Inundated Bridge: (Satellite)
New Bridge: (Satellite)
This dam is about a mile away from the GAP Trail in Confluence, PA.
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| USACE "Youghiogheny has the capability to store the equivalent run-off of 11 inches of precipitation from its 434 square mile drainage area." (This USACE source says it can store the equivalent of 21 inches of rain.) |
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| Confluence, Pennsylvania 101 posted YOUGHIOGHENY RIVER LAKE: What a difference eight years made! There was the Great St. Patrick’s Day Flood of 1936 that wreaked havoc in Confluence and forced Congress to enact the ‘Flood Control Act.’ The residents were informed of the U.S. Army Corps of Engineers plan to construct a mammoth dam in 1939. The tracks to the Confluence and Oakland Railroad were pulled up and Somerfield abandoned by 1942. World War II halted construction briefly. By 1943, the Dam was completed and filled in 1944. (Photo: U.S. Army Corps of Engineers. Visual Digital Library.) Confluence, Pennsylvania 101 shared |
I didn't notice the hydropower plant until I noticed the "Outflow Playground." Because the powerhouse is downstream from the dam, the tow of the dam is grass.
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| Satellite |
The 12mw powerhouse has two units, and averages 46gwh per year. It went online in 1998. [hydroreform]
The powerhouse must have been added to the end of the outlet works. (inis confirms that it was added to the outlet works.)
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| USACE_brochure |
I noticed that a parking lot would be underwater if the emergency spillway was active. And then I noticed that the water level is so low that the boat ramp doesn't even reach the water in this satellite image. According to Google Earth, this looks like the Nov 2016 image.
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| Satellite |
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| Confluence, Pennsylvania 101 posted A YOUGHIOGHENY DAM INTAKE is pictured. They are exposed due to the extremely low water level of the Youghiogheny River Lake. It brings to mind the postcard of an intake when the Youghiogheny Dam was under construction. Photo: Doug Knight. |
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| Confluence, Pennsylvania 101 commented on their post |
"Youghiogheny River Lake was established in 1944 with the construction of the 184-foot high, 1,604-foot wide Youghiogheny Dam....When water in the lake is extremely low, travelers and boaters can sometimes see a portion of the triple-arched sandstone Great Crossings Bridge, built in 1818 to carry the National Road across the Youghiogheny River." [GAPtrail]
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| Confluence, Pennsylvania 101 posted THE 1818 GREAT CROSSINGS BRIDGE was built to connect Somerset and Fayette Counties along the first federally funded National Road in its heyday. What once spanned the Youghiogheny River has been submerged under the Youghiogheny since 1944. When the Youghiogheny River Lake water level is low—the old bridge is brought to light. Photo: On The Road In Pennsylvania. |
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| History’s Mirror posted The Great Crossings Bridge, dedicated in 1818, is a historic structure located in Somerfield, Pennsylvania, crossing the Youghiogheny River. It holds significance as one of the early examples of stone arch bridges in the United States, an engineering feat of the time. The photograph from the early 1900s, taken by Samuel Brown Fisher (1889-1963), captures this important bridge in a time of change, showcasing the bridge's elegance and utility as it spanned the river. Fisher, a prominent photographer known for documenting the landscapes and structures of Pennsylvania, often focused on rural and historic subjects, capturing the essence of the region's past. [The rest of the description is patitudes.] |
Oct 2024:
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| Confluence, Pennsylvania 101 posted THE GREAT CROSSINGS BRIDGE (Dedicated 1818) was recorded with a 1379 water level on Wednesday, October 16, 2024. Locals have said that this has been among the lowest levels of the Youghiogheny River Lake in years. Photo: Doug Knight Water Level Info: Yough Lake Marina [In the meantime, US-40 was wiped out in North Caroline by Hurricane Helene.] |
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| Tammy Russel commented on the above post Taken on Monday [Oct 14, 2024]. |
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| Confluence, Pennsylvania 101 posted THE GREAT CROSSINGS BRIDGE (Dedicated 1818) is pictured in an almost under-the-arch perspective-from very recently. Photo (From Video): Dalton Smith. |
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| Jim Layhue commented on the above photo 1998 I think |
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| Confluence, Pennsylvania 101 posted THE GREAT CROSSINGS BRIDGE (Dedicated 1818) is pictured in yet another creative angle. What’s impressive here is the sharpness of the detail of the stones in place. Photo: Betty Moore. |
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| Jeff Hickman commented on the above post That very bridge of Summerville before the building of the dam. |
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| Confluence, Pennsylvania 101 posted UNDERNEATH THE GREAT CROSSINGS BRIDGE is pictured from Tuesday, October 22, 2024. Maximize away to observe the intricate detail of 1818 craftsmanship. Photo: Michelle Suter. |
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| Confluence, Pennsylvania 101 posted AERIAL GREAT CROSSINGS BRIDGE is pictured here. You can see the former’Bridge Street’ in Somerfield, Pennsylvania wind up to the bridge. ‘Water Street’ paralleled the Youghiogheny River—branching to the right. Aerial Drone Photo: Yough Lake Marina. Bill Hoffman: They release water to maintain the whitewater related activity's on the yough |
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| Charlie Walbridge commented on the above post See map |
Back when the town of Somerfield still existed because the dam had not yet been built.
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| Confluence, Pennsylvania 101 posted A SOMERFIELD, PENNSYLVANIA AREA AERIAL PHOTO FROM 1939 is presented. Photo: Penn Pilot (1939) 📷. Special Thanks: Michael Reed. |
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| Confluence, Pennsylvania 101 posted THE GREAT CROSSINGS BRIDGE is pictured in a newspaper article from December 28, 1998–when the Youghiogheny River Lake was at its second lowest recorded water level. 📰 Photo: Yough Lake Marina. |
Keystone Weather posted two photos with the comment: "The Great Crossings Bridge on the line of Somerset and Fayette Counties. Here is what it looked like when it was built in the 1800s and now [Nov 2024] as it emerges from the Youghiogheny River Lake due to low water levels."
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Nov 2024. This is another view that allows us to see what a full reservoir would look like.
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| Uncovering PA posted Normally, the 200-year-old Great Crossings Bridge is under 50 feet of water. However, due to the lack of rain in Somerset County, it's now exposed and a really interesting spot to visit. Find out more here: https://uncoveringpa.com/ruins-great-crossings-bridge |
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| uncoveringpa, Public Domain "This sandstone bridge measures 375 feet [114m] in length and is 40 feet [12m] tall and 30 feet [9m] wide." |
You can see some of the remnants of the town that used to here by the original river bank.
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| uncoveringpa, this webpage has some more drone photos of the bridge |
The current satellite image shows a low water level.
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| Satellite |
I fired up Google Earth to determine that the above Google Map image is from Nov 2016. Here is a full image from Aug 2019.
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| Google Earth, Aug 2019 |
More dams were planned for the Youghiogheny River, but WWII put a stop to that plan. [HistoryOfTheUpperYough]
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