Rainfall predictions associated with approaching Thanksgiving storms keep increasing. Jeff Lindner, Harris County’s meteorologist now says approaching storms will bring widespread impacts from Thursday through Saturday. He also warns that heavy rainfall may lead to street flooding and rises on area creeks/bayous. Models now show a band of 5-7 inches of rain in places.
Thursday
Lindner says a surface warm front will approach the upper TX coast early Thursday and move inland. He expects showers to increase in coverage and intensity near the front, which may approach the US 59 corridor by midday before slowing and potentially stalling Thursday afternoon.
Along and south of the warm front be prepared for isolated severe storms and excessive rainfall with inflow off the Gulf. All the elements are in place for flash flooding “and warm fronts are notorious in these sort of setups for producing excessive rainfall,” says Lindner.
The best case for inland areas is that the warm front is held closer to the coast.
Friday – Saturday
Models have now slowed down the movement of an upper level low to our west. Lindner now predicts a break in the rainfall Friday morning, before another round of widespread, heavy rains move back into the area Friday afternoon and evening.
Expect grounds to become increasingly saturated and runoff to increase. Showers may linger into midday Saturday, before this system finally exits to the east.
Rainfall Amounts
Predicted rainfall associated with the Thanksgiving storms has increased compared to earlier forecasts. That’s because of the potential for slow moving and training thunderstorms Thursday afternoon and the longer duration of rainfall now expected into Friday and Saturday.
Widespread amounts of 1-3 inches can be expected on Thursday afternoon with isolated totals upwards of 5-6 inches.
Some models show a band of 5-7 inches near the warm front Thursday afternoon and this is concerning.
Hourly rainfall rates of 2-3 inches may be possible Thursday afternoon and this will lead to rapid street flooding and significant rises on creeks and bayous.
Jeff Lindner, Harris County Meteorologist
Additional rainfall amounts of 1-3 inches can be expected Friday/Saturday on top of what falls on Thursday and this will only worsen ongoing run-off from the Thursday rainfall.
Runoff
Soils are primed for run-off with recent wetting rainfall over the region. Our main concern is street flooding, but Lindner cautions us about the potential for significant rises on area watersheds, especially if the higher totals are realized in portions of Harris County.
His greatest concern is for the southern and southeastern portions of Harris County where soils are the wettest and potential rainfall the highest. But he still isn’t confident enough to pinpoint the exact locations of the highest rainfall.
He says most watersheds can handle 3-4 inches. But if we start to exceed 5 inches, the concern for flooding from the bayous and creeks listed below will increase.
IF 5-7 inches, streams most in danger of flooding will be:
Clear Creek and its tributaries
Armand Bayou
Hunting Bayou
Halls Bayou (upper around I-45)
Little Cypress Creek
Willow Creek
South Mayde Creek (lower near Greenhouse)
Keegans Bayou (lower near Beltway 8/US 59/Wilcrest area)
Willow Waterhole
Brickhouse Gully
Spring Branch Creeks (Spring Branch, Buttermilk, Briar Branch)
If you’re out and about over the holidays, remember. Be wary of underpasses and bridges. If you can’t see the roadway, you don’t know how deep the water is. Turn around and don’t drown.
Also remember. Seven inches was the amount of rain Woodridge Village received on May 7, 2019. Woodridge now has much more stormwater detention capacity. But there are plenty of other clearcut areas around the area that don’t have much if any yet.
During Lina Hidalgo’s first term, hundreds of millions of dollars in flood-mitigation projects went to low-income watersheds while the Lake Houston Area went begging. So what does the recent election mean for the area’s flood-mitigation goals and strategies? What can we do to reduce flood risk with the deck stacked even further against us? It’s time to hit the flood-mitigation reset button.
Before the election, Democrats insisted that they still intended to complete all the projects in the 2018 Flood Bond. But now with a super-majority on Commissioner’s Court, they have the power to spend that money wherever they want with impunity.
We need to regroup and develop new strategies to attain our goals. We can no longer afford to rely so much on Harris County.
Understanding the Process
Flood mitigation has political, technical and financial aspects. They all demand coordination. After Harvey, Guy Sconzo, former superintendent of Humble ISD, and the Lake Houston Area Chamber formed a task force with area leaders to identify the causes of flooding and work toward solutions.
After initial successes, sadly, Sconzo died. It happened shortly after the passage of the 2018 Harris County Flood Bond and the State’s Flood Infrastructure Fund. Not long thereafter, the task force disbanded. People assumed that projects would just happen. They didn’t.
Roadblocks since Harvey
No one fully understood how long the process would take, all the steps that were involved, how much projects could ultimately cost, the intense competition for funding, and how projects could languish without a coordinated effort to remove roadblocks as they arose.
We must overcome our addiction to expectations of fair treatment and learn that we must fight for our homes and safety. We must become masters of our own fate and hit the flood-mitigation reset button now. So, what to do?
These are my personal recommendations.
Re-constitute the Lake Houston Area Task Force
Educate people about the risk they still face.
Acknowledge that most of our problems originate outside the county.
Update and prioritize our goals.
Acknowledge we can’t achieve them alone and work to build bridges to those who can help.
Coordinate with them and Harris County Flood Control.
Don’t count on Harris County for much help.
Finish studies already started (i.e., Taylor Gully, Atascocita).
Check on progress of all projects monthly to ensure next steps (i.e., construction bidding) happen promptly.
Identify roadblocks and work to overcome them.
Search for alternative funding and partners if necessary. UPFRONT!
Stop assuming projects will manage themselves. Hire a project manager to report monthly to the reconstituted task force.
Starting Points
Harris County Flood Control District began engineering studies long before Harvey for the projects you now see in construction. Then, when Harvey hit and voters passed the 2018 flood bond, they were ready to go.
Other areas had to start from scratch and are still running the gauntlet of feasibility, preliminary engineering, final engineering, and environmental studies.
In the the Lake Houston Area:
HCFCD started four drainage studies and finished three (Kingwood, Huffman, Cosby). Atascocita is still underway.
San Jacinto Regional Flood Planning Group finished its preliminary report.
Who is ensuring that engineering studies consider realistic funding alternatives? How much time, effort and money have we wasted by working in silos? Maybe a renewed Lake Houston Area Flood Task Force could help with those issues.
We need earmarks for funding at the state level. But who will fight for them? How will our representatives and senators know what to fight for? And how much the projects cost?
Any area with a completed study should have a project moving forward and be looking for funding. If it doesn’t, then someone is messing up the process.
It will only be Lake Houston’s turn if someone or some group advocates for the area as they did after Harvey.
The good news in all this is that a preliminary meeting of area leaders on the City, County, State and Federal levels was held on November 8th at Congressman Dan Crenshaw’s office. Everyone attending agreed on the need to reconstitute the Task Force and hit the flood-mitigation reset button. The group also examined a number of possible issues to focus on. More news on the new Task Force as it begins to set priorities.
Posted by Bob Rehak on 11/22/2022with thanks to Dr. Charles Campbell for the post’s photo.
1911 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/2018/12/Campbell-sunrise-12_3_18-small.jpg?fit=1500%2C1114&ssl=111141500adminadmin2022-11-22 18:52:202022-11-22 21:24:31Time for Lake Houston Area to Hit Flood-Mitigation Reset Button
Like damage, population is one of the “weighting factors” considered in the distribution of flood-mitigation dollars. Compared to 2017 estimates of watershed populations in Harris County, 2022 estimates show that five watersheds have lost population. But overall, the county has gained 155,254 people.
The map below shows the location of each of these watersheds.
Harris County Watersheds by Harris County Flood Control District
Reasons for Shifts Unclear
I had wondered whether the five major floods in Harris County between 2000 and 2020 (Allison, Tax Day, Memorial Day, Harvey and Imelda) would cause the most heavily flood-damaged areas to lose population. But that seems not to be the case.
The most heavily damaged watershed (Brays) lost the most population (in raw numbers). But the second most heavily damaged watershed (Greens) gained more than 16,000 people, the second largest gain.
I found no meaningful correlation between flood damage and population loss or growth. Nor do data suggest that flood-mitigationspending has much influence either. Contradictory examples abound. And statistical correlations rate as negligible to weak.
Five Watersheds Lost Population
Compared to the previous Census estimates from 2017:
Brays lost 5,822 people (0.8%)
Cedar lost 4,153 people (11.1%)
Hunting lost 1,112 people (1.4%)
Little Cypress lost 727 people (1.6%)
Vince lost 176 people (0.2%).
In percentages, Cedar Bayou lost the most population. Cedar was the sight of the Arkema disaster which blocked evacuation routes along Highway 90 during Harvey. The watershed currently has only about 37,000 people, ranking it 20th among the 23 watersheds in Harris County.
In five major storms between 2000 and today (Allison, Tax Day, Memorial Day, Harvey and Imelda), flood damage varied widely within those five watersheds:
Brays flooded 32,240 structures, the most of any watershed.
Cedar flooded 2,274.
Hunting flooded 15,763.
Little Cypress flooded 1,040.
Vince flooded 4,152.
18 Watersheds Gained Population
Eighteen other watersheds gained population and also had widely varying degrees of flood damage. These, too, showed little correlation.
Altogether, the county’s watersheds gained 155,254 people, despite 226,729 damaged structures during the five major storms.
Negligible Correlation of Flooding and Population Gain/Loss
The “population flees flooding” hypothesis didn’t hold much water.
Flood damage and “number of residents lost” correlated at only a 0.16 level – insignificant. Flood damage and “percent of residents lost” correlated at only 0.28, extremely weak.
A perfect correlation is 1.0. It indicates that for every unit of change in one variable, there is a corresponding unit of change in another variable. However, that was far from the case here. Variations seemed random.
The County has a strong draw: jobs. Also, family, friends, neighbors and support networks remain powerful attractions that keep most people anchored.
The new HCFCD data do not suggest why gains and losses occurred.
Top reasons for relocation typically include: greater safety, better schools, better housing, new jobs, and upgrading from apartments to homes.
LMI Population Trends
HCFCD also measures “LMI population.” LMI stands for Low-to-Moderate Income. The Census Bureau defines LMI as “families making less than the average for the region.”
Harris County has 42.6 % LMI residents. So 57.4% of residents make above the average for the region.
This is important because the LMI percentage plays a huge role in partnership grants from the US Department of Housing and Urban Development (HUD). Most, but not all, HUD grants go to areas with LMI populations higher than 70%. A notable exception is the pending $750 million HUD Harvey flood-mitigation grant. It only requires that 50% of the money benefits LMI households.
The latest HCFCD data shows that watersheds at bothends of the income spectrum lost LMI population. We still have the same eight LMI-majority watersheds we had in 2017. However, one deserves special mention.
Brays’ LMI population declined so significantly that it almost flipped from the “majority LMI” category to “majority upper income.” It went from 58% to 51% LMI.
Sixteen other watersheds gained LMI population. Some had huge flood losses; others had few.
The correlation between total flood damage and LMI Population Gain/Loss is .34, slightly higher than for the entire population but still considered “weak.”
Here are Harris County’s watersheds ranked in order of LMI population percentage.
As of 11/21/2022
My next post will discuss how the distribution of flood-mitigation funds relates to population changes and other factors. I will also discuss what the prospects for flood mitigation in the Lake Houston Area are during Lina Hidalgo’s second administration. Don’t miss it.
Posted by Bob Rehak on 11/21/22, based on data provided by HCFCD in response to a FOIA Request
1910 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/2018/10/HarrisCountyWatersheds.jpg?fit=1500%2C972&ssl=19721500adminadmin2022-11-21 11:40:152022-11-21 12:46:59Five Watersheds Lose Population While Harris County Gains Slightly
Powerful Thanksgiving Storms Could Bring Flooding
Rainfall predictions associated with approaching Thanksgiving storms keep increasing. Jeff Lindner, Harris County’s meteorologist now says approaching storms will bring widespread impacts from Thursday through Saturday. He also warns that heavy rainfall may lead to street flooding and rises on area creeks/bayous. Models now show a band of 5-7 inches of rain in places.
Thursday
Lindner says a surface warm front will approach the upper TX coast early Thursday and move inland. He expects showers to increase in coverage and intensity near the front, which may approach the US 59 corridor by midday before slowing and potentially stalling Thursday afternoon.
Along and south of the warm front be prepared for isolated severe storms and excessive rainfall with inflow off the Gulf. All the elements are in place for flash flooding “and warm fronts are notorious in these sort of setups for producing excessive rainfall,” says Lindner.
The best case for inland areas is that the warm front is held closer to the coast.
Friday – Saturday
Models have now slowed down the movement of an upper level low to our west. Lindner now predicts a break in the rainfall Friday morning, before another round of widespread, heavy rains move back into the area Friday afternoon and evening.
Expect grounds to become increasingly saturated and runoff to increase. Showers may linger into midday Saturday, before this system finally exits to the east.
Rainfall Amounts
Predicted rainfall associated with the Thanksgiving storms has increased compared to earlier forecasts. That’s because of the potential for slow moving and training thunderstorms Thursday afternoon and the longer duration of rainfall now expected into Friday and Saturday.
Widespread amounts of 1-3 inches can be expected on Thursday afternoon with isolated totals upwards of 5-6 inches.
Some models show a band of 5-7 inches near the warm front Thursday afternoon and this is concerning.
Additional rainfall amounts of 1-3 inches can be expected Friday/Saturday on top of what falls on Thursday and this will only worsen ongoing run-off from the Thursday rainfall.
Runoff
Soils are primed for run-off with recent wetting rainfall over the region. Our main concern is street flooding, but Lindner cautions us about the potential for significant rises on area watersheds, especially if the higher totals are realized in portions of Harris County.
His greatest concern is for the southern and southeastern portions of Harris County where soils are the wettest and potential rainfall the highest. But he still isn’t confident enough to pinpoint the exact locations of the highest rainfall.
He says most watersheds can handle 3-4 inches. But if we start to exceed 5 inches, the concern for flooding from the bayous and creeks listed below will increase.
IF 5-7 inches, streams most in danger of flooding will be:
Thursday’s Excessive Rainfall Potential
If you’re out and about over the holidays, remember. Be wary of underpasses and bridges. If you can’t see the roadway, you don’t know how deep the water is. Turn around and don’t drown.
Also remember. Seven inches was the amount of rain Woodridge Village received on May 7, 2019. Woodridge now has much more stormwater detention capacity. But there are plenty of other clearcut areas around the area that don’t have much if any yet.
Friday’s Excessive Rainfall Potential
Keep your eye on the sky if you head out the door this holiday. Don’t let the Thanksgiving storms ruin your holidays.
Posted by Bob Rehak on 11/23/22 based on a forecast by HCFCD
1912 Days since Hurricane Harvey
Time for Lake Houston Area to Hit Flood-Mitigation Reset Button
During Lina Hidalgo’s first term, hundreds of millions of dollars in flood-mitigation projects went to low-income watersheds while the Lake Houston Area went begging. So what does the recent election mean for the area’s flood-mitigation goals and strategies? What can we do to reduce flood risk with the deck stacked even further against us? It’s time to hit the flood-mitigation reset button.
Before the election, Democrats insisted that they still intended to complete all the projects in the 2018 Flood Bond. But now with a super-majority on Commissioner’s Court, they have the power to spend that money wherever they want with impunity.
We need to regroup and develop new strategies to attain our goals. We can no longer afford to rely so much on Harris County.
Understanding the Process
Flood mitigation has political, technical and financial aspects. They all demand coordination. After Harvey, Guy Sconzo, former superintendent of Humble ISD, and the Lake Houston Area Chamber formed a task force with area leaders to identify the causes of flooding and work toward solutions.
After initial successes, sadly, Sconzo died. It happened shortly after the passage of the 2018 Harris County Flood Bond and the State’s Flood Infrastructure Fund. Not long thereafter, the task force disbanded. People assumed that projects would just happen. They didn’t.
Roadblocks since Harvey
No one fully understood how long the process would take, all the steps that were involved, how much projects could ultimately cost, the intense competition for funding, and how projects could languish without a coordinated effort to remove roadblocks as they arose.
For instance:
12-Step Plan for Flood Mitigation
We must overcome our addiction to expectations of fair treatment and learn that we must fight for our homes and safety. We must become masters of our own fate and hit the flood-mitigation reset button now. So, what to do?
These are my personal recommendations.
Starting Points
Harris County Flood Control District began engineering studies long before Harvey for the projects you now see in construction. Then, when Harvey hit and voters passed the 2018 flood bond, they were ready to go.
Other areas had to start from scratch and are still running the gauntlet of feasibility, preliminary engineering, final engineering, and environmental studies.
In the the Lake Houston Area:
Who is ensuring that engineering studies consider realistic funding alternatives? How much time, effort and money have we wasted by working in silos? Maybe a renewed Lake Houston Area Flood Task Force could help with those issues.
We need earmarks for funding at the state level. But who will fight for them? How will our representatives and senators know what to fight for? And how much the projects cost?
Any area with a completed study should have a project moving forward and be looking for funding. If it doesn’t, then someone is messing up the process.
Reliable sources tell me not to expect much from Harris County. Rodney Ellis wants to rub our noses in the Woodridge Village land purchase every chance he gets. So, we have to accept that and work around it.
First Meeting Held on Reconstituting Task Force
The good news in all this is that a preliminary meeting of area leaders on the City, County, State and Federal levels was held on November 8th at Congressman Dan Crenshaw’s office. Everyone attending agreed on the need to reconstitute the Task Force and hit the flood-mitigation reset button. The group also examined a number of possible issues to focus on. More news on the new Task Force as it begins to set priorities.
Posted by Bob Rehak on 11/22/2022 with thanks to Dr. Charles Campbell for the post’s photo.
1911 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.
Five Watersheds Lose Population While Harris County Gains Slightly
Like damage, population is one of the “weighting factors” considered in the distribution of flood-mitigation dollars. Compared to 2017 estimates of watershed populations in Harris County, 2022 estimates show that five watersheds have lost population. But overall, the county has gained 155,254 people.
The map below shows the location of each of these watersheds.
Reasons for Shifts Unclear
I had wondered whether the five major floods in Harris County between 2000 and 2020 (Allison, Tax Day, Memorial Day, Harvey and Imelda) would cause the most heavily flood-damaged areas to lose population. But that seems not to be the case.
The most heavily damaged watershed (Brays) lost the most population (in raw numbers). But the second most heavily damaged watershed (Greens) gained more than 16,000 people, the second largest gain.
I found no meaningful correlation between flood damage and population loss or growth. Nor do data suggest that flood-mitigation spending has much influence either. Contradictory examples abound. And statistical correlations rate as negligible to weak.
Five Watersheds Lost Population
Compared to the previous Census estimates from 2017:
In percentages, Cedar Bayou lost the most population. Cedar was the sight of the Arkema disaster which blocked evacuation routes along Highway 90 during Harvey. The watershed currently has only about 37,000 people, ranking it 20th among the 23 watersheds in Harris County.
In five major storms between 2000 and today (Allison, Tax Day, Memorial Day, Harvey and Imelda), flood damage varied widely within those five watersheds:
18 Watersheds Gained Population
Eighteen other watersheds gained population and also had widely varying degrees of flood damage. These, too, showed little correlation.
Altogether, the county’s watersheds gained 155,254 people, despite 226,729 damaged structures during the five major storms.
Negligible Correlation of Flooding and Population Gain/Loss
The “population flees flooding” hypothesis didn’t hold much water.
A perfect correlation is 1.0. It indicates that for every unit of change in one variable, there is a corresponding unit of change in another variable. However, that was far from the case here. Variations seemed random.
If long-time Harris County residents are moving to higher ground, they may be replaced by newcomers unaware of flood risks.
The County has a strong draw: jobs. Also, family, friends, neighbors and support networks remain powerful attractions that keep most people anchored.
The new HCFCD data do not suggest why gains and losses occurred.
Top reasons for relocation typically include: greater safety, better schools, better housing, new jobs, and upgrading from apartments to homes.
LMI Population Trends
HCFCD also measures “LMI population.” LMI stands for Low-to-Moderate Income. The Census Bureau defines LMI as “families making less than the average for the region.”
Harris County has 42.6 % LMI residents. So 57.4% of residents make above the average for the region.
This is important because the LMI percentage plays a huge role in partnership grants from the US Department of Housing and Urban Development (HUD). Most, but not all, HUD grants go to areas with LMI populations higher than 70%. A notable exception is the pending $750 million HUD Harvey flood-mitigation grant. It only requires that 50% of the money benefits LMI households.
The latest HCFCD data shows that watersheds at both ends of the income spectrum lost LMI population. We still have the same eight LMI-majority watersheds we had in 2017. However, one deserves special mention.
Sixteen other watersheds gained LMI population. Some had huge flood losses; others had few.
The correlation between total flood damage and LMI Population Gain/Loss is .34, slightly higher than for the entire population but still considered “weak.”
Here are Harris County’s watersheds ranked in order of LMI population percentage.
My next post will discuss how the distribution of flood-mitigation funds relates to population changes and other factors. I will also discuss what the prospects for flood mitigation in the Lake Houston Area are during Lina Hidalgo’s second administration. Don’t miss it.
Posted by Bob Rehak on 11/21/22, based on data provided by HCFCD in response to a FOIA Request
1910 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.