1/4/25 – In a Houston-area-flooding context, we usually consider erosion as a negative. It reduces the capacity of streams, channels and Lake Houston. It can also form sediment dams like mouth bars that back water up.
But elsewhere, many consider erosion a tourist attraction. And I’m not just talking about the Grand Canyon.
Welcome to Sedona
During the holidays, I took a break from blogging about flooding to join a family reunion near colorful Sedona, Arizona. We actually stayed in the Village of Oak Creek, an unincorporated area about five miles south of the main part of Sedona.
Always alert for photo ops, I launched my drone from the back porch of our rented home and captured some photos of red rock, blue sky and spectacular erosion.
Looking NWSame angle but closer. Notice different color in uppermost strata.Looking NE. Closer shot, still looking NE. Again, notice different colors in upper layers.
The rocks around Sedona are famously red due to their high concentration of iron oxide. Millions of years ago, the Sedona region was covered by a vast shallow sea that deposited layers of sediments rich in iron minerals.
Over time, these iron-rich layers were uplifted due to tectonic activity. The iron in the rocks reacted with oxygen, resulting in oxidation – the same chemical reaction that gives rust its red color.
Then, erosion sculpted the landscape – over millions of years. It exposed these oxidized rock layers, which now dominate the area and give Sedona its iconic red hue. But why did the land erode in some areas and not others?
Caprock Protects Some Areas from Erosion
The spectacularly steep cliffs around Sedona can be attributed to the uneven distribution of what geologists call “caprock.” The term refers to the hard, erosion-resistant rock layers that sit atop mesas, buttes, and cliffs. These layers protect the softer rock below from erosion, helping to shape the striking red rock formations that make Sedona famous.
The caprock was formed from ancient sand dunes and marine deposits about 250–275 million years ago during the Permian period. Over time, these deposits solidified into dense rock layers responsible for Sedona’s intricate geological artistry.
The Value of Rust and Erosion
Sedona reportedly received approximately 4 million visitors last year, rivaling the Grand Canyon. That’s more people than live in Houston and almost as many as live in Harris County. Sedona’s stunning red rock formations and outdoor recreational opportunities make it a major attraction for both domestic and international travelers.
Rainfall and Flooding
Sedona receives an average of 19 inches of rainfall per year – less than 40% of Houston’s average rainfall. However, Sedona still experiences three types of flooding:
Flash Flooding:
Sudden, intense thunderstorms during the monsoon can cause flash floods. The steep terrain and rocky surfaces around Sedona lead to rapid runoff, overwhelming dry washes and creek beds.
Flash floods are particularly hazardous in areas like Oak Creek Canyon, where narrow canyons can funnel water quickly.
River Flooding:
Sedona’s primary waterway, Oak Creek, can flood after prolonged rainfall or snowmelt from higher elevations. Heavy storms, particularly in winter, can cause the creek to rise significantly, affecting nearby properties and recreational areas.
Urban Flooding:
Heavy rain can overwhelm local drainage systems, leading to localized flooding in lower-lying areas.
Oak Creek flooded badly from severe winter storms in 2005. One of the most significant floods in recent memory, it damaged homes, businesses and bridges.
In 2023, heavy rains led to flash floods that temporarily closed hiking trails and roads.
Such floods sculpted the landscape you see in the photos above.
More About Sedona
Spanish explorers first passed through the area as early as the 1500s.
Homesteading began in the late 1800s.
Sedona became a popular filming location for Western movies due to its dramatic landscapes. Films like “Stagecoach” (1939) and “Broken Arrow” (1950) were shot in the area, bringing international attention to Sedona.
Improved roads and infrastructure led to a tourism boom beginning in the 1950s.
Today, Sedona is known for its outdoor activities (hiking, mountain biking, and jeep tours), yoga retreats, art galleries, and night skies. Re: the last point, Sedona is designated as an International Dark Sky Community. Star gazers enjoy freedom from “light pollution” – there were no streetlights where we stayed!
Posted by Bob Rehak on 1/4/2025
2685 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2025/01/20241227-DJI_20241227172839_0609_D.jpg?fit=1100%2C619&ssl=16191100adminadmin2025-01-04 11:08:102025-01-04 19:30:44Sedona: Erosion on a Spectacular Scale
1/3/25 – Jeff Lindner, Harris County’s Meteorologist, provided this official holiday tornado report. Southeast Texas experienced a highly active period of severe weather from 12/24/24 through 12/28/24. It included several tornado outbreaks on both the 26th and 28th.
Said Lindner, “While it is not uncommon to have severe weather and tornados in southeast Texas during the winter months, it is a bit unusual to have back-to-back outbreaks one day apart.”
“Most tornados in this region are small and of low-end intensity (EF-0 or EF-1). It is rare to see the higher intensity EF-3 and longer track tornadoes here locally, but they do occasionally happen,” said Lindner.
He provided the following holiday tornado report on the two main days.
December 26th Tornadoes
Five tornados occurred across southeast Texas on Thursday, the 26th. They included 2 EF-1 and 3 EF-0 tornados.
EF-1 tornados (on the Enhanced Fujita scale) have winds from 73-112 mph that can cause moderate damage.
EF-0 tornados have winds less than 73 mph that generally cause light damage.
1. El Campo TX (Wharton County)
Rating: EF-1
Peak Wind: 95mph
Path Length: .50 mile
Path Width: 50 yards
This tornado began three miles northeast of El Campo and was on the ground for roughly half of a mile. The tornado mostly moved across open farmland, but one well constructed outbuilding (barn) was impacted and destroyed yielding the EF-1 rating. It is possible this tornado was stronger over the open farm fields, but without any available damage indicators, this will remain unknown.
2.Southwest Harris County (NW of Meadows Place)
Rating: EF-1
Peak Wind: 90mph
Path Length: .05 mile
Path Width: 25 yards
A brief tornado occurred one mile north-northwest of Meadows Place in southwest Harris County along Plumbrook Drive. It damaged a few houses and overturned a delivery truck. One of the houses sustained roof and outside-facing wall damage resulting in the EF-1 damage rating.
3. Northern Liberty County (SE of Cleveland TX)
Rating: EF-0
Peak Wind: 75mph
Path Length: 6.8 miles
Path Width: 50 yards
This tornado began nine miles northwest of Dayton Lakes and moved eastward across mostly rural northern Liberty County. It damaged trees and two mobile homes consistent with winds of 65-75mph, earning it an EF-0 rating.
4.Lake Houston/Huffman (NE Harris County)
Rating: EF-0
Peak Wind: 60mph
Path Length: 2.1 miles
Path Width: N/A
HPD Lake Patrol and other video confirmed a tornado (waterspout) over Lake Houston north of FM 1960 that moved eastward across the lake and moved ashore along the eastern side of the lake in a wooded area. Survey teams were unable to find any damage near where the tornado reached the shoreline and the tornado dissipated quickly while moving onshore.
5.Dayton TX (Liberty County)
Rating: EF-0
Peak Wind: 60mph
Path Length: 1.1 miles
Path Width: 25 yards
A small tornado developed seven miles west of Dayton and moved across mainly open farm and ranch land. It downed a few trees. That helped storm spotters that captured the funnel cloud on video confirm that it was, in fact a tornado.
December 28 Tornados
Linder also said, “A more significant and damaging tornado event occurred from late morning to late afternoon on the 28th. Five tornadoes occurred from two primary supercell thunderstorms that moved across the area. Unfortunately, these tornadoes resulted in more significant damage with injuries and one fatality. Two EF-3, one EF-2, and two EF-1 tornados moved over the area.”
Paths of 5 tornados associated with two supercells on 12/28/24.
1. Brookshire Tornado (Waller and western Harris Counties)
Rating: EF-1
Peak Wind: 100mph
Path Length: 10.9 miles
Path Width: 150 yards
This tornado began west of FM 2855 in southern Waller County three miles north of Brookshire where a mobile home was moved off its foundation. The tornado continued northeast where it impacted a small area of houses south of Beckendorff Road and Noel Lane.
It rolled and completely destroyed one mobile home. Several other structures sustained roof and window damage. It also overturned vehicles in a driveway. Damage fell into both EF-0 and low-end EF-1 categories. The tornado continued northeast into a newly built subdivision where it destroyed 1-2 houses under construction and a brick privacy wall.
It then crossed FM 529 at Pitts Road just south of a Centerpoint power substation where it knocked down a power pole. Debris fanned across an open field and a subdivision detention basin.
The tornado then entered the Windward Subdivision near its southeastern edge. There, it damaged roofs, windows, and fences of 5-10 homes. One house lost all south-facing windows along with portions of the roof’s deck and outside facing wall siding.
This qualifies as EF-1 damage with winds estimated around 100 mph. The tornado weakened as it moved north-northeast and dissipated west of John Paul Landing in northwest Harris County.
Brookshire Tornado Path
2. Porter Heights to Splendora Tornado (Montgomery County)
Rating: EF-3
Peak Wind: 140mph
Path Length: 10.3 miles
Path Width: .65 mile
Injuries: 4
The same supercell that produced a Katy tornado continued northeast across northwest Harris County. It crossed the Bridgeland subdivision, then SH 249 near Spring Cypress, and continued northeast toward I-45/SH99. Both radar and Hooks Airport staff observed rotation, but not on the ground.
Porter Heights/Splendora Tornado Pathon 12/28/24.
As this storm entered Montgomery County, the velocity increased and radar showed a debris ball near Porter Heights. Wind removed the entire roof structures of 1-2 homes. One brick house suffered complete outside wall failure and several interior wall failures. The twister also rolled a nearby mobile home, completely destroying it.
Damage indicated winds in the 140-145 mph EF-3 range.
Jeff Lindner, Harris County Meteorologist
The tornado then crossed FM 1314 where it destroyed large sections of a metal rental facility and a nearby mobile home. At this point, damage indicated high-end EF-1 or low-end EF-2.
The tornado weakened some while moving northeast across several rural streets and houses, but still caused significant tree damage. It then intensified as it moved into the Pickering Road area southwest of FM 1485. The twister heavily damaged or destroyed several RV’s and mobile homes. It completely removed the roof of Fire Station 154 and damaged three fire trucks. The twister even picked one up and rotated it 90 degrees.
North of FM 1485, it damaged several homes before crossing SH 242 into the Harrington Trails subdivision, removing nearly the entire roof of one home. The storm also completely destroyed several houses under construction.
The tornado continued northeast toward Splendora High School and dissipated in an open field after it crossed FM 2090.
Most of the storm’s track qualified as EF-1 or EF-2. Only a small portion near the beginning in Porter Heights rated EF-3. Four people suffered injuries.
3. Liverpool to Hillcrest Tornado (Brazoria County)
Rating: EF-2
Peak Wind: 125mph
Path Length: 8.8 miles
Path Width: 300 yards
Injuries: 5
Fatalities: 1
This tornado began four miles ENE of Liverpool along CR 172 in a rural area and tracked into Hillcrest southeast of Alvin. Most damage indicated EF-0 or EF-1 strength. But at Walt Disney Elementary School several large sections of the roof were ripped off and portions of an exterior wall failed. That indicated EF-2 (125mph) strength.
The storm also flipped and destroyed a mobile home causing a fatality. The tornado dissipated prior to reaching the Galveston County line.
Brazoria County Tornado Pathon 12/28/24
4. Dickinson to Bacliff (Galveston County)
Rating: EF-1
Peak Wind: 90mph
Path Length: 7.40 miles
Path width: 850 yards
The Brazoria County supercell produced another tornado near the intersection of Hughes Road between I-45 and HWY 3. It moved northeast across FM 517 and HWY 146, causing EF-1 damage to several homes with its 90 mph winds east of Dickinson High School. Along most of its path, the storm featured EF-0 (60-80 mph) winds. It downed trees, fences, and power poles and caused some roof damage.
The tornado continued east across Galveston Bay and reached into Chambers County.
Dickinson to Bacliff Tornado Pathon 12/28/24
5. Chambers County
Rating: EF-3
Peak Wind: 140mph (Chambers)/160mph (Jefferson)
Path Length: 22 miles
Path Width: 400 yards
Injuries: 1 (Chambers) and (4 injuries in Jefferson County)
The Brazoria and Galveston County supercell intensified over Galveston Bay before tracking into Chambers County near Smith Point. The tornado destroyed several mobile homes along FM 1941, where EF-3 damage was noted.
The tornado then crossed HWY 124 destroying high-tension power-transmission towers with 140mph winds. The towers supplied power to High Island and the Bolivar Peninsula. Winds also lofted and rolled a pickup truck near Smith Point Road resulting in one injury.
This was a significant tornado. It impacted mainly rural areas of Chambers County before crossing all of southern Jefferson County where high end EF-3 (160 mph winds) damage occurred in Hampshire TX. The tornado then moved between Port Arthur and Sabine Pass into southern Louisiana.
Chambers to Jefferson County Tornado Pathon 12.28/24
The holidays are usually happy times. But severe weather made them less so for many people in 2024.
Posted by Bob Rehak on 1/3/24 based on information provided by Harris County Meteorologist Jeff Lindner
2684 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2025/01/12.28-tornados-e1735935355135.png?fit=1100%2C567&ssl=15671100adminadmin2025-01-03 14:23:472025-01-04 05:16:28Official Holiday Tornado Report from HCFCD
12/29/24 – Several rounds of intense rain in the past week triggered a slew of emails from concerned residents about the need for better construction management practices to control sediment-laden runoff.
Chris Summers, a retired commercial photographer, included pictures of the runoff from the Foster Elementary site in Kingwood’s Trailwood Village. Contractors recently cleared the site for reconstruction of the school. Summer’s photos illustrate the dangers from sediment pollution and the need for better construction management practices.
A Major Source of Sediment Pollution
Construction site runoff is a major source of sediment pollution. Construction typically involves large-scale disturbance of soil, which can significantly increase the amount of sediment carried away by stormwater runoff. This sediment-laden runoff can have serious environmental impacts, especially when it enters local water bodies, such as Lake Houston..
Clearing, excavating and grading disturb soil. Stripping away vegetation makes soil more prone to erosion. So, when it rains, the exposed soil can easily wash away into nearby water systems.
In many cases, vegetation or other stabilization measures (e.g., erosion control blankets, mulching) may not be installed until later stages of construction, leaving the site vulnerable to sediment loss in the meantime.
Construction sites are most vulnerable during heavy rainfalls, which can lead to significant runoff, especially from areas without adequate sediment-control measures.
In many cases, construction schedules are not aligned with seasonal weather patterns, so sites may be left exposed during periods of heavy rain. This can lead to water-quality degradation, increased costs for water treatment, higher water bills, and infrastructure damage.
Excessive sediment can clog stormwater systems, leading to flooding and costly repairs.
Regulations and Best Management Practices
Due to the significant environmental impact of construction-site runoff, many countries and regions have strict regulations and Best Management Practices (BMPs) to control it. In the U.S., for example, the Clean Water Act requires construction sites to control stormwater discharges through permits such as the National Pollutant Discharge Elimination System (NPDES) permit. This often includes implementing sediment control measures like silt fences, sediment basins, and erosion control methods.
Rainfall and Soil Saturation in Last Week
The HCFCD gage at West Lake Houston Parkway and the San Jacinto West Fork shows that the area near Foster Elementary received about 2 inches of rain in the last few days.
That made the soil go from “wet” to “saturated.”
And that radically increased runoff.
Photos of Foster Elementary Construction Site After Heavy Rains
Summers’ photos show the need for better construction management practices to control sediment-laden runoff.
Silty water streamed out of the site after an intense rain.
The flow was steady and strong.
Water exited the site in multiple places and filled half the street.
Inlets had no protection. (See #8 below).
The site had large areas of disturbed and unprotected soil.
Runoff left inches of soil in the street. Imagine what the storm sewer looked like…
…especially since storm-sewer inlets were unprotected by any of the usual methods. (Again, see #8 below.)
Ways to Reduce Sediment-Laden Runoff
Here are several common and effective methods used to minimize silt-laden runoff. They represent best construction management practices.
1. Silt Fencing intercepts and slows down water flow, allowing sediment to settle before water flows off the construction site. It’s normally installed around the perimeter.
2. Sediment Basins & Traps capture sediment from runoff until it settles out of suspension.
3. Erosion Control Mats or Blankets stabilize disturbed soil and prevent erosion. They are most often used during the early stages of construction.
4. Mulching with organic materials – such as straw, hay, or wood chips – helps to protect soil while promoting vegetation growth. They are most effective when applied immediately after soil is disturbed.
5. Planting Vegetative Cover, such as fast-growing grass, can also help stabilize soil and reduce runoff. Plant roots bind the soil, making it less susceptible to erosion. Vegetation also slows down the flow of water, reducing the energy available to carry away sediment.
6. Sediment Control Logs (Wattles) are tubular barriers filled with straw or other materials. When placed along the contours of the construction site, they capture sediment before it leaves the site.
7. Stormwater Diversion Channels direct runoff to sediment-control ponds or a controlled discharge areas.
8. Stormwater-Inlet Protection, such as sandbags, can be placed around stormwater inlets to capture sediment before it enters the storm drainage system.
9. Shallow temporary or Permanent Vegetative Swales collect runoff and allow it to slowly infiltrate into the soil while trapping sediment in the vegetation and soil.
10. Construction Entrance/Exit Stabilization with gravel minimizes the tracking of mud onto roads from construction vehicles. But the gravel must be regularly maintained.
11. Grading can help control water flow and minimize erosion by directing water flow away from disturbed areas towards sediment control features.
12. Geotextiles can also provide erosion control and soil stabilization.
Need for Regular Inspections
Regular inspections and maintenance ensure that all erosion and sediment control measures are installed functioning properly.
Compare the measures in this list to the photos above. With the exception of gravel at the entrance, Summers’ photos show that few of these measures appeared to be implemented at the Foster construction site.
Posted by Bob Rehak on 12/29/24 with photos by Chris Summers
2679 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/2024/12/2024-079-020-storm-runoff.jpg?fit=800%2C450&ssl=1450800adminadmin2024-12-29 14:06:572024-12-29 18:06:28Better Construction Management Practices Could Reduce Silt-Laden Runoff
Sedona: Erosion on a Spectacular Scale
1/4/25 – In a Houston-area-flooding context, we usually consider erosion as a negative. It reduces the capacity of streams, channels and Lake Houston. It can also form sediment dams like mouth bars that back water up.
But elsewhere, many consider erosion a tourist attraction. And I’m not just talking about the Grand Canyon.
Welcome to Sedona
During the holidays, I took a break from blogging about flooding to join a family reunion near colorful Sedona, Arizona. We actually stayed in the Village of Oak Creek, an unincorporated area about five miles south of the main part of Sedona.
Always alert for photo ops, I launched my drone from the back porch of our rented home and captured some photos of red rock, blue sky and spectacular erosion.
The rocks around Sedona are famously red due to their high concentration of iron oxide. Millions of years ago, the Sedona region was covered by a vast shallow sea that deposited layers of sediments rich in iron minerals.
Over time, these iron-rich layers were uplifted due to tectonic activity. The iron in the rocks reacted with oxygen, resulting in oxidation – the same chemical reaction that gives rust its red color.
Then, erosion sculpted the landscape – over millions of years. It exposed these oxidized rock layers, which now dominate the area and give Sedona its iconic red hue. But why did the land erode in some areas and not others?
Caprock Protects Some Areas from Erosion
The spectacularly steep cliffs around Sedona can be attributed to the uneven distribution of what geologists call “caprock.” The term refers to the hard, erosion-resistant rock layers that sit atop mesas, buttes, and cliffs. These layers protect the softer rock below from erosion, helping to shape the striking red rock formations that make Sedona famous.
The caprock was formed from ancient sand dunes and marine deposits about 250–275 million years ago during the Permian period. Over time, these deposits solidified into dense rock layers responsible for Sedona’s intricate geological artistry.
The Value of Rust and Erosion
Sedona reportedly received approximately 4 million visitors last year, rivaling the Grand Canyon. That’s more people than live in Houston and almost as many as live in Harris County. Sedona’s stunning red rock formations and outdoor recreational opportunities make it a major attraction for both domestic and international travelers.
Rainfall and Flooding
Sedona receives an average of 19 inches of rainfall per year – less than 40% of Houston’s average rainfall. However, Sedona still experiences three types of flooding:
Oak Creek flooded badly from severe winter storms in 2005. One of the most significant floods in recent memory, it damaged homes, businesses and bridges.
In 2023, heavy rains led to flash floods that temporarily closed hiking trails and roads.
Such floods sculpted the landscape you see in the photos above.
More About Sedona
Spanish explorers first passed through the area as early as the 1500s.
Homesteading began in the late 1800s.
Sedona became a popular filming location for Western movies due to its dramatic landscapes. Films like “Stagecoach” (1939) and “Broken Arrow” (1950) were shot in the area, bringing international attention to Sedona.
Improved roads and infrastructure led to a tourism boom beginning in the 1950s.
Today, Sedona is known for its outdoor activities (hiking, mountain biking, and jeep tours), yoga retreats, art galleries, and night skies. Re: the last point, Sedona is designated as an International Dark Sky Community. Star gazers enjoy freedom from “light pollution” – there were no streetlights where we stayed!
Posted by Bob Rehak on 1/4/2025
2685 Days since Hurricane Harvey
Official Holiday Tornado Report from HCFCD
1/3/25 – Jeff Lindner, Harris County’s Meteorologist, provided this official holiday tornado report. Southeast Texas experienced a highly active period of severe weather from 12/24/24 through 12/28/24. It included several tornado outbreaks on both the 26th and 28th.
Said Lindner, “While it is not uncommon to have severe weather and tornados in southeast Texas during the winter months, it is a bit unusual to have back-to-back outbreaks one day apart.”
“Most tornados in this region are small and of low-end intensity (EF-0 or EF-1). It is rare to see the higher intensity EF-3 and longer track tornadoes here locally, but they do occasionally happen,” said Lindner.
He provided the following holiday tornado report on the two main days.
December 26th Tornadoes
Five tornados occurred across southeast Texas on Thursday, the 26th. They included 2 EF-1 and 3 EF-0 tornados.
1. El Campo TX (Wharton County)
This tornado began three miles northeast of El Campo and was on the ground for roughly half of a mile. The tornado mostly moved across open farmland, but one well constructed outbuilding (barn) was impacted and destroyed yielding the EF-1 rating. It is possible this tornado was stronger over the open farm fields, but without any available damage indicators, this will remain unknown.
2. Southwest Harris County (NW of Meadows Place)
A brief tornado occurred one mile north-northwest of Meadows Place in southwest Harris County along Plumbrook Drive. It damaged a few houses and overturned a delivery truck. One of the houses sustained roof and outside-facing wall damage resulting in the EF-1 damage rating.
3. Northern Liberty County (SE of Cleveland TX)
This tornado began nine miles northwest of Dayton Lakes and moved eastward across mostly rural northern Liberty County. It damaged trees and two mobile homes consistent with winds of 65-75mph, earning it an EF-0 rating.
4. Lake Houston/Huffman (NE Harris County)
HPD Lake Patrol and other video confirmed a tornado (waterspout) over Lake Houston north of FM 1960 that moved eastward across the lake and moved ashore along the eastern side of the lake in a wooded area. Survey teams were unable to find any damage near where the tornado reached the shoreline and the tornado dissipated quickly while moving onshore.
5. Dayton TX (Liberty County)
A small tornado developed seven miles west of Dayton and moved across mainly open farm and ranch land. It downed a few trees. That helped storm spotters that captured the funnel cloud on video confirm that it was, in fact a tornado.
December 28 Tornados
Linder also said, “A more significant and damaging tornado event occurred from late morning to late afternoon on the 28th. Five tornadoes occurred from two primary supercell thunderstorms that moved across the area. Unfortunately, these tornadoes resulted in more significant damage with injuries and one fatality. Two EF-3, one EF-2, and two EF-1 tornados moved over the area.”
1. Brookshire Tornado (Waller and western Harris Counties)
This tornado began west of FM 2855 in southern Waller County three miles north of Brookshire where a mobile home was moved off its foundation. The tornado continued northeast where it impacted a small area of houses south of Beckendorff Road and Noel Lane.
It rolled and completely destroyed one mobile home. Several other structures sustained roof and window damage. It also overturned vehicles in a driveway. Damage fell into both EF-0 and low-end EF-1 categories. The tornado continued northeast into a newly built subdivision where it destroyed 1-2 houses under construction and a brick privacy wall.
It then crossed FM 529 at Pitts Road just south of a Centerpoint power substation where it knocked down a power pole. Debris fanned across an open field and a subdivision detention basin.
The tornado then entered the Windward Subdivision near its southeastern edge. There, it damaged roofs, windows, and fences of 5-10 homes. One house lost all south-facing windows along with portions of the roof’s deck and outside facing wall siding.
This qualifies as EF-1 damage with winds estimated around 100 mph. The tornado weakened as it moved north-northeast and dissipated west of John Paul Landing in northwest Harris County.
2. Porter Heights to Splendora Tornado (Montgomery County)
The same supercell that produced a Katy tornado continued northeast across northwest Harris County. It crossed the Bridgeland subdivision, then SH 249 near Spring Cypress, and continued northeast toward I-45/SH99. Both radar and Hooks Airport staff observed rotation, but not on the ground.
As this storm entered Montgomery County, the velocity increased and radar showed a debris ball near Porter Heights. Wind removed the entire roof structures of 1-2 homes. One brick house suffered complete outside wall failure and several interior wall failures. The twister also rolled a nearby mobile home, completely destroying it.
The tornado then crossed FM 1314 where it destroyed large sections of a metal rental facility and a nearby mobile home. At this point, damage indicated high-end EF-1 or low-end EF-2.
The tornado weakened some while moving northeast across several rural streets and houses, but still caused significant tree damage. It then intensified as it moved into the Pickering Road area southwest of FM 1485. The twister heavily damaged or destroyed several RV’s and mobile homes. It completely removed the roof of Fire Station 154 and damaged three fire trucks. The twister even picked one up and rotated it 90 degrees.
North of FM 1485, it damaged several homes before crossing SH 242 into the Harrington Trails subdivision, removing nearly the entire roof of one home. The storm also completely destroyed several houses under construction.
The tornado continued northeast toward Splendora High School and dissipated in an open field after it crossed FM 2090.
Most of the storm’s track qualified as EF-1 or EF-2. Only a small portion near the beginning in Porter Heights rated EF-3. Four people suffered injuries.
3. Liverpool to Hillcrest Tornado (Brazoria County)
This tornado began four miles ENE of Liverpool along CR 172 in a rural area and tracked into Hillcrest southeast of Alvin. Most damage indicated EF-0 or EF-1 strength. But at Walt Disney Elementary School several large sections of the roof were ripped off and portions of an exterior wall failed. That indicated EF-2 (125mph) strength.
The storm also flipped and destroyed a mobile home causing a fatality. The tornado dissipated prior to reaching the Galveston County line.
4. Dickinson to Bacliff (Galveston County)
The Brazoria County supercell produced another tornado near the intersection of Hughes Road between I-45 and HWY 3. It moved northeast across FM 517 and HWY 146, causing EF-1 damage to several homes with its 90 mph winds east of Dickinson High School. Along most of its path, the storm featured EF-0 (60-80 mph) winds. It downed trees, fences, and power poles and caused some roof damage.
The tornado continued east across Galveston Bay and reached into Chambers County.
5. Chambers County
The Brazoria and Galveston County supercell intensified over Galveston Bay before tracking into Chambers County near Smith Point. The tornado destroyed several mobile homes along FM 1941, where EF-3 damage was noted.
The tornado then crossed HWY 124 destroying high-tension power-transmission towers with 140mph winds. The towers supplied power to High Island and the Bolivar Peninsula. Winds also lofted and rolled a pickup truck near Smith Point Road resulting in one injury.
This was a significant tornado. It impacted mainly rural areas of Chambers County before crossing all of southern Jefferson County where high end EF-3 (160 mph winds) damage occurred in Hampshire TX. The tornado then moved between Port Arthur and Sabine Pass into southern Louisiana.
The holidays are usually happy times. But severe weather made them less so for many people in 2024.
Posted by Bob Rehak on 1/3/24 based on information provided by Harris County Meteorologist Jeff Lindner
2684 Days since Hurricane Harvey
Better Construction Management Practices Could Reduce Silt-Laden Runoff
12/29/24 – Several rounds of intense rain in the past week triggered a slew of emails from concerned residents about the need for better construction management practices to control sediment-laden runoff.
Chris Summers, a retired commercial photographer, included pictures of the runoff from the Foster Elementary site in Kingwood’s Trailwood Village. Contractors recently cleared the site for reconstruction of the school. Summer’s photos illustrate the dangers from sediment pollution and the need for better construction management practices.
A Major Source of Sediment Pollution
Construction site runoff is a major source of sediment pollution. Construction typically involves large-scale disturbance of soil, which can significantly increase the amount of sediment carried away by stormwater runoff. This sediment-laden runoff can have serious environmental impacts, especially when it enters local water bodies, such as Lake Houston..
Clearing, excavating and grading disturb soil. Stripping away vegetation makes soil more prone to erosion. So, when it rains, the exposed soil can easily wash away into nearby water systems.
In many cases, vegetation or other stabilization measures (e.g., erosion control blankets, mulching) may not be installed until later stages of construction, leaving the site vulnerable to sediment loss in the meantime.
Construction sites are most vulnerable during heavy rainfalls, which can lead to significant runoff, especially from areas without adequate sediment-control measures.
In many cases, construction schedules are not aligned with seasonal weather patterns, so sites may be left exposed during periods of heavy rain. This can lead to water-quality degradation, increased costs for water treatment, higher water bills, and infrastructure damage.
Regulations and Best Management Practices
Due to the significant environmental impact of construction-site runoff, many countries and regions have strict regulations and Best Management Practices (BMPs) to control it. In the U.S., for example, the Clean Water Act requires construction sites to control stormwater discharges through permits such as the National Pollutant Discharge Elimination System (NPDES) permit. This often includes implementing sediment control measures like silt fences, sediment basins, and erosion control methods.
Rainfall and Soil Saturation in Last Week
The HCFCD gage at West Lake Houston Parkway and the San Jacinto West Fork shows that the area near Foster Elementary received about 2 inches of rain in the last few days.
That made the soil go from “wet” to “saturated.”
And that radically increased runoff.
Photos of Foster Elementary Construction Site After Heavy Rains
Summers’ photos show the need for better construction management practices to control sediment-laden runoff.
Silty water streamed out of the site after an intense rain.
The flow was steady and strong.
Water exited the site in multiple places and filled half the street.
Inlets had no protection. (See #8 below).
The site had large areas of disturbed and unprotected soil.
Runoff left inches of soil in the street. Imagine what the storm sewer looked like…
…especially since storm-sewer inlets were unprotected by any of the usual methods. (Again, see #8 below.)
Ways to Reduce Sediment-Laden Runoff
Here are several common and effective methods used to minimize silt-laden runoff. They represent best construction management practices.
1. Silt Fencing intercepts and slows down water flow, allowing sediment to settle before water flows off the construction site. It’s normally installed around the perimeter.
2. Sediment Basins & Traps capture sediment from runoff until it settles out of suspension.
3. Erosion Control Mats or Blankets stabilize disturbed soil and prevent erosion. They are most often used during the early stages of construction.
4. Mulching with organic materials – such as straw, hay, or wood chips – helps to protect soil while promoting vegetation growth. They are most effective when applied immediately after soil is disturbed.
5. Planting Vegetative Cover, such as fast-growing grass, can also help stabilize soil and reduce runoff. Plant roots bind the soil, making it less susceptible to erosion. Vegetation also slows down the flow of water, reducing the energy available to carry away sediment.
6. Sediment Control Logs (Wattles) are tubular barriers filled with straw or other materials. When placed along the contours of the construction site, they capture sediment before it leaves the site.
7. Stormwater Diversion Channels direct runoff to sediment-control ponds or a controlled discharge areas.
8. Stormwater-Inlet Protection, such as sandbags, can be placed around stormwater inlets to capture sediment before it enters the storm drainage system.
9. Shallow temporary or Permanent Vegetative Swales collect runoff and allow it to slowly infiltrate into the soil while trapping sediment in the vegetation and soil.
10. Construction Entrance/Exit Stabilization with gravel minimizes the tracking of mud onto roads from construction vehicles. But the gravel must be regularly maintained.
11. Grading can help control water flow and minimize erosion by directing water flow away from disturbed areas towards sediment control features.
12. Geotextiles can also provide erosion control and soil stabilization.
Need for Regular Inspections
Regular inspections and maintenance ensure that all erosion and sediment control measures are installed functioning properly.
Compare the measures in this list to the photos above. With the exception of gravel at the entrance, Summers’ photos show that few of these measures appeared to be implemented at the Foster construction site.
Posted by Bob Rehak on 12/29/24 with photos by Chris Summers
2679 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.