1964 90mw Eufaula Dam and Lake on Canadian River in Oklahoma

(Satellite)

Eufaula Lake is also (more commonly?) called Lake Eufaula. It is the largest in Oklahoma and one of the largest man-mad lakes in the world. "Congress approved construction of the Eufaula Dam which serves to provide flood control, water supply, navigation and hydroelectric power generation to the area. Built from concrete and earthen embankment the dam is 3,200 feet long and 114 feet high. Constructed by the United States Army Corps of Engineers, it has three turbines and a capacity of 90 megawatts....With beautiful scenery and 800+ miles of shoreline, Lake Eufaula is a favorite spot for fishing, boating, skiing, kayaking and other water activities. Lake Eufaula attracts more than 2.5 million visitors annually and offers several camping and cabin options for visitors."   [PorchesAndPastures] (I'm surprised to see navigation specified as one of the functions of the dam since there are no locks.)

USACE-Facebook, Jun 23, 2015
[48,000cfs at an pool elevation of 597.60'.]

I found this dam when I noticed on a map that Big Boy was going across just the lobe of a huge lake. In fact, Lake Eufaula is the largest lake in Oklahoma.

River Rail Photo posted

Yoo·faa·luh. While Union Pacific Railroad's 4014 (Alco, 4-8-8-4) has been traveling around the system, it has seen all kinds of terrain from mountains to canyons. One of the more distinctive views could be enjoyed on Thursday, August 12, 2021 as the "The Big Boy" skirted the shores of Lake Eufaula near Crowder Point, Oklahoma. Drivers on the parallel road, U.S. Route 69, were turning their heads as the unique power sped along by the water towards its last stop for the day in McAlester, Oklahoma.

Flickr: https://flic.kr/p/2mhW1tp

 

USACE, cropped via EncyclopediaBritannica
"The Eufaula Dam (1964) on the Canadian River impounds one of the world’s largest man-made lakes, covering 102,500 acres (41,500 hectares)."

USACE via PublicRadioTulsa (This also has a video)
[Releasing 172kcfs in 2015]

In the chart below I wondered why they would be releasing (spilling) 31cfs rather than saving it for hydropower. Then I realized that 31cfs is basically a gate leak. Then I noticed the Gate Settings of "1 Sluice Gates open 0.1 FT." So it is a leak because they can't close one of the gates all of the way. I'm surprised that the USACE uses "sluice gate" as a generic term for spillway gate because sluice gate is also a specific type of gate design. The photo at the top of these notes clearly shows that this dam uses Tainter gates.

USACE, Part 1

USACE, Part 2

USACE-map via TravelOK at 50%

I zoomed in on an area that includes the town of Eufaula because I wanted to confirm that there is no light green area along the shore of that town. That means the town is built on enough of a hill that water won't come inland as the lake level rises during a flood event. I included Fourtainhead State Park and the Eufaula WMA (my guess: Water Management Area) to illustrate an area where any facilities that are built there have to be designed to tolerate periodic flooding. The economy of the area has become dependent on 2.5 million visitors per year and bass fishing. So the USACE has to listen about small businesses hurting whenever the dam does its job of flood control. I read a comment asking why the USACE doesn't open the gates before predicted rain storms to reduce the flood levels. USACE did not respond in public but invited the commentator to come take a guided tour. Is the bottom of the gates at the conservation level? If so, they can't lower the lake further in anticipation of a flood event.  The first paragraph of these notes lists the four functions of the dam as intended by Congress. Note that the list does not include recreation. But a recreation industry develops around USACE created lakes and the locals think that is the function of the dam. Many small businesses are dependent on the lake level to not dramatically exceed the conservation level. They should contribute to a fund during the good times so that they can withdraw from that fund during the flood times. From what I have seen of YouTube search results, 2015 and 2019 were the recent years that had floods.

USACE-map via TravelOK at 100%

The lake level exceeded 595' twice in 2015. In February, it was within a third of a foot (0.32') of topping the dam and caused releases of 171 kcfs. "In 1990, the Lake Eufaula lake level reached a record level of 599.70 feet, just barely squeaking under the maximum level of 600 feet and nearly an amazing 15 feet higher than normal. The United States Army Corps of Engineers had to release 235,000 cubic feet per second to control the flooding by opening the Eufaula Dam’s gates up 18 feet." [PorchesAndPastures]

uslakes-level via uslakes

Screenshot, May 13, 2015. Gates at 3' passing 48 kcfs but they didn't give a lake level.