RUMFORD — Other than Saturday’s 52 degrees, spring has yet to arrive in Western Maine, which doesn’t bode well for rivers and streams if a sudden warm-up and heavy rain occur.

Although stream flows and dam levels remain low and groundwater levels are normal to below normal, the problem is a heavy snowpack taking on water from rains and ice still several feet thick.

As spring progresses, the probability of major rainstorms and warm temperatures increases, Bruce Fitzgerald, director of the Maine Emergency Management Agency, said Wednesday in a Maine River Flow Advisory Commission conference call.

The significant snowpack and river ice greatly add to the risk factors for flooding. Therefore, the flood potential is “above normal to significantly above normal,” said Greg Stewart, a U.S. Geological Survey hydrologist.

“The longer you carry the risk factors forward, the greater the potential for flooding,” said Lynette Miller, MEMA public information coordinator.

That’s why state and local officials are closely monitoring conditions statewide.

“We’re still very concerned about flooding and we’re watching the weather,” Fitzgerald said. “There is a lot of snow still out there, so the potential is still very high, so we’ll watch this and keep our fingers crossed for when spring decides to show up.”

The Androscoggin River in Rumford was running at 4 to 4½ feet Wednesday into Thursday morning, which is 11 feet below flood stage, according to the National Weather Service’s hydrology report.

In Auburn, by Thursday morning, the Androscoggin was expected to rise to near 5 feet, which is 8 feet below flood stage.

In Mexico, the Swift River was starting to carve a channel through ice and snow still several feet thick. It flowed briskly farther downriver in Rumford before disappearing under the ice and snow.

Typically, stream flows start increasing in early March as snow begins melting. But last month, temperatures were below freezing and below zero for many days. Rivers, lakes and ponds continued to make ice, which is very unusual. The snowpack increased.

According to the Maine Cooperative Snow Survey, snowpack depths as of April 1 ranged from 18 to 42 inches in Oxford and Franklin counties from Rumford and Farmington north. The water content in that snow ranged from 7 to 11 inches.

For this time of year, the water content is in the upper 25 percent to upper 10 percent of historical values, said Bob Marvinney of the Maine Geological Survey.

Stewart said there’s been very little runoff. He said the ice jam potential in the foothills of Maine is well above normal.

“We’re two to three weeks behind where we would be in a normal winter for snow density and stream recharge,” Stewart said.

Snow density (the relative amount of water in the snow) is relatively dry right now, meaning any rainfall would be absorbed by the snowpack.

“With this snow density, if we had 2 inches of rain over the mountains, nothing will happen, because the snowpack is at 0.25 to 0.30 (of an inch in) density,” Stewart said. “It will absorb it.”

That’s why if the state gets a big rainstorm in coastal and southern Maine, flooding will begin there first.

“Any rain inland will be absorbed by the snowpack,” Stewart said.

That rain will come late Friday night into Saturday and on Tuesday, April 8, said Tom Hawley, a hydrologist with the National Weather Service in Gray.

“Over the next 10 to 14 days, temperatures will average below normal and precipitation will be above normal,” Hawley said.

The storm on Friday and Saturday is expected to begin as sleet and snow in the western mountains before changing over to between half an inch and three-quarters of an inch of rain.

Next Tuesday’s storm will be more significant, he said. It’s expected to dump more than an inch of rain on the coast and southern Maine and an inch in the mountains if it doesn’t start as snow or sleet, Hawley said.

He said high temperatures would be in the 40s but lower than Portland’s average high of 48 degrees for this time of year, while low temperatures will range from the teens to the 20s.

Those temperatures will support a slow snow melt and ice erosion, which is good, he said.

However, going into the middle of April with a heavy snowpack raises the flood potential to above average, Hawley said.

The flood potential for the Androscoggin River “is well above normal,” because there is a lot of water on the ground at its headwaters, he said. He’s anticipating more snowfall there as well.

“The ice jam potential on the Androscoggin River and its tributaries is above normal,” Hawley said. “The sun is trying to work on the ice south of Auburn, so there will be no issues there, but there may be some issues in Rumford.”

tkarkos@sunjournal.com

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