Early indications show chance for flooding this spring in central N.D.
JAMESTOWN, N.D.--Early signs indicate a chance for flooding this spring along the James River, according to Daryl Ritchison, extension meteorologist for North Dakota State University. "We're on pace to set a snow record or match the bad winters o...
JAMESTOWN, N.D.-Early signs indicate a chance for flooding this spring along the James River, according to Daryl Ritchison, extension meteorologist for North Dakota State University.
"We're on pace to set a snow record or match the bad winters of 1996 and 1997 and 2009 through 2011," he said. "Right now we're equal to or within an inch of where we were in 2009."
Jerry Bergquist, Stutsman County emergency manager, said Jamestown received about 100 inches of snow in the 1996 to 1997 winter.
Bob Martin, dam manager for the Army Corps of Engineers at Pipestem Dam, said the first snowpack measurement of the year exceeds measurements from some of the major flood years in recent Jamestown history.
He measured 21.8 inches of snow with a moisture equivalent of 2.69 inches of water on Jan. 3 at Pipestem Dam. That compares to 20.4 inches of snow and 3.9 inches of moisture in early January 2011 and 18.6 inches of snow and 3.65 inches of moisture in early February of 2009.
"We're kind of matching up to the years 2009 and 2011," Martin said. "We had a lot of activity in the spring of those years."
The James River saw significant flooding in the springs of 2009 and 2011 after winters with above average snow accumulations.
Ritchison said early winter snows don't necessarily mean a spring flood.
"It (snow or rain) has to continue to match those kind of spring events," he said.
The three-month forecast from the National Weather Service for January through March calls for below normal temperatures for Jamestown. The area is on the edge of an above normal precipitation forecast.
Bergquist said it is too early to worry about flooding.
"Although we're all thinking about it," he said. "We have to wait and see, but things are stacking up against us."
One of Bergquist's concerns is the amount of debris, mostly fallen trees and brush, in the James River in Jamestown.
The flood of 2009 cleared the river of much of the debris. During the 2011 flood, the river flowed faster and handled a larger flow of water at a lower level than other floods, Bergquist said.
"The debris has accumulated since 2011," he said. "We can't count on handling the amount of water we handled in the past. Handling 1,800 cfs (cubic feet per second combined from Pipestem and Jamestown dams) won't be the same this year as in previous years."
In previous years, 1,800 cfs combined releases were considered the maximum flow through Jamestown without requiring dikes.
The city of Jamestown and Jamestown Parks and Recreation Department are cooperating on a project to clear fallen trees on public land at Nickeus Park this month. The project is designed to determine the feasibility and cost of doing a larger debris removal project through Jamestown, Bergquist said.
"No matter how that goes, they can't clear all the trees before spring," he said.
The major factors that could create a flood are outside of human control and include the amount of rain and snow this winter and how the snowpack melts in the spring.
"The nastiest floods usually have an April rain," Ritchison said.
Ritchison said spring weather with thawing temperatures during the day and below freezing temperatures at night would also reduce the chance of flooding. The cycle of thawing and freezing weather slows the melt and spreads the runoff over a longer time reducing flooding, he said.
Another factor could be the depth of the frost in the ground, Martin said.
The warm fall weather prevented the ground from freezing early, he said. Then, heavy snow blanketed the ground before the cold weather.
"A contractor told me the frost is only 4 inches deep," Martin said. "The snowcover now will keep the frost from getting much deeper."
The less frost in the ground, the quicker the ground will thaw. Once the ground thaws, some water soaks away rather than running into streams contributing to flooding, he said.
But there are some factors already pointing to the possibility of flooding, especially in the headwater areas of the James and Sheyenne rivers.
"Wells and Sheridan counties have more snow than Jamestown does," Ritchison said. "They have 50 inches of snow, a foot more than Jamestown."
Snowmelt from those areas will run into the James and Sheyenne rivers and Pipestem Creek before flowing through Jamestown and Valley City.
"I hope I'm wrong," Ritchison said. "But I think a moderate flood stage is a starting point this year. Anymore snow or rain and we could go up from there."