Sunday, July 13, 2025

1938,1991 Mississippi Lock and Dam #3 near Red Wing, MN

(Satellite)

USACE
"Constructed and placed in operation July 1938. The site underwent major rehabilitation from 1988 through 1991. The dam is 365' [111m] long with four roller gates. More than 2,000 feet [610m] of earth embankment with a series of upstream spot dikes completes the structure to create Pool 3."

USACE, St. Paul District posted
In celebration of our 250th anniversary we #TBT to July 21, 1938, when construction was completed on Lock and Dam 3 in Welch, Minnesota.  
The dam is 365 feet long and includes four submersible roller gates. With 2009 federal and American Recovery and Reinvestment Act contributions, an 862-foot-long guide wall extension was completed in April 2011 and a closure dike to mitigate outdraft conditions near the guide wall was completed in October 2011.

RepublicanEagle, File photo

A view with the roller gates all of the way up.
2:14 video @ 0:41

Steve Nieckarz, Aug 2018

Steve Nieckarz, Aug 2018

USACE_report
I'm writing this on Jul 13, 2025, and the gates are all the way up for dams 3, 5a, 9 and 10.

The lock closes when the flow exceeds 125kcfs. [RepublicanEagle]

1907+1922 Black Street Bridge and Old Dam on Great Miami River

1907: (Archived Bridge Hunter; Bridge Hunter)
Dam: (Satellite)

April 2025 Flood


This Apr 2025 post showed up in my feed in July. This is part of the reason the Ohio River got so high in Apr 2025.
Butler County Sheriff's Office posted 0:21 video

Same video

shrews48, Aug 2020

shrews48, Aug 2020

1907 Bridge


It is pin connected.
Postcard via BridgeHunter_1907
"Destroyed by flood 1913; replaced 1922"

1922 Bridge


A view comparable to the flooded view above. The bridge has seven spans.
Street View, Aug 2024

HistoricBridges
This 708' (216m) long bridge has spans of 93' (28m).
"This bridge is a long, multi-span concrete arch bridge noted for its architectural beauty and lack of alteration. Many such bridges that used to exist in Ohio in cities like Dayton and Columbus have been demolished, therefore this bridge has become fairly rare."

2009 photo by James Baughn via BridgeHunter_1922

Saturday, July 12, 2025

Los Angeles, CA: New 18' Outfall (Effluent) Tunnel Collapsed, All 31 Workers Escaped Unharmed

(Satellite)

lacsd, p1

The yellow cylinder to the left of the opening is the basket that the crane used to bring up eight workers at a time. The workers had to climb over a 12-15' pile of loose soil leaving just 3' at the top of the tunnel. Only minor injuries were reported among the 27 workers and 4 rescuers.
ABCnews

ABCnews @ 1:14

The old tunnels were built in 1937 and 1958. The tunnels dump treated wastewater into the ocean. [lacsd, p2] If I remember correctly, they were 8' and 12' in diameter. The new tunnel is 18'.
lacsd, p3

In this view, we can see in the lower-left corner a stockpile of the segments that the Tunnel Boring Machine (TBM) uses to line the tunnel. This news report said the workers had to walk 5 miles to the entrance. Other reports indicated that they had to walk about a mile to get to the shuttle that would take them the last 5 miles to the entrance. The tunnel's planned length is 7 miles.
ABCnews
"There was a location that squeezed the tunnel and forced it to partially collapse." [Robert Ferrante, Chief Engineer & General Manager, LA County Sanitation Districts @ 0:45]

Satellite

"The cave-in apparently happened between the tunnel boring machine, 5 miles in from the only entrance, and the construction crew working 6 miles in, said Michael Chee, spokesperson for the Los Angeles County Sanitation Districts, which is in charge of the nearly $700 million project. The workers were about 400 feet underground....Firefighters said workers had to climb over 12 to 15 feet of fallen dirt and debris to reach the tunnel boring machine and then were transported by vehicle back to the opening. Some people had to be pulled out....The workers were operating the boring machine when the collapse occurred said Robert Ferrante, chief engineer and general manager for the sanitation districts. 'A section that they have already built had squeezing ground and had a collapse, a partial collapse,' he told reporters." [Associated Press article by Damian Dovarganes and Julie Watson in the July 11, 2025, edition of Chicago Tribune]
The first sentence confused me when I read it because a TBM works at the end of the tunnel. Given Robert's comment, I think the TBM was six miles in, and the collapse happened around the 5-mile mark. It is scary to learn that the soil pressure could cave in the concrete segments that are installed to hold the ground up. Perhaps grouting hadn't reached its full strength.

lacsd, p5

This diagram makes me appreciate that the Deep Tunnels dug in Chicagoland were through competent rock.
lacsd, p7

The contract for the Clearwater Project was awarded for $630,500,000 in Jan 2019 with a "notice to proceed" in Apr 2019. The main shaft was dug Jan-Jul, 2020. The TBM was delivered in Oct 2020, and mining began in Jan 2022. As of July 24, 2024, 4.4 miles had been dug, and completion was expected to be in 2Q 2025. [lacsd, p4,5] (I'm writing this July 12, 2025, so that schedule has already slipped.)

"Today [I could not find a date on the webpage], the Sanitation Districts of Los Angeles County (Sanitation Districts) awarded a $630 million construction contract for the Clearwater Project to Dragados USA, Inc....Dragados brings extensive tunneling expertise to the Clearwater Project. The firm has completed more than 530 underground projects in 20 countries, totaling over 800 miles of tunnel. For a recent project in Seattle, Washington, Dragados utilized a 57‐foot diameter tunnel boring machine, which was the largest tunneling machine in the world at that time. “We look forward to working on this important infrastructure project,” said Tom Robertson, Vice President of Dragados. “Our vast experience in tunneling through a wide range of geological conditions will be an asset for the Clearwater Project.”" [cwea]
The Seattle tunnel project was a disaster. The TBM got stuck. They had to dig an access shaft, bring the TBM head up for repair, then lower the head back down to the machine. I had started detailed notes on the tunnel project while it was still in progress, but I got so depressed that I quit following the project. I would not be surprised if lawsuits are still in progress. They were very lucky that it got stuck below vacant land rather than under downtown buildings.
Dec 14, 2020: Mammoet posted
#MilestoneMonday: After a year of meticulous planning, #Mammoet liberated the 1,700t tunnel boring machine, "Big Bertha", in just 16 hours after it had stalled approximately 36m (120 ft.) underground in #Seattle.

1874,1958 Capon Lake Whipple Truss Bridge over Cacapon River near Wardensville, WV

(no Archived Bridge Hunter; no Bridge Hunter; no Historic Bridges; Satellite)

John Cowgill posted
A  Whipple  Truss  Bridge  in  Capon  Bridge,  West  Virginia,  U.S.A.
Jason Burford: This is actually in Capon Lake abt 12 miles from Capon Bridge. 1 of 2 surviving Whipple's in WV.
Capon Bridge on the other hand has a very nice 1933 Parker through truss.

Digitally zoomed to Facebook resolution and then doubled

Street View, Oct 2023

Street View, Jul 2023

Friday, July 11, 2025

1954,1970,1987 Lake Houston Dam and UP Bridge on San Jacinto River in Houston, TX

Dam: (Satellite)
Bridge: (Archived Bridge Hunter; Bridge Hunter; no Historic Bridges; Satellite)

CoastalWaterAuthority

twdb
The spillway is 3,160 (963m) long, and the two earth embankments have a total length of 8,600 (2.6km). Between the spillway and the eastern embankment there is two Tainter gates.

n, Jul 2017

They plan to improve the spillway between 2028 and 2030 with a budget of $160m. [EngageHouston]

stantec
"Built in 1954, Lake Houston Dam is the only source of surface drinking water for over two million Houston, Texas residents."
[I could not find a date for the "elegant engineering solution."]

ReduceFlooding
"CWA is planning to add eleven new tainter gates to the dam for an additional 79,000 cubic feet per second of controlled discharge capacity."

The additional gates will allow them to draw down the lake level faster in anticipation of a major storm. They are also working on long term plans to replace the dam. [ReduceFlooding_Apr_2025]

CommunityImpact
The plan is "to add 11 gates to the spillway dam's existing four-gate structure." [However, only two of the holes in the existing structure actually have gates.]

This is the post that motivated these notes.
Union Pacific Railroad posted
This month’s calendar photo features UP 8393 leading a manifest train across Lake Houston, Texas.
📸 Photo by Stephen Foyt.

Patrick Feller Flickr, License: Creative Commons Attribution (CC BY)
Railroad Bridge over Lake Houston, Texas 1104091512BW
I had to be on the other side of the lake to check a project. A friend on that side has kayaks and we went out on the lake and headed toward the railroad bridge.

1937,1985,2026 IN-46 over Whitewater River

(Archived Bridge Hunter; Bridge Hunter; no Historic Bridges; Satellite)

Street View, Oct 2024

Indiana Department of Transportation: Southeast posted two photos with the comment:
How about a Monday afternoon project update? 🙌
📍 S.R. 46 over Whitewater River - Dearborn Co.
🔄 UPDATE: Crews have successfully removed the aged bridge deck on two of the five truss bridge spans and will soon begin rehabilitating steel members of the bridge (includes repairs, sandblasting and painting), constructing the new bridge deck surface, as well as complete joint replacement work. 
Initial project information is here: https://bit.ly/4kb4qku
1

2

Four of the five spans are over flood plains.
Satellite

The five spans do make an impressive barrel view.
Street View, Mar 2019

2010 photo by Anthony Dillon via BridgeHunter

It sounds like they plan on saving the trusses by rehabilitating them.
in
The I-70 bridge is nearby. More of the $10.6m project will be done in 2026.


Thursday, July 10, 2025

1980 North San Gabriel Dam and Lake Georgetown upstream of Georgetown, TX

(Satellite)

usace, p2

"The North San Gabriel Dam is approximately 6,650 feet (2,027 m) long, 162 feet (49 m) high....The reservoir has a normal storage capacity of 37,100 acre-ft (45,762 Ml) and maximum capacity of 236,500 acre-ft (291,718 Ml). The surface area of the reservoir is 1,310 acres (530 ha) and the total catchment area is 246 square miles (637 square kilometres). The dam has a 1000 feet (305 m) wide uncontrolled spillway with a maximum discharge capacity of 342000 cubic feet per second (9684 cubic metres per second)." [DamsOfTheWorld]

Conservation pool is 791', and flood pool (spillway elevation) is 834'. Maximum design water surface is 856.2', and the top is 861'. [twdb]

July 4, 2025, Flood


A bunch of thunderstorms trained over Central Texas on the morning of July 4, 2025, causing flash floods that killed at over 100 people. The San Gabriel River also got lots of water.

I've learned that "full" is considered conservation pool. So, the dam can hold 236,500/37,100 = 637%. And the lake fills slower as the elevation goes up because there is more land to spread out on.
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