“SESSION A: SEDIMENT SOURCES AND TRANSPORT PROCESSES” made months worth of arguments, complaints and frustrating meetings suddenly fall into sharp focus. I quickly realized our problem.
I can’t post the paper here for copyright reasons. So I will link to it and quote brief passages in a review. The author was Ronald J.Gibbs, Center for Colloidal Science, College of Marine Studies, University of Delaware.
His paper begins by looking at the largest rivers in the world and rank ordering them by their discharge (flow) rates. He then talks about factors that influence sedimentation, such as soil types, river gradient, and weather events.
Rare Weather Plays Mammoth Role in Sedimentation
In case after case, extreme weather played a hugely dominant role in sediment transport. For instance…
…in one storm on the Delaware River, a two day discharge represented three full years of average discharge.
An even more spectacular example: a storm struck the Eel River in California. “In a three day period, the Eel River carried more sediment past Scotia, California than it had during the previous seven years.”
“In ten days, the transport was equivalent to the previous ten average years.”
“To put this into perspective, the total suspended discharge for the Eel River was 168 million tons that year, which compares with the 184 million tons carried by the Mississippi River past St. Louis during the same year.” I had never even heard of the Eel River, so this caught my attention.
Difficulty of Measuring
The authors’ point: This tremendous variability, occurring over a period of many years, is exceedingly difficult to sample and to understand because it is normally very expensive to prepare for sampling these types of rare events. However, sudden events are extremely significant in terms of quantity of sediments discharged…”
A Storm Like Harvey
Another example: the Susquehanna, which flows south through eastern Pennsylvania before entering Maryland and Chesapeake Bay. Gibbs referenced another study that estimated sediment discharged in one week (June 22–28, 1972) during a major storm. “The Susquehanna River probably discharged greater than 50 x 10(6) metric tons of suspended sediment than had been discharged during the past three decades, and probably even during the past half century.”
50 million more tons of sediment in one week than during the previous fifty years!
Annual Patterns Follow Extremes, Too
Gibbs looked at both extremely rare events like this and typical annual patterns. He found that,
“During 1 percent of a year (3.6 days), most rivers discharge better than one-half to two-thirds of their sediments for that year.”
These observations illustrate how important rare events are in transporting sediment. Gibbs says, “They dominate deposition over many years and greatly affect dredging and shoaling activities.”
I knew that most sediment transport happened during floods. But I until I read this study, I did not understand how extreme the disparities between normal and flood transport were.
Implications for Regulators and Legislators
Suddenly, the tumblers clicked into place. I understood why the Brown & Root study quoted sediment transport figures for the West Fork, Spring Creek and Cypress Creek, and then told people to ignore them; they measured suspended solids when the streams were moving only at about 60 cfs, not 131,000 cfs as during Harvey.
Suddenly, I also understood how TACA, the TCEQ and state legislators could conclude that mining in floodways was OK. They look at the 99%, not the 1%. But the 1% is when all the damage occurs.
As a business person, I might have made the same mistake. Conventional wisdom dictates that you design systems for the 99%, and that you’ll go broke chasing that last 1%. Or more to the point, the last .2%.
Design for Disaster: The 1% Solution
Very few industries design for extreme events. In the airline business, the cost of a crash is unthinkable. Nuclear power plants simply cannot go out of control. Every pacemaker has to work. For almost everything else, 99% success gets you a nice Christmas bonus and a promotion. But when the cost of failure is a major portion of the nation’s fourth largest city…
As a legislator, you listen to the carefully crafted arguments of TACA and say to yourself, “This was a force majeure event, an act of God. We can’t ask them to design their mines for that. They’ll go broke!” And you never stop to think, “Yes, I can. No, they won’t. It’s simple. I ask them to move out of the floodway. It doesn’t cost them a dime out of pocket. They just don’t mine so close to the river.”
At least you don’t realize it’s that easy until the sediment sent downstream by Hurricane Harvey dams the river and contributes to wiping out 16,000 homes, 3,300 businesses, a college, a high school, a hospital, a fire station, entire subdivisions, and entire shopping centers. Repairs for all of the above also wiped out billions in equity, college funds and retirement savings.
We Need to Fix A Business Model that Destroys Growth
If that doesn’t move you, consider that it also slowed the growth of an area from 6% to 1%. That’s what happened in the Humble ISD right after voters approved a $575 million bond referendum.
Attention: governor, developers, aggregate producers, concrete manufacturers, legislators, mayors, city council members, county commissioners, chambers of commerce, do you really want to bet on a business model that destroys growth?
Sometimes, it makes more sense to think of the 1% solution than the 99%. This is one of those times. In fact, the 1% is the ONLY thing we should be focusing on as we consider legislation to fix the broken sand mining model. What good is building cheap roads if you drive residents to move out of state?
These are my opinions on matters of public policy and protected under First Amendment of the U.S. Constitution and the Anti-SLAPP statute of the Great State of Texas.
Posted by Bob Rehak on 12/16/2018
474 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2018/10/KWDriveAndForestGarden1.jpeg?fit=1200%2C1597&ssl=115971200adminadmin2018-12-16 21:49:302018-12-17 10:20:3399% Solutions to a 1% Problem Are No Solutions at All
When Great Lakes (Dredge #2) punched through the side bar at River Grove Park last week, I got a rare chance to take some close up pictures of men at work. Here’s what the “cutter basket” of a dredge looks like when it’s clean. Just looking at it, the teeth inspire fear. It looks like a nightmare out of a John Carpenter movie.
The rows of teeth stir up sand, and saw through roots and submerged deadwood. Pumps then suction the sand through the holes between the blades. Photo courtesy of Don Harbour.
Why Dredging Can Be So Slow
However, submerged plant material sometimes gets caught in the teeth and clogs the inlet. This slows the intake of sand. To restore the flow, the dredge operator calls for a service crew, lifts the cutter basket out of the water, and men remove the debris by hand. It was a real productivity show-stopper.
Before cleaning, roots and weeds clog the cutter basket. During cleaning, men manually remove debris, such as the weeds you see in the background, that get caught on teeth.Half hour later, after cleaning, the dredge finally lowers the cutter basket back into the water and resumes dredging. Note the pile of debris now in the boat.
For those who care to dig a little deeper into dredging, this web site explains how companies vary the shapes of cutter baskets to reduce the number of these time out situations.
There’s a real science to the way they design these things. The objective is to reduce the number of unwanted objects that make it into the pipe. If the pipe clogs, it could take much longer to fix.
Posted by Bob Rehak on December 15, 2018
473 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2018/12/Cutterhead.jpg?fit=856%2C914&ssl=1914856adminadmin2018-12-15 00:30:202018-12-15 11:17:17Picking the Teeth of a Dredge
It’s hard for me to write this because I hate government regulation. But when an industry acts so irresponsibly in the pursuit of profit that it endangers my safety, my family, my property, and my community, I will fight to regulate it. I am at that point now with the Texas Aggregate and Concrete Association, which represents sand miners.
The Problem
During Harvey, 131,000 cubic feet of water per second raced down the West Fork … through approximately 20 square miles of sand mines … located in the floodway … below a major dam … in a subtropical climate … prone to hurricanes and torrential rainfalls … where floods would blow through dikes made of sand … and reroute the river through the center of mines. (I’m guessing the Safety Committee was overruled.)
As a result, an abnormally large amount of sediment washed downstream; clogged rivers, streams and ditches; and helped create massive sediment dams. Those dams contributed to the flooding of thousands of homes and businesses with water contaminated by sewage when treatment plants were also overwhelmed.
I don’t care how much TACA contributes to the economy or politicians. The flooding they helped create cost Kingwood College $60 million, Humble ISD $100 million, TexDoT $20 million, homeowners billions, businesses billions more, retirees their savings, and taxpayers $70 million for dredging. But worst of all, it cost 13 people their lives and endangered the life of my community. Forty-four percent of the businesses in the Lake Houston Area Chamber were damaged due to the flood.
Moreover, we have not yet begun to tally the long-term health costs of wading through floodwaters contaminated with sewage and years spent repairing moldy homes while trying to live in them.
The river took a shortcut through this West Fork mine during Harvey, blowing through dikes and roads as it carried sediment downstream. In other mines, it even swept away stockpiles. The sediment swept downstream contributed to the growth of massive sandbars like this one that almost totally blocks the West Fork where it meets Lake Houston. As much as ten feet was deposited in this area during Harvey (five below water/five above). It continues to back water up throughout the Humble/Kingwood corridor.
If you want more responsible sand mining, the time to fight for it is now.
Remember the Most Important Thing
To reduce sediment during floods, move sand mining out of the flood plain. This should not be a huge economic burden. Houston became the fourth largest city in America overnight without sand mines in the floodway of the San Jacinto.
The Solution
Start with your state senator and state representative. Urge them to sponsor legislation that:
Contact friends and relatives in other parts of the state. Urge them to do the same with their representatives and senators. Let them know that without their support, the homes, lives, businesses and health of their constituents could also be endangered by the same irresponsible business practices. It’s good to be business friendly, but not good to be resident hostile.
Contact the heads of the transportation committees in the House and Senate. Contact Governor Abbott and Lieutenant Governor Patrick. Urge them to demand that TexDoT refrains from purchasing any sand produced in floodways. TexDoT is the miners’ biggest customer.
If they refuse to support legislation that enforces responsible operation of sand mines, ask if they will support a progressive tax on sand mines. The tax would be based on their distance from the river. The further from the river, the lower the tax. Set the tax so that mining in or near a flood plain becomes disadvantageous and mining outside of the flood plain creates a cost advantage.
Contact other groups or associations that you belong to that may have lobbying efforts in place that could help. We need allies to counteract the millions that TACA has spent on lobbying and political contributions. For instance, is your insurance through USAA? They have an active lobbying effort and the flooding affected them adversely. They would form a natural ally. Look for similar allies – through your work, your church, your bank, your trade associations, insurance company, or environmental groups you support. You can bet TACA is doing the same – with developers, contractors and their trade associations.
Ask your local city council and county representatives to endorse your efforts. Sad to say, but a letter or call from them counts more than letters from an ordinary citizen.
Put extra effort against committee chairs in the State Senate and House. They have seniority and clout. If this comes down to “scratch my back and I’ll scratch yours” at the end of the session, their influence could make the difference.
Keep track of your efforts. If you are so inclined, let me know about them. I will tabulate the results and publish them periodically.
Some Tips
Start a grass roots movement in your neighborhood, church or club. Reach out to friends, neighbors and relatives – especially those who flooded.
Personal letters count for more than form letters.
Be polite.
Tell them how flooding personally affected you and why you feel regulation is important.
Emphasize that what happened here could happen anywhere in the state and that mining in floodways is not necessary for economic growth.
In fact, it can contribute to flooding that causes people to move away.
Tomorrow I will post fact sheets for your reference on key issues related to sand mining and their role in flooding. Refer people to them.
This battle will not be won or lost because Dan Huberty or Brandon Creighton endorse it. It will be won or lost in places like West Texas and North Texas that don’t often flood. The majority of the votes live there. So cast a wide net. Remember: silence is an endorsement of the way things are now. If you want change, let others know. Speak up now.
As always, these thoughts represent my opinions on matters of public policy. They are protected by the First Amendment of the United States Constitution and the Anti-SLAPP Statute of the Great State of Texas.
Posted by Bob Rehak on December 13, 2018
472 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2018/08/Subject-Mine-During-Harvey.jpg?fit=1103%2C886&ssl=18861103adminadmin2018-12-14 00:58:462018-12-15 00:48:42How to Protect Yourself from Flooding Due to Sand Mining
99% Solutions to a 1% Problem Are No Solutions at All
Today, I read a scientific article that talked about 99% solutions to 1% problems. It hit me between the eyes with the force of a freight train. It was written 30 years before Hurricane Harvey for a 1987 symposium sponsored by the U.S. Navy called Sedimentation Control to Reduce Maintenance Dredging of Navigational Facilities in Estuaries.
“SESSION A: SEDIMENT SOURCES AND TRANSPORT PROCESSES” made months worth of arguments, complaints and frustrating meetings suddenly fall into sharp focus. I quickly realized our problem.
I can’t post the paper here for copyright reasons. So I will link to it and quote brief passages in a review. The author was Ronald J.Gibbs, Center for Colloidal Science, College of Marine Studies, University of Delaware.
His paper begins by looking at the largest rivers in the world and rank ordering them by their discharge (flow) rates. He then talks about factors that influence sedimentation, such as soil types, river gradient, and weather events.
Rare Weather Plays Mammoth Role in Sedimentation
In case after case, extreme weather played a hugely dominant role in sediment transport. For instance…
An even more spectacular example: a storm struck the Eel River in California. “In a three day period, the Eel River carried more sediment past Scotia, California than it had during the previous seven years.”
“To put this into perspective, the total suspended discharge for the Eel River was 168 million tons that year, which compares with the 184 million tons carried by the Mississippi River past St. Louis during the same year.” I had never even heard of the Eel River, so this caught my attention.
Difficulty of Measuring
The authors’ point: This tremendous variability, occurring over a period of many years, is exceedingly difficult to sample and to understand because it is normally very expensive to prepare for sampling these types of rare events. However, sudden events are extremely significant in terms of quantity of sediments discharged…”
A Storm Like Harvey
Another example: the Susquehanna, which flows south through eastern Pennsylvania before entering Maryland and Chesapeake Bay. Gibbs referenced another study that estimated sediment discharged in one week (June 22–28, 1972) during a major storm. “The Susquehanna River probably discharged greater than 50 x 10(6) metric tons of suspended sediment than had been discharged during the past three decades, and probably even during the past half century.”
Annual Patterns Follow Extremes, Too
Gibbs looked at both extremely rare events like this and typical annual patterns. He found that,
These observations illustrate how important rare events are in transporting sediment. Gibbs says, “They dominate deposition over many years and greatly affect dredging and shoaling activities.”
I knew that most sediment transport happened during floods. But I until I read this study, I did not understand how extreme the disparities between normal and flood transport were.
Implications for Regulators and Legislators
Suddenly, the tumblers clicked into place. I understood why the Brown & Root study quoted sediment transport figures for the West Fork, Spring Creek and Cypress Creek, and then told people to ignore them; they measured suspended solids when the streams were moving only at about 60 cfs, not 131,000 cfs as during Harvey.
As a business person, I might have made the same mistake. Conventional wisdom dictates that you design systems for the 99%, and that you’ll go broke chasing that last 1%. Or more to the point, the last .2%.
Design for Disaster: The 1% Solution
Very few industries design for extreme events. In the airline business, the cost of a crash is unthinkable. Nuclear power plants simply cannot go out of control. Every pacemaker has to work. For almost everything else, 99% success gets you a nice Christmas bonus and a promotion. But when the cost of failure is a major portion of the nation’s fourth largest city…
As a legislator, you listen to the carefully crafted arguments of TACA and say to yourself, “This was a force majeure event, an act of God. We can’t ask them to design their mines for that. They’ll go broke!” And you never stop to think, “Yes, I can. No, they won’t. It’s simple. I ask them to move out of the floodway. It doesn’t cost them a dime out of pocket. They just don’t mine so close to the river.”
At least you don’t realize it’s that easy until the sediment sent downstream by Hurricane Harvey dams the river and contributes to wiping out 16,000 homes, 3,300 businesses, a college, a high school, a hospital, a fire station, entire subdivisions, and entire shopping centers. Repairs for all of the above also wiped out billions in equity, college funds and retirement savings.
We Need to Fix A Business Model that Destroys Growth
If that doesn’t move you, consider that it also slowed the growth of an area from 6% to 1%. That’s what happened in the Humble ISD right after voters approved a $575 million bond referendum.
Sometimes, it makes more sense to think of the 1% solution than the 99%. This is one of those times. In fact, the 1% is the ONLY thing we should be focusing on as we consider legislation to fix the broken sand mining model. What good is building cheap roads if you drive residents to move out of state?
These are my opinions on matters of public policy and protected under First Amendment of the U.S. Constitution and the Anti-SLAPP statute of the Great State of Texas.
Posted by Bob Rehak on 12/16/2018
474 Days since Hurricane Harvey
Picking the Teeth of a Dredge
When Great Lakes (Dredge #2) punched through the side bar at River Grove Park last week, I got a rare chance to take some close up pictures of men at work. Here’s what the “cutter basket” of a dredge looks like when it’s clean. Just looking at it, the teeth inspire fear. It looks like a nightmare out of a John Carpenter movie.
The rows of teeth stir up sand, and saw through roots and submerged deadwood. Pumps then suction the sand through the holes between the blades. Photo courtesy of Don Harbour.
Why Dredging Can Be So Slow
However, submerged plant material sometimes gets caught in the teeth and clogs the inlet. This slows the intake of sand. To restore the flow, the dredge operator calls for a service crew, lifts the cutter basket out of the water, and men remove the debris by hand. It was a real productivity show-stopper.
For those who care to dig a little deeper into dredging, this web site explains how companies vary the shapes of cutter baskets to reduce the number of these time out situations.
There’s a real science to the way they design these things. The objective is to reduce the number of unwanted objects that make it into the pipe. If the pipe clogs, it could take much longer to fix.
Posted by Bob Rehak on December 15, 2018
473 Days after Hurricane Harvey
How to Protect Yourself from Flooding Due to Sand Mining
It’s hard for me to write this because I hate government regulation. But when an industry acts so irresponsibly in the pursuit of profit that it endangers my safety, my family, my property, and my community, I will fight to regulate it. I am at that point now with the Texas Aggregate and Concrete Association, which represents sand miners.
The Problem
During Harvey, 131,000 cubic feet of water per second raced down the West Fork … through approximately 20 square miles of sand mines … located in the floodway … below a major dam … in a subtropical climate … prone to hurricanes and torrential rainfalls … where floods would blow through dikes made of sand … and reroute the river through the center of mines. (I’m guessing the Safety Committee was overruled.)
As a result, an abnormally large amount of sediment washed downstream; clogged rivers, streams and ditches; and helped create massive sediment dams. Those dams contributed to the flooding of thousands of homes and businesses with water contaminated by sewage when treatment plants were also overwhelmed.
I don’t care how much TACA contributes to the economy or politicians. The flooding they helped create cost Kingwood College $60 million, Humble ISD $100 million, TexDoT $20 million, homeowners billions, businesses billions more, retirees their savings, and taxpayers $70 million for dredging. But worst of all, it cost 13 people their lives and endangered the life of my community. Forty-four percent of the businesses in the Lake Houston Area Chamber were damaged due to the flood.
Moreover, we have not yet begun to tally the long-term health costs of wading through floodwaters contaminated with sewage and years spent repairing moldy homes while trying to live in them.
If you want more responsible sand mining, the time to fight for it is now.
Remember the Most Important Thing
The Solution
Keep track of your efforts. If you are so inclined, let me know about them. I will tabulate the results and publish them periodically.
Some Tips
This battle will not be won or lost because Dan Huberty or Brandon Creighton endorse it. It will be won or lost in places like West Texas and North Texas that don’t often flood. The majority of the votes live there. So cast a wide net. Remember: silence is an endorsement of the way things are now. If you want change, let others know. Speak up now.
As always, these thoughts represent my opinions on matters of public policy. They are protected by the First Amendment of the United States Constitution and the Anti-SLAPP Statute of the Great State of Texas.
Posted by Bob Rehak on December 13, 2018
472 Days after Hurricane Harvey