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Help Wanted: Can You Explain This Strange Splashing in Water Near RR Bridge Repairs?

On March 6, I flew over the Union Pacific bridge repairs near 59 and the West Fork and noticed some splashing I could not explain. I’ve been on a fruitless search for answers ever since. So now I’m enlisting your help. But first a quick update on the status of repairs.

Update on Repairs

Not much had visibly changed since the previous month on February 23rd. I observed that:

  • The north side of the river looked considerably cleaner.
  • Virtually all supports for the north side of the temporary bridge had been removed.
  • Virtually all of the old supports between the new supports for the main bridge were gone.
  • The big red crane was starting to retreat back to the southern side of the river.
  • Some sort of underwater cutting torch operation was in progress.
  • Pontoon-based lifting equipment was retrieving cut pipe and old cement from the river bottom.
Incremental changes since Feb. 23 flyover. This and all photos below taken March 6.

Enlargement Reveals Splashing

However, when I downloaded the images at home and reviewed them on a big screen, I saw something I could not explain. I saw a giant splash in the water under the bridge that went up at least 10 feet. At first I thought something fell from the bridge. But there was nothing on the bridge as you can see above.

Strange splash in water near old support. Caught at 1/8000th of a second from a helicopter 250 feet away.

Further review of the images reveal tanks of industrial gas, likely used for underwater cutting torches.

Tanks of what might have been acetylene for underwater torches.

Then I noticed the same splash in the same place in dozens of other images as the helicopter circled around the bridge.

Similar splash in same spot several seconds later from different camera position. Also at 1/8000th of a second.

Something falling could have created the splash in one frame. But not multiple frames. Especially since I was shooting at 1/8000th of a second to minimize vibration from the helicopter.

Shot from other side of bridge about 30 seconds later.

The series of shots shows continuous splashing in a virtually identical pattern.

26 Frames Taken 3 Seconds Apart Show Similar Splash

It took almost a minute and a half to circle the operation. During that time, I took 26 shots. Each shot shows water “erupting” in the same place, the same pattern, and to roughly the same height. All while workers sat by unconcerned!

So this was a normal part of the operation. But what caused it? I’m not familiar with underwater cutting. However, I’m guessing, with all the offshore experts in Houston, someone can explain it.

Photo of same site when workers no present by Mike Combat Wilcox.

Mike Combat Wilcox sent me this image from his boat when workers were not present. No workers. No splash. Hmmmm. The mystery deepens.

Two Ways to Help

A hearty corona-virus-free handshake through social media to anyone who has the answer. I will publish it…with a credit if you can explain it.

And let’s have some fun while we’re at it. We need more of that these days.

I’ll also publish a separate list of “creative” answers from the clueless (like me). Try to make people laugh with those. For instance, were the splashes actually “oil company stocks taking a nosedive during corona week”? You get the idea. Have fun people! If you can. I know its painful.

On a More Serious Note

Here’s another wide shot that shows the progress of bridge re-construction. Remember, the goal: widen supports so trees don’t get caught in them during the next flood.

But widening supports requires removing the old ones. Piece by piece. That’s where the cutting and pulling comes in.

If you have possible explanations (real or humorous), please reply through the contact page on ReduceFlooding.com.

Posted by Bob Rehak with image from Mike Combat Wilcox on 3/18/2020

932 Days after 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