COMMENT OF THE DAY: WHERE’S HOUSTON’S REAL-TIME FLOOD MAP? 
“Has anyone posted a map of the residential streets that flooded yesterday? I’ve seen neighborhoods mentioned wholesale, but I also understand it was hit-and-miss from street to street. Thank you!” [Heather, commenting on Houston Floods Again; Kingwood’s Rise; How the East End Got Its Rail] Illustration: Lulu
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And a follow-up question; how many, if any, of these locations weren’t known flood-prone areas? This appeared to be a significant flooding event with the warnings out there that this was going to be bad well before any of the rain had started falling. I understand it’s difficult/costly to start redirecting traffic in advance of major flooding, but it definitely makes me question our disaster preparedness in a city that should be expecting these exact type of events on at least an annual basis.
What a moronic question. Houston has had street to street flood variances since Houston has had streets. So has every city in every flood since the begining of time.
This idea of what is flood prone and what is not is ridiculous! Any and every part, even areas that have “never flooded before” are prone to some kind of flooding when enough water falls in a limited amount of time. It is the nature of living in Houston.
Somebody should tell the newbies that the streets are part of the flood control system. Street flooding is expected and in fact planned for. The “STORMWATER DESIGN REQUIREMENTS” chapter of the CoH Design Manual states:
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“Street Drainage: Street ponding of short duration is anticipated and designed to contribute to the overall drainage capacity of the system.
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“Streets shall be designed so that consecutive high points in the street will provide for a gravity flow of drainage to the ultimate outlet.”
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“The maximum depth of ponding at high points shall be 6 inches above top of curb.”
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“The maximum depth of ponding at low points shall be 18 inches above top of curb.”
But what would all those news people that keep reporting on how flooded it is at 610 and Westpark and Memorial and Shepherd do if you had a map that showed you where it was actually flooded?
@joel: No one knew this much rain was coming over such a short period of time. This wasn’t a tropical storm. It was some rain that was much bigger than anyone expected.
@Memebag, i really don’t agree with that though. It was known well in advance that there would be flash flooding and I fully expected the bayou to overflow it’s banks looking at the forecast 7pm Sunday. This is in reference to just a few locations like 45@Main where it was mentioned they only had about 15 minutes to ditch their cars and leave thus all the stranded/flooded out cars, but at some point during the night you could easily say these parts of town have received X amount of rain and with Y amount of rain still to come these locations will be flooding in a few hours. Understood it’s basically a cost/logistics issue, but definitely seems odd to me to have drivers taken by surprise at known flash flood locations.
Don’t forget that a real time flood map would require the installation of sensors all over the city, which would not be cheap. Localized street flooding is highly unpredictable, being caused by a wide variety of factors like rainfall amount, water level in bayous, and trash in storm drains. It would be useful for Public Works to track reports of street flooding as a guide to prioritize which storm drains to check first.
I am happy that Houston does have completely separated storm and sanitary sewers, unlike other cities where heavy rains cause the sanitary sewers to send too much liquid into the waste treatment plants.
There was no real time flood map that I know of. Twitter was the closest real time news available with the #HoustonFlood hastag turning up images in real time as people posted them.
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KHOU Weathercaster app for the smartphone has a good program to see real time weather patterns.
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All areas in Houston close to new box store construction are potential flood targets even if it doesn’t rain very bad. The residents near the HEB at Bunker Hill got flooded in 2009 (when it didn’t even rain that hard) and had to fight HEB and Costco to put in retention ponds which prevented the area from getting wiped out this time around.
Has all that Upper Kirby work done any flood mitigation yet?
http://www.harriscountyfemt.org
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Click on ‘ponding’ to show where water typically collects after downpours – obviously exacerbated with a Monday-type event. Unfortunately the ‘zoom in’ isn’t all that close.
@joel: The rain gauge data doesn’t back you up. The rain gauge at Rice and Braes Bayou showed 9 inches fell over 4 hours. Nothing before that, nothing after. That was right before the bayou topped its banks. Looking back through the NWS severe weather archives, you’ll see there was a Severe Thunderstorm Warning Monday night, but not a Flash Flood Warning.
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And you say you knew it would flood Sunday night? Are you really saying we should have shut down I-45 all day Memorial Day because you knew it was going to flood the next day?
http://www.harriscountyfemt.org/
The Harris County Flood Education Mapping Tool is a good spot to look if you aren’t already familiar with where the low spots are in Houston. I would be interested in seeing a comparison between this maps predictions and actual flooding. Based on the numbers I saw the past few days, the rain storm landed Houston in somewhere between a 10-year and 50-year flooding scenario, in terms of risk. This risk range is not specifically cover in this tool, but you can read between the lines a little bit.
There are a couple reasons why an actual map would deviate from the actual flooding map. In Houston, the effectiveness of drainage systems can dramatically impact the area of the flooding areas. So flooding can vary from storm to storm based on effectiveness of man-made systems. The other factor that would impact flood plains from storm to storm would be where rain actually falls. The center of a storm could be anywhere, and rainfall is never uniform across the city.
I hope that there is some type of feedback process between actual flooding and FEMAs predicted floop maps.
Thanks, all. To clarify, I had the original comment above. I didn’t ask for a real-time map — that was added in the headline. I was looking for a map in the aftermath. I was mostly curious which streets in my area made it out of Allison unscathed and then got hammered this time and vice versa. Several houses near Brays were demo’d/built up with post-Allison insurance payouts, so those were easy to ID as “flooded” later on. If I were so inclined, I could tailgate around and see who has furniture on the street, but I don’t want to be the jerk who lookie loos. It could just as easily have been me this time, and I am very, very grateful that it wasn’t.
Ross – Public Works DOES track reports of street flooding as a guide to prioritize maintenance and replacement/capacity upgrades of the storm drainage system. Call 3-1-1 to get a report officially in the system.
In the absence of a real-time flood map, why don’t we use the red-light traffic cameras that we spent so much time and money installing to visually monitor roads for flooding?
I believe you can get real time flood detection from Google maps. All major streets have red, yellow, or green colors to indicate traffic congestion. However, if a major street gets severely flooded, the (satellite?) sensor that Google doesn’t work and the colors disappear. Also, leading up to that area, it’s usually red because cars got flooded and trapped on the roads.
I use the Harris County Flood Emergency Warning website as the closest thing to a real-time report on the bayous. It won’t help for streets but, if you know the bayou that you have to cross is flooded, you just might want to stay off of that road.
The website gets its data from level sensors: http://www.harriscountyfws.org/