UPDATE: With overnight storms and more rainfall over Tulsa and areas to the west, the lake level in Keystone Reservoir inched up and U.S. Army Corps of Engineers data showed a slight increase in the release from levels in the 254,000 cfs range to 255,500 early Sunday.
Straight-line winds and possible tornados caused extensive damage in Sapulpa and across south Tulsa overnight and left thousands without electricity.
Oklahoma Mesonet online maps showed 12-hour rain totals early Sunday of an additional inch near Skiatook to 1.5 to 2 inches over the Arkansas and Cimarron river basins across Osage County and southwest to Logan County. The weekly totals for much of that area now totals from 10 to 12 inches.
The National Weather Service online forecasts called for a 30 percent chance of thunderstorms through Sunday morning in the Tulsa area, and areas to the north and west, with clearing skies heading into afternoon and Memorial Day.
Flows into Keystone Lake began to climb early Sunday, after the inflows dropped down to levels equal to and below the amount being released late Friday and at times on Saturday. Inflows crept as high as 282,000 cfs early Sunday. The lake level hit its highest point of this flood event at 755.82 feet at 7 a.m. The maximum lake level is 757, Corps officials have said.
Upstream at Kaw Reservoir the lake level remains above the official flood pool level with a consistent 105,000 cfs release and inflow fluctuating in the 90,000 range, but the Arkansas River at Ralston, still in major flood level, is predicted to rise to 22.5 feet by 1 p.m. Sunday, just 6 inches shy of its record flood level, according to the National Weather Service Hydrologic Prediction Service online charts. Flow there rose to 181,674 cfs at 7 a.m. Sunday, according to the Corps.
After falling to 19 feet with reduced flows Saturday, the Cimarron River also was forecast to rise is forecast to again rise to 25 feet Monday, according Weather Service charts. The Cimarron’s flow at Ripley rose from 47,000 cfs to nearly 65,000 cfs from midnight to 7 a.m. Sunday.
The Verdigris River at Claremore is predicted to continue to climb to 47.6 feet into Monday, it’s highest point in this event. Oologah Lake reservoir upstream remained more than 4 feet above the top of its flood pool but was inching down with less inflow Sunday.
Below is an earlier version of this story.
The 70-year-old Tulsa County levee system will bear heavy pressure at least until Wednesday, and residents living nearby are at “very high” risk if they don’t evacuate, Tulsa Mayor G.T. Bynum said Saturday.
Due to heavy rains in the area, the U.S. Army Corps of Engineers announced that it will continue to release water from Keystone Dam at its current rate until Wednesday — three days longer than the Corps initially had hoped.
The release, currently at about 255,000 cubic feet per second, won’t raise the current levels of the Arkansas River in Tulsa; but it is applying pressure on levees like never before, according to city and county officials.
In 1986, the city’s flood of record, the levees bore pressure for about 12 hours. This year, they’re expected to bear that same type of pressure nearly 12 times as long.
If one of the levees experiences a significant breach, residents living behind them won’t have much time to evacuate. Officials warned Saturday that residents should be making evacuation preparations now.
“They were built for a reason and they are there to protect people. And they are protecting people right now,” Bynum said during a press conference at the Tulsa Police Department’s downtown headquarters. “But they are also over 70 years old, and they are earthen levees. And they have never been tested like they will be over the next four or five days.
“And so folks need to take that into consideration. If you and your family live behind it, the level of risk that you have in staying there is very high. And it’s an unnecessary risk.”
The Corps originally planned to taper down the Keystone Dam release rate sometime Sunday. But after more rain fell throughout saturated northeast Oklahoma — with Miami receiving more than 1.2 inches and Tulsa seeing about seven-tenths of an inch — overnight Friday, the Corps opted to extend the rate of 255,000 cfs to Wednesday.
The levee system has already experienced high pressure for more than 36 hours. A levee in west Tulsa began leaking on Thursday, prompting the emergency creation of a new levee in the area of West 41st Street and South Elwood Avenue in order to protect homes in the Garden City neighborhood.
The Tulsa Area Emergency Management Agency recommended contingency plans for residents living:
• east of River City Park Road and west of 65th West Avenue south of U.S. 412.
• between 65th West Avenue and Newblock Park south of U.S. 412.
“Right now is the time you need to be preparing to move to higher ground. Find a friend. Find a family member,” TAEMA executive director Joe Kralicek said. “We’re not trying to panic you, but we do urge you to take this very seriously and prepare.”
David Williams, chief of hydrology and hydraulic engineering for the Corps’ Tulsa District, said “we are experiencing a historic flood not only in Tulsa but in all of northeast Oklahoma.”
“We have been experiencing a moderate flood along the Arkansas River in Tulsa. We are experiencing a catastrophic flood in Muskogee and points below that location,” Williams said. “In fact, the flood in those locations may be the flood of record.”
The town of Braggs in Muskogee County is without power until water levels recede there, and access to the city through highways is blocked due to flooding.
The Oklahoma Turnpike Authority announced it would allow motorists to use the Muskogee Turnpike free of charge from the U.S. 69 entrance to Oklahoma 165. U.S. 62 is closed between Oklahoma 80 near Fort Gibson and Oklahoma 65, and Oklahoma 10 is closed at Big Greenleaf Creek located about 3½ miles south of Braggs. U.S. 69 southbound is also closed north of Muskogee.
Although flooding in Tulsa County has largely been confined to low-lying areas near the Arkansas River and in designated 100-year floodplains, Bynum said he did not want residents near levees to wait and see whether their homes or lives would be endangered.
He noted a breach could give people only minutes to flee, while the gradual releases of water from the Keystone Dam allow residents to have several hours’ notice.
“You don’t know what the extent of any breach might be. It may be a small leak which can be fixed by the Corps or by our on-retainer contractor (Crossland Construction) and then there’s no issue. But there could be a larger breach that occurs and then you don’t have enough time for people to relocate.”
Bynum warned residents that the river’s current is “extraordinary. Even the strongest swimmer cannot handle the current that’s out there, let alone the debris that’s in it or the toxins and wildlife that’s in it. This isn’t just for little kids. This is for adults, too. Stay out of the water.”
Tulsa County Board of Commissioners Chairwoman Karen Keith said the levees are “in a precarious situation that they’ve never been in,” noting the ground continues to soften around them due to prolonged water exposure.
“We will have water standing on their edges for now, what, 140 hours?” she said. “That’s what we think now. We know additional water could be heading our way. I really ask you to just go ahead, even if you didn’t have water in ‘86, to please take precautions and go stay with some relatives.”
Keith said the National Guard will be sending personnel in order to ensure someone is monitoring the levees at all times. She said the Corps also has a sand machine to expedite filling sandbags, which can be picked up free of charge at the Mabee Center parking lot at Oral Roberts University, 7777 S. Lewis Ave., or at the Jenks Softball Field at 1701 N. Birch St.
The Jenks location, according to TAEMA, will have bags to fill, though residents in need will have to bring their own shovels.
Bynum said first responders and police have been assigned to areas west of downtown to help protect the property of those who choose to proactively leave and to assist with safe evacuation efforts.
He said the patrols will also be on hand to arrest “anybody that might take advantage of folks who are trying to do the right thing.”
“Everything’s working the way it should right now,” Bynum said of the situation. “But in every step of the way throughout this event, we’ve always wanted to side with an abundance of caution.”
Chief Photographer Tom Gilbert went up in a helicopter to show what the flooding looked like on Friday.