I just received an email from Jeff Lindner, Director of Hydrologic Operations Division/Meteorologist for Harris County Flood Control District about a potential tropical development.
Linder says, “There has been little mention of the Atlantic tropics thus far this hurricane season…even though we are already on our “E” storm. Most of the storms have been focused in the sub-tropical north Atlantic away from the generally hostile conditions in the deep tropics and far removed from any land interaction.”
National Hurricane Center Five Day Graphical Tropical Weather Outlook gives this tropical disturbance a 20% chance of tropical formation over the next five days.
Conditions in Tropics Becoming More Favorable for Tropical Development
“However conditions are starting to slowly change and as is usual for mid-August, conditions are becoming more favorable for tropical development in the deep tropics or that region between Africa and the Caribbean Sea,” said Lindner.
Tropical Wave 99L
Lindner continued: “A tropical wave roughly 850 miles east of the southern Windward Islands has shown an increase in deep convection today. This convection (thunderstorms) remains fairly disorganized at this time. Significant amounts of Saharan Air (dusty air from the deserts of N Africa) have been generally keeping the formation of convection to a minimum for the last 2 months, but 99L has found itself far to the south (near 8N) and mainly south of the dusty air across the mid Atlantic. This system has also found itself near/under a building ridge of high pressure aloft and removed from the anomalous strong wind shear thus far this year across the Caribbean Sea and Atlantic.”
“Conditions appear at least marginally favorable for some slow development of this feature as it moves W to WNW over the next 48-72 hours.”
“There is little to no model support for this feature to develop, but we shall see what the 00Z and 12Z models suggest. At the 800pm this evening, the Hurricane Center is giving this system a 20% chance of tropical development over the next 5 days as it moves generally toward the eastern Caribbean Sea.”
Lindner Cautions Against Looking Too Far into Future
“Reminder: it is important as we move into the heart of hurricane season to get information from trusted sources – especially on social media. Posts showing where a storm could be 7-9 days from now and at some level of intensity should not be believed and it is important to refrain from sharing such posts without proper context,” cautioned Lindner.
Peak of Hurricane Season is September 10
The statistical peak of hurricane season for this area is September 10, so we are still almost a month away. Nevertheless, be prepared. Check your your hurricane kit now. Don’t leave important matters for the last minute.
SJRA Still Lowering Lake Conroe
The San Jacinto River Authority (SJRA) has been steadily lowering Lake Conroe by 275 cubic feet per second to create extra capacity in the lake. From a normal level of 201 mean feet above sea level (MSL), the goal was to reduce the lake to 199 MSL by August 15 and maintain that level until the end of September. This is to create an additional buffer against downstream flooding until the Army Corps can restore the carrying capacity of the West Fork.
The countdown to D-Day (dredging day) continues. Preparation for the U.S. Army Corps of Engineers Emergency Dredging Project on the West Fork is kicking into high gear. Here are some pics from the job site and the latest schedule for when various activities will start.
Schedule for U.S. Army Corps of Engineers West Fork Emergency Dredging Project
Dozens of trucks are delivering equipment to the mobilization site.
Traffic management at the site is a major concern, prompting the Corp to request the public stay a safe distance away.
Thousands of sections of dredge pipe have been delivered to a massive “pipe farm.”
Contractor and Army Corps representatives review dredging plans at mobilization site headquarters.
Actual dredging should begin within the next two weeks. While staff and material are being organized for the dredging operation, clean up crews will remove more dead trees and other debris from the river and placement sites.
Example of debris removal from Lake Houston before dredging. This shot actually shows a city-contracted crew working on the East Fork during July. Corps crews will be conducting similar work.
Difference Between City Dredging and Corp Dredging
(NOTE: THIS POST HAS BEEN UPDATED WITH THE FOLLOWING INFO SINCE THE ORIGINAL POST) What is the difference between the city debris removal and the debris removal that the corps is doing? I went back into the contract requirements. Division 2, Section 02 41 01.01 45 stipulates, “General debris consists of trees and other vegetation within limits of dredging in the river, under the West Lake, Houston Parkway bridge, and upland areas that are to be dredged or excavated. General debris may also include, but is not limited to, metal bands, pallets, pieces of broken cable, rope, concrete rubble, construction materials, broken piles, etc. and may be encountered in the same area as above.”
So I see three main differences. The Corps subcontractor will: 1) only be working within the area to be dredged, 2) remove other types of materials that the city did not, 3) Also be responsible for cleaning up the placement areas, which the city did not.
Section 1.3.2 of the same document stipulates how they are being paid. Basically, it’s by the ton, but they are also being compensated for the cost of equipment, labor and material. The government is inspecting the scales. The complete contract requirements and plans are posted on the Reports page of this web site under Sedimentation/Dredging/Army Corps.
Additional Info About Army Corps West Fork Dredging Project
Below are some videos posted by the Corps that explain how we got to this point and how the project will progress.
The first explains how the Corps conducted the site survey.
Jim Blackburn, JD, professor of environmental law at Rice and Phil Bedient, PhD., a professor of engineering also at Rice, have just released an important new study called Houston a Year After Harvey: Where We Are and Where We Need to Be . Because of the length, detail, intricate maps and charts, and file size, this is best viewed on something larger than a smartphone.
Written for the Average Adult
Three things immediately become apparent when reviewing this 55-page report. It’s wide ranging in scope. It’s an excellent work of scholarship. And it’s well written; the average adult should be able to understand all the key concepts without difficulty.
Houston A Year After Harvey: Three Major Sections
It’s an excellent summary of what happened during Harvey, how the community is responding, and what still needs to be done – major watershed by major watershed.
The Problems of Obsolete Flood Plain Maps
This paper is organized into three main sections. First, the issues of obsolete 100-year floodplain maps and increasing rainfall are discussed because they are key to fully understanding the current dilemma and shaping alternative concepts for long-term protection. Whether or not you believe in climate change, the case for revising flood maps is pretty compelling based on the math alone. We’ve had five so-called 500-year storms in the last 25 years. Are we just spectacularly unlucky? Or do we need to revisit the assumptions and underlying math?
Any time you try to predict the frequency of rarely observed or unobserved events, such as 500-year storms, you venture way out on a limb. The data on which you base assumptions is thin. Worse, one of the fundamental precepts of extreme value analysis (EVA) is that nothing changes during the 500 years under analysis.
Good luck with that. Five hundred years ago, the U.S., Texas, Houston, developers, gasoline, F150s and sand mining didn’t even exist. As we get more data and update assumptions, flood maps are being redrawn. So are the guidelines which form the basis for different types of development. Instead of raising new homes two feet above the 100 year flood plain, officials are now talking about two feet above the 500-year flood plain.
Issues that Need to Be Addressed Watershed by Watershed
The second part of Houston A Year After Harvey is a geographic overview of the flood issues and potential responses to various watersheds across Harris County.
The discussion of the West Fork of the San Jacinto goes from pages 28-30. It starts with a discussion of sedimentation, where the sediment is coming from and why we need stronger regulation of sand mining.
In regard to sedimentation, the reports also discusses the need for dredging to restore the river’s carrying capacity.
Finally, in regard to the San Jacinto, the report discusses the need to change the operating philosophy for the dams on Lake Conroe and Lake Houston to enable pre-release as a strategy for flood mitigation. This has already happened, they note, with the approval of the TCEQ to temporarily lower the level of Lake Conroe during the peak of hurricane season.
Different Solution Sets for Different Flooding Issues
The third major portion of Houston A Year After Harvey discusses different flood management concepts for three zones of the Houston area that have different flooding issues.
The authors break the county up into three major zones, A, B and C. A stretches from Addicks/Barker to the Katy Prairie. B covers the central part of the county. And C covers coastal areas.
The discussion of Zone B (which includes the Lake Houston and San Jacinto River) includes explanations for many of the projects listed on the Harris County Flood Control District Flood Bond that we are now voting on. See pages 42 through 45.
But don’t stop there. There’s also a great description for how the Ike Dike could work in Zone C.
How All the Pieces of the Flood Bond Fit Together
All in all, Houston A Year After Harvey makes a great case for the flood bond, without ever really setting out to do that. It will help give you a better understanding for how our drainage problems affect the people around us and vice versa.
Conditions in Atlantic Becoming More Favorable for Tropical Development
I just received an email from Jeff Lindner, Director of Hydrologic Operations Division/Meteorologist for Harris County Flood Control District about a potential tropical development.
Linder says, “There has been little mention of the Atlantic tropics thus far this hurricane season…even though we are already on our “E” storm. Most of the storms have been focused in the sub-tropical north Atlantic away from the generally hostile conditions in the deep tropics and far removed from any land interaction.”
National Hurricane Center Five Day Graphical Tropical Weather Outlook gives this tropical disturbance a 20% chance of tropical formation over the next five days.
Conditions in Tropics Becoming More Favorable for Tropical Development
“However conditions are starting to slowly change and as is usual for mid-August, conditions are becoming more favorable for tropical development in the deep tropics or that region between Africa and the Caribbean Sea,” said Lindner.
Tropical Wave 99L
Lindner continued: “A tropical wave roughly 850 miles east of the southern Windward Islands has shown an increase in deep convection today. This convection (thunderstorms) remains fairly disorganized at this time. Significant amounts of Saharan Air (dusty air from the deserts of N Africa) have been generally keeping the formation of convection to a minimum for the last 2 months, but 99L has found itself far to the south (near 8N) and mainly south of the dusty air across the mid Atlantic. This system has also found itself near/under a building ridge of high pressure aloft and removed from the anomalous strong wind shear thus far this year across the Caribbean Sea and Atlantic.”
“There is little to no model support for this feature to develop, but we shall see what the 00Z and 12Z models suggest. At the 800pm this evening, the Hurricane Center is giving this system a 20% chance of tropical development over the next 5 days as it moves generally toward the eastern Caribbean Sea.”
Lindner Cautions Against Looking Too Far into Future
“Reminder: it is important as we move into the heart of hurricane season to get information from trusted sources – especially on social media. Posts showing where a storm could be 7-9 days from now and at some level of intensity should not be believed and it is important to refrain from sharing such posts without proper context,” cautioned Lindner.
Peak of Hurricane Season is September 10
The statistical peak of hurricane season for this area is September 10, so we are still almost a month away. Nevertheless, be prepared. Check your your hurricane kit now. Don’t leave important matters for the last minute.
SJRA Still Lowering Lake Conroe
The San Jacinto River Authority (SJRA) has been steadily lowering Lake Conroe by 275 cubic feet per second to create extra capacity in the lake. From a normal level of 201 mean feet above sea level (MSL), the goal was to reduce the lake to 199 MSL by August 15 and maintain that level until the end of September. This is to create an additional buffer against downstream flooding until the Army Corps can restore the carrying capacity of the West Fork.
However, recent rains have been refilling the lake almost as fast as the SJRA is lowering it. At the time of this post, the level was at 200.01 MSL. Visit SJRA.net to see the current level and release rate.
I am sure they will increase the discharge rate if this or any other storm approaches to get to their target of 199 MSL.
In short, nothing to worry about now. But keep your antenna up.
Posted by Bob Rehak on August 15, 2018
351 Days since Hurricane Harvey.
Activity at Army Corps Dredge Command Site Kicking into High Gear
The countdown to D-Day (dredging day) continues. Preparation for the U.S. Army Corps of Engineers Emergency Dredging Project on the West Fork is kicking into high gear. Here are some pics from the job site and the latest schedule for when various activities will start.
Schedule for U.S. Army Corps of Engineers West Fork Emergency Dredging Project
Thousands of sections of dredge pipe have been delivered to a massive “pipe farm.”
Contractor and Army Corps representatives review dredging plans at mobilization site headquarters.
Actual dredging should begin within the next two weeks. While staff and material are being organized for the dredging operation, clean up crews will remove more dead trees and other debris from the river and placement sites.
Example of debris removal from Lake Houston before dredging. This shot actually shows a city-contracted crew working on the East Fork during July. Corps crews will be conducting similar work.
Difference Between City Dredging and Corp Dredging
(NOTE: THIS POST HAS BEEN UPDATED WITH THE FOLLOWING INFO SINCE THE ORIGINAL POST) What is the difference between the city debris removal and the debris removal that the corps is doing? I went back into the contract requirements. Division 2, Section 02 41 01.01 45 stipulates, “General debris consists of trees and other vegetation within limits of dredging in the river, under the West Lake, Houston Parkway bridge, and upland areas that are to be dredged or excavated. General debris may also include, but is not limited to, metal bands, pallets, pieces of broken cable, rope, concrete rubble, construction materials, broken piles, etc. and may be encountered in the same area as above.”
So I see three main differences. The Corps subcontractor will: 1) only be working within the area to be dredged, 2) remove other types of materials that the city did not, 3) Also be responsible for cleaning up the placement areas, which the city did not.
Section 1.3.2 of the same document stipulates how they are being paid. Basically, it’s by the ton, but they are also being compensated for the cost of equipment, labor and material. The government is inspecting the scales. The complete contract requirements and plans are posted on the Reports page of this web site under Sedimentation/Dredging/Army Corps.
Additional Info About Army Corps West Fork Dredging Project
Below are some videos posted by the Corps that explain how we got to this point and how the project will progress.
The first explains how the Corps conducted the site survey.
https://www.youtube.com/watch?v=xvQNwKOOmeA
The next shows an aerial tour of the project.
https://www.youtube.com/watch?v=Cu4-cwsdFNc
And the final one explains their value engineering process.
https://www.youtube.com/watch?v=2se5YdNRGdA
Posted by Bob Rehak on August 14, 2018
350 Days after Hurricane Harvey
Houston A Year After Harvey: Where We Are And Where We Need To Be
Jim Blackburn, JD, professor of environmental law at Rice and Phil Bedient, PhD., a professor of engineering also at Rice, have just released an important new study called Houston a Year After Harvey: Where We Are and Where We Need to Be . Because of the length, detail, intricate maps and charts, and file size, this is best viewed on something larger than a smartphone.
Written for the Average Adult
Three things immediately become apparent when reviewing this 55-page report. It’s wide ranging in scope. It’s an excellent work of scholarship. And it’s well written; the average adult should be able to understand all the key concepts without difficulty.
Houston A Year After Harvey: Three Major Sections
It’s an excellent summary of what happened during Harvey, how the community is responding, and what still needs to be done – major watershed by major watershed.
The Problems of Obsolete Flood Plain Maps
This paper is organized into three main sections. First, the issues of obsolete 100-year floodplain maps and increasing rainfall are discussed because they are key to fully understanding the current dilemma and shaping alternative concepts for long-term protection. Whether or not you believe in climate change, the case for revising flood maps is pretty compelling based on the math alone. We’ve had five so-called 500-year storms in the last 25 years. Are we just spectacularly unlucky? Or do we need to revisit the assumptions and underlying math?
USGS did this recently and designated Harvey a 42-year flood at the West Fork and Grand Parkway.
Any time you try to predict the frequency of rarely observed or unobserved events, such as 500-year storms, you venture way out on a limb. The data on which you base assumptions is thin. Worse, one of the fundamental precepts of extreme value analysis (EVA) is that nothing changes during the 500 years under analysis.
Good luck with that. Five hundred years ago, the U.S., Texas, Houston, developers, gasoline, F150s and sand mining didn’t even exist. As we get more data and update assumptions, flood maps are being redrawn. So are the guidelines which form the basis for different types of development. Instead of raising new homes two feet above the 100 year flood plain, officials are now talking about two feet above the 500-year flood plain.
Issues that Need to Be Addressed Watershed by Watershed
The second part of Houston A Year After Harvey is a geographic overview of the flood issues and potential responses to various watersheds across Harris County.
The discussion of the West Fork of the San Jacinto goes from pages 28-30. It starts with a discussion of sedimentation, where the sediment is coming from and why we need stronger regulation of sand mining.
In regard to sedimentation, the reports also discusses the need for dredging to restore the river’s carrying capacity.
Finally, in regard to the San Jacinto, the report discusses the need to change the operating philosophy for the dams on Lake Conroe and Lake Houston to enable pre-release as a strategy for flood mitigation. This has already happened, they note, with the approval of the TCEQ to temporarily lower the level of Lake Conroe during the peak of hurricane season.
Different Solution Sets for Different Flooding Issues
The third major portion of Houston A Year After Harvey discusses different flood management concepts for three zones of the Houston area that have different flooding issues.
The authors break the county up into three major zones, A, B and C. A stretches from Addicks/Barker to the Katy Prairie. B covers the central part of the county. And C covers coastal areas.
The discussion of Zone B (which includes the Lake Houston and San Jacinto River) includes explanations for many of the projects listed on the Harris County Flood Control District Flood Bond that we are now voting on. See pages 42 through 45.
But don’t stop there. There’s also a great description for how the Ike Dike could work in Zone C.
How All the Pieces of the Flood Bond Fit Together
All in all, Houston A Year After Harvey makes a great case for the flood bond, without ever really setting out to do that. It will help give you a better understanding for how our drainage problems affect the people around us and vice versa.
The entire report is posted on this web site with permission of Rice University’s Baker Institute for Public Policy and SSPEED Center. ©2018 James A. Baker III Institute for Public Policy of Rice University. It will be permanently stored in the Reports Section under the Hurricane Harvey tab for easy future access.
Posted on August 13, 2018 by Bob Rehak
349 Days Since Hurricane Harvey