LYONS — Swollen streams are running faster than normal in northern Colorado while an enormous snowpack begins to melt in the mountains above.
With reservoirs too full to help absorb the expected rush, municipal, county and state crews are scrambling to strengthen improvements in the same areas wrecked by last fall’s flooding.
A snowpack that the National Weather Service ranks among the highest in the past 35 years is poised to melt and cause flooding in normal conditions. Instead, snowmelt will rake across a landscape left fragile by September’s historic floods.
Crews hope spring flooding doesn’t endanger the millions of dollars in repairs that already have been made.
Whether the crews have done enough in time is a question that can be answered only by Mother Nature.
“Nobody is quite sure how things are going to respond,” said Bill McCormick, Colorado’s chief of dam safety.
September’s floods plowed through this region, obliterating the stream banks, dams and ditches that help funnel water from the mountains to the plains. In Larimer County, the flood damaged or destroyed 65 culverts and bridges.
Still about three weeks from the typical peak of the northern Colorado snowmelt, creeks and rivers are already being tested.
“There’s more water running in the streams this year than I’ve seen in 35 years of doing this,” said Randy Gustafson, water resource administrator for Greeley who has worked his entire career at the filter plant that the city operates in Bellvue at the mouth of Poudre Canyon.
Wednesday morning, he and Kallie Bauer, a state dam-safety engineer, inspected and gave the A-OK to the Milton Seaman Reservoir. The dam there is continuously rated “high risk” because if it fails, “people in Fort Collins will die,” Gustafson said.
The dam, however, survived last fall’s flood in good shape and is capable of handling much more than even that historic flood, Bauer said.
Historic snowmelt
How high the water rises depends partly on how warm the temperature gets at higher elevations, where the snow awaits. Areas above the flood zones have a snowpack of about 150 percent of its 30-year average, and some areas are closer to 250 percent, according to water managers.
The agency already is telling people in Jefferson, Boulder and Larimer counties to brace for flooding.
Complicating matters, reservoirs that normally empty out in the fall and make room for the snowmelt in the spring refilled in September, McCormick said.
Water storage statewide was already at 89 percent of average at the end of March, when only a fraction of the snowpack had melted, according to the Colorado Water Conservation Board.
In other words, reservoirs will provide little or no harbor for the massive snowmelt still to come. The rest will travel downriver.
“They’re going to spill a lot sooner this year, there’s no doubt about that,” McCormick said.
Residents in the area hit hardest last fall are worried about any level of flooding and the further damage it could do.
“I don’t even want to think about the creek rising,” said Ben Huff, whose home near the Big Thompson River outside Drake is one of the few that can still be inhabited after the last flood. “And the ground under our house is so soft; I don’t want any more water underneath it, or it might slip on down the hill.
Under threat
The recurrence of washed-out canyon roads is a disaster the Colorado Department of Transportation is hurriedly trying to avert this spring. The highway department made emergency repairs to reopen major roads last fall, but the fixes were temporary. The plan was to make more durable repairs when the weather improved in the spring.
The work to fix the problems that ruined the fall-tourism season is now complicating travel in the spring.
On Wednesday — a sunny, dry afternoon — the 20-mile drive on U.S. 36 from Estes Park to Lyons took more than an hour. The route narrowed to one lane of bumpy, dusty dirt road in several locations, and 10- to 20-minute stops were common, as road crews and heavy equipment worked nearby.
“We’re kind of in a race against time to beat the snowmelt,” said CDOT spokeswoman Amy Ford. “We’re certainly hoping (flooding will be manageable), but we can’t leave that to chance.”
Crews were blasting away the hillside this week to move U.S. 36 as far from the water as possible, she said.
Boulder County officials are concerned the snowmelt could lead to landslides and could create artificial dams made of debris lifted by the higher water levels. Crews hope to have 85 percent of the debris removed and sediment dredged by Thursday, said county spokeswoman Gabi Boerkircher.
The county is urging those who see tilting trees and utility poles — possible signs of an impending landslide — to call 911. Besides unusually high water, people should also report unusually low water, because it could indicate the water is dammed by debris upstream. A collapse could trigger a flash flood, Boerkircher said.
On the Eastern Plains, dozens of irrigation ditches are still under repair from the floods, so the abundant water will be of little use to thousands of acres of farmland.
“The runoff this year is shaping up to be a good year for water — but whether we’re able to take advantage of it, we don’t know yet,” said Sean Cronin, executive director of the St. Vrain and Left Hand Water Conservancy District, which lost 44 of its 94 ditches in the fall flood. Ten had been repaired as of April 1, and another 21 could be completed by Thursday.
For a lot of the major growers, the pace of federal help proved too slow, so they raised the money for repairs among those who share the water in the ditches to help get the work going sooner.
“They said, ‘We have no choice; this is our livelihood,’ ” Cronin said.
Brian Werner, spokesman for the Northern Colorado Water Conservancy District, said the combination of last fall’s floods, the snowpack and the potential wet spring — on the back of several years of drought — show the need for more reservoirs.
More storage would provide a rainy-day account for water providers to draw from in drier times, he said.
On top of about 1 million acre-feet from the Colorado-Big Thompson water system, the Northern Colorado Water Conservancy District already has projects on the board to store another 300,000 acre-feet. An acre-foot is generally enough to serve the needs of two families of four for a year.
“We’re still trying to build reservoirs so we can spread that water out from the wet years to the dry ones,” Werner said.
For Lyons resident Connie Starnes, getting through the spring is the highest priority for government work.
“We can’t live like this,” she said. “Nobody wants to go through anything like that ever again, and having to worry about it again isn’t any fun.”
Joey Bunch: 303-954-1174, jbunch@denverpost.com or twitter.com/joeybunch
