Correction: 6/6/25 @ 10:25 PM. The traffic switch scheduled for tonight has been delayed without explanation. It’s not yet clear when it will occur.
6/6/25 – A major Northpark traffic switch is scheduled to begin tonight at 9 PM on the westbound lanes between Loop 494 and US59, according to Ralph De Leon, project manager. Traffic will be rerouted from the center of the project to the recently completed new concrete on the north side of the thoroughfare.
The old center lanes will then be closed off for demolition, installation of new drainage and repaving.
De Leon did not say how long it would take to implement the NorthPark traffic switch. However, he did say that work in the center lanes should last about six months.
Map supplied by De Leon, project manager for Lake Houston Redevelopment Authority.
This shot taken at a lower angle today may help readers visualize the Northpark traffic switch. I’ve highlighted the new route for westbound traffic in red.
Crews have already placed temporary asphalt pavement for switch.
As traffic approaches 59, the detour will widen to three lanes, with one used for turning right. It only appears to narrow because of the distance.
In other Northpark news today…
Boring Under Tracks Starts
Crews started pushing the first of the steel pipes under the railroad tracks. The pipes will convey stormwater from the area west of 59 east to the Kingwood Diversion Ditch.
Tracks that hold boring machine are anchored to pit floor. The machine then forces steel pipe (rust colored) through a temporary hole in the pit wall.Wider shot shows the beginning of the receiving pit near Loop 494 on the other side of the tracks.Workers will weld additional sections of pipe onto the previous section(s) and push them through until they reach the receiving pit.
Then they will start over again and push a second parallel pipe under the tracks to create the needed drainage capacity.
Estimated duration for the bore operation is approximately 4 weeks.
Elsewhere on Northpark Today
Contractors placed more rebar for future concrete pours. With utility conflicts in the rear view mirror, the project should start to look more like an assembly line operation.
I have received no news yet from Montgomery County Precinct 4 about the engineering review of the Enclave Detention basin. More news to follow. At noon today, culvert work appeared to have stopped short of the basin. The issue had to do with a notation on construction plans showing the basin potentially overflowing into the evacuation route for 78,000 people during extreme storms.
For More Information
See this look-ahead schedule on the Lake Houston Redevelopment Authority Project website. Major activities scheduled for the next two weeks include:
Twin 60″ bores under the railroad tracks
Parking lot drainage tie-ins
Culvert and inlet installation from the Kolache Factory to Public Storage
Prepping the sub-grade and pouring concrete in the same area
Posted by Bob Rehak on 6/6/25
2838 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/2025/06/20250606-DJI_20250606123423_0104_D-copy.jpg?fit=1100%2C619&ssl=16191100adminadmin2025-06-06 16:57:322025-06-06 22:40:15Northpark Traffic Switch Starts Friday at 9
6/5/25 – Harris County Flood Control District (HCFCD) is seeking to negotiate an agreement with the University of Oklahoma to help enhance the county’s Gauge Adjusted Radar Rainfall system. See Item 103 on the 6/12/25 agenda.
The system tells how much rain has fallen over a specific area during a certain period, thus providing input for the county’s flood forecasting model. Upgrades will:
Make it significantly easier to evaluate rainfall data using a more intuitive and interactive platform.
Provide a cloud-based data archive to overcome limitations in current workflows.
Enable “nowcasting” with rainfall estimates updated as frequently as every 10 minutes.
What is Gauge Adjusted Radar Rainfall?
Gauge Adjusted Radar Rainfall (GARR) systems estimate rainfall by combining radar-based precipitation estimates with ground-based rain-gauge measurements. The two together produce more accurate rainfall data over wider areas.
Radar can provide rainfall data over large areas with high frequency (e.g., every 5 minutes), but it’s prone to errors due to beam blockage, calibration issues, or interpreting non-rain targets (such as birds or dust) as rain.
Rain gauges give point-accurate rainfall measurements, but huge distances/gaps exist between gages. And rainfall is rarely uniform across wide areas.
Hypothetical image created by ChatGPT. Demonstrates differences in technologies.
Gauge adjusted radar rainfall systems blend both types of data. They use the broad coverage of radar but “correct” or adjusts the radar estimates using actual gauge readings. Great advances in the systems have been made in recent years.
Is It Good?
Yes. GARR is generally considered superior to using radar or gauges alone. It is widely used by agencies like the National Weather Service, USGS, and local flood control districts (e.g., HCFCD).
According to ChatGPT, the systems offer multiple benefits.
Benefits of Gauge Adjusted Radar Rainfall
Benefit
Explanation
Improved Accuracy
Combines radar’s spatial resolution with gauge accuracy, reducing biases in radar-only estimates.
Better Coverage
Provides rainfall estimates across areas with few or no gauges
Real-Time Utility
Enables near real-time rainfall mapping, critical for flood forecasting and emergency response.
Hydrologic Modeling
Offers high-resolution inputs for stormwater modeling, floodplain mapping, and watershed management.
Event Verification
Allows engineers and flood managers to verify how much rain actually fell over an entire basin during a storm.
How is GARR Used?
GARR data is often used in:
Post-storm analysis
Designing detention basins
Flood alert systems
Atlas 14 and extreme rainfall calibration
GARR systems are widely used for both real-time monitoring and hydrologic planning. And they are particularly valuable in flood-prone areas.
Success Stories
Harris County Flood Control
During Hurricane Harvey in 2017, GARR data provided near real-time insight into rainfall distribution — helping emergency managers prioritize rescues, issue flood alerts, and allocate resources.
Post-storm, GARR helped analyze where detention basins were effective and where flooding exceeded expected design thresholds.
HCFCD reportedly credits GARR with saving lives and informing infrastructure improvements after Harvey.
San Antonio River Authority (SARA)
SARA integrated GARR into its real-time models to monitor stormwater flow in the river basin. It:
Improved rainfall inputs to models that simulate flooding during storms
Enabled automated forecasts of creek levels and road closures
Reduced false positives/negatives from radar-only systems.
They used it to improve public safety, automated alerts and floodgate operations.
North Carolina
Mecklenburg County (Charlotte) uses GARR to fill data gaps across watersheds and create real-time flood forecasts with more accurate rainfall inputs.
They credit GARR systems with improved warning lead times and better informed design updates for critical infrastructure like culverts and detention ponds.
Recent Advances in GARR
HCFCD hopes to improve accuracy and operational capabilities that support improved flood forecasting. The District did not elaborate with more specifics, but GARR technology has improved greatly in recent years. Advances include:
1. Integration of AI and Machine Learning
Artificial intelligence (AI) and machine learning techniques are improving GARR system accuracy. For instance, deep learning models have been employed to enhance precipitation “nowcasting” for emergency response.
2. Enhanced Data Assimilation Techniques
Advances in data assimilation now allow seamless integration of GARR data into hydrological models for more accurate flood forecasting.
3. Development of High-Resolution GARR Products
Companies like AEM have developed GARR products with resolutions as fine as 1 km² and temporal resolutions of 5 minutes. Such resolution is essential for urban planning, infrastructure design, and real-time flood monitoring.
4. Application in Urban Flood Management
During the unprecedented rainfall event in the United Arab Emirates in April 2024, GARR data played a crucial role in analyzing the hydrologic and flood impacts.
5. Expansion of Historical Data Archives
Organizations like OneRain have expanded their historical radar data archives, providing GARR data back to 1993. This helps planners analyze trends and infrastructure resilience to develop disaster risk reduction strategies.
HCFCD Request and Rationale
HCFCD hopes to provide an enhanced Gage Adjusted Radar Rainfall (GARR) Multi-Radar Multi-Sensor (MRMS) product that improves flood forecasting in Harris County.
This project expands the initial agreement between HCFCD and the National Severe Storms Laboratory (NSSL). That agreement established a limited Multi-Radar Multi-Sensor (MRMS) domain over Harris County using HCFCD’s dense rain gauge network.
The new agreement should enhance the accuracy and operational capability of HCFCD’s GARR MRMS system. It will integrate verification tools, cloud-based processing, and sub-hourly nowcasting capabilities. These improvements should lead to better spatial representation of rainfall, improved short-term forecasting, and ultimately strengthen flood risk prediction and response efforts across Harris County.
Looking for a summer science project for your student? Here it is.
Posted by Bob Rehak on 6/5/25and updated on 6/6/25
2837 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2025/06/20250605-ChatGPT-Image-Jun-5-2025-at-09_16_21-PM.jpg?fit=1100%2C1100&ssl=111001100adminadmin2025-06-05 21:40:322025-06-06 10:01:07HCFCD Seeks to Enhance its Gauge Adjusted Radar Rainfall System
6/5/25 – The Northpark Drive Expansion Project has been a beehive of activity recently.
A major traffic switch will happen Friday.
Crews have paved several blocks of new westbound lanes and are working their way toward the railroad tracks.
They have finished the first pit for boring under the UnionPacific tracks and are getting ready to place the boring machine into it. They have also started excavating the receiving pit on the west side of the tracks.
Contractors at the Northpark Enclave continue to work even as Montgomery County Precinct 4 is trying to set up a meeting between Montgomery County Engineering, City of Houston, EHRA (the Enclave’s engineering company), and HNTB (the Lake Houston Redevelopment Authority’s engineering company). The purpose: to discuss concerns about potential overflow from the development’s retention pond during extreme weather events into the evacuation route for 78,000 people.
Lane Switch
Westbound traffic between Loop 494 and US59 will be routed to recently paved lanes on the north side of Northpark starting Friday, June 6.
According to Ralph De Leon, Northpark Expansion project manager, “Beginning June 6th at 9pm, Harper Brothers Construction will shift westbound Northpark Drive traffic to the newly constructed westbound lanes.”
The contractor will then install new storm sewer pipes and construct new concrete roadway between the eastbound and westbound lanes. This shift should last approximately 6 months. And no additional lane changes will take place during that time in that area.
De Leon provided this map to help motorists understand Friday’s change.
Beginning 6.6.25 at 9 PM
That same area looks like this from a lower angle.
Crews will reroute traffic to the lanes on the right with the orange traffic cones.
Westbound traffic now in the middle will move to the right and crews will begin work in the middle.
Paving
During the last few months, work on the north side of Northpark east of the railroad tracks has focused mainly on utility relocations and drainage installation. Now, crews are starting to pave that area working from east to west – toward the tracks.
Note the fresh concrete on the left below.
Looking East along Northpark DriveReverse angle. Looking W from same location. Crews are working on pavement prep work, i.e., rebar placement.
Boring Under Union Pacific Tracks
Steel pipe previously stockpiled south (left) of Northpark has been moved to the north side in preparation for the bore.Workers have completed the steel frame for the boring operation and poured a concrete floor for the bore pit.
They have also placed a section of railroad tracks into the pit. The boring machine will later be placed on the tracks.
On the far side of the tracks, you can see them starting to excavate the receiving pit.
Two steel pipes will run under the tracks side by side to convey storm water toward the Diversion Ditch from the area on the west side of Loop 494. As crews push each section in, they will weld a new section on.
Enclave Construction
Contrary to earlier reports, construction at the Enclave has not stopped during a peer review of the subdivision’s drainage.
Photo taken 6/4/25 at approximately 2 PMshowed activity throughout the site.
Victoria Bryant, Montgomery County Precinct 4 Project Coordinator says that she is trying to set up a meeting between the engineering companies, MoCo Engineering and the City of Houston.
Pictures below show activity on the site.
Culvert installation almost reached the development’s detention basinat 2PM on 6/4/25.More drainage being installed on 6/3/25Pipes going in the ground.Also on 6/3/25.
Drainage Concerns
Meanwhile, construction plans show that the detention basin could overflow into the only evacuation route for 78,000 people during extreme rainfall events.
Enlarged and cropped detail from construction plans.
But it doesn’t take a 100-year rainfall to create a 100-year flood in the Kingwood Diversion Ditch.
The photo below taken by Kingwood flood activist Chris Bloch during the May 2024 flood shows runoff in the Kingwood Diversion Ditch reaching above the bottom of the Northpark Drive Bridge, which was above the predicted 100-year flood level.
But the closest Harris County Flood Control rain gage showed that the May 2024 event that caused water to reach that high was approximately a 5-year rainfall by today’s Atlas-14 standard.
Photo courtesy of Chris Bloch
But there’s more. Plans for the bridge show that the bottom is at 75.76 feet.
About a half mile downstream, drainage from the Enclave and the rest of Kings Mill crosses under Russell Palmer Road and enters into the Diversion Ditch.
Water in the Diversion Ditch at the bridge was higher than the crown of Russell Palmer Road at the detention basin.
When water in a receiving ditch is higher than water in a connected detention basin, it creates back-pressure on the water in the basin. Water can actually flow into the basin from the ditch.
At a minimum, higher water in the Diversion Ditch would slow the water coming out of Kings Mill and the Enclave. That raises the height of stormwater in the detention basin(s) and keeps it there longer.
Also, note that the outfall pipe for the Kings Mills Detention Basins is at the BOTTOM of the Diversion Ditch. (See below.) That exacerbates the back-pressure issue.
Route of stormwater from Kings Mill Detention Basin (right) to Kingwood Diversion Ditch (left)
Conclusion: Mismatch Between Regulations and Reality
The Diversion Ditch has become seriously overburdened with runoff from subdivisions that were developed when the rainfall probability estimates used by Montgomery County were 40% lower than they are for this area today.
That may or may not cause the Enclave detention basin to overflow into Northpark during a REAL 100-year event. It will be interesting to see what the engineers determine. Only they can tell how high, how far, and how long the water will back up.
Chances are small that the Enclave detention basin will overflow into Northpark during an evacuation. But the stakes are huge.
Posted by Bob Rehak on 6/4/25
2836 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/2025/06/20250604-NorthPark-Traffic-Switch-06-06-2025R.jpg?fit=1100%2C712&ssl=17121100adminadmin2025-06-04 20:17:332025-06-05 13:46:02Northpark Update: Lane Switch, Paving, Tunneling, Enclave
Northpark Traffic Switch Starts Friday at 9
Correction: 6/6/25 @ 10:25 PM. The traffic switch scheduled for tonight has been delayed without explanation. It’s not yet clear when it will occur.
6/6/25 – A major Northpark traffic switch is scheduled to begin tonight at 9 PM on the westbound lanes between Loop 494 and US59, according to Ralph De Leon, project manager. Traffic will be rerouted from the center of the project to the recently completed new concrete on the north side of the thoroughfare.
The old center lanes will then be closed off for demolition, installation of new drainage and repaving.
De Leon did not say how long it would take to implement the NorthPark traffic switch. However, he did say that work in the center lanes should last about six months.
This shot taken at a lower angle today may help readers visualize the Northpark traffic switch. I’ve highlighted the new route for westbound traffic in red.
As traffic approaches 59, the detour will widen to three lanes, with one used for turning right. It only appears to narrow because of the distance.
In other Northpark news today…
Boring Under Tracks Starts
Crews started pushing the first of the steel pipes under the railroad tracks. The pipes will convey stormwater from the area west of 59 east to the Kingwood Diversion Ditch.
Then they will start over again and push a second parallel pipe under the tracks to create the needed drainage capacity.
Estimated duration for the bore operation is approximately 4 weeks.
Elsewhere on Northpark Today
Contractors placed more rebar for future concrete pours. With utility conflicts in the rear view mirror, the project should start to look more like an assembly line operation.
I have received no news yet from Montgomery County Precinct 4 about the engineering review of the Enclave Detention basin. More news to follow. At noon today, culvert work appeared to have stopped short of the basin. The issue had to do with a notation on construction plans showing the basin potentially overflowing into the evacuation route for 78,000 people during extreme storms.
For More Information
See this look-ahead schedule on the Lake Houston Redevelopment Authority Project website. Major activities scheduled for the next two weeks include:
Posted by Bob Rehak on 6/6/25
2838 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.
HCFCD Seeks to Enhance its Gauge Adjusted Radar Rainfall System
6/5/25 – Harris County Flood Control District (HCFCD) is seeking to negotiate an agreement with the University of Oklahoma to help enhance the county’s Gauge Adjusted Radar Rainfall system. See Item 103 on the 6/12/25 agenda.
The system tells how much rain has fallen over a specific area during a certain period, thus providing input for the county’s flood forecasting model. Upgrades will:
What is Gauge Adjusted Radar Rainfall?
Gauge Adjusted Radar Rainfall (GARR) systems estimate rainfall by combining radar-based precipitation estimates with ground-based rain-gauge measurements. The two together produce more accurate rainfall data over wider areas.
Gauge adjusted radar rainfall systems blend both types of data. They use the broad coverage of radar but “correct” or adjusts the radar estimates using actual gauge readings. Great advances in the systems have been made in recent years.
Is It Good?
Yes. GARR is generally considered superior to using radar or gauges alone. It is widely used by agencies like the National Weather Service, USGS, and local flood control districts (e.g., HCFCD).
According to ChatGPT, the systems offer multiple benefits.
Benefits of Gauge Adjusted Radar Rainfall
How is GARR Used?
GARR data is often used in:
GARR systems are widely used for both real-time monitoring and hydrologic planning. And they are particularly valuable in flood-prone areas.
Success Stories
Harris County Flood Control
During Hurricane Harvey in 2017, GARR data provided near real-time insight into rainfall distribution — helping emergency managers prioritize rescues, issue flood alerts, and allocate resources.
Post-storm, GARR helped analyze where detention basins were effective and where flooding exceeded expected design thresholds.
HCFCD reportedly credits GARR with saving lives and informing infrastructure improvements after Harvey.
San Antonio River Authority (SARA)
SARA integrated GARR into its real-time models to monitor stormwater flow in the river basin. It:
They used it to improve public safety, automated alerts and floodgate operations.
North Carolina
Mecklenburg County (Charlotte) uses GARR to fill data gaps across watersheds and create real-time flood forecasts with more accurate rainfall inputs.
They credit GARR systems with improved warning lead times and better informed design updates for critical infrastructure like culverts and detention ponds.
Recent Advances in GARR
HCFCD hopes to improve accuracy and operational capabilities that support improved flood forecasting. The District did not elaborate with more specifics, but GARR technology has improved greatly in recent years. Advances include:
1. Integration of AI and Machine Learning
Artificial intelligence (AI) and machine learning techniques are improving GARR system accuracy. For instance, deep learning models have been employed to enhance precipitation “nowcasting” for emergency response.
2. Enhanced Data Assimilation Techniques
Advances in data assimilation now allow seamless integration of GARR data into hydrological models for more accurate flood forecasting.
3. Development of High-Resolution GARR Products
Companies like AEM have developed GARR products with resolutions as fine as 1 km² and temporal resolutions of 5 minutes. Such resolution is essential for urban planning, infrastructure design, and real-time flood monitoring.
4. Application in Urban Flood Management
During the unprecedented rainfall event in the United Arab Emirates in April 2024, GARR data played a crucial role in analyzing the hydrologic and flood impacts.
5. Expansion of Historical Data Archives
Organizations like OneRain have expanded their historical radar data archives, providing GARR data back to 1993. This helps planners analyze trends and infrastructure resilience to develop disaster risk reduction strategies.
HCFCD Request and Rationale
HCFCD hopes to provide an enhanced Gage Adjusted Radar Rainfall (GARR) Multi-Radar Multi-Sensor (MRMS) product that improves flood forecasting in Harris County.
This project expands the initial agreement between HCFCD and the National Severe Storms Laboratory (NSSL). That agreement established a limited Multi-Radar Multi-Sensor (MRMS) domain over Harris County using HCFCD’s dense rain gauge network.
The new agreement should enhance the accuracy and operational capability of HCFCD’s GARR MRMS system. It will integrate verification tools, cloud-based processing, and sub-hourly nowcasting capabilities. These improvements should lead to better spatial representation of rainfall, improved short-term forecasting, and ultimately strengthen flood risk prediction and response efforts across Harris County.
Looking for a summer science project for your student? Here it is.
Posted by Bob Rehak on 6/5/25 and updated on 6/6/25
2837 Days since Hurricane Harvey
Northpark Update: Lane Switch, Paving, Tunneling, Enclave
6/5/25 – The Northpark Drive Expansion Project has been a beehive of activity recently.
Lane Switch
Westbound traffic between Loop 494 and US59 will be routed to recently paved lanes on the north side of Northpark starting Friday, June 6.
According to Ralph De Leon, Northpark Expansion project manager, “Beginning June 6th at 9pm, Harper Brothers Construction will shift westbound Northpark Drive traffic to the newly constructed westbound lanes.”
The contractor will then install new storm sewer pipes and construct new concrete roadway between the eastbound and westbound lanes. This shift should last approximately 6 months. And no additional lane changes will take place during that time in that area.
De Leon provided this map to help motorists understand Friday’s change.
That same area looks like this from a lower angle.
Westbound traffic now in the middle will move to the right and crews will begin work in the middle.
Paving
During the last few months, work on the north side of Northpark east of the railroad tracks has focused mainly on utility relocations and drainage installation. Now, crews are starting to pave that area working from east to west – toward the tracks.
Note the fresh concrete on the left below.
Boring Under Union Pacific Tracks
They have also placed a section of railroad tracks into the pit. The boring machine will later be placed on the tracks.
Two steel pipes will run under the tracks side by side to convey storm water toward the Diversion Ditch from the area on the west side of Loop 494. As crews push each section in, they will weld a new section on.
Enclave Construction
Contrary to earlier reports, construction at the Enclave has not stopped during a peer review of the subdivision’s drainage.
Victoria Bryant, Montgomery County Precinct 4 Project Coordinator says that she is trying to set up a meeting between the engineering companies, MoCo Engineering and the City of Houston.
Pictures below show activity on the site.
Drainage Concerns
Meanwhile, construction plans show that the detention basin could overflow into the only evacuation route for 78,000 people during extreme rainfall events.
But it doesn’t take a 100-year rainfall to create a 100-year flood in the Kingwood Diversion Ditch.
The photo below taken by Kingwood flood activist Chris Bloch during the May 2024 flood shows runoff in the Kingwood Diversion Ditch reaching above the bottom of the Northpark Drive Bridge, which was above the predicted 100-year flood level.
But the closest Harris County Flood Control rain gage showed that the May 2024 event that caused water to reach that high was approximately a 5-year rainfall by today’s Atlas-14 standard.
But there’s more. Plans for the bridge show that the bottom is at 75.76 feet.
About a half mile downstream, drainage from the Enclave and the rest of Kings Mill crosses under Russell Palmer Road and enters into the Diversion Ditch.
Water in the Diversion Ditch at the bridge was higher than the crown of Russell Palmer Road at the detention basin.
When water in a receiving ditch is higher than water in a connected detention basin, it creates back-pressure on the water in the basin. Water can actually flow into the basin from the ditch.
At a minimum, higher water in the Diversion Ditch would slow the water coming out of Kings Mill and the Enclave. That raises the height of stormwater in the detention basin(s) and keeps it there longer.
Also, note that the outfall pipe for the Kings Mills Detention Basins is at the BOTTOM of the Diversion Ditch. (See below.) That exacerbates the back-pressure issue.
Conclusion: Mismatch Between Regulations and Reality
The Diversion Ditch has become seriously overburdened with runoff from subdivisions that were developed when the rainfall probability estimates used by Montgomery County were 40% lower than they are for this area today.
That may or may not cause the Enclave detention basin to overflow into Northpark during a REAL 100-year event. It will be interesting to see what the engineers determine. Only they can tell how high, how far, and how long the water will back up.
Chances are small that the Enclave detention basin will overflow into Northpark during an evacuation. But the stakes are huge.
Posted by Bob Rehak on 6/4/25
2836 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.