The Texas Water Development Board (TWDB) has reorganized the sea of flood-related information and redesigned the TexasFlood.org website to provide a more user-friendly resource for Texans who want to increase their flood awareness and preparedness.
Given the deadly nature of flood events and the rapid timeframe in which they can occur, remaining flood-ready is essential.
One Feature Shows Flood Spread and Inundated Buildings by Gage Height
TexasFlood.org provides fundamental information on emergency preparation for and recovery from flood events, as well as web tools to better understand flood risk, in a format that is easy to access and easy to understand.
Select a gage and a height and see instantly how far the floodwaters will spread. This shows spread based on the USGS Gage at FM1485 and the East fork.
I selected the height of the highest gage reading during the May floods this year at FM1485 and the East Fork. Then I zoomed in and found that 36 structures were in danger of being inundated. You can even see their locations!
Information like this is not only useful when considering purchasing a building, but also when considering whether to evacuate.
Other Useful Features
TexasFlood.org also features resources and tools that allow users to:
Review lake levels and river heights
Check current precipitation totals and weather conditions
Evaluate potential flood risk
See the impacts of different hypothetical flooding scenarios
Identify and connect with their local floodplain administrator
Learn the primary types of flooding and basics of flood insurance
The website highlights the reasons why emergency preparedness is vital to proper flood preparedness, including the importance of floodproofing and awareness of second-order damages after a flood event.
One-Stop Information Shop
The TWDB has gathered important information from other local, state, and federal entities to provide the most relevant information for Texans in one convenient online location. Hurricane season runs through November 30 each year. And historically speaking, 80% of the storms for this year are still in front of us. Just today, the National Hurricane Center highlighted another area of concern in the Atlantic, bringing the active total to three.
So TWDB encourages all Texans to check out the revamped TexasFlood.org. Learn how to pack a flood kit, download resources to prepare family, review individual flood risk, plan an evacuation route, and more.
Posted by Bob Rehak on 8/7/2021 based on a press release by TWDB
1439 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/08/20210807-Screen-Shot-2021-08-07-at-8.33.26-PM.jpg?fit=1200%2C659&ssl=16591200adminadmin2021-08-07 20:49:572021-08-07 20:53:35Improved TexasFlood.org Website Shows Spread of Floodwaters and Inundated Buildings by Gage Height
Below is a quick digest of six flood-related stories affecting the Lake Houston Area.
Dredging is a Slow Go
Mechanical dredgers are slowly working their way through the channel south of Royal Shores. It connects the East and West Forks of the San Jacinto. Without dredging, the dredging equipment itself would not be able to make it through the channel.
However, the pace of the dredging is painfully slow. You can see the progress by comparing the two pictures below. I took them 22 days apart.
Taken on July 11, 2021Taken on August 2, 2021. Google Earth shows they went a little more than 600 feet in a little more than three weeks.
At about 200 feet per week with about 2,000 more feet to go, they should reach the East Fork in about another ten weeks.
Several boaters have commented on how the dredges can wait hours for a pontoon to ferry dirt back to the placement site. Their net takeaway: very inefficient. During a July 8 meeting at the Kingwood Community Center, Stephen Costello called this method of dredging “unsustainable.” He’s sooooo right. We will run out of luck long before we run out of places to dredge.
Mechanical dredging (shown in the photos above) is far slower and less efficient than hydraulic. Great Lakes hydraulic dredges removed 500,000 cubic yards of sediment from the mouth bar area in just two months – July and August of 2019. DRC’s mechanical dredges removed another 600,000+ cubic yards in the 19 months between January 2020 and July 2021.
Interestingly, Google Earth shows that when the dredgers reach the East Fork, they will be closer to the Triple PG Sand Mine in Porter than the current placement area south of River Grove Park. The Triple PG mine will also be less than half the distance of a mine that the Army Corps previously pumped spoils to from the mouth bar– the Eagle Sorters Mine on the West Fork.
Hmmmm. Triple PG. A placement area for East Fork spoils? A return to hydraulic dredging? Interesting thoughts.
Seasonal Lowering of Lake Conroe
Seasonal lowering of Lake Conroe has started as planned. SJRA is releasing 75 cubic feet per second, according to their dashboard.
Seasonal release is shown as a City of Houston (COH) Diversion.
When the lowering started on August 2, a day late, the lake was at 200.87. So releasing 75 CFS has brought the lake down .19 feet, a little more than 2 inches. Barring large rainfalls, this rate should reach the objective of 200 feet by September 1.
The National Hurricane Center shows two areas of concern in the Atlantic as of 2PM, Friday August 6th.
A few hundred miles south of the Cabo Verde Islands, a tropical wave (orange area) and a broad area of low pressure could turn into a tropical depression by late this weekend or early next week. Formation chance through 5 days…medium…60 percent.
Another tropical wave approaching the Lesser Antilles is a lower threat. NHC predicts development, if any, of this system will be slow and occur early next week. Formation chance through 5 days…low…20 percent.
NOAA Issues Mid-Season Hurricane Outlook
Another forecast released two days ago by NOAA says that atmospheric conditions are still conducive for an above-average hurricane season. See their predictions in the right hand column below. These numbers include the five named storms so far this season.
Attorney General Lawsuit Against Triple PG Mine Still Active
Craig Pritzlaff of the TCEQ assures me that despite visible lack of progress in the Attorney General’s lawsuit against the Triple PG mine for illegal discharges, the AG has not dropped the case. “Indeed, very few, if any, cases referred to the AG for civil prosecution are ever dropped,” he says. “Litigation, particularly environmental litigation, is a complicated and lengthy process. That process was further complicated by the COVID-19 pandemic, which halted court dockets across the State throughout 2020 and into 2021.”
Condos 250 Feet from 250,000 CFS
A Chinese developer is building yet more condos even closer to the West Fork in the Kings Harbor neighborhood.
See new construction bottom center. Lai finished the units at the right earlier this year. The nearest unit above will be about 250 feet from the San Jacinto West Fork.
During Harvey, more than 250,000 cubic feet per second came through this area. It flooded homes and businesses more than 10,000 feet from the river.
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/08/20210802-DJI_0286.jpg?fit=1200%2C799&ssl=17991200adminadmin2021-08-06 16:46:402021-08-07 19:38:36Digest: Updates on Six Lake Houston Area Flood-Related Stories
Did you know that one-third of the area in Harris County now has impervious cover? That Montgomery County had a 57.12% net increase of impervious surface area between 2001 and 2019? Or that 10% of land cover in the Lower 48 states changed during that same period? I discovered these and a multitude of other fascinating facts in a recently updated United States Geological Survey (USGS) website dedicated to monitoring changes in land cover, for example, from forested to developed.
When you live in an area for a long time, it’s easy to forget what happened two decades ago. And when you move to a new area, you just accept what is and don’t worry about what was.
But USGS gives you a quick and easy way to see and quantify changes in land use down to the county level. It’s useful in telling you where flood threats could develop over time and how fast they are developing.
About the USGS National Land Cover Database
USGS recently released updated land cover maps for the lower 48 United States. They show how the country’s landscapes have changed over an 18 year period in two- to three-year increments. It’s called the United States National Land Cover Database (NLCD). And it’s the fastest way to see how your county is changing.
Updates include 2001, 2004, 2006, 2008, 2011, 2013, 2016, and 2019.
Developed using Landsat imagery, NLCD classifies land cover into 16 groups with 30-meter resolution. The data includes both land-cover and urban imperviousness changes.
USGS claims 91 percent accuracy for the NLCD data. For more detail about how NLCD was developed see: Changes to the National Land Cover Database. More than nine billion pixels make up the land-cover dataset.
The USGS National Land Cover Database’s suite of GIS mapping products even includes a layer that defines the intensity of impervious surfaces across the United States. This information is used in runoff modeling, urban heat estimation, and a variety of other applications.
Mapping Land Cover Change in U.S. Over Time
Users can visualize land cover changes in the United States by accessing the the Enhanced Visualization and Analysis (EVA) tool. The online mapping tool was developed by USGS in partnership with the National Oceanic and Atmospheric Administration.
The tool allows users to select any county in the Lower-48 United States and generate a custom report on land cover change, developed areas, cropland change, and other factors.
Only one caution: the USGS site does not work with Apple’s Safari Browser. Mac users can use Firefox without problems, however. I have not tested other Mac browsers.
Almost one fifth of the land cover changed type (18.23%).
Developed portions of the county increased from 54.42% to 65.85% of the total acreage, a 20.99% percent net increase of developed area.
Forested parts of the county went from 10.64% to 6.29%, a percent net decrease of 40.92%.
The percent covered in wetlands went down from 8.28% to 7.02%, another percent net decrease of 15.24%.
The percentage of impervious surface increased from about a quarter to a third (26.28% to 33.39%), a percent net increase of 27.05%.
Screen showing development changes in Harris County with corresponding percentages of impervious cover. Green dots represent changes in land use.Clicking on icons in left column brings up different types of information.
MoCo Changes at a Glance
During the same period, in Montgomery County:
Even more land cover changed type (18.99%).
Developed portions of the county increased from 21.1% of the land area to 28.27%, a 33.97% net increase.
Impervious cover increased from 5.78% off the land area to 9.08%, a 57.12% increase.
Forested land decreased from 42.98% of the county to 38.96%, a 9.16% net decrease.
Wetlands decreased from 12.17% of the county to 11.35%, a 6.74% net decrease.
Agricultural land decreased from 12.28% to 10.31% of the county, a 16.04% net decrease.
Red areas represent areas in Montgomery County that changed land-cover type between 2001 and 2019.
Another screen showing areas in Montgomery County developed between 2001 and 2019.
Key Lesson
This database and GIS mapping system dramatize how quickly the region is growing and land use is changing.
Flood mitigation is or should be a two-pronged effort. We must fix problems that already exist downstream while hopefully preventing future problems from developing upstream. It’s not a just question of one county spending money to help prevent problems in another. It’s about surrounding counties protecting themselves. The outward expansion is relentless. People at the edge today will be downstream from someone else tomorrow.
There’s little anyone can do to change the FACT of development. But we can change the NATURE of development. If all new developments retained their own rain, no one would ever be doomed to the flood-mitigation treadmill of keeping up with ever-increasing amounts of upstream runoff.
Montgomery County already has a serious flooding problem of its own. Thousands of people flooded there during Harvey and Imelda.
Posted by Bob Rehak on 8/5/2021based on USGS information
1437 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/08/Harris-Developed.jpg?fit=1200%2C582&ssl=15821200adminadmin2021-08-05 17:34:302021-08-06 11:42:27USGS Says One Third of Harris County Now Impervious Cover
Improved TexasFlood.org Website Shows Spread of Floodwaters and Inundated Buildings by Gage Height
The Texas Water Development Board (TWDB) has reorganized the sea of flood-related information and redesigned the TexasFlood.org website to provide a more user-friendly resource for Texans who want to increase their flood awareness and preparedness.
Given the deadly nature of flood events and the rapid timeframe in which they can occur, remaining flood-ready is essential.
One Feature Shows Flood Spread and Inundated Buildings by Gage Height
TexasFlood.org provides fundamental information on emergency preparation for and recovery from flood events, as well as web tools to better understand flood risk, in a format that is easy to access and easy to understand.
I selected the height of the highest gage reading during the May floods this year at FM1485 and the East Fork. Then I zoomed in and found that 36 structures were in danger of being inundated. You can even see their locations!
Information like this is not only useful when considering purchasing a building, but also when considering whether to evacuate.
Other Useful Features
TexasFlood.org also features resources and tools that allow users to:
The website highlights the reasons why emergency preparedness is vital to proper flood preparedness, including the importance of floodproofing and awareness of second-order damages after a flood event.
One-Stop Information Shop
The TWDB has gathered important information from other local, state, and federal entities to provide the most relevant information for Texans in one convenient online location. Hurricane season runs through November 30 each year. And historically speaking, 80% of the storms for this year are still in front of us. Just today, the National Hurricane Center highlighted another area of concern in the Atlantic, bringing the active total to three.
So TWDB encourages all Texans to check out the revamped TexasFlood.org. Learn how to pack a flood kit, download resources to prepare family, review individual flood risk, plan an evacuation route, and more.
Posted by Bob Rehak on 8/7/2021 based on a press release by TWDB
1439 Days since Hurricane Harvey
Digest: Updates on Six Lake Houston Area Flood-Related Stories
Below is a quick digest of six flood-related stories affecting the Lake Houston Area.
Dredging is a Slow Go
Mechanical dredgers are slowly working their way through the channel south of Royal Shores. It connects the East and West Forks of the San Jacinto. Without dredging, the dredging equipment itself would not be able to make it through the channel.
However, the pace of the dredging is painfully slow. You can see the progress by comparing the two pictures below. I took them 22 days apart.
At about 200 feet per week with about 2,000 more feet to go, they should reach the East Fork in about another ten weeks.
Several boaters have commented on how the dredges can wait hours for a pontoon to ferry dirt back to the placement site. Their net takeaway: very inefficient. During a July 8 meeting at the Kingwood Community Center, Stephen Costello called this method of dredging “unsustainable.” He’s sooooo right. We will run out of luck long before we run out of places to dredge.
Mechanical dredging (shown in the photos above) is far slower and less efficient than hydraulic. Great Lakes hydraulic dredges removed 500,000 cubic yards of sediment from the mouth bar area in just two months – July and August of 2019. DRC’s mechanical dredges removed another 600,000+ cubic yards in the 19 months between January 2020 and July 2021.
Interestingly, Google Earth shows that when the dredgers reach the East Fork, they will be closer to the Triple PG Sand Mine in Porter than the current placement area south of River Grove Park. The Triple PG mine will also be less than half the distance of a mine that the Army Corps previously pumped spoils to from the mouth bar– the Eagle Sorters Mine on the West Fork.
Hmmmm. Triple PG. A placement area for East Fork spoils? A return to hydraulic dredging? Interesting thoughts.
Seasonal Lowering of Lake Conroe
Seasonal lowering of Lake Conroe has started as planned. SJRA is releasing 75 cubic feet per second, according to their dashboard.
When the lowering started on August 2, a day late, the lake was at 200.87. So releasing 75 CFS has brought the lake down .19 feet, a little more than 2 inches. Barring large rainfalls, this rate should reach the objective of 200 feet by September 1.
The Lake Conroe Association is still fighting the lowering in Montgomery County District Court. Judge Mike Mays set a hearing date for Tuesday, August 24, 2021 at 2PM.
Tropics Heating Up
The National Hurricane Center shows two areas of concern in the Atlantic as of 2PM, Friday August 6th.
A few hundred miles south of the Cabo Verde Islands, a tropical wave (orange area) and a broad area of low pressure could turn into a tropical depression by late this weekend or early next week. Formation chance through 5 days…medium…60 percent.
Another tropical wave approaching the Lesser Antilles is a lower threat. NHC predicts development, if any, of this system will be slow and occur early next week. Formation chance through 5 days…low…20 percent.
NOAA Issues Mid-Season Hurricane Outlook
Another forecast released two days ago by NOAA says that atmospheric conditions are still conducive for an above-average hurricane season. See their predictions in the right hand column below. These numbers include the five named storms so far this season.
Attorney General Lawsuit Against Triple PG Mine Still Active
Craig Pritzlaff of the TCEQ assures me that despite visible lack of progress in the Attorney General’s lawsuit against the Triple PG mine for illegal discharges, the AG has not dropped the case. “Indeed, very few, if any, cases referred to the AG for civil prosecution are ever dropped,” he says. “Litigation, particularly environmental litigation, is a complicated and lengthy process. That process was further complicated by the COVID-19 pandemic, which halted court dockets across the State throughout 2020 and into 2021.”
Condos 250 Feet from 250,000 CFS
A Chinese developer is building yet more condos even closer to the West Fork in the Kings Harbor neighborhood.
During Harvey, more than 250,000 cubic feet per second came through this area. It flooded homes and businesses more than 10,000 feet from the river.
The developer is also hoping to sell/develop that grassy area in the bottom center of the photo for $1.45 million.
I guess money has a short memory.
That concludes this month’s digest.
Posted by Bob Rehak on 8/6/2021
1438 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
USGS Says One Third of Harris County Now Impervious Cover
Did you know that one-third of the area in Harris County now has impervious cover? That Montgomery County had a 57.12% net increase of impervious surface area between 2001 and 2019? Or that 10% of land cover in the Lower 48 states changed during that same period? I discovered these and a multitude of other fascinating facts in a recently updated United States Geological Survey (USGS) website dedicated to monitoring changes in land cover, for example, from forested to developed.
When you live in an area for a long time, it’s easy to forget what happened two decades ago. And when you move to a new area, you just accept what is and don’t worry about what was.
But USGS gives you a quick and easy way to see and quantify changes in land use down to the county level. It’s useful in telling you where flood threats could develop over time and how fast they are developing.
About the USGS National Land Cover Database
USGS recently released updated land cover maps for the lower 48 United States. They show how the country’s landscapes have changed over an 18 year period in two- to three-year increments. It’s called the United States National Land Cover Database (NLCD). And it’s the fastest way to see how your county is changing.
Updates include 2001, 2004, 2006, 2008, 2011, 2013, 2016, and 2019.
Developed using Landsat imagery, NLCD classifies land cover into 16 groups with 30-meter resolution. The data includes both land-cover and urban imperviousness changes.
USGS claims 91 percent accuracy for the NLCD data. For more detail about how NLCD was developed see: Changes to the National Land Cover Database. More than nine billion pixels make up the land-cover dataset.
The USGS National Land Cover Database’s suite of GIS mapping products even includes a layer that defines the intensity of impervious surfaces across the United States. This information is used in runoff modeling, urban heat estimation, and a variety of other applications.
Mapping Land Cover Change in U.S. Over Time
Users can visualize land cover changes in the United States by accessing the the Enhanced Visualization and Analysis (EVA) tool. The online mapping tool was developed by USGS in partnership with the National Oceanic and Atmospheric Administration.
The tool allows users to select any county in the Lower-48 United States and generate a custom report on land cover change, developed areas, cropland change, and other factors.
Only one caution: the USGS site does not work with Apple’s Safari Browser. Mac users can use Firefox without problems, however. I have not tested other Mac browsers.
I ran two quick searches on Harris and Montgomery Counties by going to the EVA tool mentioned above. The findings astonished me.
Harris County Changes At a Glance
Between 2001 and 2019, in Harris County:
MoCo Changes at a Glance
During the same period, in Montgomery County:
Key Lesson
This database and GIS mapping system dramatize how quickly the region is growing and land use is changing.
Flood mitigation is or should be a two-pronged effort. We must fix problems that already exist downstream while hopefully preventing future problems from developing upstream. It’s not a just question of one county spending money to help prevent problems in another. It’s about surrounding counties protecting themselves. The outward expansion is relentless. People at the edge today will be downstream from someone else tomorrow.
There’s little anyone can do to change the FACT of development. But we can change the NATURE of development. If all new developments retained their own rain, no one would ever be doomed to the flood-mitigation treadmill of keeping up with ever-increasing amounts of upstream runoff.
Montgomery County already has a serious flooding problem of its own. Thousands of people flooded there during Harvey and Imelda.
Posted by Bob Rehak on 8/5/2021 based on USGS information
1437 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.