The Harris County Flood Control District (HCFCD) issued its first and final report on Tropical Storm Beta today. The 24-page report found that only 25-30 homes in Harris County flooded from the storm, none in the Lake Houston Area. In most places, streams and bayous remained well within their banks. The report also says that HCFCD flood-reduction projects along Braes and Sims Bayous prevented the flooding of 930 structures. The combination of low rainfall intensities, frequent breaks in heavy rainfall, and dry grounds going into the event likely helped reduce the number of homes flooded, according to the report.
Understanding the Uniqueness of Storms
As with all such HCFCD reports, this one presents a treasure trove of statistics, graphs, charts and illustrations. Taken together, they help you understand the uniqueness of individual storms and how to compare them to each other.
Frequent Breaks in Storm Prevented More Severe Flooding
Tropical Storm Beta could have been much worse. The report says, “While Beta did produce heavy rainfall over the county, there were frequent breaks in the training rain bands.”
Overall rainfall intensities were generally in the 1.0-2.0 inch per hour range.
HCFCD final report on tropical storm beta
Most storm drains in the City of Houston are designed to handle 2″ per hour. The report continued, “The lower rainfall rates along with breaks in heavy rainfall allowed most creeks and bayous and internal drainage systems to effectively carry storm water capacities with limited flooding.”
2- to 10-Year Rains in Most Harder-Hit Areas
In most of the harder-hit areas, the storm dropped between 2- and 10-year rains. Those included Clear Creek, Brays Bayou, Keegans Bayou, Willow Waterhole, Buffalo Bayou, White Oak Bayou and Cypress Creek. One place along Sims Bayou recorded a 50-year rain. All other Harris County watersheds had generally less than a 50% (2-yr) rainfall exceedance probability, says the report. Those rainfall exceedance probabilities correspond to new Atlas-14 rates adopted after Harvey.
Intense Short-Duration Rains Cause Most Street Flooding
House flooding in Harris County correlates strongly to the intensity of short duration rainfall rates. In Tropical Storm Beta, short duration rainfall rates generally fell below intensities that lead to widespread and significant house flooding from:
Overwhelming capacity of primary drainage systems or…
Exceeding capacities of bayous and creeks.
The following chart compares the maximum rainfall amounts recorded in Harris County from Tropical Storm Imelda, Hurricane Harvey, Tropical Storm Allison, and Tropical Storm Beta for various time periods.
From page 3 of HCFCD’s Final Report on Tropical Storm Beta.
The chart above compares the maximum rainfall amounts recorded in Harris County from Tropical Storm Imelda, Hurricane Harvey, Tropical Storm Allison, and Tropical Storm Beta for various time periods.
For the 1-hr rainfall rate, Beta was nearly 50% lower than Imelda, Allison, and Harvey and nearly 8-10 inches lower for the 3-hr rainfall rates.
HCFCD Final Report on Beta
Beta Rates Lower than Other Recent Major Storms
As the chart above shows, rainfall rates associated with Tropical Storm Beta fell significantly below other recent tropical storms that impacted Harris County. The lower rainfall rates were likely a function of a dry air mass wrapping into the circulation, and a general lack of organized and persistent thunderstorm activity.
Beta’s short duration rainfall rates remained slow enough that drainage systems could remain effective. Additionally, dry grounds leading into the event allowed the first few inches of rainfall to be absorbed, helping to reduce run-off.
Jeff Lindner, Harris County Meteorologist
Dramatic NW to SE Rainfall Gradient
The maximum rainfall over 48 hours shows a dramatic gradient aligning from northwest to southeast. As you can see from the iso-map below, people in the Lake Houston Area received less than a third of the rainfall that people received on the southwest side of Houston.
Posted by Bob Rehak on 10/5/2020based on information from Harris County Flood Control
1133 Days after Hurricane Harvey and 382 after Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/10/Screen-Shot-2020-10-05-at-2.22.51-PM.png?fit=1064%2C572&ssl=15721064adminadmin2020-10-05 15:10:032020-10-05 15:24:08Final HCFCD Report on Tropical Storm Beta Finds Only 25-30 Homes Flooded
Two more tropical systems are heading into the Gulf of Mexico this week. The National Hurricane Center (NHC) predicts the first, Tropical Storm Gamma, will hook around the Yucatan and then turn north Wednesday into Thursday. It should be in the central Bay of Campeche by Friday, still headed north.
Forecast Track for Tropical Storm Gamma
The NHC predicts the second, potential tropical cyclone #26, will intensify into a hurricane and reach the central Gulf Coast of the U.S. by Friday. While a wide range of uncertainty exists regarding its track, dangerous storm surge and coastal flooding from Louisiana to the Florida Panhandle is almost a certainty, according the the NHC. Increasing swells and elevated tides will be possible along the Texas coast from mid- into late-week given both systems over the Gulf of Mexico, according to Jeff Lindner, Harris County meteorologist.
Potential Tropical Cyclone #26 should turn into Tropical Storm Delta on Monday then track NW, reaching hurricane strength before landfall.
Lindner also predicts Delta could become a Cat 2 or even a Cat 3 hurricane before reaching land.
No Impact Predicted for Texas At This Time
At this time (Sunday night, 10/4/2020 at 9:45PM), Lindner also feels that Houston area should feel no direct impacts from either TS Gamma or what will likely become TS Delta.
Double Trouble Again
Earlier this year, we had two tropical systems in the Gulf simultaneously. That was only the second time that occurred since 1933. Now it will occur again…in the SAME year with Gamma and what will become Delta. Meteorologists are already starting to talk about potential interaction between the tropical systems, the so-called Fujiwhara effect.
Posted by Bob Rehak on 10/4/2020 at 9:45 PM based on data from HCFCD and the NHC
1132 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/10/233230_5day_cone_no_line_and_wind.png?fit=897%2C736&ssl=1736897adminadmin2020-10-04 22:04:362020-10-04 22:04:48Two More Tropical Systems Heading Into Gulf This Week
The Texas Commission on Environmental Quality (TCEQ) has fined Quadvest $5,625 for a 48,000-gallon sewage spill in Colony Ridge, a large and growing development in Liberty County near the San Jacinto East Fork and Plum Grove. Quadvest supplies water and sewer services for the development.
The violation occurred in Camino Real, a Colony Ridge subdivision with almost 3500 lots. It happened at a lift station approximately 1,000 feet north-northeast of the intersection of Paul Campbell Loop Road and Plum Drive.
Discharge with Bluish Color Kills Fish
The complainant alleged that the discharge had a bluish color and killed fish. The TCEQ complaint says people were exposed to unsafe levels of pollutants, however, no deaths were reported in relation to the incident except for fish.
Photo of discharge in Maple Branch Creek
TCEQ says Quadvest “failed to prevent the unauthorized discharge of wastewater into or adjacent to any water in the state. Specifically, on July 22, 2019, an electrical failure at Camino Real Lift Station-H located at 342 Road 5002 caused the pumps to fail, resulting in approximately 48,000 gallons of wastewater being discharged into Maple Branch Creek, killing approximately 30 fish.”
Cleanup and Fine Cost Quadvest More Than $105,000
In July, 2019, Quadvest cleaned up the mess. TCEQ estimated the cost at more than $100,000. Then in June 2020, Quadvest CEO Simon Sequeira agreed to pay an additional penalty of $5,625.
Previous Related Violations
During the year before the unauthorized discharge, the TCEQ issued four other notices of violations to Quadvest for:
Sewage overflowing from a manhole at an estimated rate of 10-25 gallons per minute
Failure to maintain an operational alarm system for emergency conditions
Twice failing to secure its lift station from intruders (August and November 2018)
Since this incident, other sewage problems have occurred in Colony Ridge. Stormwater can wash this fecal contamination into adjoining streams and bayous which empty into the East Fork and Lake Houston, the source of drinking water for 2 million people.
More Colony Ridge fecal contamination bubbling up from underground and flowing toward Tarkenton Bayou. Photo taken in June 2020.
Posted by Bob Rehak on 10/4/2020
1132 Days since Hurricane Harvey and 381 since Imelda
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/2020/06/Black-water.jpg?fit=1200%2C2133&ssl=121331200adminadmin2020-10-04 18:05:332020-10-04 18:05:56TCEQ Fines Quadvest for 48,000 Gallon Sewage Spill in Colony Ridge
Final HCFCD Report on Tropical Storm Beta Finds Only 25-30 Homes Flooded
The Harris County Flood Control District (HCFCD) issued its first and final report on Tropical Storm Beta today. The 24-page report found that only 25-30 homes in Harris County flooded from the storm, none in the Lake Houston Area. In most places, streams and bayous remained well within their banks. The report also says that HCFCD flood-reduction projects along Braes and Sims Bayous prevented the flooding of 930 structures. The combination of low rainfall intensities, frequent breaks in heavy rainfall, and dry grounds going into the event likely helped reduce the number of homes flooded, according to the report.
Understanding the Uniqueness of Storms
As with all such HCFCD reports, this one presents a treasure trove of statistics, graphs, charts and illustrations. Taken together, they help you understand the uniqueness of individual storms and how to compare them to each other.
Frequent Breaks in Storm Prevented More Severe Flooding
Tropical Storm Beta could have been much worse. The report says, “While Beta did produce heavy rainfall over the county, there were frequent breaks in the training rain bands.”
Most storm drains in the City of Houston are designed to handle 2″ per hour. The report continued, “The lower rainfall rates along with breaks in heavy rainfall allowed most creeks and bayous and internal drainage systems to effectively carry storm water capacities with limited flooding.”
2- to 10-Year Rains in Most Harder-Hit Areas
In most of the harder-hit areas, the storm dropped between 2- and 10-year rains. Those included Clear Creek, Brays Bayou, Keegans Bayou, Willow Waterhole, Buffalo Bayou, White Oak Bayou and Cypress Creek. One place along Sims Bayou recorded a 50-year rain. All other Harris County watersheds had generally less than a 50% (2-yr) rainfall exceedance probability, says the report. Those rainfall exceedance probabilities correspond to new Atlas-14 rates adopted after Harvey.
Intense Short-Duration Rains Cause Most Street Flooding
House flooding in Harris County correlates strongly to the intensity of short duration rainfall rates. In Tropical Storm Beta, short duration rainfall rates generally fell below intensities that lead to widespread and significant house flooding from:
The following chart compares the maximum rainfall amounts recorded in Harris County from Tropical Storm Imelda, Hurricane Harvey, Tropical Storm Allison, and Tropical Storm Beta for various time periods.
The chart above compares the maximum rainfall amounts recorded in Harris County from Tropical Storm Imelda, Hurricane Harvey, Tropical Storm Allison, and Tropical Storm Beta for various time periods.
Beta Rates Lower than Other Recent Major Storms
As the chart above shows, rainfall rates associated with Tropical Storm Beta fell significantly below other recent tropical storms that impacted Harris County. The lower rainfall rates were likely a function of a dry air mass wrapping into the circulation, and a general lack of organized and persistent thunderstorm activity.
Dramatic NW to SE Rainfall Gradient
The maximum rainfall over 48 hours shows a dramatic gradient aligning from northwest to southeast. As you can see from the iso-map below, people in the Lake Houston Area received less than a third of the rainfall that people received on the southwest side of Houston.
To see the entire 24-page report, click here. For easy future reference, this report can also be found under the Major Storms Tab on the Reports page.
Posted by Bob Rehak on 10/5/2020 based on information from Harris County Flood Control
1133 Days after Hurricane Harvey and 382 after Imelda
Two More Tropical Systems Heading Into Gulf This Week
Two more tropical systems are heading into the Gulf of Mexico this week. The National Hurricane Center (NHC) predicts the first, Tropical Storm Gamma, will hook around the Yucatan and then turn north Wednesday into Thursday. It should be in the central Bay of Campeche by Friday, still headed north.
The NHC predicts the second, potential tropical cyclone #26, will intensify into a hurricane and reach the central Gulf Coast of the U.S. by Friday. While a wide range of uncertainty exists regarding its track, dangerous storm surge and coastal flooding from Louisiana to the Florida Panhandle is almost a certainty, according the the NHC. Increasing swells and elevated tides will be possible along the Texas coast from mid- into late-week given both systems over the Gulf of Mexico, according to Jeff Lindner, Harris County meteorologist.
Lindner also predicts Delta could become a Cat 2 or even a Cat 3 hurricane before reaching land.
No Impact Predicted for Texas At This Time
At this time (Sunday night, 10/4/2020 at 9:45PM), Lindner also feels that Houston area should feel no direct impacts from either TS Gamma or what will likely become TS Delta.
Double Trouble Again
Earlier this year, we had two tropical systems in the Gulf simultaneously. That was only the second time that occurred since 1933. Now it will occur again…in the SAME year with Gamma and what will become Delta. Meteorologists are already starting to talk about potential interaction between the tropical systems, the so-called Fujiwhara effect.
Posted by Bob Rehak on 10/4/2020 at 9:45 PM based on data from HCFCD and the NHC
1132 Days since Hurricane Harvey
TCEQ Fines Quadvest for 48,000 Gallon Sewage Spill in Colony Ridge
The Texas Commission on Environmental Quality (TCEQ) has fined Quadvest $5,625 for a 48,000-gallon sewage spill in Colony Ridge, a large and growing development in Liberty County near the San Jacinto East Fork and Plum Grove. Quadvest supplies water and sewer services for the development.
The violation occurred in Camino Real, a Colony Ridge subdivision with almost 3500 lots. It happened at a lift station approximately 1,000 feet north-northeast of the intersection of Paul Campbell Loop Road and Plum Drive.
Discharge with Bluish Color Kills Fish
The complainant alleged that the discharge had a bluish color and killed fish. The TCEQ complaint says people were exposed to unsafe levels of pollutants, however, no deaths were reported in relation to the incident except for fish.
TCEQ says Quadvest “failed to prevent the unauthorized discharge of wastewater into or adjacent to any water in the state. Specifically, on July 22, 2019, an electrical failure at Camino Real Lift Station-H located at 342 Road 5002 caused the pumps to fail, resulting in approximately 48,000 gallons of wastewater being discharged into Maple Branch Creek, killing approximately 30 fish.”
Cleanup and Fine Cost Quadvest More Than $105,000
In July, 2019, Quadvest cleaned up the mess. TCEQ estimated the cost at more than $100,000. Then in June 2020, Quadvest CEO Simon Sequeira agreed to pay an additional penalty of $5,625.
Previous Related Violations
During the year before the unauthorized discharge, the TCEQ issued four other notices of violations to Quadvest for:
None of the violations was self-reported. Click here for the full TCEQ report.
Part of Larger Problem
Since this incident, other sewage problems have occurred in Colony Ridge. Stormwater can wash this fecal contamination into adjoining streams and bayous which empty into the East Fork and Lake Houston, the source of drinking water for 2 million people.
Posted by Bob Rehak on 10/4/2020
1132 Days since Hurricane Harvey and 381 since Imelda
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.