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 Hurricane Harvey- August, 2017 
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Post Hurricane Harvey- August, 2017
UPDATED: HOW WILL HOUSTON HANDLE THE DELUGE OF HURRICANE HARVEY?

This story has been updated as of 8:47 pm ET.

Hurricanes are classified according to their wind speed. But a truer measure of their destructive potential would also include their moisture level. Just before making landfall on Friday night, Hurricane Harvey jumped up to become a category 4 hurricane, with sustained winds of 130 miles per hour. More dangerously, though, it’s also packing enough moisture to drop 20 inches or more of rain across Texas’ gulf coast.

As early as Wednesday, Governor Greg Abbot declared a state of emergency so the gulf region would be eligible for federal disaster relief. They’ll likely need it. The current forecast predicts that Harvey, which was downgraded to a tropical storm on Saturday, will stall out over east Texas for days. Yet, while seven counties had ordered evacuations by Friday, Houston—home to 2.3 million people—didn't. Its mayor told residents to weather it out, rather than clog highways leading out of the city.

And by Sunday evening, Harris County—Houston’s encircling jurisdiction—became one of 18 counties across Texas that had been declared a federal disaster area. (Those counties contain 7 million people, nearly a quarter of the state's population.) In the city of Houston, nine shelters have opened up to take in people fleeing their homes.

This isn’t Houston's first rodeo: The city designed its layout for drainage, with copious reservoirs and dams, to store and shed the downpour without inundating residents. But the region’s front line of defense are its wetlands. These soak up moisture that would otherwise flood Houston. And this weekend’s deluge threatens to overrun both the built and natural systems.

“Just to give you a lowdown on the area, it’s wet, it’s flat, and it’s gonna be really wet in the next couple days,” says John Jacob, the director of the Texas Coastal Watershed Program at Texas A&M University. Any rain that falls in Harris County can run to sea through any of the county’s 22 watersheds. That might sound like a lot of drainage potential, but the highest point in the county is only 125 feet above sea level, which means the water can pool up pretty quickly.

To mitigate the buildup, Houston turns to two main engineered systems: the Addicks and Barker dams and reservoirs. “These were designed to protect the downtown area,” says Randy Cephus, a spokesperson for the Army Corps of Engineers Galveston Division. “They are dry reservoirs, meaning the dams are wide open and water is flowing freely until the heavier rains arrive.” The flood-prone city has one of the most sophisticated networks of gauges in the country. Once those reach critical levels, the dam’s safety officer will order the floodgates closed, and the reservoirs will fill up.

Combined, the Addicks and Barker reservoirs can hold 410,000 acre-feet of water. Twenty inches of rain across Harris County adds up to about 1,894,980 acre-feet. Don’t let that number scare you: Harris County has all those other watersheds, plus attendant flood control schema (which I’ll get into a little later). But neither should you be relieved. Addicks and Barker are on the northwestern end of Houston, which means a lot of the water they take up will come from outside Harris County. Acts of God don’t abide by earthly borders.

Addicks and Barker are also in the middle of a $75 million safety upgrade. The system was built in the 1930s, and the Army Corps of Engineers recently finished a coffer dam that will function in place of the regular flow. And the construction crews still on the ground might actually help things out. “We were able to modify the contract on the heavy equipment and resources like the quarry, so they can help us out, moving rocks and sandbags in a more expeditious manner,” says Cephus.

The Houston suburbs have their own protective measures. One of the biggest projects is Brays Bayou, the watershed of which encompasses 700,000 people. Parts of this watershed flooded in 2015 and 2016. The Brays Bayou Project—a joint endeavor of the Army Corps and Harris County Flood Control District—is several years behind schedule on a $480 million upgrade. Project manager Gary Zika says the upgrade is almost complete. For this flood, his workers will focus on keeping drains clear of rubbish and keeping the public aware of the flood levels.
Houston, and much of east Texas, was built over a wet coastal plain. “Historically, when we consider the undisturbed landscape, 30 percent of it was covered with wetlands,” says Jacob. “That gave us about ⅓ an acre-foot of water retention in every acre of land.” That’s pretty significant, considering Harris County currently requires every paved acre of land to have ½ acre foot of water retention. Paving them over just means humans have to spend more money creating building artificial means to store and route storm runoff to the sea. All that free water storage has been lost to agriculture and urban sprawl.

The wetlands are important, but they aren’t magic. “If you get 16, 17, 18 inches, the prairie is going to flood,” says Jacob. But he points out that the built retention is only meant to hold 100-year flood event type rainfall. “Well, 15 to 20 inches, like what’s going to fall this weekend, is more like a 20-year storm,” says Jacob. The measure of a storm’s destructive potential is a sliding scale.


(Continued)

https://www.wired.com/story/how-will-ho ... ne-harvey/


Last edited by Royal on Mon Aug 28, 2017 6:30 am, edited 1 time in total.



Mon Aug 28, 2017 6:29 am
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Post Re: Hurricane Harvey- August, 2017
Continued...

Unprecedented Rainfall, Unprecedented Flooding
At 8:00 pm on Friday night the Corps ordered both dams closed. Two hours later, Harvey made landfall near Rockport, Texas. Over the next 24 hours, the storm dumped more than 24 inches of rain over sections of Houston, according to the National Weather Service. The NWS declared a flash flood emergency Sunday evening, following reports of water reaching the second stories of houses and apartment buildings in the southern parts of the city. The weather service is warning that over the next few days rainfall could reach as much as 50 inches in some places, which would be the highest levels ever recorded in the state of Texas.
“I know for a fact this is the worst flood Houston has ever experienced,” an NWS meteorologist told a Houston Chronicle reporter.

What does that mean for the city's dams? As of Sunday evening, the Addicks reservoir had risen to just over 98 feet, and Barker to 93 feet, according to Corps statistics and the Harris County flood warning system. Corps officials announced Sunday evening that because of the extreme nature of the ongoing weather in the area, they will have to release intermittent amounts of water from both reservoirs to reduce the risk to the heart of downtown—home to the city's largest hospital, as well as the George R. Brown Convention Center, which is preparing to shelter 1,000 people Sunday night.

The releases will likely occur late Sunday evening into early Monday morning, and are expected to submerge roadways and perhaps some homes immediately adjacent to the reservoirs. If the rain continues to fall at its current pace, it's also likely that water will go over the uncontrolled spillways at the ends of both dams. And while that's an intentional part of the dams' designs, it will be the first time in their 60-plus year history that it's ever happened.

“Typically we just close the gates until it stops raining,” says Mario Beddingfield, a hydraulic engineer with the Army Corps of Engineer’s Galveston District, reached by phone Sunday night. But given the magnitude of this storm, the releases are looking more and more necessary to keep the integrity of the dams in place. “It still may go over the ends, but at least we can reduce the amount that goes uncontrolled downstream into downtown.”

The Corps expressed utmost confidence that their structures are working the way they're supposed to. But in an unfolding natural disaster of unprecedented scale, even they don't know what's going to happen next. They're working with state, county, and federal officials to get the best information they can to residents near the reservoirs and in downtown. But everyone is still just taking it an hour (and an inch) at a time.

https://www.wired.com/story/how-will-ho ... ne-harvey/


Mon Aug 28, 2017 6:30 am
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Post Re: Hurricane Harvey- August, 2017
The water release from Addicks Reservoir was planned to begin at 2 a.m. Monday with Barker to follow 24 hours later, officials stated earlier during a press conference. However Lindner tweeted Monday at 12:21 a.m. that the water release had started.

Residents along Addicks and Barker Reservoirs are being asked as part of non-mandatory evacuation to leave their homes, as the Corps of Engineers will start a slow, controlled release of water the reservoirs.

Officials told residents not to leave their homes Sunday night. They are being stressed to leave Monday due to uncertain conditions on the roads.

"The idea is to prepare tonight, pack up what you need, put it in your vehicle, then in the morning, they should leave, Jeff Lindner with Harris County Office of Emergency Management said.

The controlled release is expected to impact thousands of homes. The rising water situation could put too much pressure on the dams if the water is not released not.

"That is something you don't want to happen. You don't want to have an uncontrolled problem at the dam," Lindner added.

Additionally, the controlled release will make the Buffalo Bayou flooding even worse. Officials have put out maps to show the people who need to get to higher ground.


http://www.khou.com/weather/hurricanes/ ... /468348109


Mon Aug 28, 2017 7:01 am
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Post Re: Hurricane Harvey- August, 2017
Image

Cooked burgers during the storm on Friday afternoon.

Folks in Houston area break out boats an rescue neighbors.

We got this...


Tue Aug 29, 2017 1:45 am
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Post Re: Hurricane Harvey- August, 2017
Thought it got you.

For the next major quake in Cali, I'll make sure to keep you in suspense.


Tue Aug 29, 2017 9:40 am
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Post Re: Hurricane Harvey- August, 2017
Harvey v1.0
(c)2017 Mother Nature

Initializing
Location Gulf of Campeche
dir 315
wind on
rain on
speed slow
rain output min 11 teragallon
rain output max unlimited
allow eye on
allow destruction on
ignore weather patterns off

start

show storm
send message hello gulf coast


Wed Aug 30, 2017 5:40 pm
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Post Re: Hurricane Harvey- August, 2017


Wed Aug 30, 2017 5:42 pm
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Post Re: Hurricane Harvey- August, 2017
What are the water levels? What were the highest for your area?

How did the birds and animals do?


Wed Aug 30, 2017 10:11 pm
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Post Re: Hurricane Harvey- August, 2017
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The bridge is about 500 feet away and about 6 or 8 feet above the bridge.

In Houston, water is every where. There were road near overpasses with water up near the elevate roads. The video coverage shows much. Around houses up to 4 or 5 feet in many places.


Wed Aug 30, 2017 11:53 pm
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Post Re: Hurricane Harvey- August, 2017
Interstate-10 east of Houston looks like an ocean -- with waves


Thu Aug 31, 2017 2:30 am
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