Water levels on the Yellowstone River have risen nearly five feet in Billings since Sunday and could go up another foot by the end of the week.
Weather and water watchers around the region, however, don't anticipate damaging floods anywhere along the course of the river between Yellowstone Park and the confluence of the Missouri at the Montana-North Dakota border.
High water poses the biggest threat at Livingston, where the Yellowstone approached flood stage Tuesday and is expected to climb slightly above it by the end of the week.
"Even if it reaches flood stage, we are still doing good," said Belinda Van Nurden, Park County Disaster and Emergency Services director. "We're not really anticipating anything."
Flood stage at Livingston is 8.5 feet. At 2 p.m. Tuesday, water lapped up to 8.34 feet on the gauge. Sally Springer, meteorologist at the National Weather Service Office in Billings, said that Thursday or Friday, the river should hit its peak at 8.6 to 8.8 feet.
"I really don't think it will go above 9 feet," she said.
Whether the highest water comes Thursday or Friday depends on the weather, Springer said. Thursday's forecast is for 90-degree temperatures with a 30 percent chance of afternoon thundershowers. That could mean a peak Thursday.
Friday temperatures are expected to be in the mid-70s, she said, and that could slow snowmelt feeding the rivers.
"We are absolutely keeping an eye on it," Van Nurden said.
She gets updates on the river twice a day from the weather service and personally patrols the most flood-prone areas. Park County crews are checking bridges to make sure debris doesn't jam the channel.
The river set a new May 27 record at Livingston with a flow of 21,200 cubic feet per second on Tuesday morning.
Some Park County creeks have overflowed their banks, Van Nurden said, but they are doing what they are supposed to do, flooding harmlessly onto adjacent fields.
According to the National Weather Service, at flood stage, some minor overflow will occur in the lowest areas along the river and on the road that connects the island with the rest of the town. Van Nurden said the road is designed to let the water wash over, which should present no problems.
If water gets to 9.1 feet, other roads will be washed out or covered with water, and water could reach homes on the island.
High temperatures over Memorial Day weekend started snowmelt flowing out of the mountains, said Roy Kaiser, water-supply specialist for the U.S. Natural Resource and Conservation Service in Bozeman.
"Melt rates are running above average, but they're not at extremes," he said.
The Yellowstone, usually one of the last Montana basins to melt, should peak this week in Livingston, he said. It probably won't crest in Billings until early June, Kaiser said.
But the river is making some impressive strides this week in Billings. It began its rise on Sunday with gauge height at about 5 feet. By 2 p.m. on Tuesday, it was at 9.46 feet. Springer expects it will be up to 10.3 to 10.5 feet by Friday.
The Yellowstone at Billings is not in imminent danger of flooding. Flood stage at Billings is 13 feet.
It's been awhile since the area has seen flow this high on the Yellowstone. The last really high water was June 12, 1997, when the gauge height reached 15 feet. That was the second-highest flow on record. The record was set in 1918, when the river peaked at 15.40 feet.
The record for high water at Livingston was set in 1997, when the gauge read 10.72 feet. Van Nurden said water has squeaked passed flood stage in the two previous years with little ill effect. Last year, the river peaked at 8.81 feet on June 2. That was the fifth-highest crest on record.
Springer said that the weather service will watch Rock Creek near Red Lodge as the snowmelt continues. The creek is forecast to hit a gauge height of 7 feet during the next six days. Flood stage is 7.5 feet.
Reservoirs, including the stubbornly low Bighorn Lake, are at last starting to see some inflows. Tim Felchle, Montana reservoir-operations chief for the Bureau of Reclamation, said that on Tuesday the lake was 2.5 feet above the 3,580-foot level required to launch boats.
Inflows were coming in at about 4,000 cubic feet per second on Tuesday, exceeding releases into the Bighorn River that have been held at 1,300 cfs all year to help the reservoir recover from record low water levels.
Felchle said he may be able to boost releases into the Bighorn River to 1,500 cfs soon. The bare minimum release for maintaining a healthy fishery is 1,500 cfs.
More good news. Darrell Cook, superintendent at Bighorn Canyon National Recreation Area, said that, as soon as water levels on the lake reach 3,590 feet, the marina can be opened. Felchle said the lake could start coming up a foot a day if inflows continue to increase.
Lorna Thackeray can be reached 657-1314 or at email@example.com.