The Texas Water Development Board published a new video today in their Texas Water Newsroom. The title: “Data from the sky informs flood planning on the ground.” The video explains how Lidar (light detection and ranging) data helps develop accurate, up-to-date flood maps.
900X Higher Resolution
Surveyors can acquire high resolution data quickly from the air using pulses of light.
Lasers mounted under planes pulse hundreds of thousands of times per second producing incredibly detailed images of the terrain.
Texas Water Development Board
The data has one square-meter resolution compared to the old standard of 30 square-meters used in older USGS surveys. That’s a 900x improvement (1m x 1m vs. 30m x 30m) in resolution.
That increased resolution lets mapmakers see much more detail in the landscape, including low areas where water tends to pool during floods.
Play the Video
Filtering Out Buildings and Foliage Reveals Terrain
By filtering out portions of the spectrum, say those that have to do with buildings and foliage…
Screen Capture from TWDB Video
…scientists can reveal the terrain under them.
Lidar Now FEMA Requirement for Mapping
FEMA now requires the use of Lidar in floodplain mapping. As the state continues to grow rapidly, Lidar helps floodplain modelers better understand what is happening on the ground during a flood.
Inspiring the Next Generation
This is a fascinating little video. It has enough meat for curious adults. It also has a wow factor for students that might someday inspire interest in science, technology or engineering careers.
Updated Harris County Floodplain Maps
Harris County Flood Control District uses Lidar data to help develop the next generation of flood maps for the region. FEMA last updated the maps in 2007 as a result of massive flooding from Tropical Storm Allison. The District could release preliminary maps as early as 2022. But it could then take several more years for FEMA to review and approve them. The FEMA process involves a lengthy public comment period.
Source: Harris County Flood Control District.
Posted by Bob Rehak on 9/16/2020
1114 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/09/Lidar-Terrain.jpg?fit=1200%2C671&ssl=16711200adminadmin2020-09-16 16:06:552020-09-16 16:18:27How LIDAR is Used to Develop New Flood Maps
Harris County Precinct One Commissioner Rodney Ellis
Garcia Also Wanted to Add New Condition
Precinct 2 Commissioner Adrian Garcia also wanted to add a new condition. He wanted to get the City to give Harris County Flood Control District (HCFCD) a place on the City’s planning commission. At this point in the meeting, it looked like the motion could die again.
However, Houston Mayor Pro Tem DAVE MARTIN assured Precinct 2 Commissioner Adrian Garcia that he would fight to get HCFCD a place on the Planning Commission. Garcia then decided to vote for the motion. Earlier this month, the two jointly requested the Planning Commission to consider higher flood mitigation standards in their planning decisions.
How Vote Went Down
Garcia emphasized that he didn’t like the Woodridge Village motion per se, but that he trusted Martin to get the County a seat on the planning commission. Thus, he would vote for the Woodridge earnest money proposal.
Veteran observers of Commissioners Court say this was the first time Ellis, Hidalgo and Garcia contemplated splitting their vote. Previously, they have always voted as a block.
Commissioners Jack Cagle and Steve Radack had already voted for the motion. When Garcia flipped, Ellis and Judge Lina Hidalgo read the handwriting on the wall. They also voted for the Woodridge earnest money contract at that point. The final vote: 5-0.
What Comes Next
At this point, final language of the Inter-Local Agreement with the City must be hammered out in the next 120 days. The City must also agree to the conditions listed above by:
Identifying land worth half the purchase price
Contributing assets or cash equal to half the purchase and development costs
Updating certain regulations affecting flood plain development
It also seems to me that the County must develop plans for Woodridge so that it can estimate costs and how much the City will have to contribute.
Finally, Perry Homes and its subsidiary, Figure Four Partners, must agree to all the conditions and sign the earnest money contract.
There is still a long road ahead for this deal. But today was a great step forward. At least we’re on the road now, thanks in large part to Commissioner Jack Cagle and Houston Mayor Pro Tem Dave Martin who refused to let this deal die.
Posted by Bob Rehak on 9/15/2020
1113 Days after Hurricane Harvey and 362 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/09/Rodney-Ellis-9.15.20-mtg.jpg?fit=1200%2C796&ssl=17961200adminadmin2020-09-15 19:04:062020-09-15 19:29:07Harris County Commissioners Approve Negotiation of Earnest Money Contract for Woodridge Village
For the last few months, New Caney ISD has been clearing an approximately 60-acre site between Sorters-McClellan Road and US59 south of the Kingwood Medical Center. But only now have they started work on the detention pond. The site, formerly a par-3 golf course, will become home to the School District’s third high school.
Detention Pond Work Finally Underway
In the last few days, contractors have finally started excavating a planned detention pond at the southern end of the site. They appear to be using the dirt to build up the northern part of the site where the high school and playing fields will go. This two-part operation is a procedure called “cut and fill” in the industry.
Neighboring residents feared a repeat of Woodridge Village, as contractors clearcut the site without installing detention.
A storm, such as Imelda last year, could have accelerated sheet flow from the site and flooded them. However, so far, no major storms have hit the area this year. Everyone has lucked out to date.
However, clearing a site of this size and excavating the detention last increases risk. That increased risk argues for the City to adopt building code regulations that minimize the time between clearing and excavation of detention ponds.
It can be done. Some builders excavate ponds immediately and store the dirt in huge piles to redistribute after the rest of the site is cleared.
Pictures from 4 Corners of Site
Here are some pictures taken Friday, September 11. They show the operation in progress from the four corners of the site.
Looking west. South is to the left. The big pit being excavated in the middle of the picture will be the retention pond for the high school complex.Note the loaded truck heading off to the right (north).Looking south from the northeastern corner of the site toward the San Jacinto River, Humble and Deerbook Mall in the background.Looking SE from the NW corner of the site, you can see how dramatically this site slopes toward the upper right. That’s Sorters Road on the right.From the SW corner of the site looking NE toward Insperity and the Kingwood Medical Center, you can see excavated dirt being hauled to the upper portions of the site to build it up. US59 cuts diagonally through the upper right of the frame.
Project Scope
To put the size of this site in perspective, the New Caney ISD high school #3 is approximately:
Twice as big as the HCA Kingwood Medical Center site
Three times larger than Insperity’s complex
Six times larger than the Lowes site across US59.
It will contain the school, athletic fields, parking lots and the detention pond.
General plan for New Caney High School #3
The area west of the site along Sorters Road will be expanded to accommodate traffic. Even though the site is in Montgomery County, it sits entirely within the City of Houston. The City has handled all permitting for the project.
The District’s 2018 Bond Fund will pay for the project so it should not affect taxes, according to a Houston Chronicle article.
Posted by Bob Rehak on 9/14/2020
1112 Days since Hurricane Harvey and 361 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/09/20200911-RJR_0914.jpg?fit=1200%2C800&ssl=18001200adminadmin2020-09-14 14:38:032020-09-14 14:44:35Development Watch: Detention Pond for New Caney ISD High School Number 3 Finally Started
How LIDAR is Used to Develop New Flood Maps
The Texas Water Development Board published a new video today in their Texas Water Newsroom. The title: “Data from the sky informs flood planning on the ground.” The video explains how Lidar (light detection and ranging) data helps develop accurate, up-to-date flood maps.
900X Higher Resolution
Surveyors can acquire high resolution data quickly from the air using pulses of light.
The data has one square-meter resolution compared to the old standard of 30 square-meters used in older USGS surveys. That’s a 900x improvement (1m x 1m vs. 30m x 30m) in resolution.
That increased resolution lets mapmakers see much more detail in the landscape, including low areas where water tends to pool during floods.
Play the Video
Filtering Out Buildings and Foliage Reveals Terrain
By filtering out portions of the spectrum, say those that have to do with buildings and foliage…
…scientists can reveal the terrain under them.
Lidar Now FEMA Requirement for Mapping
FEMA now requires the use of Lidar in floodplain mapping. As the state continues to grow rapidly, Lidar helps floodplain modelers better understand what is happening on the ground during a flood.
Inspiring the Next Generation
This is a fascinating little video. It has enough meat for curious adults. It also has a wow factor for students that might someday inspire interest in science, technology or engineering careers.
Updated Harris County Floodplain Maps
Harris County Flood Control District uses Lidar data to help develop the next generation of flood maps for the region. FEMA last updated the maps in 2007 as a result of massive flooding from Tropical Storm Allison. The District could release preliminary maps as early as 2022. But it could then take several more years for FEMA to review and approve them. The FEMA process involves a lengthy public comment period.
Posted by Bob Rehak on 9/16/2020
1114 Days since Hurricane Harvey
Harris County Commissioners Approve Negotiation of Earnest Money Contract for Woodridge Village
Harris County Commissioners Court just approved a motion authorizing negotiation of an earnest money contract with Figure Four Partners, Ltd. (Item 14G on today’s agenda). The contract will lock in the purchase price of 267.35 acres in Montgomery County for the Woodridge Village stormwater detention basin. The amount: $14,019,316 – $5,100,770 below the appraised value.
Conditions Must Still Be Met Before Purchase
The City of Houston still must meet certain conditions and commitments before the actual purchase comes up for a vote. Within 120 days, the City must:
Ellis Tried to Add More Conditions
In at least five previous meetings, Precinct One Commissioner Rodney Ellis successfully delayed the vote by adding new conditions to the motion.
True to form, he tried again today. He wanted to use the purchase as leverage to get the City to adopt his “equity” guidelines. Those guidelines rank flood bond projects in his district above those in others.
Garcia Also Wanted to Add New Condition
Precinct 2 Commissioner Adrian Garcia also wanted to add a new condition. He wanted to get the City to give Harris County Flood Control District (HCFCD) a place on the City’s planning commission. At this point in the meeting, it looked like the motion could die again.
However, Houston Mayor Pro Tem DAVE MARTIN assured Precinct 2 Commissioner Adrian Garcia that he would fight to get HCFCD a place on the Planning Commission. Garcia then decided to vote for the motion. Earlier this month, the two jointly requested the Planning Commission to consider higher flood mitigation standards in their planning decisions.
How Vote Went Down
Garcia emphasized that he didn’t like the Woodridge Village motion per se, but that he trusted Martin to get the County a seat on the planning commission. Thus, he would vote for the Woodridge earnest money proposal.
Veteran observers of Commissioners Court say this was the first time Ellis, Hidalgo and Garcia contemplated splitting their vote. Previously, they have always voted as a block.
Commissioners Jack Cagle and Steve Radack had already voted for the motion. When Garcia flipped, Ellis and Judge Lina Hidalgo read the handwriting on the wall. They also voted for the Woodridge earnest money contract at that point. The final vote: 5-0.
What Comes Next
At this point, final language of the Inter-Local Agreement with the City must be hammered out in the next 120 days. The City must also agree to the conditions listed above by:
It also seems to me that the County must develop plans for Woodridge so that it can estimate costs and how much the City will have to contribute.
Finally, Perry Homes and its subsidiary, Figure Four Partners, must agree to all the conditions and sign the earnest money contract.
There is still a long road ahead for this deal. But today was a great step forward. At least we’re on the road now, thanks in large part to Commissioner Jack Cagle and Houston Mayor Pro Tem Dave Martin who refused to let this deal die.
Posted by Bob Rehak on 9/15/2020
1113 Days after Hurricane Harvey and 362 since Imelda
Development Watch: Detention Pond for New Caney ISD High School Number 3 Finally Started
For the last few months, New Caney ISD has been clearing an approximately 60-acre site between Sorters-McClellan Road and US59 south of the Kingwood Medical Center. But only now have they started work on the detention pond. The site, formerly a par-3 golf course, will become home to the School District’s third high school.
Detention Pond Work Finally Underway
In the last few days, contractors have finally started excavating a planned detention pond at the southern end of the site. They appear to be using the dirt to build up the northern part of the site where the high school and playing fields will go. This two-part operation is a procedure called “cut and fill” in the industry.
A storm, such as Imelda last year, could have accelerated sheet flow from the site and flooded them. However, so far, no major storms have hit the area this year. Everyone has lucked out to date.
However, clearing a site of this size and excavating the detention last increases risk. That increased risk argues for the City to adopt building code regulations that minimize the time between clearing and excavation of detention ponds.
It can be done. Some builders excavate ponds immediately and store the dirt in huge piles to redistribute after the rest of the site is cleared.
Pictures from 4 Corners of Site
Here are some pictures taken Friday, September 11. They show the operation in progress from the four corners of the site.
Project Scope
To put the size of this site in perspective, the New Caney ISD high school #3 is approximately:
It will contain the school, athletic fields, parking lots and the detention pond.
The area west of the site along Sorters Road will be expanded to accommodate traffic. Even though the site is in Montgomery County, it sits entirely within the City of Houston. The City has handled all permitting for the project.
The project should take about another two years to complete. New Caney ISD hopes to open the school in August of 2022.
The District’s 2018 Bond Fund will pay for the project so it should not affect taxes, according to a Houston Chronicle article.
Posted by Bob Rehak on 9/14/2020
1112 Days since Hurricane Harvey and 361 since Imelda