Flash flooding and flooding will be possible Wednesday into Thursday. A band of heavy rainfall may form Wednesday morning from College Station to Crockett and heavy rainfall may continue to occur through the day. Gulf moisture will also move into the area and cause additional rainfall mainly east of I-45.
Southeast Texas has already had rainfall the last seven days which will cause any additional rainfall to runoff. Isolated thunderstorms may cause brief heavy rainfall of 1 inch an hour. Overall areas in the watch may get 2 to 3 inches of rainfall with isolated bands of 4 inches.
Potential Flood Impacts
In urban areas, street flooding and flooding of underpasses and typical low lying areas can be be expected. Bayous and creeks may have rapid rises and could reach out of banks. Rural low lying areas, low water crossings and poor drainage areas may flood. Rises on area rivers can be expected and this could extend river flooding that is on going.
PRECAUTIONARY/PREPAREDNESS ACTIONS
A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.
Additional Guidance from Harris County Flood Control
Jeff Lindner, Harris County Flood Control’s meteorologist added this:
Widespread rainfall…some heavy…will lead to rises on area watersheds and potentially some flooding of creeks and rivers.
Upper level storm system is digging into the SW US and will impact the state for the next 24-36 hours.
As moisture increases from the SSW this evening, light rain and showers will develop and spread NNE into the area. A secondary front from roughly Lake Livingston to Columbus will likely remain stationary and be the focus for rainfall production tonight into early Wednesday in that region. Expect numerous showers and thunderstorms to develop by midday along the coast and inland south of the stalled inland front…this rainfall will likely become heavier in nature and slightly more convective with potentially higher rainfall rates. Upper level system will move across the area early Thursday with rains continuing before dry WNW winds sweep across the area in the afternoon ending rainfall.
Rainfall Amounts
Widespread rainfall of 2-3 inches looks likely over much of the area with isolated totals of 4-5 inches. Some fairly decent agreement in the models today with respect to two rainfall maximums over the area…the first over our NW/N counties tonight in Wednesday and then a second Wednesday afternoon into Thursday morning from Houston ENE toward Liberty and then NE toward Lake Livingston. WPC has expended the slight risk of excessive rainfall exceeding flash flood guidance to include a larger part of SE TX. Think maximum hourly rainfall rates will be on the order of .5 to 1.25 inches which most urban areas will be able to handle. Overall fairly long duration of rainfall over a fairly large area will lead to significant amounts of run-off especially into area river systems as well as the creeks in northern Harris County.
Flash Flood Guidance
Flash Flood Guidance for the area is between 3.0-4.4 inches for 6-hrs which seems high and a review of soil saturation levels via the NASA SPORT webpage shows saturation levels of 65-70% over much of the area…or you can walk in the yard and quickly tell that the ground is still very wet from the rainfall on Sunday. Think much of what falls is going to run-off given how wet the ground is and widespread amounts of dormant vegetation.
Several watersheds are still high from the rainfall last Thursday and rainfall of this magnitude will likely result in renewed rises on nearly all watersheds. Main concern will be the Trinity and San Jacinto basins, along with the Navasota and Brazos. In Harris County, significant rises on Spring, Cypress, Little Cypress, Willow, Cedar, and the creeks that feed into Addicks and Barker Reservoirs are likely. Will also include lower Greens (east of US 59) and Halls, Hunting. Some of these watersheds may rise to levels that would impact low lying areas and roadways near the creek or bayou.
Flooding Probable on East and West Forks
Flooding on both the East and West Forks of the San Jacinto River (low lands and streets) certainly looks probable. At this time the threat for significant creek and bayou flooding as well as any flooding of structures is low.
Current thinking is that watersheds will see similar responses to last Thursday morning…although a few may see higher levels since they will be starting at higher current flows versus last Thursday.
Think hourly rainfall rates will be low enough to prevent widespread street flooding, but street flooding in areas of poor drainage and in rural areas where roadside ditches or small creeks spill onto the roadway will be possible.
Posted by Bob Rehak on 1/1/2019
480 Days Since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2019/01/Balcom_25.jpg?fit=1500%2C1000&ssl=110001500adminadmin2019-01-01 18:30:232019-01-01 18:30:29Flash Flood Watch Issued from 6 a.m. Wednesday to Noon Thursday
Yesterday, the area where a developer proposes a new high-rise development flooded for the fifth time this year. This underscores the need for remediation before any permitting.
It wasn’t an especially heavy rain last week. Kingwood received about 2.5 inches. Areas upstream averaged 3 to 4 inches. Yet the West Fork came out of its banks and flooded River Grove Park for the fifth time this year (February 26, March 28/29, July 4, December 7/8, December 27). The USGS Gage at US59 showed that the flood crested at about midnight. The crest reached almost 50 feet at US59.
The West Fork at US 59 crested at almost 50 feet from the most recent rains. In the days preceding, SJRA released 5-7,000 cfs from Lake Conroe.
Jim Zura of Zura Productions took his drone to River Grove during the last light before the overnight crest. The video shows that although the road was still useable, many of the park’s popular amenities were not. The playground, soccer fields, boat ramp and boardwalk all flooded.
Earlier this year, the US Army Corps of Engineers found that excessive sedimentation in the river contributed to excessive flooding. The frequency of these floods supports that conclusion. The Corps began dredging in late September to remove sediment, but has completed only about 20% of the project so far. Downstream blockages remain. And the biggest – at the mouth of the West Fork – is not even within the scope of the current dredging project.
The end of Zura’s video shows the soccer fields and adjoining property, including a small lake in the floodway. This flood gives us a glimpse of how a minor rain would affect the proposed high-rise development there.
Watch all the way to the end!
The frequency of these floods underscores the need to consider the implications of permitting such a major development – especially when officials know the engineering is based on obsolete data and flood maps that in no way reflect current realities.
Until remediation efforts are complete, officials should postpone consideration of the permit. Remediation efforts include:
Dredging the West Fork all the way from US59 to Lake Houston
Creating additional upstream detention
Adding flood gates to Lake Houston
Restoring the conveyance of local drainage ditches and streams.
Rainfalls of the magnitude that caused these five floods should happen about once every 2 years according to Harris County Flood Control. This year they happened five times: 10X greater than expected. A review of peak crest data since 1929 roughly confirms these expectations. In the 80 year since then, the river crested over 50 feet only 40 times.
A review of the same data shows that the river has crested over 57 feet 9 times in the last 80 years and six times since 1994.
I believe excessive sedimentation played a role in this frequency increase. Instead of flooding every other year like this, we’re flooding almost every other month. That’s significant enough to put the brakes on development in the floodway, at least until we understand the extent of the problems and can fix them.
These are my opinions on matters of public policy. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statutes of the Great State of Texas.
Posted by Bob Rehak on December 31, 2018
489 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2018/12/Zura2.jpg?fit=1500%2C843&ssl=18431500adminadmin2018-12-30 13:08:172019-01-26 08:03:54Drone Video Underscores Dangers of Development without Remediation
Warning: NOT for the feint of heart. Together they contain more than 300 pages! Frankly, permit evaluation is far more complex than I imagined.
Site of proposed marina after Harvey. Fresh sand deposits reached almost five feet in height. River Grove Park is beyond this, to the right of the giant sand bar which the Army Corps just dredged through. The drainage ditch it blocked drains the western third of Kingwood.
Plea for Expert Advice
I’m publishing the presentations here because thousands of engineers, project managers, and lawyers with technical backgrounds live in the Lake Houston area. With your help, I’m hoping we can sort through the material and determine a productive response to the Corps’ Public Notice.
As you review these, keep in mind what the Corps wants: “…to solicit your comments and information to better enable us to make a reasonable decision on factors affecting the public interest.” The Public Notice goes into great detail about the scope of the project but focuses largely on the environmental impact of introducing “68,323 cubic yards of fill material into 42.35 acres of wetlands and an estimated 285 cubic yards of fill material into 771 linear feet of streams adjacent to the West Fork San Jacinto River.”
Key Elements of Solicitation
Other key points to consider in the Public Notice include:
“A preliminary review of this application indicates that an Environmental Impact Statement (EIS) is not required. Since permit assessment is a continuing process, this preliminary determination of EIS requirement will be changed if data or information brought forth in the coordination process is of a significant nature.”
They say, “Our evaluation will also follow the guidelines published by the U.S. Environmental Protection Agency pursuant to Section 404 (b)(1) of the Clean Water Act (CWA).”
“The TCEQ is reviewing this application under Section 401 of the CWA and in accordance with Title 30, Texas Administrative Code Section 279.1-13 to determine if the work would comply with State water quality standards.”
“The decision whether to issue a permit will be based on an evaluation of the probable impacts, including cumulative impacts, of the proposed activity on the public interest.”
They then define the public interest as: “All factors, which may be relevant to the proposal, will be considered: among those are conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shore erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs and, in general, the needs and welfare of the people.”
Background Information on Corps’ Permit Evaluation Process
I pray that people, their property, and their safety count for as much as birds and fish in this process. However, I’ve talked to several birders lately who are abuzz about eagle spottings near the project site.
All of us are smarter than any one of us. Please help!
Submit Comments
Remember comments are due by January 29, 2019. If no comments are received, the Corps will assume there are no objections to the project. To submit comments: Reference USACE file number, SWG-2016-00384, and send to:
Evaluation Branch, North Unit
Regulatory Division, CESWG-RD-E
U.S. Army Corps of Engineers
P.O. Box 1229
Galveston, Texas 77553-1229
409-766-3869 Phone
409-766-6301 Fax
swg_public_notice@usace.army.mil
Posted by Bob Rehak on 12/30/2018
488 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2018/03/Harvey-SanJac_180.jpg?fit=2000%2C1333&ssl=113332000adminadmin2018-12-29 22:14:312019-01-13 12:38:25Army Corps Permit Evaluation Process
Flash Flood Watch Issued from 6 a.m. Wednesday to Noon Thursday
The National Weather Service in Houston/Galveston has issued a Flash Flood Watch for a large portion of southeast Texas…including Harris, Madison, Montgomery, Liberty, San Jacinto, Walker, Waller and Washington Counties. From Wednesday morning through Thursday morning.
Flash flooding and flooding will be possible Wednesday into Thursday. A band of heavy rainfall may form Wednesday morning from College Station to Crockett and heavy rainfall may continue to occur through the day. Gulf moisture will also move into the area and cause additional rainfall mainly east of I-45.
Southeast Texas has already had rainfall the last seven days which will cause any additional rainfall to runoff. Isolated thunderstorms may cause brief heavy rainfall of 1 inch an hour. Overall areas in the watch may get 2 to 3 inches of rainfall with isolated bands of 4 inches.
Potential Flood Impacts
In urban areas, street flooding and flooding of underpasses and typical low lying areas can be be expected. Bayous and creeks may have rapid rises and could reach out of banks. Rural low lying areas, low water crossings and poor drainage areas may flood. Rises on area rivers can be expected and this could extend river flooding that is on going.
PRECAUTIONARY/PREPAREDNESS ACTIONS
A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.
Additional Guidance from Harris County Flood Control
Jeff Lindner, Harris County Flood Control’s meteorologist added this:
Widespread rainfall…some heavy…will lead to rises on area watersheds and potentially some flooding of creeks and rivers.
Upper level storm system is digging into the SW US and will impact the state for the next 24-36 hours.
As moisture increases from the SSW this evening, light rain and showers will develop and spread NNE into the area. A secondary front from roughly Lake Livingston to Columbus will likely remain stationary and be the focus for rainfall production tonight into early Wednesday in that region. Expect numerous showers and thunderstorms to develop by midday along the coast and inland south of the stalled inland front…this rainfall will likely become heavier in nature and slightly more convective with potentially higher rainfall rates. Upper level system will move across the area early Thursday with rains continuing before dry WNW winds sweep across the area in the afternoon ending rainfall.
Rainfall Amounts
Widespread rainfall of 2-3 inches looks likely over much of the area with isolated totals of 4-5 inches. Some fairly decent agreement in the models today with respect to two rainfall maximums over the area…the first over our NW/N counties tonight in Wednesday and then a second Wednesday afternoon into Thursday morning from Houston ENE toward Liberty and then NE toward Lake Livingston. WPC has expended the slight risk of excessive rainfall exceeding flash flood guidance to include a larger part of SE TX. Think maximum hourly rainfall rates will be on the order of .5 to 1.25 inches which most urban areas will be able to handle. Overall fairly long duration of rainfall over a fairly large area will lead to significant amounts of run-off especially into area river systems as well as the creeks in northern Harris County.
Flash Flood Guidance
Flash Flood Guidance for the area is between 3.0-4.4 inches for 6-hrs which seems high and a review of soil saturation levels via the NASA SPORT webpage shows saturation levels of 65-70% over much of the area…or you can walk in the yard and quickly tell that the ground is still very wet from the rainfall on Sunday. Think much of what falls is going to run-off given how wet the ground is and widespread amounts of dormant vegetation.
Several watersheds are still high from the rainfall last Thursday and rainfall of this magnitude will likely result in renewed rises on nearly all watersheds. Main concern will be the Trinity and San Jacinto basins, along with the Navasota and Brazos. In Harris County, significant rises on Spring, Cypress, Little Cypress, Willow, Cedar, and the creeks that feed into Addicks and Barker Reservoirs are likely. Will also include lower Greens (east of US 59) and Halls, Hunting. Some of these watersheds may rise to levels that would impact low lying areas and roadways near the creek or bayou.
Flooding Probable on East and West Forks
Flooding on both the East and West Forks of the San Jacinto River (low lands and streets) certainly looks probable. At this time the threat for significant creek and bayou flooding as well as any flooding of structures is low.
Current thinking is that watersheds will see similar responses to last Thursday morning…although a few may see higher levels since they will be starting at higher current flows versus last Thursday.
Think hourly rainfall rates will be low enough to prevent widespread street flooding, but street flooding in areas of poor drainage and in rural areas where roadside ditches or small creeks spill onto the roadway will be possible.
Posted by Bob Rehak on 1/1/2019
480 Days Since Hurricane Harvey
Drone Video Underscores Dangers of Development without Remediation
Yesterday, the area where a developer proposes a new high-rise development flooded for the fifth time this year. This underscores the need for remediation before any permitting.
It wasn’t an especially heavy rain last week. Kingwood received about 2.5 inches. Areas upstream averaged 3 to 4 inches. Yet the West Fork came out of its banks and flooded River Grove Park for the fifth time this year (February 26, March 28/29, July 4, December 7/8, December 27). The USGS Gage at US59 showed that the flood crested at about midnight. The crest reached almost 50 feet at US59.
Jim Zura of Zura Productions took his drone to River Grove during the last light before the overnight crest. The video shows that although the road was still useable, many of the park’s popular amenities were not. The playground, soccer fields, boat ramp and boardwalk all flooded.
Earlier this year, the US Army Corps of Engineers found that excessive sedimentation in the river contributed to excessive flooding. The frequency of these floods supports that conclusion. The Corps began dredging in late September to remove sediment, but has completed only about 20% of the project so far. Downstream blockages remain. And the biggest – at the mouth of the West Fork – is not even within the scope of the current dredging project.
The end of Zura’s video shows the soccer fields and adjoining property, including a small lake in the floodway. This flood gives us a glimpse of how a minor rain would affect the proposed high-rise development there.
Until remediation efforts are complete, officials should postpone consideration of the permit. Remediation efforts include:
Rainfalls of the magnitude that caused these five floods should happen about once every 2 years according to Harris County Flood Control. This year they happened five times: 10X greater than expected. A review of peak crest data since 1929 roughly confirms these expectations. In the 80 year since then, the river crested over 50 feet only 40 times.
A review of the same data shows that the river has crested over 57 feet 9 times in the last 80 years and six times since 1994.
I believe excessive sedimentation played a role in this frequency increase. Instead of flooding every other year like this, we’re flooding almost every other month. That’s significant enough to put the brakes on development in the floodway, at least until we understand the extent of the problems and can fix them.
These are my opinions on matters of public policy. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statutes of the Great State of Texas.
Posted by Bob Rehak on December 31, 2018
489 Days since Hurricane Harvey
Army Corps Permit Evaluation Process
The post about the proposed high-rise development in the floodplain/floodway of the San Jacinto River received thousands of views and hundreds of comments. I’ve also received lots of advice including two presentations by concerned residents. The presentations linked below discuss the Corps’ permit evaluation process.
Warning: NOT for the feint of heart. Together they contain more than 300 pages! Frankly, permit evaluation is far more complex than I imagined.
Plea for Expert Advice
I’m publishing the presentations here because thousands of engineers, project managers, and lawyers with technical backgrounds live in the Lake Houston area. With your help, I’m hoping we can sort through the material and determine a productive response to the Corps’ Public Notice.
Key Elements of Solicitation
Other key points to consider in the Public Notice include:
Background Information on Corps’ Permit Evaluation Process
The first presentation sent to me describes the Corps permitting process and requirements to the Society of American Engineers.
The second goes into additional detail about the Corps regulatory program and how they make decisions. They developed it for a TxDOT conference.
I pray that people, their property, and their safety count for as much as birds and fish in this process. However, I’ve talked to several birders lately who are abuzz about eagle spottings near the project site.
All of us are smarter than any one of us. Please help!
Submit Comments
Remember comments are due by January 29, 2019. If no comments are received, the Corps will assume there are no objections to the project. To submit comments: Reference USACE file number, SWG-2016-00384, and send to:
Posted by Bob Rehak on 12/30/2018
488 Days since Hurricane Harvey