In late December 2023, the San Jacinto River Authority (SJRA) released the third part of its massive, years-long sedimentation study. SJRA labeled the report “Technical Memorandum 3: Annual Sediment Supply and Storage.” Only seven more steps remain in the 10-step effort.
The Larger Context
The ten steps include:
Inventorying available existing data (January 2023)
Characterizing the subwatersheds (January 2023)
Quantify sediment supply and storage volumes in three representative subwatersheds(just released)
Sediment transport modelling
Extrapolate subwatershed data to entire basin and prioritize sediment sources for investigation
Investigation of hotspots to prioritize management opportunities
Conceptual solution and strategy development
Identification of potential partners
Identifying sources for technical and financial assistance
Synthesize previous findings into final plan and publish
The study team collected data from three watersheds in the Upper San Jacinto River Basin: Winters Bayou/East Fork, Peach Creek/Caney Creek, and Walnut Creek/Spring Creek (also referred to as the Willow Creek area in the study). They collected samples, measured isotope concentrations, and performed a chemical analysis to determine a “fingerprint” for sediment originating in those areas. Investigators then compared fingerprints of sediment taken from Lake Houston to identify the likely source or origin.
They also measured erodibility of river banks by assessing such factors as bank height, angle, and material; root depths and density; proportion of the bank covered by vegetation, rocks, logs, etc.; and stability of soil strata.
High-Level Finding
Matt Barrett, SJRA’s Water Resources and Flood Management Director, said, “The key data obtained in the efforts described in TM 3 was the determination of where sediment appears to be originating in the sub-watersheds (i.e. upland runoff vs. streambank erosion).”
“Our findings are that sediment appears to be originating primarily from eroding streambanks.”
Matt Barrett, SJRA Water Resources and Flood Management Director
The study did not directly examine the relative contributions of clear cutting, construction practices and sand mining to sedimentation.
Other Findings
Regardless, the study yielded interesting information about the soil in each area sampled.
Erosion rates (ft/yr) at the three locations varied by more than 3X. When measured in tons/ft/yr, they varied by 4X.
At all three streambank sites, samples were composed of varying proportions of sand, silt, and clay, with sand the most prevalent component. Samples taken from floodplains varied more, but bore a resemblance to the corresponding streambank samples.
Samples from the East Fork San Jacinto stream bank and floodplain had more than 50% fine-grained composition, i.e., silt and clay. See table below.
Study authors say, “…the relatively high proportions of fines in the East Fork … samples indicate(s) appreciable upland sediment contribution, consistent with the Pb-210 data.” (See Page 26). Pb is the chemical abbreviation for lead.
Highest Levels of Lead Coming from East Fork
Chemical sampling of Lake Houston sediments indicates that the highest percentage of lead, a naturally occurring element, was found in the East Fork Mouth Bar.
Looking farther upstream at three possible sources of the lead (upland areas, stream banks, floodplains), the authors found that floodplains and upland areas contributed more than streambanks.
It’s impossible to determine the exact point of origin of the lead at this point in the study, say the authors.
The report never mentions Colony Ridge per se. Investigation of “hotspots” won’t happen until Step 6. (See list above.)
However, in my opinion, more study is merited to see whether the lead came from the Colony Ridge area. It has been the largest land-disturbing activity in the East Fork watershed in recent years.
Widespread destruction of wetlands in the massive Colony Ridge development may have contributed to the high lead levels. Wetlands can be pollution-catching powerhouses, according to a University of Waterloo study.
Head Scratchers
In the meantime, I’m wondering how the SJRA’s sedimentation study could have omitted the West Fork San Jacinto as a sampling site. The study does not explain. Barrett said only that they couldn’t afford to sample every watershed.
Yet the West Fork has the largest concentration of sand mines in the region (more than 20 square miles in a 20 mile reach of the river).
Typical West Fork Sand Mine
However, the report never mentions the phrase “sand mines.” In one paragraph on page 31, it does mention APOs (aggregate production operations). But I had to laugh. It said that ReduceFlooding.com reported “several purported breaches” of APO berms on the West Fork.
In this context, “purported” means “suspected” according to Webster’s Third International Dictionary.
Sampling Concern: Avoiding the Obvious?
I guess they didn’t see the hundreds of photographs that I took of mine breaches or mines pumping their waste into the river. Nor did they read the TCEQ investigation about a 56-million-gallon release of sludge that turned the West Fork white.
Confluence of Spring Creek and West Fork (right). White water originated from breach of dike at Liberty Mine.
West Fork is to the right.But study chose to sample areas upstream on the left.
A friend of mine with a PhD in market research once told me that good research often confirms what in retrospect should have been obvious. But the SJRA study isn’t even sampling the obvious.
No telling where their sedimentation study will go at this point. This reminds me of the SJRA’s sand trap study. It recommended relying on a sediment gage upstream from all the sand mines.
Are they avoiding the obvious in their choice of areas they sampled?
Ultimate Goal
When I asked Barrett what he hoped the study would accomplish, he said, “The ultimate goal is to develop conceptual sediment mitigation solutions and implementation strategies. These could be infrastructure projects (stream restoration, sand traps, etc.).”
He continued, “Or they could be best management practices that could be recommended to appropriate government bodies (recommending riparian buffer or enhanced stormwater protection plan requirements that a county could implement, for example).
“These solutions will be included in the Sediment Management Plan, which will provide a ‘menu’ of projects that could be implemented to help mitigate the negative impacts of sedimentation.”
I’ll withhold judgement until we get to the end of this road.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2019/11/RJR_4154-e1775771233982.jpg?fit=1100%2C733&ssl=17331100adminadmin2024-01-16 09:15:002024-01-16 09:34:08SJRA Releases Third Part of Sedimentation Study
Kingwood Residences HTX II LLC is clearing 11.5 acres of land on West Lake Houston Parkway (WLHP) without the normal safeguards to control sediment-laden runoff. In recent weeks, concerned residents have emailed me multiple pictures like the ones below.
No silt fence to retain sediment-laden runoff on site.Instead, runoff is draining into the street and storm sewers.
Normally, contractors would protect storm drains by catching silt with sand bags placed in the gutters. But this afternoon, I saw none of those either…even though the contractors were working furiously on a Sunday afternoon.
The buildup of sediment in our rivers, streams, and channels was a primary contributing cause of flooding. So why don’t contractors exercise greater caution?
Nature of Phase II Still Uncertain
The land in question is adjacent to another 19.7 acres to the northwest owned by the same developer. That land was cleared starting in 2022.
Contractors have been building apartments since then. The work was supposed to be complete by the end of last year, but is still in progress.
However, the address – Kings River Commercial Road – and the developer’s website, suggest it may be commercial. The website boasts that the developer specializes in high-end, mixed-use apartment complexes within walking distance of retail.
Kingwood Residences HTX and HTX II LLC are limited liability companies owned by High Street Residential, a wholly owned operating subsidiary of Trammell Crow Company in Dallas. Their local headquarters are on 2800 POST OAK BLVD STE 400, HOUSTON TX 77056-6169.
More Photos Taken on 1/14/24
All photos below were all taken today, 1/14/24.
Looking N toward San Jacinto West Fork out of sight in background. West Lake Houston Parkway is on left next to soupy area in foreground.
According to the Harris County Flood Control District (HCFCD) gage at the West Fork and WLHP less than a mile north, this area last received rain on January 8 and it totaled only .4 inches.
Reverse angle, looking S. WLHP on right. Kings Park Way cuts through middle of frame.Detention basin for Phase I (middle left) may or may not serve Phase II. Cleared trees stacked three stories high.
Enough Detention?
For properties this size, HCFCD requires .65 acre feet of stormwater detention basin capacity per acre of developed land. That comes out to roughly 20 acre feet for these combined properties.
I have requested drainage analyses and construction plans from HCFCD but have not yet received them. More news when I do.
According to the U.S. Fish and Wildlife Service, no wetlands exist on either parcel of land. And current FEMA flood maps show both parcels are out of floodplains.
The primary flooding concerns for these properties appear to be making sure they have sufficient detention capacity and that they don’t clog storm drains with sediment.
Ten Elements of an Effective Erosion and Sediment Control (ESC) Plan
The EPA lists 10 elements of an effective erosion control plan.
Minimize Needless Clearing and Grading
Protect Waterways and Stabilize Drainage Ways
Phase Construction to Limit Soil Exposure and Compaction
Stabilize Exposed Soils Immediately
Protect Steep Slopes and Cuts
Install Perimeter Controls to Filter Sediments
Employ Advanced Sediment Settling Controls
Certify Contractors on ESC Plan Implementation
Adjust ESC Plan at Construction Site
Assess ESC Practices After Storms
In fairness, the developer has left a natural border and phased construction. That’s good. But as the resident photos above show, they are not preventing sediment from leaving the site.
Posted by Bob Rehak 1/14/24
2329 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/01/20240114-DJI_0108.jpg?fit=1100%2C733&ssl=17331100adminadmin2024-01-14 17:29:262024-01-14 18:06:51Developer Clearing Land Without Normal Safeguards
Excavation of the decorative ponds that will double as Northpark detention basins at US59 began this week.
Contractors will stockpile the dirt in two places for now: behind Duncan Donuts and at a sand mine on Sorters-McClellan Road several blocks to the west. Contractors will use the dirt later to level the road surface and build access ramps for the bridge over the Union-Pacific Railroad tracks.
In other Northpark-expansion news this week, Entergy still has not started moving its utility poles and transformer.
However, CenterPoint has almost finished relocating its gas line under the road’s center drainage ditch to the south side of the road. CenterPoint also surveyed the north side of the street to place a second line there.
Finally, the Lake Houston Redevelopment Authority (LHRA) is close to finalizing a drainage agreement with the Union-Pacific Railroad. For more details, see below.
Beginning of Entry Pond Excavation
Contractors will excavate the entry ponds/detention basins in several stages. For now, they will excavate down to the water table. Later, they will excavate below the water table, pumping water into new storm sewers as they dig.
Then they will place a liner at the bottom of each pond.
Finally, the ponds will be filled to the level of the storm sewers with a combination of well- and rainwater. But that will come much later.
The distance between the top of water in the ponds and the surface of the ground will retain stormwater to help prevent flooding of the intersection during heavy rains.
The photos below were all taken on 1/13/2024.
Looking at beginning of excavation of north pond. US59 and feeder on left, Northpark on right.Looking west toward US59 bridge. These contractors appear to be defining the margins of the pond.Note stakes.Excavated dirt on right waiting for shipment to a stockpile.Note storm drain on left and the wet earth that indicates proximity to water table.
Bens Branch, which crosses under 59 farther north, often overflows and backs up toward the Northpark intersection. The pipe above will carry water into the pond instead, thus reducing flood risk.
Start of one stockpile behind Duncan Donuts and Public Storage.
Where the Dirt Will Go
The stockpiled dirt will eventually be used to level the roadway over box culverts (when installation is complete) and also to build up ramps for the bridge over the railroad tracks.
When contractors finish placing box culverts, the stockpiled dirt will help level the center of the roadway, which will contain two additional lanes of traffic – one going each direction.
The bed must be raised to the level of the manhole shown above.Looking west toward 59. Power lines belong to Entergy. They must be moved back to approximately where the fire hydrant is now.Yellow/green flags indicate route of new CenterPoint gas line.
Moving the utility poles back will create room for turn lanes next to the bridge over the rail tracks. The turn lanes must be at ground level for traffic turning north or south onto Loop 494.
Project managers first asked Entergy to move its power lines 2020. The utility still has taken no action. Ditto for the transformer below located near the Exxon station at 59.
Entergy transformer in red circle must also be moved back tomake way for additional turn lanes.
An Entergy consultant claimed the company needed 50 weeks to move the transformer above.
The City is reportedly considering legal action against Entergy because of construction delays.
Railroad Agreement Should Be Resolved by End of January
In the good-news department, the last remaining issue with UP will hopefully be resolved within a couple weeks, according to project manager Ralph De Leon. The Lake Houston Redevelopment Authority sought permission to tunnel stormwater under the UP tracks to Ditch One. The railroad company required no more than a quarter-inch displacement of the tracks. Engineers figured out way to do it by splitting the flow from one pipe through two smaller pipes.
The Agreement covers both the aerial easement over UP’s tracks for the bridge and the railroad’s acceptance of the Construction Plans. The stormwater drainage pipes under the tracks held up UP’s final approval of the plans. Now that that has been resolved, UPRR is ready to accept the plans.
Approval by the City will occur in the form of an Ordinance adopted by City Council.
The City of Houston contributed $15.4 million to the Northpark Project. Here is the contract between the City and Lake Houston Redevelopment Authority.
For More Information
De Leon said, “Once the UP agreement is signed, and CenterPoint and Entergy relocate their utilities, we can start building roads. Residents should then see a significant increase in in construction activity.”
SJRA Releases Third Part of Sedimentation Study
In late December 2023, the San Jacinto River Authority (SJRA) released the third part of its massive, years-long sedimentation study. SJRA labeled the report “Technical Memorandum 3: Annual Sediment Supply and Storage.” Only seven more steps remain in the 10-step effort.
The Larger Context
The ten steps include:
SJRA applied for a TWDB grant to study sedimentation in July of 2020 and accepted the grant in July 2021.
Sediment Supply and Storage Methodology/Findings
The study team collected data from three watersheds in the Upper San Jacinto River Basin: Winters Bayou/East Fork, Peach Creek/Caney Creek, and Walnut Creek/Spring Creek (also referred to as the Willow Creek area in the study). They collected samples, measured isotope concentrations, and performed a chemical analysis to determine a “fingerprint” for sediment originating in those areas. Investigators then compared fingerprints of sediment taken from Lake Houston to identify the likely source or origin.
They also measured erodibility of river banks by assessing such factors as bank height, angle, and material; root depths and density; proportion of the bank covered by vegetation, rocks, logs, etc.; and stability of soil strata.
High-Level Finding
Matt Barrett, SJRA’s Water Resources and Flood Management Director, said, “The key data obtained in the efforts described in TM 3 was the determination of where sediment appears to be originating in the sub-watersheds (i.e. upland runoff vs. streambank erosion).”
The study did not directly examine the relative contributions of clear cutting, construction practices and sand mining to sedimentation.
Other Findings
Regardless, the study yielded interesting information about the soil in each area sampled.
At all three streambank sites, samples were composed of varying proportions of sand, silt, and clay, with sand the most prevalent component. Samples taken from floodplains varied more, but bore a resemblance to the corresponding streambank samples.
Samples from the East Fork San Jacinto stream bank and floodplain had more than 50% fine-grained composition, i.e., silt and clay. See table below.
Study authors say, “…the relatively high proportions of fines in the East Fork … samples indicate(s) appreciable upland sediment contribution, consistent with the Pb-210 data.” (See Page 26). Pb is the chemical abbreviation for lead.
Highest Levels of Lead Coming from East Fork
Chemical sampling of Lake Houston sediments indicates that the highest percentage of lead, a naturally occurring element, was found in the East Fork Mouth Bar.
Looking farther upstream at three possible sources of the lead (upland areas, stream banks, floodplains), the authors found that floodplains and upland areas contributed more than streambanks.
It’s impossible to determine the exact point of origin of the lead at this point in the study, say the authors.
The report never mentions Colony Ridge per se. Investigation of “hotspots” won’t happen until Step 6. (See list above.)
However, in my opinion, more study is merited to see whether the lead came from the Colony Ridge area. It has been the largest land-disturbing activity in the East Fork watershed in recent years.
Widespread destruction of wetlands in the massive Colony Ridge development may have contributed to the high lead levels. Wetlands can be pollution-catching powerhouses, according to a University of Waterloo study.
Head Scratchers
In the meantime, I’m wondering how the SJRA’s sedimentation study could have omitted the West Fork San Jacinto as a sampling site. The study does not explain. Barrett said only that they couldn’t afford to sample every watershed.
Yet the West Fork has the largest concentration of sand mines in the region (more than 20 square miles in a 20 mile reach of the river).
However, the report never mentions the phrase “sand mines.” In one paragraph on page 31, it does mention APOs (aggregate production operations). But I had to laugh. It said that ReduceFlooding.com reported “several purported breaches” of APO berms on the West Fork.
In this context, “purported” means “suspected” according to Webster’s Third International Dictionary.
Sampling Concern: Avoiding the Obvious?
I guess they didn’t see the hundreds of photographs that I took of mine breaches or mines pumping their waste into the river. Nor did they read the TCEQ investigation about a 56-million-gallon release of sludge that turned the West Fork white.
Neither does the report mention the terms “development” or “land clearing” – recognized by the EPA as major sources of sedimentation.
That contributed to this sludge fest on the West Fork.
A friend of mine with a PhD in market research once told me that good research often confirms what in retrospect should have been obvious. But the SJRA study isn’t even sampling the obvious.
No telling where their sedimentation study will go at this point. This reminds me of the SJRA’s sand trap study. It recommended relying on a sediment gage upstream from all the sand mines.
Are they avoiding the obvious in their choice of areas they sampled?
Ultimate Goal
When I asked Barrett what he hoped the study would accomplish, he said, “The ultimate goal is to develop conceptual sediment mitigation solutions and implementation strategies. These could be infrastructure projects (stream restoration, sand traps, etc.).”
He continued, “Or they could be best management practices that could be recommended to appropriate government bodies (recommending riparian buffer or enhanced stormwater protection plan requirements that a county could implement, for example).
“These solutions will be included in the Sediment Management Plan, which will provide a ‘menu’ of projects that could be implemented to help mitigate the negative impacts of sedimentation.”
I’ll withhold judgement until we get to the end of this road.
For More Information
Read the entire 66-page Technical Memorandum 3. And review other documents currently posted on the SJRA Sedimentation Study website.
Posted by Bob Rehak on 1/16/24
2331 Days since Hurricane Harvey
Developer Clearing Land Without Normal Safeguards
Kingwood Residences HTX II LLC is clearing 11.5 acres of land on West Lake Houston Parkway (WLHP) without the normal safeguards to control sediment-laden runoff. In recent weeks, concerned residents have emailed me multiple pictures like the ones below.
Normally, contractors would protect storm drains by catching silt with sand bags placed in the gutters. But this afternoon, I saw none of those either…even though the contractors were working furiously on a Sunday afternoon.
The buildup of sediment in our rivers, streams, and channels was a primary contributing cause of flooding. So why don’t contractors exercise greater caution?
Nature of Phase II Still Uncertain
The land in question is adjacent to another 19.7 acres to the northwest owned by the same developer. That land was cleared starting in 2022.
Contractors have been building apartments since then. The work was supposed to be complete by the end of last year, but is still in progress.
It’s not clear what the developer plans to put on Phase II’s land, which was purchased from Pinehurst Trail Holdings LLC in June 2023.
However, the address – Kings River Commercial Road – and the developer’s website, suggest it may be commercial. The website boasts that the developer specializes in high-end, mixed-use apartment complexes within walking distance of retail.
Kingwood Residences HTX and HTX II LLC are limited liability companies owned by High Street Residential, a wholly owned operating subsidiary of Trammell Crow Company in Dallas. Their local headquarters are on 2800 POST OAK BLVD STE 400, HOUSTON TX 77056-6169.
More Photos Taken on 1/14/24
All photos below were all taken today, 1/14/24.
According to the Harris County Flood Control District (HCFCD) gage at the West Fork and WLHP less than a mile north, this area last received rain on January 8 and it totaled only .4 inches.
Enough Detention?
For properties this size, HCFCD requires .65 acre feet of stormwater detention basin capacity per acre of developed land. That comes out to roughly 20 acre feet for these combined properties.
I have requested drainage analyses and construction plans from HCFCD but have not yet received them. More news when I do.
According to the U.S. Fish and Wildlife Service, no wetlands exist on either parcel of land. And current FEMA flood maps show both parcels are out of floodplains.
The primary flooding concerns for these properties appear to be making sure they have sufficient detention capacity and that they don’t clog storm drains with sediment.
Ten Elements of an Effective Erosion and Sediment Control (ESC) Plan
The EPA lists 10 elements of an effective erosion control plan.
In fairness, the developer has left a natural border and phased construction. That’s good. But as the resident photos above show, they are not preventing sediment from leaving the site.
Posted by Bob Rehak 1/14/24
2329 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
Excavation of Northpark Detention Basins Starts
Excavation of the decorative ponds that will double as Northpark detention basins at US59 began this week.
Contractors will stockpile the dirt in two places for now: behind Duncan Donuts and at a sand mine on Sorters-McClellan Road several blocks to the west. Contractors will use the dirt later to level the road surface and build access ramps for the bridge over the Union-Pacific Railroad tracks.
In other Northpark-expansion news this week, Entergy still has not started moving its utility poles and transformer.
However, CenterPoint has almost finished relocating its gas line under the road’s center drainage ditch to the south side of the road. CenterPoint also surveyed the north side of the street to place a second line there.
Finally, the Lake Houston Redevelopment Authority (LHRA) is close to finalizing a drainage agreement with the Union-Pacific Railroad. For more details, see below.
Beginning of Entry Pond Excavation
Contractors will excavate the entry ponds/detention basins in several stages. For now, they will excavate down to the water table. Later, they will excavate below the water table, pumping water into new storm sewers as they dig.
Then they will place a liner at the bottom of each pond.
Finally, the ponds will be filled to the level of the storm sewers with a combination of well- and rainwater. But that will come much later.
The distance between the top of water in the ponds and the surface of the ground will retain stormwater to help prevent flooding of the intersection during heavy rains.
The photos below were all taken on 1/13/2024.
Bens Branch, which crosses under 59 farther north, often overflows and backs up toward the Northpark intersection. The pipe above will carry water into the pond instead, thus reducing flood risk.
Where the Dirt Will Go
The stockpiled dirt will eventually be used to level the roadway over box culverts (when installation is complete) and also to build up ramps for the bridge over the railroad tracks.
When contractors finish placing box culverts, the stockpiled dirt will help level the center of the roadway, which will contain two additional lanes of traffic – one going each direction.
Moving the utility poles back will create room for turn lanes next to the bridge over the rail tracks. The turn lanes must be at ground level for traffic turning north or south onto Loop 494.
Project managers first asked Entergy to move its power lines 2020. The utility still has taken no action. Ditto for the transformer below located near the Exxon station at 59.
An Entergy consultant claimed the company needed 50 weeks to move the transformer above.
The City is reportedly considering legal action against Entergy because of construction delays.
Meanwhile, Entergy continues to promote its social responsibility, even as it holds up construction of the only all-weather evacuation route for 78,000 people.
Railroad Agreement Should Be Resolved by End of January
In the good-news department, the last remaining issue with UP will hopefully be resolved within a couple weeks, according to project manager Ralph De Leon. The Lake Houston Redevelopment Authority sought permission to tunnel stormwater under the UP tracks to Ditch One. The railroad company required no more than a quarter-inch displacement of the tracks. Engineers figured out way to do it by splitting the flow from one pipe through two smaller pipes.
The Agreement covers both the aerial easement over UP’s tracks for the bridge and the railroad’s acceptance of the Construction Plans. The stormwater drainage pipes under the tracks held up UP’s final approval of the plans. Now that that has been resolved, UPRR is ready to accept the plans.
Approval by the City will occur in the form of an Ordinance adopted by City Council.
The City of Houston contributed $15.4 million to the Northpark Project. Here is the contract between the City and Lake Houston Redevelopment Authority.
For More Information
De Leon said, “Once the UP agreement is signed, and CenterPoint and Entergy relocate their utilities, we can start building roads. Residents should then see a significant increase in in construction activity.”
For more information about the project including construction plans, visit the project pages of the LHRA/Tirz 10 website. Or see these posts on ReduceFlooding:
Posted by Bob Rehak on 1/13/24
2328 Days since Hurricane Harvey