Sand Mine Dike Remains Open for Years

In my last post, I talked about how certain sand mines on the San Jacinto could help reduce the rate of sedimentation in the river by following best management practices (BMPs) found in other areas. Those BMPs included:

  1. Locate mines outside of floodways.
  2. Establish performance bonds to cover the cost of cleanup.
  3. Increase the width of dikes.
  4. Decrease the slope of dikes.
  5. Control erosion with vegetation.
  6. Replant areas not actively being mined.
  7. Avoid clearing areas that will not soon be mined.
  8. Protect stockpiles from flooding.
  9. Mine only above the thalweg (deepest part of the river).
  10. Establish performance bonds to guarantee remediation of breaches and/or repurposing of mined areas once mining is complete

This Mine Missed 9 out of 10

The State of Texas does not require these BMPs for sand mines on the San Jacinto. But it should. Here’s a case study in what happens if you ignore these principles.

The wide shot below was taken in January of 2010. Notice the muddy brown area in the middle of the shot. Also notice the breach in the dike on the left hand side of the brown area and the stockpile right above it. Finally, notice that un-vegetated area in the point on the far left.

That’s where the original mined area was back in the 1980s. Whoever mined it at that point took sand directly from the river bank. Regardless, it was never replanted and the entire area remains vulnerable to erosion to this day.

That’s important because this mine, like all but one on the the West Fork, lies largely in the floodway. See the cross-hatched area below in the USGS flood hazard map.

As a result of being in the floodway, here’s what happened to it during Hurricane Harvey. Note multiple breaches in the dikes, the loss of the stockpile, and swirling floodwaters flowing through the mine from upper left to lower right. Finally note that Harvey inundated that original mined area that was not replanted.

This made me curious, so I reviewed the historical imagery for this location in Google Earth. Here’s the same mine in 2016. Same story. Just not quite as bad. They lost about a third of the stockpile. And nasty brown water flowed straight through the pits closest to the river.

Next, I zoomed in on the breach and scrolled back through time. It first showed up in 2006.

By early 2011, they were building roads out to the breach.

Here it is in late 2011. Note how the river below the breach has become clogged with sand.

In 2013, still wide open. Another flood. More sediment flushed downstream.

In 2014, still open!

In 2016, they’ve rebuilt the dike! But it’s skinny. Very vertical. Un-vegetated. And you can already see cracks and major signs of erosion developing in it.

Then along comes another flood at the end of the year.

And by the next day, most of the dike has been washed away.

By 2017, it was fixed again.

Then along came Harvey. And there it went again.

Spike the Dike

So how did this mine score overall? If you were applying these principles, it received an almost unperfect score.

  1. Locate mines outside of floodways.
  2. Establish performance bonds to cover the cost of cleanup.
  3. Increase the width of dikes.
  4. Decrease the slope of dikes.
  5. Control erosion with vegetation.
  6. Replant areas not actively being mined.
  7. Avoid clearing areas that will not soon be mined.
  8. Protect stockpiles from flooding.
  9. Mine only above the thalweg (deepest part of the river).
  10. Establish performance bonds to guarantee remediation of breaches and/or repurposing of mined areas once mining is complete

The breach first showed up in 2006 and was still open in 2014! Goin’ for the record! How much sand and sediment wound up downstream as a result?

No telling exactly. But whatever it was, they won’t be picking up the tab for the cleanup. You will be (Point #10)…which underscores the need for the State to adopt common sense guidelines like these. Perhaps if it had, we wouldn’t have had as much damage during Harvey.

As always, these are my opinions on a matter of public policy, protected by the First Amendment of the U.S. Constitution and the Anti-SLAPP statutes of the great State of Texas.

Posted on August 3, 2018 by Bob Rehak

339 Days since Hurricane Harvey

 

Best Management Practices that Could Reduce Sedimentation of the San Jacinto If Sand Mines Always Followed Them

Large areas within this mine are unvegetated and unmined, making them more susceptible to erosion.

Introduction

This post ties together months of research. It began with observations about Texas sand mines that did not seem to follow best practices adopted in the rest of the world.

My comments do not apply equally to all sand mines; some sand mines already follow these recommendations to varying degrees. My goal is not to condemn sand mines in general, but to suggest opportunities for improvement in some.

This post contains 75 footnotes at the end. Follow them back to hundreds of photos, posts, studies, presentations and articles that illustrate the issues at hand. 

Background

During Hurricane Harvey, millions of cubic yards of sand and silt migrated downstream into the Lake Houston area.[1],[2] Some originated from natural sources.[3] Some also likely originated from approximately 20 square miles of sand mines that have sprung up around the headwaters of Lake Houston.[4] The exact proportion by source is difficult to determine. However, the sand mining industry denies responsibility.[5]

Industry’s main argument is that floodwater inside the mines has insufficient velocity to carry sand and silt outside of the mine and into the river. However, photographic evidence, gravel deposited in dunes downstream, and USGS floodwater velocity measurements, taken together, contradict this argument.[6],[7]

Industry also cites a Brown & Root regional sedimentation survey for the San Jacinto Watershed. It showed that suspended solids in Cypress and Spring Creeks were greater than in the West Fork.[8] This study was conducted in the late 1990s and published in 2000 before the rapid growth of sand mining on the West Fork. Section 1.3.3 also cautions that these samples were taken at low-flow periods and should not be used to predict sedimentation during floods, when most sediment migrates.

“…the sediment load estimates presented herein may not adequately account for … sediment load during significant flood periods. … The monitoring program should be conducted during and following major flood events to verify the dominant sediment movements [emphasis added].”[9]

The sand mining industry, in essence, is saying, “Because more suspended solids come from Spring and Cypress Creeks during low flow periods, sand can’t be coming from the West Fork during floods,” a logical fallacy.

Sand mines in floodway. Sand bars within mine were caused during “river capture”. They prove sand was carried downstream. This photo taken on 10/28/2018 (after Harvey) also shows repairs to mine wall. During floods, the river tries to cut across meanders, runs through the mines, and scours pits.

This contention ignores several key facts:

  1. The landscape has changed dramatically since the Brown & Root report due to the rapid growth of sand mining.
  2. Sedimentation issues arise primarily as a result of floods, not normal flows.
  3. The sand mining industry is distorting Brown & Root findings.
  4. The vast majority of sand mines are on the West Fork and lie downstream from the Lake Conroe Dam, which released 79,100 cubic feet of water per second (cfs) during Harvey. That brought the West Fork peak flow in the area of the mines up to 130,000 cfs – 60% more peak flow than Spring Creek (82,100 cfs) and 364% more than Cypress Creek (28,100 cfs).[10]
  5. Sedimentation surveys of Lake Houston during the last 20 years show an increasing rate of sedimentation consistent with the growth of sand mining.[11],[12]

All of this suggests that sand mines contribute to AND increase natural rates of sedimentation.

After slowly building for years, the sand bar at the mouth of the West Fork has virtually tripled in size since 2015, threatening homes, businesses and infrastructure. The current Army Corps Emergency Dredging project will not address this and it is not clear where the money will come from to do so.

As the floodwaters from Harvey receded, massive amounts of sand became apparent. It clogged the San Jacinto River.[13] It left nearly continuous, bright, white trails of sand all the way from mines to the mouth of the San Jacinto – far in excess of the volume that was in the river before the flood.[14] It blocked drainage ditches.[15] It contributed to flooding that damaged thousands of homes and businesses.[16]

Removing these blockages could cost taxpayers and government hundreds of millions of dollars. The Army Corps of Engineers is already spending almost $70 million to dredge a two-mile stretch of new sand bars and dunes blocking the West Fork and local drainage ditches.[17] These blockages contribute to higher floods with smaller rains and continue to put Lake Houston area communities at increased risk for flooding.[18]

Dredging the remaining 11 miles of the West and East Forks in the Humble, Kingwood and Huffman areas will cost even more. Harris County Flood Control has included $50 million for dredging those reaches in its 2018 flood bond referendum and is seeking three partners to contribute similar amounts. If that is enough to restore normal flow to the East and West Forks, the total cost of dredging would be $270 million.

However, that may not be enough. A recent report compiled by two Lake Houston area geologists[19] studied the size and impact of a large sand bar at the mouth of West Fork that now causes the West Fork to flow uphill before it reaches Lake Houston. The size of this one sand bar alone likely exceeds the scope of USACE’s current dredging project by several fold.[20]

Many states and countries have established best management practices (BMPs) for sand mining to avoid such costs, and to help reduce erosion and consequent damage.[21]

If these BMPs were universally practiced by Texas sand mines, they could help increase margins of safety, reduce risks associated with future flooding, and reduce the costs associated with cleanup.

 

The first two recommendations below are already practiced in Texas, but only on a small portion of the Brazos River.[22] The other recommendations represent things that Texas sand mines should do to improve performance relative to the best management practices elsewhere.[23]

Recommendations

  1. Locate mines outside of floodways.
  2. Establish performance bonds to cover the cost of cleanup.
  3. Increase the width of dikes.
  4. Decrease the slope of dikes.
  5. Control erosion with vegetation.
  6. Replant areas not actively being mined.
  7. Avoid clearing areas that will not soon be mined.
  8. Protect stockpiles from flooding.
  9. Mine only above the thalweg (deepest part of the river).
  10. Establish performance bonds to guarantee remediation of breaches and/or repurposing of mined areas once mining is complete

Discussion

  1. Locate mines outside of floodways.

A precedent exists. The 79th Texas Legislature enacted Senate Bill 1354, creating the John Graves Scenic Riverway on the Brazos River. This established a pilot program that will last until 2025. Its goal: to enhance water-quality protection by establishing specific regulations for quarries within the watershed. Regulations adopted under SB 1354 require a permit that forces new mines to operate outside of the 100-year floodplain.[24]

Prohibited activities include the operation of any quarry within 1,500 feet of a navigable water body, subject to specific exceptions.[25]

Currently, all but one sand mine on the San Jacinto lies partially or wholly within a floodway.[26] A common definition for a floodway is “the main channel of the river during a flood.” As Harvey proved, operating within a floodway puts both the mines and downstream communities at risk.

Miners prefer floodways because they typically contain concentrated deposits of sand. Less overburden also makes sand less expensive to mine. This increases profitability.[27]

However, when floodwaters invade mines, they can carry sand and silt downstream. Satellite and aerial images taken during and after Hurricane Harvey show that the river breached dikes, flowed across point bars, eroded stockpiles, destroyed a road, and carried exposed sand and sediment downstream.[28],[29]

While miners profit from mining in floodways, downstream communities bear the cleanup costs. Who will pay that cost? Currently, the answer is tax and rate payers through the City of Houston, Harris County, Coastal Water Authority, State of Texas, and Federal Government.[30]

When sand mines choose to operate in the floodway, industry profits and taxpayers take the loss.

Taxpayers are, in effect, forced to subsidize sand and gravel mines by bearing the clean-up costs.

 

By allowing mines to locate within floodways and then externalize costs, the State encourages risky behavior that can flood homes and damage entire communities.[31] In the future, not permitting mines to operate in floodways could reduce flood risks.

Some say, “You can’t regulate for 1000-year events like Harvey. That would damage industry.” That criticism, however, ignores the USGS report on peak streamflows during Harvey.[32] Issued in July 2018, it reclassified storm probabilities for areas affected by Harvey.

USGS now estimates, based on flow data at the Grand Parkway and the West Fork, that Harvey was NOT a 1000-year storm. USGS now says that a storm with the volume of Harvey has a 2.4 annual exceedance probability. That would make Harvey a 42-year storm.[33] On the East Fork, which received more rainfall during Harvey than the West Fork, the situation is even more dire. The sand mine on Caney Creek, which sits at the confluence of twofloodways, received a 33-year flood. And according to USGS, Harvey was only the fourth highest flood on record for that gage.[34]

Moreover, given the height and width of some mine dikes on the West Fork, it does not even take a storm of Harvey’s magnitude to breach dikes. Historical satellite imagery shows that West Fork mine dikes have been breached repeatedly, including during a non-tropical storm in 2015.[35]

  1. Establish performance bonds to cover the cost of cleanup.

Performance bonds are another major provision of the John Graves pilot program. Although performance bonds in that area ensure restoration and reclamation of mines, the strategy could be applied on the San Jacinto to ensure cleanup and repairs after floods.[36]

It is unclear whether a coalition of governmental entities will even be able to cover cleanup costs from Harvey. If it is possible, it could take years to build the coalition and budget funds for remediation. That delays cleanup and increases flood risk for more than a quarter million people.[37]

Therefore, mining companies that choose to operate in floodways should post performance bonds that guarantee cleanup can be completed in time to reduce risk from additional flooding.

This simple provision will help ensure a true cost accounting for sand that doesn’t allow mines to externalize mitigation costs associated with risky practices (i.e., locating mines in floodways, operating with dikes that won’t withstand the pressure of floods, etc.).

  1. Increase the width of dikes.

This point is related to #1 above about setbacks from rivers. Mines create dikes, in most cases, by not removing a thin strip of natural land between dredging pits and rivers. Currently, some mines operate so close to the river’s edge that floodwaters breach their dikes repeatedly.[38]

The wider the dikes, the stronger and less likely they are to fail. Wider dikes with gentler slopes can also sustain natural vegetation which binds their soil and reduces erosion. Wider dikes create a greater safety margin over time, especially against erosion on the cut bank sides of rivers. Wider dikes, if forested, can slow currents entering/leaving mines and trap sand.[39] And finally, wider dikes give the river room to expand during floods; that’s because some mines pile sand on top of natural dikes to increase their height. This artificially constricts the cross section of the river.

Engineers say that mechanical protections, which are prone to failure during high flows, are a poor substitute for natural protection.[40]

Because of the high volume of flow down the San Jacinto West Fork, especially when Lake Conroe opens its flood gates, 50-foot and 100-foot wide dikes have proven ineffective.[41]

Pits may operate for decades. During that time, their dikes may be eroded from both sides, especially when operators mine below the level of the thalweg (deepest part of the river bottom). When operators mine below the thalweg, levee breach, river capture, and subsequent erosion are virtual certainties during large flood events.[42]

For all these reasons, many states and countries often require greater setbacks between mines and rivers than Texas does. Texas has no requirement according to correspondence with the TCEQ, although it does require a 50-foot setback from adjoining property, and some might consider the river adjoining property because it belongs to the State of Texas.[43]

In contrast, many states require a 100-foot setback. Malaysia requires 50 meters. Some countries require 100 meters. Canada requires 450 meters for mining tar sands. Alaska requires a 1000-foot setback from all public water sources.[44] Louisiana requires a 1000-foot setback from public water supply wells.[45]

Washed out road INSIDE sand mine during Harvey. To all those who say currents inside the mines during a flood are not strong enough to pick up sand, I say, “Explain this.” Image from 8/30/2017.

San Jacinto floods have breached even 100-foot dikes because of the high volume of flow, especially when the SJRA releases water from the Lake Conroe dam.[46] SJRA reported that during Harvey, the flow at Highway 99 was 130,000 cubic feet per second, far higher than on Spring or Cypress Creeks.[47] One West Fork mine operator stated that the Good Friday flood of 2018 breached his dikes – even when there was norelease from the Lake Conroe Dam.[48]

The San Jacinto River Authority has been forced to release water from the Lake Conroe Dam in each of the last three years to preserve the dam during heavy rains. The amounts ranged from 7,000 to almost 80,000 cubic feet per second.[49]

High release rates, added to already heavy rainfalls, illustrate why it may be difficult to establish one safe setback distance for all of Texas. Considering site-specific criteria such as proximity to dams and highly developed areas, slope of floodplains, width of floodways, potential peak flows, and location of cutbanks may yield safer setbacks.[50]

In general, though, the wider the setback, the stronger the dike, the greater its resistance to erosion (especially over time), the less risk to the mine, and the safer downstream communities are.

  1. Decrease the slope of dikes.

BMPs in other states and countries also recommend gently slopingdikes to strengthen their resistance. They frequently recommend ratios of 1:3 or 1:4 (height:width).[51] Malaysia recommends up to a 1:10 ratio because low slopes help establish vegetation.[52] The near-vertical slope of many West Fork dikes means they receive direct, rather than glancing blows from floodwater.

Angled surfaces deflect and diffuse incoming energy. Nowhere is this principle more evident than in the design of military, supersonic aircraft that handle wind forces at thousands of miles per hour.[53]

  1. Control erosion with vegetation.

Sloping dikes more gradually strengthens their resistance to floods, but by itself will not prevent erosion, especially on cutbanks. Planting them with grass and/or native trees and other vegetation can bind the soil, slow water down, reduce erosion and help retain sand within the mine boundaries.[54]

Virtually all states and countries recommend planting native grasses and trees to help bind soil.[55] Revegetating after plants have been removed can take years. Therefore, the best, cheapest and simplest practice is to leave native vegetation in place and simply not remove it wherever possible when constructing mines

  1. Replant areas not actively being mined.

Mining has exposed 20 square miles of sand surface to erosion along the West Fork between I-45 and I-69 and along the East Fork in Porter.[56] Not all of that area is actively being mined. Loose sand, exposed to floodwaters, exposes downstream communities to unnecessary risk. Replanting with native grasses and trees can bind the soil, reduce water velocity and reduce erosion during floods. Keeping soil in place is the best way to keep it out of rivers.

Louisiana best management practices state: “It is prudent to practice good soil conservation and seed bare ground during the post-mining phase to aid in minimizing and/or reducing the potential for stormwater to wash sediment loads from unvegetated areas into nearby waterways. Natural regeneration takes time and during that process much sediment could be washed away as sheet, rill or gully erosion over that period.”[57]

  1. Avoid clearing areas that will not soon be mined.

Delay grubbing until the last possible moment to reduce erosion and risk from floodwaters. (Same theory as #6.)

The Louisiana best management practices for sand mining state: “It is very important to only clear and grub acreage needed for the immediate term. Clearing or grubbing too much land too early in the construction phase of the mining operation will dramatically increase the potential for environmental impacts from surface water runoff and will increase the costs to control runoff from the mining site.”[58]

Large areas of mines on both the East and West Forks have been grubbed years before they were mined. These areas then flooded and contributed disproportionately to downstream sedimentation.[59]

  1. Protect stockpiles from flooding.

Sand in stockpiles is especially vulnerable during floods because it is so loose. During Harvey, sand mines adjacent to Kingwood lost four of six stockpiles completely. Another eroded severely. Only one escaped with little loss, the one on the highest ground, protected by a large swath of trees. Mines that locate stockpiles in floodways risk losing their entire inventory and contributing disproportionately to downstream sedimentation.[60],[61]

Half of this mine lies within not one, but two floodways (cross-hatched areas). The part of the stockpile that eroded most is in the the 100-year floodplain. See right side of red circle.

  1. Mine only above the thalweg.

Thalweg is pronounced taal-veg. It is a geological term for the deepest part of a river. West Fork sand mines remove sand to depths approaching 50 feet. That’s far below the West Fork’s thalweg.

The greater the differential between river bottom and pit bottom, the greater the likelihood of pit capture[62]during floods. Water migrates from areas of high pressure to low and from high elevation to low. With dikes of only fifty feet or less, river capture of mines is a virtual certainty during floods.[63],[64] This increases river bottom erosion upstream. It alters the gradient of the river. And it creates a hungry water effect downstream that contributes to bank erosion, property loss, tree loss, infrastructure damage, and increased sedimentation.[65]

All these things happened during Harvey when the river ruptured dikes and cut across point bars through sand pits.

In separate reviews of scientific literature and on-site studies, Ladson and Judd, and Jacobs Engineering described the ways rivers capture pits.[66]

  • Lateral migration of the river channel into the pit
  • Sub-surface piping from surface water into pits and subsequent failure of pit walls
  • Water cascading into a gravel pit as flood waters rise
  • Erosion by water returning to the river from the pit as the flood recedes.

Ladson and Judd also found that floodplain mining can have delayed impacts.[67]

  • “The low-resistance…high-flow conveyance path provided by the open area of a gravel mine can alter floodplain hydraulics during high flows.”
  • “Mining on floodplains may reduce groundwater levels on adjacent areas where water is removed by pumping and may affect groundwater quality.”
  • “Floodplain mines may lead to river channel changes that include erosion, bed degradation and damage to infrastructure.”

Sand removed from a pit also creates a void that induces river water as well as ground water from surrounding areas to migrate into the pit. This can reduce the flow in the river and negatively impact aquatic species.

When the water table drops below the level of roots, surface vegetation can also die back, contributing to more erosion.[68]

Finally, mining below the thalweg loots water from river authorities. Mines use state property to process their product without paying for it, unlike smaller businesses and individuals, who must pay fees to subsidence districts, water authorities and municipalities based on usage.[69] Pits expose more water to air, increasing evaporation and water loss.

By mining above the level of the thalweg, all these problems can be reduced or avoided, including those of fairness and equitable treatment.

     10. Establish performance bonds to guarantee remediation of breaches and/or repurposing of mined areas once mining is complete.

 Reclamation or remediation of sand mines, and repair of breaches should also be covered by performance bond(s). Obtaining a permit requires a mine to file a remediation plan, but it does not force mines to remediate. Operators can simply walk away from pits, creating safety hazards, eyesores, and economic development headaches for communities.[70]

Defunct Humble sand mine on North Houston Road just north of Townsend Blvd. Note steep, unvegetated slopes, lack of berms, and lack of fencing, all violations of best practices in most states. Luckily, this pit will be filled with spoils from the Army Corps dredging project and then graded to match surroundings. 

On the positive side, mines can be turned into lakes for residential communities, storage pits for spoils, parks, storm water detention facilities, marinas and wetlands.[71]

But these all represent costs long after all the profit has left the site with the last sand truck. Abandoned pits and equipment, in some cases, remain eyesores in the community that discourage economic development.[72]

In two observed cases, mine dikes were damaged in storms, yet no one repaired the breaks for years. West Fork mine dikes have remained broken for three years in one case and six in another, while rainwater has washed accumulated pit sediment into the river.[73],[74]

Performance bonds should cover not just the cost of remediation but also the cost of maintenance (i.e., mowing, watering, fencing, etc.) until abandoned property can stabilize and/or be sold.

Conclusion:

Rates of sedimentation on the West Fork have increased rapidly in recent years.[75] This likely was the result of three unusually heavy rains in 2015, 2016, and 2017. Harvey was the coup de grâce.

It was also a wake-up call. It exposed the weaknesses in Texas regulations. It  underscored the importance of adopting common-sense best management practices like those outlined above to help improve public safety, reduce damage to infrastructure, and avoid such widespread flood damage to homes and businesses in the future.

The consequences of ignoring these recommendations potentially include:

  • Destruction of downstream communities through increased flooding…again
  • More loss of life
  • Unfair imposition of remediation costs on taxpayers
  • Hidden “subsidies” that distort the true cost of cement and its usage
  • Loss of faith in the ethical standards of businesses and the free enterprise system
  • Loss of faith in government institutions to protect people and property
  • Loss of home and business values
  • Reduction of property tax income to city and county governments
  • Reduction in perception that Texas is a desirable place to live.

If we are to maintain faith in government, private enterprise and free markets, we must have a full and fair cost accounting that recognizes the damage and cleanup costs due to sand from mines. These costs have been externalized by miners. For decades, this issue remained invisible because the problem was sub-acute. That made it easy for government to “kick the can down the road.” Harvey changed all that.

The problem is now critical and must be addressed.

Increased rates of sedimentation are putting Lake Houston itself at risk. The Lake currently represents the source of drinking water for approximately 600,000 people. But the City of Houston expects to have 2 million people using surface water from the lake within the next few years as new water treatment plants come online. The increasing rate of reduction in its capacity conflicts directly with the expected increase in customers.

Destruction like we experienced during Harvey is rarely caused by one thing. It results from multiple failures on multiple levels. They compound each other. To restore and maintain margins of public safety, we need to address each cause. To the extent that sand mines contributed to the problem, they can also help solve it by modifying business practices as described above.

How You Can Help

This is an election year. TACA has tripled its lobbying budget. But TACA can’t vote and you can. Make this an election issue and quiz each candidate for their positions on common sense regulations affecting sand mines.

These are my opinions of a matter of public policy protected under the First Amendment of the U.S. Constitution and the Anti-SLAPP statutes of the great State of Texas.

For a downloadable, printable copy of this document including footnotes, click on Best Management Practices for Sand Mines.

Posted by Bob Rehak on August 1, 2018

338 Days since Hurricane Harvey

#####

Footnotes

[1]https://reduceflooding.com/2018/07/06/army-corps-of-engineers-awards-dredging-bid-on-west-fork-emergency-project/. USACE will remove 1.8 million cubic yards from a 2 mile stretch where some of the worst deposits are found. When complete, eleven miles will remain to be dredged. The cost to remove sediment from the first 2-miles is $69,814,060.

[2]https://reduceflooding.com/2018/07/27/why-we-must-remove-mouth-bar-on-west-fork-of-san-jacinto/

[3]Spring and Cypress Creeks

[4]https://reduceflooding.com/2018/05/22/where-did-all-the-sand-come-from/

[5]https://reduceflooding.com/2018/06/07/taca-spells-out-industry-position-on-societal-and-environmental-benefits-of-sand-mining/

[6]https://reduceflooding.com/2018/06/23/do-local-sand-mines-follow-best-management-practices/

[7]https://reduceflooding.com/2018/07/25/a-closer-look-at-sand-issues-on-the-east-fork-of-the-san-jacinto/

[8]https://reduceflooding.com/wp-content/uploads/2018/03/BrownRoot-Dredging-Recs.pdf

[9]Page 15, https://reduceflooding.com/wp-content/uploads/2018/03/BrownRoot-Dredging-Recs.pdf

[10]https://reduceflooding.com/wp-content/uploads/2018/03/Hurricane-Harvey-Peak-Inflows-36×24.pdf

[11]https://reduceflooding.com/2018/07/01/a-model-for-the-future-of-the-san-jacinto/

[12]https://reduceflooding.com/wp-content/uploads/2018/03/Harvey-Flood-Full-Length-8.pdf

[13]https://reduceflooding.com

[14]See 450+ photos at https://reduceflooding.com/gallery/

[15]https://reduceflooding.com/2018/03/19/how-deep-was-the-sand-deposited-by-harvey-at-river-grove-park/

[16]https://reduceflooding.com/2018/06/10/damage-map-neighborhoods-in-lake-houston-area-hardest-hit-by-harvey/

[17]https://reduceflooding.com/2018/07/06/army-corps-of-engineers-awards-dredging-bid-on-west-fork-emergency-project/

[18]https://reduceflooding.com/2018/04/11/army-corps-finishes-sedimentation-survey-field-work-on-first-leg-of-west-fork/and https://reduceflooding.com/2018/04/03/4-33-inches-of-rain-created-the-third-largest-flood-in-16-years-on-the-east-fork-of-the-san-jacinto/

[19]https://reduceflooding.com/wp-content/uploads/2018/07/Mouth-Bar-Rev-16.pdf

[20]https://reduceflooding.com/wp-content/uploads/2018/07/Mouth-Bar-Rev-16.pdf

[21]https://reduceflooding.com/sand-mining/

[22]https://reduceflooding.com/2018/07/01/a-model-for-the-future-of-the-san-jacinto/

[23]Personal observations derived from a study of best and actual practices

[24]Page 6, https://www.tceq.texas.gov/assets/public/comm_exec/pubs/sfr/087_08.pdf

[25]Page 5, https://www.tceq.texas.gov/assets/public/comm_exec/pubs/sfr/087_08.pdf

[26]https://hazards-fema.maps.arcgis.com/apps/webappviewer/index.html?id=8b0adb51996444d4879338b5529aa9cd

[27]Consultation with three different geologists

[28]https://reduceflooding.com/2018/06/23/do-local-sand-mines-follow-best-management-practices/,

[29]https://reduceflooding.com/wp-content/uploads/2018/03/West-Fork-Sand-Stockpiles2.pdfand https://reduceflooding.com/2018/07/25/a-closer-look-at-sand-issues-on-the-east-fork-of-the-san-jacinto/

[30]Item CI-61, Page 8 in project list of Harris County Flood Bond Proposal, https://www.hcfcd.org/media/2881/2018bondprojecttable2018-07-19-1600.pdf

[31]https://reduceflooding.com/2018/06/10/damage-map-neighborhoods-in-lake-houston-area-hardest-hit-by-harvey/and https://reduceflooding.com/2018/07/25/a-closer-look-at-sand-issues-on-the-east-fork-of-the-san-jacinto/

[32]https://reduceflooding.com/wp-content/uploads/2018/07/sir20185070.pdf

[33]https://reduceflooding.com/2018/07/11/usgs-report-on-peak-streamflows-during-harvey-significantly-revises-flood-probabilities/  Note: this number is currently being verified by USGS, Harris County Flood Control and FEMA.

[34]Page 9, Gage 08070500, line 32, https://reduceflooding.com/wp-content/uploads/2018/07/sir20185070.pdf

[35]https://reduceflooding.com/2018/06/23/do-local-sand-mines-follow-best-management-practices/

[36]Page 7, https://www.tceq.texas.gov/assets/public/comm_exec/pubs/sfr/087_08.pdf

[37]Lake Houston Area Chamber of Commerce estimates current population is 286,000.

[38]https://reduceflooding.com/2018/06/23/do-local-sand-mines-follow-best-management-practices/

[39]https://reduceflooding.com/2018/05/04/two-modest-proposals-to-reduce-the-amount-of-sand-coming-downstream/

[40]Page 2, https://reduceflooding.com/wp-content/uploads/2018/07/Jacobs_and_Moroka_2015_Risk_assessment_of_floodplain_mining_pits_in_the_mid-Goulburn_Valley.pdf

[41]https://reduceflooding.com/2018/07/22/how-floodplain-mining-can-lead-to-river-capture/

[42]https://reduceflooding.com/2018/07/22/how-floodplain-mining-can-lead-to-river-capture/

[43]Correspondence with TCEQ.

[44]See https://reduceflooding.com/sand-mining/  Compare best practices from various states and countries by searching on the word “setbacks” within regulations from various states and countries.

[45]Page 18, https://reduceflooding.com/wp-content/uploads/2018/06/LouisianaRecommendedBMPs.pdf

[46]https://reduceflooding.com/2018/07/22/how-floodplain-mining-can-lead-to-river-capture/

[47]https://reduceflooding.com/wp-content/uploads/2018/03/Hurricane-Harvey-Peak-Inflows-36×24.pdf

[48]Conversation between SJRA board members and mine executive during mine tour.

[49]https://reduceflooding.com/wp-content/uploads/2018/05/2018_FloodWarn_Training_Kingwood.pdf

[50]See Section 3.3, https://reduceflooding.com/wp-content/uploads/2018/07/Jacobs_and_Moroka_2015_Risk_assessment_of_floodplain_mining_pits_in_the_mid-Goulburn_Valley.pdf. This report contains an excellent discussion of mitigation strategies for both new and existing pits beginning on page 47.

[51]Compare best practices found on this page: https://reduceflooding.com/sand-mining/

[52]https://reduceflooding.com/wp-content/uploads/2018/06/Malaysia-Sand-mining.pdf

[53]http://www.migflug.com/jetflights/the-10-fastest-aircraft-in-the-world.html

[54]Page 47, https://reduceflooding.com/wp-content/uploads/2018/07/Jacobs_and_Moroka_2015_Risk_assessment_of_floodplain_mining_pits_in_the_mid-Goulburn_Valley.pdf

[55]For example, see page 11 of Louisiana Best Management Practices for description. https://reduceflooding.com/wp-content/uploads/2018/06/LouisianaRecommendedBMPs.pdf.

[56]Estimate calculated from Google Earth.

[57]Page 29, https://reduceflooding.com/wp-content/uploads/2018/06/LouisianaRecommendedBMPs.pdf

[58]Page 20, https://reduceflooding.com/wp-content/uploads/2018/06/LouisianaRecommendedBMPs.pdf

[59]https://reduceflooding.com/2018/07/25/a-closer-look-at-sand-issues-on-the-east-fork-of-the-san-jacinto/

[60]https://reduceflooding.com/gallery/page/15/

[61]https://reduceflooding.com/wp-content/uploads/2018/03/West-Fork-Sand-Stockpiles2.pdf

[62]https://reduceflooding.com/wp-content/uploads/2018/07/Austrailia-Ladson-Mining-River-Stability.pdf

[63]https://reduceflooding.com/2018/07/22/how-floodplain-mining-can-lead-to-river-capture/

[64]Page 20, https://reduceflooding.com/wp-content/uploads/2018/07/Jacobs_and_Moroka_2015_Risk_assessment_of_floodplain_mining_pits_in_the_mid-Goulburn_Valley.pdf

[65]Pages 251-255, https://reduceflooding.com/wp-content/uploads/2018/07/Austrailia-Ladson-Mining-River-Stability.pdf

[66]Page 251, https://reduceflooding.com/wp-content/uploads/2018/07/Austrailia-Ladson-Mining-River-Stability.pdf

[67]Page 250, https://reduceflooding.com/wp-content/uploads/2018/07/Austrailia-Ladson-Mining-River-Stability.pdf

[68]Page 255, https://reduceflooding.com/wp-content/uploads/2018/07/Austrailia-Ladson-Mining-River-Stability.pdf

[69]Personal experience as a business owner.

[70]https://reduceflooding.com/2018/07/01/a-model-for-the-future-of-the-san-jacinto/

[71]https://reduceflooding.com/wp-content/uploads/2018/06/TACA-White-Paper.pdf

[72]https://reduceflooding.com/2018/06/07/taca-spells-out-industry-position-on-societal-and-environmental-benefits-of-sand-mining/

[73]https://reduceflooding.com/2018/06/07/taca-spells-out-industry-position-on-societal-and-environmental-benefits-of-sand-mining/

[74]https://reduceflooding.com/2018/06/23/do-local-sand-mines-follow-best-management-practices/

[75]https://reduceflooding.com/2018/07/27/why-we-must-remove-mouth-bar-on-west-fork-of-san-jacinto/

 

Mobilization in Full Swing For Army Corps Dredging Project

The countdown has begun to D-Day – Dredging Day. D-Day is still a month away, but things are changing on the ground. Finally. Mobilization has begun for the U.S. Army Corps of Engineers Emergency Dredging Project on the West Fork of the San Jacinto.

During the last week, the winning bidder has been out surveying the lake, planning the job, and ordering equipment and materials. Now the hard work has started.

Roads are being built to the staging area. Equipment is being installed. Pipeline is being laid. For all those who doubted this day would ever come, here are the pictures that prove it’s happening.

Building a road to the launch site. All photos courtesy of the US Army Corps of Engineers

Grading the road.

Dock area shaping up.

Containers and heavy equipment arriving.

Generators in tow.

Heavy equipment and dredge pipe.

What to Expect When

Right now, crews are setting up the staging area. This week, pipeline arrives and crews will begin installing it. By August 18, two dredges will arrive in pieces by truck. Crews will then begin assembling and launching them.

On August 20, general debris removal will begin. By September 1, the dredges should be sucking sand out of the river and pumping it into placement sites. That process will continue until next April.

Phase Two?

At that point, unless funding has been approved to extend the dredging to include the mouth bar, the contractor, Great Lakes Dredge and Dock will begin removing its equipment from the river and cleaning up after themselves.

The cost of mobilization and demobilization – $17,900,000 out of approximately $69,800,000 – represents almost exactly 25% of the contract. The time also represents about 25% of the total time allotted.

For Your Own Safety…

For safety reasons, the Army Corps respectfully requests the public to stay away from the staging area. The amount of heavy equipment in use and the fast pace of work make this important. The Corps is not publishing details of the staging area’s location, though that will soon become apparent due to the increase in traffic. Just remember, these people have a large job to do and little time to do it. Please respect the demands on their time and respect the perimeter of the job site for your own safety. In the next eight months, they will move enough sand to fill up the Astrodome and then some.

Posted by Bob Rehak on July 31, 2018

336 Days since Hurricane Harvey

Seasonal Lowering of Lake Conroe Begins August 1

On August 1, the City of Houston Public Works Department, the San Jacinto River Authority (SJRA) and the Coastal Water Authority (CWA) plan to begin lowering the level of Lake Conroe as part of a joint operations plan to mitigate flooding threats during the peak of hurricane season. The plan calls for lowering Lake Conroe gradually through small releases – about an inch a day – until the lake level reaches 199 msl (mean feet above sea level).

Intent of gradual lowering of Lake Conroe is to avoid another 79,000 cubic-feet-per-second release rate as we experienced during Harvey. Until normal flow is restored to the West Fork, Lake Conroe will be lowered temporarily and seasonally to mitigate flood risk.

Lake Conroe to Be Lowered 2 Feet Through September

This initial lowering will last through the end of September to create additional storage in Lake Conroe which could delay releases and minimize release rates during a storm, thereby providing a buffer against flooding for residents who live downstream of the dam.

The next lowering would occur during the peak of the spring rainy season – from April 1 – May 31, 2019. However, that lowering would only be by a foot – to 200 msl, because the rain threat is usually lower in spring.

Only Until Dredging Restores River’s Flow

The joint operations plan calls for continuing to lower Lake Conroe seasonally in this manner while the U.S. Army Corps of Engineers dredges the West Fork of the San Jacinto to restore flow.

Hurricane Harvey deposited tremendous amounts of silt in the West Fork which  physically changed the river’s ability to safely pass water during storms. Hence, the dredging.

Phase-One Dredging Has Already Started

Phase one will go from River Grove Park to the West Lake Houston Parkway bridge. Great Lakes, the contractor hired by the Corps, has 269 more days to complete the initial phase.

Phase-Two Still Needs Funding

The total project could take longer. Community leaders are now working furiously to arrange funding to dredge the remainder of the west fork, including the mouth bar.

Mobilization and demobilization comprise 25 percent of the total phase one project costs (approximately $18 million out of almost $70 million). Having phase two ready to start before phase one ends could save that money, creating extra value for taxpayers and enabling even more dredging, say for instance, on the East Fork.

Temporary Lake Conroe Lowering Could Last Up to 3 Years

The City, SJRA, and CWA will continue the seasonal lowerings for up to three three years. They will monitor progress of the dredging and annually re-evaluate the need to lower Lake Conroe. If the river’s flow is restored before three years, the temporary lowering would cease.

Lakes will Operate under Two Different Strategies

LAKE CONROE
Lake Conroe is located upstream from Lake Houston. Large pre-releases immediately before a storm run the risk of pushing water into Lake Houston at a rate that could flood residents. Therefore, the SJRA will release at a much more gradual, controlled rate and maintain the lower level until the largest flood threat passes.

LAKE HOUSTON
Lake Houston, as the lowest lake on the river system, can pre-release more safely. Therefore CWA will pre-release from Lake Houston if the National Weather Service predicts more than 3 inches of rain within the San Jacinto River basin in a 48-hour period. Coastal Water Authority will lower Lake Houston to 41.5 feet from its normal elevation of 42.5 feet.

To track lake levels visit:

  • Lake Conroe – www.sjra.net
  • Lake Houston – www.coastalwaterauthority.org

4 Million People Depend on City for Water

Lake Conroe and Lake Houston comprise two of the largest parts of the City’s drinking water system. More than 4 million Houstonians and residents of the greater Houston region rely on water provided by the City.

Posted by Bob Rehak on July 30, 2018

335 Days since Hurricane Harvey

How Much Would the Flood Bond Cost You?

When considering property tax implications of the proposed $2.5 billion flood bond, start with how much you currently pay in Harris County Flood Control District (HCFCD) taxes. Hint: It’s very little.

Only about 1.4% of Typical Property Tax Bill Currently Goes to Flood Control

Only about 1.4% of the average annual property tax bill now goes to Flood Control. The rest funds schools, cities, hospitals, law enforcement, etc. How much you currently pay each year in flood control taxes depends on your home’s value and your exemptions. See some representative costs below.

What homes assessed at representative price points will pay in additional taxes if the Harris County Flood Control Bond passes.

Amount Will Vary Depending on Age, Assessment and Exemptions

If your home is assessed at $200,000 and you are under 65, you pay only $45 annually for flood control.  If over 65 in that same home, you pay no flood control taxes.

In a worst-case scenario, Harris County says the flood-control portionof your taxes would double. Would doubling one of the numbers above create a hardship for you? Or would it help you sleep better?

Remember, any increase applies only to the flood control portion of your tax bill, not the entire bill.

Less than Cost of Flood Insurance

Any increase would be gradual. Bonds are only sold when projects are ready to start. Harris County expects no increase at all until 2020 at the earliest.

Flood Control improvements cost much less than flood insurance. And unlike flood insurance, they might actually prevent your home from being damaged.

Protecting Home and Community Values

Once implemented, the flood mitigation measures in the bond package will help make our entire community more resistant to flooding. That’s important. It helps protect your home’s value, your schools, businesses, roads, bridges and other infrastructure. That helps keep your community growing and makes it attractive for people looking to relocate. In the long run, rising home values will pay you back many times over for your investment in flood control. So send a signal to the world that we’re willing to invest in our future.

How to Check Your Current Assessed Value

To see how much you pay right now, go to hcad.org, click on “Property Search”, then “Real Property” followed by “Search by Address.”

Posted by Bill Fowler on July 29, 2018

334 Days since Hurricane Harvey

Why We Must Remove Mouth Bar on West Fork of San Jacinto

The U.S. Army Corps of Engineers originally solicited bids to dredge the West Fork of the San Jacinto from 59 to Lake Houston, a distance of 8 miles. At some point in the project, the Corps limited the scope to 2.1 miles –  from River Grove Park to the West Lake Houston Parkway bridge – for reasons never made clear. Perhaps they ran out of money when they had to double the volume they were dredging in that 2.1 miles. Regardless, that meant leaving a huge sandbar in place at the mouth of the river (see below).

I have been concerned about that bar ever since they excluded it from the scope. I wasn’t the only one. Two retired geologists, Tim Garfield and R.D. Kissling, approached me after my post about reduced scope. They have more than 50 years of experience with one of the world’s most successful oil companies. Both are experts in river morphology and sedimentation.

They compiled this fascinating 28-page report about the mouth bar, which I helped them edit. It explains how the river is changing, why it’s crucial to remove the mouth bar, and what will likely happen if we don’t.

The goal of this presentation was to get the Corps to expand the scope of their current dredging project to include the bar. Why? Approximately half of all the damage that occurred in Kingwood occurred BEYOND where the Corp intends to stop dredging. If not removed, everything behind the mouth bar for miles upstream will be at greater risk of flooding.

Major Concerns From a Geologist’s Perspective

If this blockage is left in place, it will, say Garfield and Kissling:

  • Cause the river to run UPHILL
  • Create, in effect, a partial dam
  • Slow water down, back it up and elevate the water surface
  • Increase flooding upstream
  • Increase the rate of sedimentation behind it
  • Cause the river to escape its banks, flood neighborhoods and damage or destroy infrastructure

How the River Is Changing

Since the late 1970s, a delta has been forming within the river and advancing toward where the river meets the lake. You can see the 2-mile advance most clearly in this summary slide that shows Kingwood in 1977 and 2017.

Evolution of mouth bar over 40 years. The full presentation contains many intermediate images.

 

When Friendswood designed Kingwood’s drainage, it was based on a different reality. Note, for instance, what happened east of the West Lake Houston Parkway Bridge. A huge area has filled in, reducing the conveyance of the river.

The chart below shows the increasing rate of change in the Stream Mouth Bar (SMB) at the right in the photo above (the area outlined in white with the red arrow pointing to it).

Sudden exponential growth in mouth bar volume tells geologists that it has reached critical mass and is likely contributing in a major way to upstream flooding.

 

How Our Mouth Bar Contributes to Upstream Flooding

This next series of slides shows how and why the West Fork mouth bar affects flooding.

Before the Lake Houston Dam was built, water in the river dropped steadily in elevation from the site of today’s Grand Parkway all the way to the coast.

 

Since the construction of the Lake Houston Dam, water continues to drop to US59, but then it levels out. That’s because the dam backs up water that far.

 

A huge mouth bar grew up where the river enters the lake. As water slowed down and spread out, it deposits sediment. When the river is flowing at normal levels, water can find its way around the blockage without threatening neighborhoods.

 

However, during floods, the mouth bar acts as a partial dam. It creates a hydraulic jump that begins to back water up behind it. Note how the orange bar is higher on the left than on the right, relative to the blue line. That’s because the stream mouth bar increases the height of water behind it during a flood.

 

If the mouth bar were removed, water would no longer back up behind it. The river could flow freely in a flood. The dotted line represents an estimate of how much a flood like Harvey could be lowered. If the reduction were four to six feet, that could make the difference between major and minor flooding. 

In this profile, the horizontal scale is less compressed than in the charts above it, so you can visualize more easily how water is forced to flow uphill as it approaches the mouth bar. This forces water to flow uphill and the water surface to elevate behind the mouth bar, contributing to upstream flooding.

Options Going Forward

Ignoring the mouth bar and hoping it will go away is not an option.

It has nearly doubled in size in the last three years. It will force the river to flood more frequently and more extensively, causing more damage to houses and infrastructure.

I suspect that the reason the Corps did not handle this in the first place is because they were constrained by budget. So removing the mouth bar as part of a change order is not an option either.

It will likely cost far more to remove the mouth bar than it does to clear the 2.1 miles upstream.

That leaves two options recommended by the Army Corps’ Deputy District Engineer for Programs and Project Management, Dr. Ed Russo (plus another that he didn’t recommend).

  • Option 1: Russo helped draft a proposal request for consideration under Section 7001 of the Water Resources and Reform Development Act of 2014. The proposal requires a local, county, or state agency to put up a match for federal funds. Deadline is August 20. If approved by Congress this fall, the mouth bar could potentially be removed while Great Lakes still has dredging equipment on the river, saving the cost of another mobilization.
  • Option 2: Similar to 1, but without cost sharing. A partnership of local, county, state, or federal agencies can hire the Corps to be their public engineer and constructor for the project under an Interagency Agreement . This requires 100% funding by the Federal, state, county, or local agency.  There is no cost share. Hmmmm. County Bond Referendum? The State’s rainy day fund? Lots of possibilities. But they would probably take longer to work out.
  • Option 3: Go it alone.

Benefits of Removing the Mouth Bar

The Lower West Fork delta of the San Jacinto River is advancing development in size and shape.  The West Fork mouth bar and surrounding shoal sediments are constraining in-bank flow conveyance capacity.

With no action to restore flow conveyance capacity within the river’s banks, the evolving conditions will cause the river to rise out of its banks and extensively flood properties and critical infrastructure in the region.  If addressed, flood risks to developments will be reduced and the river will have the conveyance capacity to pass flood flows and flush sediment that would otherwise reduce conveyance capacity.

Removing the mouth bar would reduce flood damages to properties regionally and provide for increased resilience to flooding of properties, transportation systems, water treatment systems, public/private utilities, emergency response facilities, petrochemical industries, and other critical infrastructure, in the West Fork, San Jacinto River Watershed, Harris, Montgomery, and Liberty Counties,TX, on the order of $200 Billion.

Given that petrochemical industries in the region produce a significant amount of the Nation’s petroleum based energy products, reducing flood risks of these plants and its workers who reside in flood-prone areas, and providing for greater resiliency, is a National security benefit.  The environmental benefit of providing for this project is reduced risks of water treatment plant and chemical spills due to flooding, which is a threat to human and environmental health and safety.  The non-monetary benefits would include reduce risks to loss of life due to regional flooding, especially to residents with insufficient means.

Posted by Bob Rehak, R.D. Kissling and Tim Garfield on July 27, 2018

332 Days since Hurricane Harvey

A Closer Look at Sand Issues on the East Fork of the San Jacinto

This is what East End Park used to look like – a natural gem within the nation’s fourth largest city, an urban refuge for wildlife on the East Fork, and an island of quiet enjoyed by more than 80,000 visitors per year.

Then Things Changed

After Harvey, sand and gravel dunes covered 30 acres (about 20 percent of the park’s 150 acres). The sand destroyed wetlands. Look at the wetland image three rows up in the center of the poster. Now look below. They’re the same area!

This bridge had to be excavated from several feet of sand after Harvey. It used to cross wetlands shown in the poster above.

Here’s what the trail looked like in the opposite direction before excavation.

Standing on five feet of sand deposited in East End Park wetlands

 A bird’s nest ten feet up in a tree is now knee high because sand raised the ground elevation so much.

Natural or man-made disaster?

So I asked myself, where did all this sand come from? Was this just something that you have to accept when you live near a river? To find answers, I rented a helicopter and flew up the East Fork. Opposite East End Park, I saw this giant dune below, one of several along the way.

A new dune deposited during Harvey now blocks half of the East Fork opposite East End Park (upper right).

From ground level (below), you can see how tall it is – 10 to 12 feet. Some people who have climbed this dune tell me that it gets even higher back in the trees.

This new sand dune, created during Harvey is twice the height of the average human. A geologist told me that he doesn’t usually see changes this dramatic on a human time scale. 

Farther up the river, I started to see what the problem might be.

A 750 acre sand mine hugs the banks of Caney Creek. Note how another giant sand bar adjacent to the mine again chokes off 50 percent of Caney Creek. Such blockages are now common.

As I flew around the northern part of the mine and started looking south, I saw large areas that are not being actively mined, yet are un-vegetated. This makes sand more susceptible to erosion in floods. 

Flying closer to the giant stockpile, I noted its height relative to trees around it. Those trees typically grow up to 100 feet tall. That water tower in the background is on Kingwood Drive. 

As I got closer to the stockpile, I noted ripples/wave forms in the lower part on the left and the remnants of heavy erosion from rainfall on the right. These are signs that water had been moving through the interior of this mine pretty quickly and that the dikes around them were no barrier to erosion.

Below, note how the road that comes up from the bottom left washed out inside of the mine.

 Satellite imagery in Google Earth shows that the washout most likely happened during Harvey. It first shows up in satellite photos on 9/1/17.

I reviewed other areas within this mine in Google Earth. The mine measures more than 750 acres. The stockpile alone comprises 34 acres. The image below from 9/1/17 reveals severe erosion of this massive stockpile as Harvey’s floodwater’s receded.

Erosion in East Fork sand mine stockpile as Harvey’s floodwater’s receded.

Evidence Mounts: Clearer Picture Emerges

Satellite imagery below shows that no other sand mines are visible on the East Fork or its tributaries for miles around. None of the rivers or streams in this area seem to produce much. And all of those monster sand bars appear downstream. Hmmmm! Had we found the source of all that sand?

No other sand mines exist on Caney Creek. No huge sand bars show up above the mine; all appear below. Note that the sand bars represent only a tiny portion of the sand carried downstream; as in East End Park, huge volumes were deposited beneath the forest canopy and are not visible in satellite imagery.

Mine Located in Two Floodways; Living Dangerously

At this point, I had my suspicions. But TACA claims that “when rivers back up into a mine during floods” they slow down and drop their sediment in the pits. I puzzled over the phrase “back up,” especially because this mine, like virtually all others in the area, sits in a floodway. Actually, this one sits in TWO.

Half of this mine lies in two floodways as shown in this USGS flood hazard viewer. The part of the stockpile that eroded most is in the the 100 year floodplain (aqua). See right side of circle. Brown represents the 500 year flood plain and the cross-hatched area represents the floodway, which is defined as the main current of the river during a 100-year flood.

According to Harris County Flood Control on page 12 of their final report, more than 20,000 cubic feet of water per second came down Caney Creek. And the Flood Control District has no gauges on White Oak Creek, the tributary that comes from the west, so the real flow total was higher. I can’t imagine how water would “back up” into this particular mine during an event like Harvey, especially during the early stages when everything was rushing downstream fast enough to wash out a road and erode a mountain of sand.

But still, those TACA guys are the experts, right?

I needed a way of showing exactly how fast the water was flowing through this area. Since there are no gages, I looked at particle sizes deposited downstream. Science tells us that rivers pick up particles in a particular order as flow increases and accelerates.

Erosion and Deposition of Various Particle Sizes at Different Velocities.

Among the new sand dunes at East End Park, I found gravel…lots of it.

Dunes of gravel or small pebbles were also found in East End Park.

If the current during Harvey was strong enough to pick up 2.5 centimeter pebbles like the one below, it was definitely strong enough to pick up sand. You can even see sand mixed in with the pebbles if you look closely.

Pebble found at top of ten-foot mound in East End Park. It measures about 2.5 centimeters.

To deposit gravel this size, the river was moving at about 150 cm/second – fast enough to pick up EVERYTHING smaller, including clay, silt, sand, gravel and pebbles (items listed below the horizontal axis on the chart above). The flow rate was high enough to move every type of material found in the mine.

While the sand miners claim the river wasn’t moving fast enough to carry sand out of the mines, the physical evidence suggests a different story.

Sand deposits reach high up on trees and are killing many smaller trees. The sand came from somewhere. There’s one likely culprit in my opinion.

Homes Flooded on East Fork, Too

This entire sequence shows the risk of locating mines in floodways. Not just because of damage to nature, but because of danger to homes. Harris County Flood Control compiled this damage map.

1290 structures in Huffman and Kingwood flooded on the sand-clogged East Fork. See the purple and green totals right of the black line that bisects the purple. Those represent damaged structures in the East Fork watershed.

Harvey damaged 1290 Harris County structures in the East Fork watershed. Assuming an average loss of $250,000 for each structure and its contents, damage would total about $350,000,000 – one third of a billion dollars.

Recommended Next Steps

Even though no sedimentation surveys have yet been completed on the East Fork that could definitively link this sand to subsequent flooding, the Army Corps of Engineers has confirmed that similar sand blockages have contributed to flooding on the West Fork. (The Corps is currently embarking on a $70 million dredging project there…at taxpayer expense.)

My findings suggest that such a study should be done on the East Fork. Further, I believe that we need to:

  • Debate whether to allow sand mining in floodways, especially so close to the source of drinking water for 2 million people; sediment is rapidly filling the lake at an accelerating rate.
  • Strengthen permitting requirements, setbacks and best management practices
  • Enforce them by imposing prohibitive fines for violations.

Need to Strengthen TCEQ

Regarding the last point, in the five years from 2013 to 2017, the TCEQ found 619 violations at sand mining operations throughout Texas, but assessed only $506,151 in penalties. That’s about $101,000 per year and works out to an average of $817.69 per fine.

I know Texas is a business-friendly state; that’s why I moved here 40 years ago. But really! This is like the Legislature giving the Domino’s guy a license to speed 90mph through school zones so he can make more tips.

Those are my opinions on matters of public policy protected under the first amendment of the U.S. Constitution and the Anti-SLAPP statutes of the great State of Texas. I sincerely hope that TACA can come to the table and help structure sensible mining regulations that protect the public, not just the profits of miners. I’ll talk more about what those might be in subsequent posts.

Urgency also Needed

It’s important that we start this dialog now. If the new USGS data is correct, Harvey was not a 1000-year event; USGS estimated that the flow on Caney Creek, upstream from the mine, had an annual exceedance probability of 3.3.  See Page 9, Table 3, Line 32 for Gage #08070500 in their report titled “Characterization of Peak Streamflows and Flood Inundation of Selected Areas in Southeastern Texas and Southwestern Louisiana from the August and September 2017 Flood Resulting from Hurricane Harvey.” The report was produced in cooperation with FEMA.

That would make Harvey a 33-year event in this area. Impossible, you say! The flow measured upstream from the mine was only the fourth highest on record.

Posted by Bob Rehak on 7/25/18

331 Days since Hurricane Harvey

Milan and Lori Saunders’ Harvey Experience: “You can’t outsmart nature. Nature always wins.”

Interview by Bob Rehak

In June, I interviewed Milan Saunders, Chairman/CEO of Plains State Bank, and his daughter Lori Saunders, the bank’s COO. Both live in Kingwood Lakes with their respective families several blocks apart. I asked for this interview to learn how Harvey affected them personally and professionally, and to see whether the flood had a domino effect on other businesses beyond Houston. Spoiler alert: It did.

As we sit in a quiet corner of Amadeus, awaiting our meals, I ask Milan and Lori to start at the beginning. Both have photographic memories and brains that process information faster than computers. They begin with an almost hour-by-hour narrative of the storm’s approach. Clearly, almost a year later, the images remain vivid and painful.

Milan Saunders

It’s time to abandon ship. The Saunders household is swamped by Harvey.

Water and Plumbing Back Up

Milan: “Harvey approached the Houston area on Friday, August 25, and started dumping buckets of rain. Going into the weekend, we were tracking weather reports. On Saturday, things lightened up. Then the rains came back again. Sunday … a lot of rain. Monday … a lot of rain. By that afternoon, water was out of Lake Houston and it began to look pretty ominous. By Tuesday, water was also out of Lake Kingwood. We had only 18 inches between it and our threshold.”

Lori: “My plumbing was starting to back up on Sunday. That’s why I went over to Dad’s house.”

Milan: “Overnight, early Tuesday morning, water began to rise substantially. About 1 a.m., we wrapped the legs of our baby grand piano. In ‘94, we were spared, so I was thinking that, at worst, we would get a foot of water in the house.”

Reliving the Story While Retelling It

Milan continues the story in a series of rapid-fire images that seem to fade to black between each. “I went back to sleep. I was woken up at 6:30 in the morning. Came downstairs. At that point, I am standing in water up past my knees. I open the door and go outside. I am standing in water up to my belt. I see this rubber boat pulling in. First responders called out, ‘It’s a mandatory evacuation.’”

“I ask who they are. They say, ‘We’re firemen from Memphis, Tennessee.’ I say to myself, ‘Wait a minute!’ How did they know about it in time to get here from Memphis when I didn’t even know about it?”

Milan Saunders

Milan makes his great escape with wife and dog on a Wave Runner down Kingwood Drive

“Somehow, we managed to get our dog, a giant German Shepherd, balanced on my lap. They took us up the next street, and we got out there.”

As we delve deeper, Milan increasingly uses present tense, as though he is re-living Harvey in real time. His jaw clenches. The gets that 1000-yard stare. He is in another place and another time now.

“The next challenge is finding a place to shelter for me, my wife, my daughter, my granddaughter and grandson…which we do that afternoon.”

“I’m also worrying about the bank. We had been closed for four days already. The law says banks can’t be closed for more than three days in a row. We had already contacted our regulators to let them know that we were experiencing some really harsh difficulties.”

Never in 50 Years of Banking

“All of our employees are basically stranded. 59 is shut down. The force of water running over the highway has moved the concrete barriers on it.”

“Plains State does business far beyond Houston. We are keeping in touch with our West Texas people to help our clients out there, but our headquarters is in Humble and no one can get to it.”

“If I had had any idea this was going to happen, we would have gotten hotel rooms on the other side of the river for our employees.”

Milan Saunders

Rising tide of discontent sweeps across Kingwood

One image intrudes on another as Milan talks of his experience. He jumps from subject to subject as we nosh on our linguine.

“I lost my telephone while rescuing my granddaughter’s cat,” he says. “I lost both cars.” He begins talking in a staccato shorthand almost like he’s running down a mental checklist, a pilot evaluating options for an emergency landing. “No cars. No phone. Can’t get across the river.”

“It really made it very difficult for us to run the bank. None of our offices experienced flooding; we just couldn’t get people to the offices to move electronic files. That’s where our connections to the Fed and our core processor are.”

Lori: “A few days later, as flood waters started to subside, some folks in law enforcement told us about a way to get across the river. It was a very long way without the 59 bridge, but it worked. Some of our managers were able to get into the bank and start taking care of customers.”

Milan: “We were down five days. I’ve never experienced that in 50 years of banking.”

Bob: “Were there any repercussions for being closed five days?”

Milan: “Overall, our clients down here were very understanding. The West Texas folks didn’t understand as well. One client is a school district. They had end of month payroll to make.”

“Luckily, the superintendent’s wife worked with first responders and knew what we were up against. We were able to explain those problems and I think we have that behind us now, but it was painful for everyone, including us. We built our reputation on service and reliability. Both were beyond our control at that point.”

Meanwhile, Back at the Ranch House…

Milan: It was just an unbelievable experience getting into that house. Water up to mid chest.  Probably a foolish thing to do. All kinds of things can happen. The water wasn’t moving that fast, but it was touching the breaker boxes. Water and electricity! Not a good combination!”

“We finally got the cat out of there, but my phone went in the drink, so I lost all communication.”

“The next day, my wife and Lori had to get to the house, so we borrowed a canoe. We saw our brother in law struggling in the water. When we tried to get him into the canoe, he flipped it over. Now Lori’s phone is under water, too.”

Milan Saunders

That’s all she played.

“The hardest part for my wife was the piano. We had bought it for our girls in 1977. It was a baby grand. The force of the water had flipped it over and ripped off two of the legs.”

Nightmare Followed by a Miracle

“We had 3.5 feet of nasty water and sewage in the house. It finally subsided on Thursday afternoon. Then another part in the story began. It was just as unbelievable how folks came out to help.”

“The outpouring of help from the people of Kingwood, led by the churches, was amazing. With the help from strangers, we got everything torn out and the dehumidifiers going.”

Secrets of Dealing with Contractors

“Then I had to find some contractors who could get the rest done. Luckily, we deal with contractors all the time; I knew some very good ones. I hired one who builds hotels and high-end townhomes. I cut a cost-plus deal with him.”

Milan Saunders

Starting over. 

“I saw that a real shortage of qualified contractors was coming, so I did everything I could to sweeten the deal, but built in safeguards for us. I gave him two houses – mine and Lori’s. I guaranteed him payment every Friday night. We made up our minds about what we wanted and didn’t change anything. All he had to do was show every day and carry on the work continuously. As a result, we had two or three subs on the job site every day and avoided a lot of the problems that others have had getting contractors to show. If guys are working, you want to pay them every Friday so that they’re back on Monday.”

Milan Saunders

Kicked to the curb by Mother Nature.

“My wife is fluent in Spanish, so we could converse with subcontractors. That was another advantage.”

Repairs Completed in Record Time, But Now…

“We got the house all done by the first of December. Right now, I’m just wrestling with the insurance guys. They think I should have been able to get it done for half. But it’s unreasonable to look back and say that.”

“The IRS says you should be able to take $104 per square foot, no questions asked. Shopping for the best price in town is probably not the best idea at a time like this.”

Bob: “How long did it take the bank to get back to normal?”

Lori: “Other banks were having trouble getting personnel in. But after Labor Day, most of our staff was able to get into the bank. I remember coming to work Tuesday and seeing all the cars in the parking lot, and thinking, ‘Wow!’  We’d just been through a war zone…the craziest worst week of our lives. And there all of our people were!”

Milan: “We were also very fortunate that only three of our employees had flooded houses and two of those are sitting here with you.”

“The Craziest, Worst Week of Our Lives” Turns into a 3-Year Project

Bob: “How did you manage to cope with the business being down and your homes being destroyed at the same time?”

Lori: “You go into survival mode. You rely on others. I have really good managers. They just stepped up, personally and professionally. They knew what we were going through.”

“We lost everything. Now looking back…I wonder how we did get through it. It was just one day at a time.”

Milan Saunders

More net worth at the curb

“We knew good contractors and had great relationships with them. Not everyone had that luxury. When I drive down my street now, it breaks my heart. I still see dumpsters in the driveways and portacans…all of it. They’re still far away from getting their houses back together again.”

Bob: “What percentage of your street is finished remodeling?”

Lori: Maybe 20%. At least 80% are still not back in.”

Milan: “We have 42 houses in our part of Kingwood Lakes; only one escaped flooding. There aren’t ten that are completely finished restoring. You see lots of travel trailers. I’ve said all along that this is a three-year project and my opinion hasn’t changed.”

Fighting the Adjusters

Bob: “What’s the most common problem people have?”

Milan: “They’re all struggling with the insurance adjusters. Each adjuster sees things differently.”

“One friend’s adjuster told him that $70/sf was a starting point and that if you have cabinetry involved, you’re up to $100/sf. That matches up to what the IRS said. But some of these adjusting companies are trying to be too safe, in my opinion. They split everything up into a unit-pricing process that takes waaaay too long.”

Milan Saunders

Counter to counter, but not express

“When a cost-plus contractor shows up, he’s going to give you a quote for labor and all the receipts for materials. He’s not going to break out trim costs or caulking per square inch! Our first adjuster’s report was 40 PAGES!”

“By comparison, when our bank makes loans on a $700K house, the builder gives us pro formacosts on ONE sheet of paper. You can NOT analyze a house on a per-square-inch basis. These guys just don’t get it.”

“The other thing that has happened is that prices have all escalated by 30%.”

The Value of a Banker Who Knows Your Business

Bob: “Do you have any customers that were forced out of business by Harvey?”

Milan: “No. But many were affected.”

“We had a Holiday Inn Express in Rockport that was severely damaged. But the regulators were very proactive and encouraged banks to give people time, suspend payments, look for ways to assist them.”

“We had a dozen clients in different places that were badly affected, and we’ve worked with them.”

The Hardest Hit Clients Didn’t Have Flood Insurance

Lori: “The hardest hit were clients without flood insurance. They weren’t required to have it.
Not in a flood plain, you know!”

Milan: “We’re one of the top ten SBA lenders in this district. We’re up there with Chase and Wells. SBA requires flood insurance if you are in the 100-year flood plain. But the people that were the most affected were not in the 100-year flood plain and so consequently, they didn’t have any insurance.”

“I’ve had flood insurance for 50 years because my first house was in Bellaire. My second house was in Pearland. One time they had 35 inches in Alvin and there was no way out. We had to be rescued by helicopters down there, so when I moved to Kingwood, I insisted on flood insurance.”

Recommendations for Improving the System

Bob: “What would you change politically to help prevent another flood like Harvey?”

Milan: “Oversight needs to be regional. I think the SJRA worried too much about Lake Conroe and not enough about what would happen downstream. They need to communicate better, too. It’s incredible that guys in Memphis got the news before we did. Regional coordination and prompt notification. Those will be big parts of the answer.”

Milan Saunders

Heavy hearts and high piles: belongings on the curb, waiting for pickup

Nature Always Wins

Bob: “You work with a lot of developers. Do you have any observations about development near rivers?”

Milan: “You can’t outsmart nature. Nature always wins. We need to give Mother Nature her room.”

 

Posted By Bob Rehak on July 24, 2018

330 Days since Hurricane Harvey

How County Bond Funds Could Leverage Additional Dollars

Early voting for the $2.5 billion Harris County Flood Bond Referendum begins August 8. If approved,  the County could leverage that money to increase the amount available for flood mitigation. Matching funds from FEMA, HUD, the State, and other sources are available. These grants usually operate on a 75/25 or 90/10 basis, returning $3 to $9 for every dollar put up.

Local Dollars Leverage Matching Funds

If voters approve the $2.5 billion referendum, the bond funds could potentially bring in billions of additional dollars. Here is how funding for Flood Control District projects works. (For a printable PDF, click here.)

Partnership Matching Funds Available for Harris County Flood Control District Projects

Bond money can be used as “seed money” for some types of projects. It qualifies us to receive additional money in the form of grants from other partners such as the Federal Government, State, Coastal Water Authority or the City.

Federal dollars for Harvey flood mitigation efforts are available now, but may go elsewhere if we don’t act. Every city along the Gulf Coast is competing for available matching funds.

Partnership Projects: More Leverage but Less Control

Even though you may not be able to follow all the ins and outs of the diagram above, you should be able to see that many opportunities exist to extend the impact of our own dollars. That’s the good news. The downside is that when you start spending other people’s money, they want to have a say in how you spend it. It’s important that we understand risks as we move forward. To get more money, we must give up some control.

Q: How will projects in the bond proposal be selected and prioritized?

A: Harris County Commissioners Court directed Flood Control District staff to develop list of projects. This is not an exact list of projects that must be or will be built with bond proceeds. It represents a list of projects that would meet the goal of the bond election, which is to both assist with recovery after previous flooding events (including Harvey) and to make our county more resilient for the future.

High on the priority list are construction-ready projects with federal funding partners (such as the U.S. Army Corps of Engineers and the Federal Emergency Management Agency) that give the County “the most bang for its flood control buck.”

Q: Can the bond money be used for purposes other than flood risk reduction?

A: No. Under Texas law, bond funds in this election could only be used for the purpose approved by the voters. Bond funds will not be used to fund additional staff positions at the Harris County Flood Control District.

Q: Do bond proceeds have to be used for the specific projects recommended by the Flood Control District?

A: No. Voters will be asked to authorize bonds for flood damage reduction projects, but specific projects may be added to the list of potential projects in the future or projects on the list could be modified based upon public input.

However, officials can only spend bond money on projects supported by the Bond Language. Voters will not be voting on a specific project list, only on the language in the proposal.

Freeing Up Budget to Improve Maintenance

Maintenance is NOT in the bond proposal. Nevertheless, the bond could still improve maintenance in a roundabout way. Here’s how. About half of the Flood Control District’s current $120 million per year budget goes to capital expenditures. If approved, the bond would free up about $60 million currently focused on construction projects.

The other $60 million in the Flood Control District’s budget is devoted to Maintenance and Operations. It is roughly divided as follows: $30 million for salaries and overhead; $10 million for mowing; and $20 million for maintenance.

That $20 million currently devoted to maintaining ditches, bayous and streams, if added to the $60 million that is freed up, would make $80 million that could be devoted to improving maintenance. That means the District’s maintenance budget could quadruple.

Yea or Nay?

On balance, I like how the bond is shaping up and I trust the people in charge of it. I wish that the $50 million allocated for a dredging partnership project was a dedicated $50 million. Then, if the bond proposal passes, we might be able to get the Army Corps to extend the scope of their current dredging to include the giant sand bar at the mouth of the West Fork. Addressing that issue as a change order to the current contract could save years, save dollars, and reduce risk immediately.

Posted on June 23, 2018, by Bob Rehak

328 Days since Hurricane Harvey

How Floodplain Mining Can Lead to River Capture

In a previous post, I showed satellite and aerial images of water sweeping through a West Fork sand mine complex during Harvey. This is part of a process called river capture. In the photo below you can see the West Fork flowing into and through mines on both sides of the river during Harvey.

Dikes on both sides of the river were breached in the process. In fact, historical images in Google Earth show that they have been breached repeatedly.

During Harvey, floodwaters swept through this complex and breached dikes in multiple locations as the river took a shortcut through the mines. 

Highest Risk Scenarios for River Capture

A review of scientific literature reveals that the risk of stream diversion through pits (river capture) is increased by:

  • Proximity of pits to the river
  • Increased depth of the pit, particularly where the base of the pit is below the lowest part of the river.

The phenomenon seems common and the consequences well documented.

2014 Survey of Scientific Literature Finds 37 Examples

In 2014, Anthony Ladson and Dean Judd, two Australian researchers, found 37 instances of river capture in a review of scientific literature. They published their findings at the Seventh Annual Australian Stream Management Conference in a paper titled A review of the effect of floodplain gravel mining on river stability.

Advanced economies, they say in their introduction, require large amounts of aggregate (sand and gravel) to sustain growth. Aggregate makes up 80% of concrete and 90% of asphalt pavements. 

Many see floodplain mining as a safer way to obtain this aggregate than in-stream mining, but floodplain mining still poses substantial threats to river stability.

Dangers of River Capture

As we saw on the West Fork of the San Jacinto during Harvey, floodwaters take a shortcut through mines that are built on point bars inside meander loops.

Sand bars within sand mine, caused during “river capture” of the mine. These bars prove sand was carried downstream. This photo taken on 10/28/2018 (after Harvey) also shows repairs to mine wall. During floods, the river tries to cut across meanders, runs through the mines and carries sand downstream.

The authors say this can lead to:

  • River bed degradation
  • Bank erosion
  • Channel widening
  • Infrastructure damage or destruction
  • Loss of riparian vegetation
  • Habitat damage
  • Degradation of water quality.

Their review of local, national and international case studies showed that pit capture and subsequent river channel changes, are a common consequence of floodplain mining.

Changing River Environment and Putting Infrastructure at Risk

In their conclusion, Ladson and Judd state, “Although floodplain gravel mining has been considered a safer option than the direct extraction of gravel from a river, substantial risks to river stability and river health values remain. Floodplain gravel mining can cause change in the riverine environment, both locally and distant to the mining site, and in the short and long term.” 

“There are substantial risks to infrastructure if river diversions occur which trigger bed and bank erosion.” 

“There may be a role for river management agencies to influence the amount of mining that is undertaken, and the manner in which it is undertaken, in order to mitigate these threats.”

Mechanisms of River Capture

Another study goes into more detail. This second study, was conducted by Jacobs Engineering in 2015, also in Australia. It describes the processes behind river capture, the risks, and how to reduce them. It is titled Risk_assessment_of_floodplain_mining_pits_in_the_mid-Goulburn_Valley, The Golburn River, like the San Jacinto, meanders through relatively flat land. It also has approximately the same number of sand mines that the San Jacinto has.

Jacobs identified three risk scenarios for river capture:

  1. Lateral migration of river channel into the pit
  2. Sub-surface piping into pits and subsequent failure of pit walls
  3. Flow of water into and through the pit and subsequent erosion of the buffer strip between the channel and the excavated pit.

Some San Jacinto Mines Push Recommended Safety Margins

Jacobs assesses (page 19) that 100 meters is the minimum setback to prevent river capture from occurring. In some places on the San Jacinto, dikes are less than 15 meters wide.

Jacobs also assesses that river capture is almost certain (page 19) where the basement of the pit is more than 5 meters lower than the river. San Jacinto sand miners are mining at more than double that depth.

“The physical processes of pit capture have been well documented from case studies: incision upstream and downstream of the pit are expected, with bed adjustments continuing until the river establishes a new equilibrium and grade,” says Jacobs.

Ways to Mitigate Risk of River Capture

Jacobs identified two main ways (page 47) to reduce this risk:

  • Locate pits out of the 100-year floodplain
  • Implement controls such as levees, grade-control structures, pit setbacks, depth limits, and waterway diversions.

Sadly, all sand pits on the San Jacinto are already in the 100-year flood plain. Worse, all but one are at least partially in the FLOODWAY, which is defined as the main channel of the river during a flood.

Even more sadly, it appears that none of the measures in the second category are being applied to San Jacinto mines either.

Posted by Bob Rehak, July 22, 2018

327 Days since Hurricane Harvey