Ross Posted March 24, 2019 Share Posted March 24, 2019 8 hours ago, AnTonY said: And like I said, by not saving the beach, the SeaWall is leading to slow, but sure, destruction of the island. The event that you wish not to occur. Um, no. It's not. If the North and South jetties weren't there, you might have an argument, but the jetties prevent sand replenishment, so the beaches would be disappearing anyway. Since the jetties prevent sand from blocking Bolivar Roads, they aren't going anywhere. In addition, the Seawall not only protects the city from hurricanes, it also provides support for the sand and soil that raised the level of the island by something like 10 feet after the 1900 hurricane. Without the Seawall and the raised elevation, the North end of Galveston Island would have suffered the same washover effects that the Bolivar peninsula did during Ike. 3 Quote Link to comment Share on other sites More sharing options...
AnTonY Posted March 25, 2019 Share Posted March 25, 2019 (edited) On 3/24/2019 at 9:21 AM, Ross said: Um, no. It's not. If the North and South jetties weren't there, you might have an argument, but the jetties prevent sand replenishment, so the beaches would be disappearing anyway. Since the jetties prevent sand from blocking Bolivar Roads, they aren't going anywhere. In addition, the Seawall not only protects the city from hurricanes, it also provides support for the sand and soil that raised the level of the island by something like 10 feet after the 1900 hurricane. Without the Seawall and the raised elevation, the North end of Galveston Island would have suffered the same washover effects that the Bolivar peninsula did during Ike. The SeaWall is one of those enigmas where it was best for that time period, but is due for replacement with more refined methods thanks to understanding gained over the decades. Sort of like the changes in how Houston interacted with its bayous (from concrete channels to greenway parks). They protect the island at the cost of rapid beach erosion, thankfully, those jetties allow East Beach to continue growing. And San Luis Pass naturally ebbs and flows due to tidal location. Galveston sand dunes were actually up to 20ft in height, but they were removed for fill and beach access when the city was being built. Edited March 25, 2019 by AnTonY Quote Link to comment Share on other sites More sharing options...
arche_787 Posted March 27, 2019 Share Posted March 27, 2019 (edited) On 3/25/2019 at 2:15 PM, AnTonY said: The SeaWall is one of those enigmas where it was best for that time period, but is due for replacement with more refined methods thanks to understanding gained over the decades. Sort of like the changes in how Houston interacted with its bayous (from concrete channels to greenway parks). They protect the island at the cost of rapid beach erosion, thankfully, those jetties allow East Beach to continue growing. And San Luis Pass naturally ebbs and flows due to tidal location. Galveston sand dunes were actually up to 20ft in height, but they were removed for fill and beach access when the city was being built. The Seawall is an imperfect structure, however, a 20’ sand dune would be eroded by a catagory 4-5 hurricane. Forr what it’s worth the Seawall is an impressive construct. That and the grade raising is why Galveston was not destroyed in: 1915, 1961 (Carla), 2008 (Ike)... I’m missing another few dates from post Grade Raising. You couldn’t adequately protect a modern city with sand. The Japanese build tsunami barriers around all their coastal cities. A storm surge may not be as instantly dramatic, but it still can rip structures from foundations. Edited March 27, 2019 by arche_787 Quote Link to comment Share on other sites More sharing options...
AnTonY Posted March 27, 2019 Share Posted March 27, 2019 45 minutes ago, arche_787 said: The Seawall is an imperfect structure, however, a 20’ sand dune would be eroded by a catagory 4-5 hurricane. Forr what it’s worth the Seawall is an impressive construct. That and the grade raising is why Galveston was not destroyed in: 1915, 1961 (Carla), 2008 (Ike)... I’m missing another few dates from post Grade Raising. You couldn’t adequately protect a modern city with sand. The Japanese build tsunami barriers around all their coastal cities. A storm surge may not be as instantly dramatic, but it still can rip structures from foundations. 20ft is taller than the height of the SeaWall. Then again, I never exactly said that sand would be enough for protection. Instead, a more modern coastal protection method that balances with the environment would be ideal. Quote Link to comment Share on other sites More sharing options...
Ross Posted March 27, 2019 Share Posted March 27, 2019 20 minutes ago, AnTonY said: 20ft is taller than the height of the SeaWall. Then again, I never exactly said that sand would be enough for protection. Instead, a more modern coastal protection method that balances with the environment would be ideal. Example? Keep in mind what I posted previously about the North and South Jetties and the way they block sand migration and exist to keep the Ship Channel viable. 1 Quote Link to comment Share on other sites More sharing options...
mollusk Posted March 27, 2019 Share Posted March 27, 2019 Can you point us to a source for the idea that Galveston's dunes were 20 feet tall? Or perhaps some less developed barrier island on the Gulf coast that has such a thing? The city was raised with sand dredged from the harbor. https://www.asce.org/project/galveston-seawall-and-grade-raising-project/ 1 Quote Link to comment Share on other sites More sharing options...
AnTonY Posted March 27, 2019 Share Posted March 27, 2019 11 hours ago, Ross said: Example? Keep in mind what I posted previously about the North and South Jetties and the way they block sand migration and exist to keep the Ship Channel viable. https://www.nbcnews.com/mach/science/walls-won-t-save-our-cities-rising-seas-here-s-ncna786811 2 hours ago, mollusk said: Can you point us to a source for the idea that Galveston's dunes were 20 feet tall? Or perhaps some less developed barrier island on the Gulf coast that has such a thing? The city was raised with sand dredged from the harbor. https://www.asce.org/project/galveston-seawall-and-grade-raising-project/ Here's a pdf that explains it. Although dunes peaked to 20ft+, the average height was 12-15ft. Still enough to protect the city, had they not been removed for fill and beach access. Quote Link to comment Share on other sites More sharing options...
Elseed Posted April 16, 2019 Share Posted April 16, 2019 On 3/15/2019 at 12:26 AM, dbigtex56 said: In summary: on one side, we have Reefmonkey, an environmental engineer, who has provided both his expertise and facts and figures to support his observations. On the other, we have someone who seems to believe that mentioning the Hamptons and referring to people as "bud" (while providing absolutely nothing of substance) makes him One Cool Dude. Who should I believe? Tellin' you, I'm torn....torn. Believe whomever you want to believe. On one hand you got some NIMBY "environmental engineer" who wants, excuse me; demands people to agree with him or he's going to do the writing equivalent of slamming his hands on the ground and cry or you can choose to believe someone............on second thought, you sound exactly like a pretentious NIMBY just like Ole Reefmonkey, I don't want you on Team El Seed lol......quantity not quality.....anywho...cheers! Til next time bud! Quote Link to comment Share on other sites More sharing options...
dbigtex56 Posted April 16, 2019 Share Posted April 16, 2019 @Elseed Snappy comeback! and it took only a little over a month to come up with it. Congratulations. I probably shouldn't question the assertions of someone who lightly dismisses a mere Master's Degree while failing to provide his own bona fides. I can only assume that you have a pocket crammed with Ph.D's from Trump U. BTW, what is "the writing equivalent of slamming his hands on the ground"? Perhaps you meant "literary", and "stamping his foot on the ground". Seems that you've taken a Humpty Dumpty approach to language, where words mean what you intend them to mean and their literal meanings be damned. I have to admit that your screeds on How Nature Got It All Wrong would be amusing, had they been intended as satire. Ignorance mixed with hubris can be used to either comic or tragic effect. I'd laugh if only it wasn't so terribly sad. Your contention that I somehow could be described as a NIMBY is puzzling. I'm on record as supporting the development of low-income housing, bars and entertainment venues, and social service agencies in my own neighborhood. Or, perhaps you've come up with your own definition for that acronym which you haven't yet shared with us. In conclusion, I will somehow manage to soldier on without becoming a member of Team El Seed(y), a membership which seems to be restricted to thee, thyself, and thou. 3 Quote Link to comment Share on other sites More sharing options...
k5jri radio Posted January 29 Share Posted January 29 When walking along the beach area of Galveston, the various rock jetties (aka groins) are readily visible. Their purpose seemed to be the mitigation of the effects of beach erosion. According to a recent article in Galveston Monthly, my conjecture was correct. The rock jetties slow down the wave action, causing the incoming and outgoing waves to lose velocity. Slower incoming wave velocity inhibits the water's ability to carry the sand, causing the sand to drop off at a greater rate. Slower outgoing wave velocity likewise inhibits the water's ability to pick up stationary sand. The net effects of the reduced incoming and outgoing wave velocity results in a lower net rate of beach erosion. Quote Link to comment Share on other sites More sharing options...
k5jri radio Posted May 11 Share Posted May 11 Several members have commented about the white sand beaches east of Mobile Bay AL being more comfortable to sit or recline on than the darker sand beaches west of Mobile Bay. This is likely due (at least in part) to the more rounded shape of the white grains of sand compared to that of the darker grains of sand. This same shape property makes it easier to drive motor vehicles on darker sand beach with less likelihood of getting stuck in the sand. This happened to me once at Pensacola Beach FL when I was attempting to park my car on the side of a road. From than on, I took care to park only in designated parking areas. Sand beaches are inherently unstable with regard to the amount and distribution of sand over time. Most of the beaches I've been to on the Gulf of Mexico and the Atlantic Ocean need periodic replenishment of the sand by means of dredging equipment pumping a slurry of sand and water to the beach being replenished. My favorite beaches are those adjacent to the seawall at Galveston TX, starting with Stewart Beach and going west to the end of the seawall. Quote Link to comment Share on other sites More sharing options...
k5jri radio Posted May 14 Share Posted May 14 To clarify the comments in the previous posting: [1] The white sand beaches have sand with a more rounded shape that allows the individual grains of sand to move around one another and follow the shape of objects pressing down. This is a desirable trait when a person is reclining on the sand. [2] This same property is less desirable when rolling objects (bicycle or car tires) pass over the white sand. Quote Link to comment Share on other sites More sharing options...
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