West Fork Archives - Page 4 of 6

Crenshaw, Brady, Cruz and Cornyn Ask FEMA to Dredge More of West Fork Mouth Bar

On October 24, 2019, Congressman Dan Crenshaw, along with Texas Senators John Cornyn and Ted Cruz and Representative Kevin Brady (TX-08), sent a letter to Acting FEMA Administrator Peter Gaynor. The letter requested FEMA’s swift approval of the City of Houston’s new plan to dredge more of the San Jacinto river mouth bar.

Letter in Response to New Request Filed by City

The letter came in response to the most recent request from the City for FEMA aid on or about October 11, 2019.

While FEMA has already completed its initial 500,000 cubic-yard debris-removal mission, sediment brought by Hurricane Harvey still exists in the San Jacinto river mouth-bar. To protect Houston, Kingwood, and Humble residents from future flooding, it is imperative that the remaining debris is removed, said Congressman Dan Crenshaw.

“The City of Houston recently filed a Project Worksheet (PW) for debris removal as Category A work under the Public Assistance program,” the group of legislators wrote. “We urge you to use any and all necessary FEMA resources to expeditiously review and approve the city’s PW. Delay will only increase costs and prevent FEMA from fully leveraging presently available dredging assets.”

To see the complete letter, click here.

Great Lakes Packing Up

Great Lakes Dredge and Dock has finished its Army Corps assignment at the mouth bar. I photographed workers continuing to dismantle the company’s dredge this afternoon.

*Packing it in. Great Lakes Dismantles its dredge after a little more than a year on the West Fork. Photo taken 10/26/2019.*

*The command post opposite Marina Drive in Forest Cove was a behind of activity this afternoon.*

*Note the sections of dredge pipe stacked up in the background. It is no longer connected to the dredge.*

*Crew and survey boats, cranes and other heavy equipment still remain to support a future dredging effort…but not for long.*

The last line of the letter (“leveraging presently available dredging assets”) refers to assets other than the dredge itself. Such assets include the command post opposite Forest Cove, a second launch point in Atascocita, pipe, cranes, and other assets that could soon be removed. See photos above.

TDEM to Forward Request to FEMA

As of yesterday, according to Houston City Council Member Dave Martin, TDEM still had not forwarded the request to FEMA. However, this reportedly falls within TDEM’s normal processing time for such requests. I wouldn’t read too much into it yet. But let’s hope they hustle up. Those crews at the command site were working late into Saturday night. I’m guessing that represents overtime.

You can clearly see from the pictures above how much equipment it takes to support a dredging operation. And remember, each 40-section of dredge pipe weighs 4,000 pounds and there are about 10 miles of it! This request should not be taken lightly.

Posted by Bob Rehak on 10/26/2019

788 Days since Hurricane Harvey

Wednesday AM River, Lake Report: No Problems Yet

Here’s a river/lake report as of 7a.m. Wednesday, 9/18/19. During the early morning hours, TS Imelda was downgraded to a depression. The center of the storm moved north and is now over northern Harris County. Parts of the Lake Houston area received 4-5 inches of rain. Regardless, thanks to aggressive action by the City and luck in rainfall patterns, at this hour, no flood threat exists in our area from rivers or Lake Houston.

Little Rain So Far Upstream on West Fork

*Rainfall around Lake Conroe overnight. Source: Harris County Flood Warning System*

Luckily, very little rain fell upstream from us on the West Fork. In fact, the Lake Conroe area generally received less than a quarter inch of rain. Lake Conroe is releasing NO water at this hour. It’s level has not changed appreciably over night. It remains about 2.5 feet below normal.

West Fork and Lake Houston Still Below Normal Levels

*Rainfall in Lake Houston Area. Source: Harris County Flood Warning System*

*West Fork status at Lake Houston Parkway. Source: Harris County Flood Warning System.*

The West Lake Houston Parkway gage at the West Fork received a little more than four inches of rain in the last 24 hours. But the river is still within 6 feet of overflowing and the Lake itself is still about a foot below normal.

*Source: USGS as reported by Coastal Water Authority.*

Openning Gates Reduced Flood Threat

Looking at the right of the graph above, you can see how yesterday’s decision to open the gates on Lake Houston lowered the level by an addition 1.3 feet. This helped offset the heavy rains that fell directly over the lake an in nearby tributaries.

The heaviest rain in the Lake Houston area appears to be 5.72 inches in Liberty County on the East Fork northeast of Lake Houston Park.

Overbank Flooding Limited to Southern Harris County So Far

The only flooding in Harris County from the heavy rains yesterday occurred in the extreme southern part of the county where the heaviest rains fell.

Flash Flood Watch Remains In Effect

Remain alert throughout today. A flash flood watch remains in effect for our area through tomorrow morning and will likely be extended.

Forecasters expect the heaviest rains with daytime heating. They predict that a band of rain will set up east of US59 this afternoon.

Conditions could change rapidly, especially now that the ground is fully saturated.

In the meantime, remain alert for street flooding and avoid travel if possible.

Posted by Bob Rehak on 9/18/2019 at 7 a.m.

750 Days since Hurricane Harvey

Living Landscape: San Jacinto River Before Lake Houston and Now

Geologic change happens so slowly, most people won’t live or stay long enough in one place to perceive it. Then something happens to make you crank up the Wayback Machine and look more closely. Yesterday was one of those days for me. The Army Corps announced that it was going to begin dredging part of the West Fork mouth bar area.

That raised the question, “Which part?” That wasn’t announced. So I asked Tim Garfield, retired chief geologist for one of the world’s largest oil companies, what he would do. He felt it was important to re-establish the river’s natural channel. So I asked him where it was. (Spoiler alert: It’s between the mouth bar and Atascocita Point.) But in the process of figuring this out, I learned many more things about the mouth bar and a river I take for granted. I’ll save those for the end.

70 Years of Change on the River

Garfield led me to the Perry-Castañeda Map Collection of Texas Topographic Maps at the UT Library Online. He found this map from 1949 of Moonshine Hill. It’s exactly 70 years old! The 1949 date means we can see where the river was before the dam and lake were built in 1955.

*The San Jacinto in 1949 before Lake Houston was impounded in 1955.* *For a higher resolution version of this map,* *click here. This map shows what geologists call “the relict channel.”*

Kingwood, Atascocita and Huffman Before Settlement

This map shows areas that would eventually become Atascocita, Kingwood, and Huffman. It includes the area where the mouth bar has formed between Kings Point and Atascocita Point.

You can tell a lot by looking at this map. You can tell even more when you superimpose it over a satellite view of the area today in Photoshop. Suddenly, you see how the landscape has changed. In fact, it changed so much that I had problems aligning the two images.

Map Superimposed Over Satellite Image At Varying Opacities

However, the county line and 1960 are still in the same location. So I used those as reference points. Then I varied the opacity in the top layer (the old map) so that you could see more and more of the current landscape. At different percentages, you can see how various features have changed over time.

Here’s what the sequence looks like starting with 1949 and today. I started by cropping tighter on the area of interest, the West Fork where the Corps is dredging. I include several different opacity ratios because some changes become more apparent at one ratio than another.

Most Visible Changes

Starting from the left:

In the 33/67 image, notice how the river once meandered near US59 and how much further south it was.
In the 50/50 image, notice how much of the Romerica land was swamp in 1949…and still is.
In the 75/25 image, notice how much the river migrated north just north of Kings River estates.
In the 25/75 image, notice how much area the lake claimed.
In the 33/67 image, notice how far north the river has shifted under the West Lake Houston Parkway bridge.
In the 33/67 image, notice how Atascocita Point has grown past the relict channel.
In the 60/40 image, notice how the mouth bar grew at the confluence of a relict stream bed within the lake and the relict channel of the West Fork. You can also see this pretty clearly in the 25/75 image.
In the 25/75 image, notice how the relict West Fork channel used to hug Atascocita Shores.

Key Map

This image shows locations referenced above for those who may not be familiar with them.

Do you see other things that I did not? Please let me know through the contact form on this web site.

As the dredging program moves forward, these maps may also help inform dredging strategy. Stay tuned.

Posted by Bob Rehak on 6/13/2019

653 Days after Hurricane Harvey

East and West Forks Out of Banks Already, Flash Flood Watch Extended to 2 a.m. Wednesday

My friend, John Knoerzer, owner of Uniserve Air Conditioning, sent me this video from East End Park around sunset tonight. It shows the East Fork of the San Jacinto River has already come out of its banks. This was at about 6:22 p.m. Tuesday.

Even Gus the Poodle knows to stay away from the raging East Fork. Shown here: the North Loop Trail in East End Park.

I have no pictures from the West Fork, so this graph will have to do. It shows that the West Fork at US59 is already out of its banks and in the moderate flooding stage.

Flash Flood Watch Extended to 2AM Wednesday

Meanwhile, the National Weather Service has extended the Flash Flood Watch for Houston until 2 a.m. Wednesday. This means conditions are favorable for flooding to occur. A nearly stationary weak boundary is focusing training showers and thunderstorms across the watch area. Very heavy rainfall is occurring in a short time period, which can cause flooding of streets, creeks and bayous. With the loss of daytime heating, precipitation should begin to gradually weaken as we head into the overnight hours.

Said Jeff Lindner of Harris County Flood Control, “Rainfall amounts of 5-9 inches occurred this afternoon over NE Harris County in the Kingwood/Humble area resulting in significant street flooding. Water is taking time to go down due to the large volume of water that fell in such a short period of time.”

Areas under flash flood watch as of 8:30PM Tuesday night.

Romerica Land Going Under for 7th Time in 14 Months

Harris County’s Real Time Inundation Mapping System shows that the area below the Barrington where Romerica hopes to build it’s residential, commercial and hotel high rises is largely under water as of this writing. That will make the seventh flood in the last 14 months. At times like these, I wish people, i.e., developers with dreams, would learn to listen to nature.

Take Protective Action

Be Prepared. People should bring their pets inside and delay travel or outdoor activities during periods of heavy rainfall. If travel is unavoidable, reduce your speed to avoid hydroplaning. If a Flash Flood Warning is issued for your area, DO NOT travel.

Turn Around, Don’t Drown®: Do not drive through flooded areas. If you see water covering the road, do not attempt to cross it. Only a few inches of water can float a vehicle . If you find yourself in a dangerous situation where your vehicle is taking on water, get out of the vehicle, get to a higher position, and call 911.

Monitor Official Sources for Current Information: Harris County Flood Warning System (harriscountyfws.org), Houston TranStar (houstontranstar.org), and the National Weather Service Houston/Galveston Forecast Office (weather.gov/hgx).

Monitor Stream, Bayou, and Creek Conditions: Rain may move repeatedly across the same area, causing creeks and bayous to rise and possibly exceed their banks. Stay informed of current conditions and avoid traveling near creeks and bayous.

Avoid Traveling during Periods of Heavy Rain: Rain can reduce visibility and prevent you from seeing the road ahead, which could lead to accidents.

Posted by Bob Rehak on 5/7/19 at 8:30 PM

616 Days since Hurricane Harvey

What 470 Cubic Yards of Muck Per Hour Looks Like at 1/8000th of a Second

I visited Placement Area 1 this morning . Muck was shooting out of the “diffuser pipe” at 470 cubic yards per hour. That’s enough to fill up 47 dump trucks every hour! A truly impressive sight. So I grabbed my Nikon D5 and started clicking. Only after downloading the images did I realize that I had the shutter set to 1/8000th of a second.

Liquid Looks Like Glass at 1/8000th

Normally, when shooting flowing water, you want to use shutter speeds in the range of 1/8th to 1/60th of a second. Slower speeds blur the liquid and create a sense of motion. The faster speed, however, froze the motion and made the liquid look like glass.

In photography, sometimes mistakes make the shot. This may have been one of those times. As I stared at the effluent, I became transfixed by the thousands of bursting bubbles within it. You can also see how the further the “spray” gets from the pipe, the bursting bubbles begin to reform into smaller droplets.

Effect of Diffusion Pipe

Dredgers call this a diffusion pipe because of those rings on the end of it. They allow the dredger to control the spread of the effluent. By adjusting the spread, they can make it shoot out far like a fire hose or spread out wide.

In this case, they had it set to “wide” so that it would be more controllable.

*Diffuser pipe at Placement Area #1 shooting out effluent at 470 cubic yards per minute. Shot with a Nikon D5 at 1/8000th of a second.*

*A slightly wider shot shows sand piling up. All the water in the effluent finds its way back into the river after sediment drops out of suspension and it is filtered by gravity.*

*This shot shows three separate activities: a) the pit being filled, b) an excavator moving sand out of the flow, and c) loading a sand truck which will haul it away.*

Now Selling Sand from Placement Area #1

A worker told me that early last week, the pit owner started selling sand from the site to an asphalt company. At the present rate, they are hauling it away about half as fast as the pit is being filled. This will help create extra storage area in the pit should the US Army Corps of Engineers choose to use it for the next phase of dredging – the mouth bar.

Max Flow Rates

As impressive as this flow is, I’m told it can go even higher – up to about 1,000 cubic yards per hour. The rate depends on factors such as the density and hardness of the spoils, as well as the distance they are pumped.

Details Still Being Worked Out on Mouth Bar

Still no official word yet on details of Phase 2 – the mouth bar project. The Corps is still evaluating placement areas. It could be that they need to permit more than one to contain the entire mouth bar. However, they also need to move quickly to make sure the dredgers don’t move on to another job.

Because of the lengthy amount of time permitting a placement area can take, the Corps may try to buy time by directing spoils to one or both of the current placement areas which are already permitted.

The more sand that pit owners can sell, the more capacity they will have, and the faster phase two of West Fork dredging can start.

FEMA will not pay to remove the entire mouth bar. FEMA has been working with the Corps and the City of Houston to determine how much of the mouth bar was due to Harvey. By statute, that’s all FEMA can pay to remove.

Variables Complicate Decisions

The City, State and Harris County will have to pay to remove the rest. That’s part of the contingency planning at this point. No details have yet been released about how all the pieces of this jigsaw puzzle will fit together.

Planners are now trying to optimize for at least ten variables that I have heard discussed.

Volume due to Harvey
Time required to dredge it
Available storage in existing placement areas
Additional cost to move it to those placement areas (pipe, booster pumps, fuel, etc.)
Productivity loss due to additional distance from mouth bar
Cost versus amount funded by FEMA
Placement areas and cost for any volume FEMA does not fund
Time required to permit new placement area(s)
Where money will come from to cover what FEMA does not cover
When additional funds will be available

Not simple! We can only wish that they could make the decision in 1/8000th of a second.

Posted by Bob Rehak on 5/2/2019

611 Days since Hurricane Harvey

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