com/forums/38/topics/2877197/replies/49766335)
That means that the lowering of Lake Houston has increased the time to fill from 476 seconds or about 8 minutes to 2721 seconds or 45 minutes.
That has bought you some time, and might help a bit in a small storm but probably not much. The reality is that the San Jacinto River is a big river and it pushes a lot of water downstream and Lake Houston is not that big of a lake comparatively.
I even said here (https://texags.com/forums/38/topics/2877197/replies/49787297) that even if Lake Houston was empty it would have taken only 3.5 hours to fill.
But Bravo to them for doing something that makes it look like they are listening to the people. I can't imagine doing that as an engineer. The only thing in modern time that is worse is the theoretical physicist Angela Merkel bowing to public pressure to say that nuclear power is unsafe and instead burning wood for power in Germany...
I hate stupid people.
The peak flow rates of 400,000 cfs during the storm have already been well established here: (https://texags.com/forums/38/topics/2877197/replies/49766335)
That means that the lowering of Lake Houston has increased the time to fill from 476 seconds or about 8 minutes to 2721 seconds or 45 minutes.
That has bought you some time, and might help a bit in a small storm but probably not much. The reality is that the San Jacinto River is a big river and it pushes a lot of water downstream and Lake Houston is not that big of a lake comparatively.
I even said here (https://texags.com/forums/38/topics/2877197/replies/49787297) that even if Lake Houston was empty it would have taken only 3.5 hours to fill.
But Bravo to them for doing something that makes it look like they are listening to the people. I can't imagine doing that as an engineer. The only thing in modern time that is worse is the theoretical physicist Angela Merkel bowing to public pressure to say that nuclear power is unsafe and instead burning wood for power in Germany...
I hate stupid people.
Politicians do what they must.FHKChE07 said:
So per the Lake Houston capacity curves here (https://waterdatafortexas.org/reservoirs/individual/houston/rating-curve/twdb/2011-12-01), the decrease in surface elevation increased the storage by 24,992.59 acre ft.
The peak flow rates of 400,000 cfs during the storm have already been well established here: (https://texags.com/forums/38/topics/2877197/replies/49766335)
That means that the lowering of Lake Houston has increased the time to fill from 476 seconds or about 8 minutes to 2721 seconds or 45 minutes.
That has bought you some time, and might help a bit in a small storm but probably not much. The reality is that the San Jacinto River is a big river and it pushes a lot of water downstream and Lake Houston is not that big of a lake comparatively.
I even said here (https://texags.com/forums/38/topics/2877197/replies/49787297) that even if Lake Houston was empty it would have taken only 3.5 hours to fill.
But Bravo to them for doing something that makes it look like they are listening to the people. I can't imagine doing that as an engineer. The only thing in modern time that is worse is the theoretical physicist Angela Merkel bowing to public pressure to say that nuclear power is unsafe and instead burning wood for power in Germany...
I hate stupid people.
SJRA may be more transparent/accountable in general coming out of all of this, but the whole narrative of blaming them is just a convenience thing. No one involved during Harvey was a PR professional, and that's enough for the actual PR professionals with an agenda to capitalize on.
FHKChE07 said:
So per the Lake Houston capacity curves here (https://waterdatafortexas.org/reservoirs/individual/houston/rating-curve/twdb/2011-12-01), the decrease in surface elevation increased the storage by 24,992.59 acre ft.
The peak flow rates of 400,000 cfs during the storm have already been well established here: (https://texags.com/forums/38/topics/2877197/replies/49766335)
That means that the lowering of Lake Houston has increased the time to fill from 476 seconds or about 8 minutes to 2721 seconds or 45 minutes.
That has bought you some time, and might help a bit in a small storm but probably not much. The reality is that the San Jacinto River is a big river and it pushes a lot of water downstream and Lake Houston is not that big of a lake comparatively.
I even said here (https://texags.com/forums/38/topics/2877197/replies/49787297) that even if Lake Houston was empty it would have taken only 3.5 hours to fill.
But Bravo to them for doing something that makes it look like they are listening to the people. I can't imagine doing that as an engineer. The only thing in modern time that is worse is the theoretical physicist Angela Merkel bowing to public pressure to say that nuclear power is unsafe and instead burning wood for power in Germany...
I hate stupid people.
The Ralph "I'm helping," gif comes to mind.
Useless waste of water.
"Useless waste of water."
Chill out. It will fill back up in 8 minutes.
Chill out. It will fill back up in 8 minutes.
As a lakefront home owner it makes me butthurt to think they would lower the pool 2.5ft permanently.
I fail to see how this would reduce flooding as it does not flash flood around the lake areas...it happens slowly and typically several days after water is crashing over the spillway.
Does anyone have a Solid answer in how long the pool will be changed?
I fail to see how this would reduce flooding as it does not flash flood around the lake areas...it happens slowly and typically several days after water is crashing over the spillway.
Does anyone have a Solid answer in how long the pool will be changed?
One month ago, it hardly rained and water was up onto Deerwood golf course. That has never happened before with such little rain. I'm not an expert, but I can tell you something is wrong with that.
evestor1 said:
Does anyone have a Solid answer in how long the pool will be changed?
This is permanent.
And 94chem, yes, it will fill up in 8 minutes and then they will dump it out again and again after that.
But one day in the future, it is not going to rain for a while and I bet you will wish you had 8 billion gallons of water that we didn't piss away so that people felt better, but it didn't actually provide any flood protection. Because it does provide real drinking water protection. And so does Lake Conroe.
I addressed this earlier in this thread that drinking water is very small in relation river flow/rain. The new Luce Bayou project that is bringing additional drinking water in from the Sabine River is only 775 CFS but it is a massive drinking water infrastructure project. Compare that to the flows that happened not only during harvey but often which are so much higher. That is why reservoir storage is talked about in acre ft. Otherwise the numbers would be too big to easily talk about.
It is all fine and dandy when you have your drinking water reservoirs full to say that you don't need them, but I bet if you talked to the people of Cape Town right now, they would wish they had an extra 8 billion gallons.
Lake Conroe and Lake Houston were built\planned when the droughts of the 50s were still on everyone's minds. In fact, the droughts of the 50s are what caused the original plan and money for flood control on the west side of town to dry up. The floods of the 30s had spurred the building of the Addicks and Barker Reservoirs, but there was two more major canals and another reservoir on White Oak in the plan, but since there was a major drought going on, it was decided that the money was better spent on water supply storage and so it was. That was the buzzword of the day. Why would we ever need flood control dams because we don't have any water?
There obviously is a balance that is required. The unfortunate part of this is that the topography around lake Houston does not allow for much use for flood control. Kingwood is not the only neighborhood in Houston to be faced with this. As FEMA and HCFCD continue to update flood maps, there are going to be unhappy people, but I doubt many will be surprised as they have had water in their house before. We can continue to artificially keep these places functioning but at what cost?
I feel sorry for those that live in these places because we have more information now or because the information was not as prescient when they chose to settle there. But willingly choosing to endanger the water supply of millions to save the few thousands that live in flood-prone area seems illogical.
but alas... here we are.
And 94chem, yes, it will fill up in 8 minutes and then they will dump it out again and again after that.
But one day in the future, it is not going to rain for a while and I bet you will wish you had 8 billion gallons of water that we didn't piss away so that people felt better, but it didn't actually provide any flood protection. Because it does provide real drinking water protection. And so does Lake Conroe.
I addressed this earlier in this thread that drinking water is very small in relation river flow/rain. The new Luce Bayou project that is bringing additional drinking water in from the Sabine River is only 775 CFS but it is a massive drinking water infrastructure project. Compare that to the flows that happened not only during harvey but often which are so much higher. That is why reservoir storage is talked about in acre ft. Otherwise the numbers would be too big to easily talk about.
It is all fine and dandy when you have your drinking water reservoirs full to say that you don't need them, but I bet if you talked to the people of Cape Town right now, they would wish they had an extra 8 billion gallons.
Lake Conroe and Lake Houston were built\planned when the droughts of the 50s were still on everyone's minds. In fact, the droughts of the 50s are what caused the original plan and money for flood control on the west side of town to dry up. The floods of the 30s had spurred the building of the Addicks and Barker Reservoirs, but there was two more major canals and another reservoir on White Oak in the plan, but since there was a major drought going on, it was decided that the money was better spent on water supply storage and so it was. That was the buzzword of the day. Why would we ever need flood control dams because we don't have any water?
There obviously is a balance that is required. The unfortunate part of this is that the topography around lake Houston does not allow for much use for flood control. Kingwood is not the only neighborhood in Houston to be faced with this. As FEMA and HCFCD continue to update flood maps, there are going to be unhappy people, but I doubt many will be surprised as they have had water in their house before. We can continue to artificially keep these places functioning but at what cost?
I feel sorry for those that live in these places because we have more information now or because the information was not as prescient when they chose to settle there. But willingly choosing to endanger the water supply of millions to save the few thousands that live in flood-prone area seems illogical.
but alas... here we are.
So I looked it up for you, sir. I assume you are talking about February 25 ish. It appears that you are right, Lake Houston did go up significantly to 43.75 feet. And I looked up the rain for gauge at the Kingwood Country Club and for the days between 2/24 and 2/26, the Kingwood Country Club only got .8 inches of rain. However, remember there are many things that flow into Lake Houston. And when I looked to the west of Lake Houston I see that Spring Creek at Kuykendahl got 3.5 inches. The was one of the main feeds that led to the flooding during Harvey also. And Cypress Creek watershed all the way back to Cypress had inches of rain on it too. This is a lot of rain that was coming your way.
Lake Houston Elevation map for the time period:
https://waterdata.usgs.gov/nwis/uv?cb_00045=on&cb_00054=on&cb_00065=on&format=gif_default&site_no=08072000&period=&begin_date=2018-02-24&end_date=2018-03-03
The other thing that I have been really curious about why not more has been done about is we can see all the sediment that is in our rivers\bayous\lakes etc... but how much sediment is in our storm drains. I made reference earlier in the thread (but things were really heated) that flood insurance isn't just good for if Lake Houston comes into your kitchen, it is for any rising water. This can be from a storm drain being blocked or even something as stupid as not having good drainage around your house to let your gutters drain properly.
I hope that answers your questions or at least provides additional information.
Lake Houston Elevation map for the time period:
https://waterdata.usgs.gov/nwis/uv?cb_00045=on&cb_00054=on&cb_00065=on&format=gif_default&site_no=08072000&period=&begin_date=2018-02-24&end_date=2018-03-03
The other thing that I have been really curious about why not more has been done about is we can see all the sediment that is in our rivers\bayous\lakes etc... but how much sediment is in our storm drains. I made reference earlier in the thread (but things were really heated) that flood insurance isn't just good for if Lake Houston comes into your kitchen, it is for any rising water. This can be from a storm drain being blocked or even something as stupid as not having good drainage around your house to let your gutters drain properly.
I hope that answers your questions or at least provides additional information.
We also had non stop rain the entire month of February so the ground was super saturated.
yep, it's funny how fast people forgot the major drought we had in texas a few years ago.
When a storm drain is clogged it can cause localized flooding away from a flood zone. This is called ponding. So watch your neighbors or their yard crews to see where yard debris is going. If they are dumping it down the storm drain this could cause problems.
A joint federal/local data collection project was underway prior to Harvey. USGS wants new LIDAR collection every decade for major populated regions. Once this is collected an analysis of the topography as well as rainfall data will all be remodeled. In short, the 100year flood plain will expand. Harris County is already changing permitting rules in anticipation. The 500yr flood plain is now considered the 100 year as well.
On top of that, the Feds really need to raise rates for those in and out of the 100yr.
End result in 2-3 years will be people in the expanded 100yr receiving a new bill if they have a federally backed mortgage. And hosts of new regulations for building in the 100 year.
A joint federal/local data collection project was underway prior to Harvey. USGS wants new LIDAR collection every decade for major populated regions. Once this is collected an analysis of the topography as well as rainfall data will all be remodeled. In short, the 100year flood plain will expand. Harris County is already changing permitting rules in anticipation. The 500yr flood plain is now considered the 100 year as well.
On top of that, the Feds really need to raise rates for those in and out of the 100yr.
End result in 2-3 years will be people in the expanded 100yr receiving a new bill if they have a federally backed mortgage. And hosts of new regulations for building in the 100 year.
okay - so i spoke with a SJRA person. Was supposed to be "indefinite" not "permanent" lowering of lake houston. A few news stations misinterpreted the news.
Selfish note, I just like having the water up so my backyard is better. I am completely fine with flooding every so often to live by the lake. if you dont want to flood then move somewhere with high hills and put your house on top of one.
Unselfish note, the flooding during harvey had about zero to do with lake houston being "full" as it was over the spillway on day 2. The river system is not large enough to support massive water movements...that is called flash flooding and no amount of dredging will ever change that unless they completely empty rivers/lakes before storms. emptying lakes before storms is how cities run out of water. T&Ps should we have a drought again with the reduced pool as a baseline.
Selfish note, I just like having the water up so my backyard is better. I am completely fine with flooding every so often to live by the lake. if you dont want to flood then move somewhere with high hills and put your house on top of one.
Unselfish note, the flooding during harvey had about zero to do with lake houston being "full" as it was over the spillway on day 2. The river system is not large enough to support massive water movements...that is called flash flooding and no amount of dredging will ever change that unless they completely empty rivers/lakes before storms. emptying lakes before storms is how cities run out of water. T&Ps should we have a drought again with the reduced pool as a baseline.
Yep. Storm sewers are one of the forgotten elements of flooding.FHKChE07 said:
The other thing that I have been really curious about why not more has been done about is we can see all the sediment that is in our rivers\bayous\lakes etc... but how much sediment is in our storm drains. I made reference earlier in the thread (but things were really heated) that flood insurance isn't just good for if Lake Houston comes into your kitchen, it is for any rising water. This can be from a storm drain being blocked or even something as stupid as not having good drainage around your house to let your gutters drain properly.
I hope that answers your questions or at least provides additional information.
Way back when I was a wee lad at A&M the COSI department was in the Langford building complex. For those of you that don't know, Langford is a 3 building complex with one main building, one building that is mostly classrooms and a few offices and a shop of some sort that the architects used. There is a loading dock in the middle of all of them. Smack dab in the middle of that loading dock drive is a storm drain where all of the area slopes (impervious cover).
We were doing some prep for a competition class so we were essentially locked in the computer lab on the bottom floor of the main building facing the loading drive area for 24 hours. A huge storm hits, dumps a crap ton of rain on campus. Inside of an hour that storm drain backed up, entire loading dock and drive area was flooded and under about a foot of water. All because the storm drain had so much gravel and sand in it that it was about 90% clogged and could not push water away as fast as it should have.
Was fun to look at through the floor to ceiling windows in the lab and see a foot of water on the outside like an aquarium. Until some dip**** opened the door to that area and gave the water a place to go - into the main building, including the computer lab.
Along with the storm drains, the drainage ditches (bayous) are important. After annexation of Kingwood, there were a lot of "orphaned" bayous that neither the county, city, HOA, etc., was caring for properly. Under a recent agreement, this issue has finally been resolved. I think the agreement was for the City of Houston to maintain the storm drains, and the Harris County Flood Control District to maintain the ditches. It was a long overdue delineation of duties. I may be off on the details.
After TS Allison, my home in Elm Grove (Kingwood) was placed in the 100 year flood zone at 73' elevation. It did not flood during Allison or Harvey. When you look at the flood maps, it is obvious that the concern was overflowing of the drainage ditch 2 streets away.
In 2016 I moved out of that house, and into the 500 year flood zone. This is my home that was flooded by Harvey. It is at 58' elevation. It was considered much lower risk to flood (no storm drains, bayous, or retention pond nearby), but it did flood when Lake Houston backed up.
We moved into a rental home that is in a new subdivision; it sits at 78', and there is a retention pond that came nowhere close to flooding during Harvey. However, the neighbors told me that they lost their cars during the tax day (or Mem Day?) flood in 2016 because the storm drain couldn't handle the water. Water came all the way up the driveways and flooded some garages, too, I think.
These floods - whether Lake Houston, smaller retention ponds, storm drain, or bayou related, are all results of momentary disruptions in equilibrium (this is how I think of it in chemistry terms, Keq = kf/kr, and the rate in one direction is temporarily out of whack).
I think the Lake Houston lowering is a temporary bandaid until measures can be taken to expedite the rate at which the watershed returns to equilibrium after disruptions. Maybe it can buy some time for an event flowing at 40,000 cfps (random round number I pulled out of air), but clearly not 400,000 (~ 3 mil gal).
Not a lot of people had considered that property 18' above the spillway would be flooded, so clearly there's a learning curve.
After TS Allison, my home in Elm Grove (Kingwood) was placed in the 100 year flood zone at 73' elevation. It did not flood during Allison or Harvey. When you look at the flood maps, it is obvious that the concern was overflowing of the drainage ditch 2 streets away.
In 2016 I moved out of that house, and into the 500 year flood zone. This is my home that was flooded by Harvey. It is at 58' elevation. It was considered much lower risk to flood (no storm drains, bayous, or retention pond nearby), but it did flood when Lake Houston backed up.
We moved into a rental home that is in a new subdivision; it sits at 78', and there is a retention pond that came nowhere close to flooding during Harvey. However, the neighbors told me that they lost their cars during the tax day (or Mem Day?) flood in 2016 because the storm drain couldn't handle the water. Water came all the way up the driveways and flooded some garages, too, I think.
These floods - whether Lake Houston, smaller retention ponds, storm drain, or bayou related, are all results of momentary disruptions in equilibrium (this is how I think of it in chemistry terms, Keq = kf/kr, and the rate in one direction is temporarily out of whack).
I think the Lake Houston lowering is a temporary bandaid until measures can be taken to expedite the rate at which the watershed returns to equilibrium after disruptions. Maybe it can buy some time for an event flowing at 40,000 cfps (random round number I pulled out of air), but clearly not 400,000 (~ 3 mil gal).
Not a lot of people had considered that property 18' above the spillway would be flooded, so clearly there's a learning curve.