Runoff/snowpack news: There is little space to store runoff in South Platte River Basin reservoirs

Click on a thumbnail graphic for a gallery of snowpack data from the Natural Resources Conservation Service. The melt-out is in full swing.

From 9News.com (Nick McGurk):

“This is one of the best years we’ve had in the last decade or two,” said Brian Werner with Northern Water.

So good, he said that the state could send out the equivalent of five Horsetooth Reservoirs full of water to Nebraska this year because there’s nowhere to store it in Colorado.

“It’s helping Nebraskans, believe me, but it’s water that we have rights to that we’re not putting to use because there’s nowhere to store it,” said Werner.

It’s why he says Colorado needs more reservoirs. Glade Reservoir has been talked about for a decade. It would take water from the Poudre and store it northwest of Fort Collins.

From the Northern Colorado Business Report (Steve Lynn):

Horsetooth Reservoir and Carter Lake, which comprise Northern Colorado’s share of the Colorado-Big Thompson project, are within about one foot of being full, said Brian Werner, spokesman for the Northern Colorado Water Conservancy District.

Farmers currently are using river water from ditches to irrigate their cropland, but generally use Colorado-Big Thompson project water later in the summer. The project collects water from the Western Slope and delivers it to the Front Range through a 13-mile tunnel the runs beneath Rocky Mountain National Park.

From the Fort Collins Coloradoan (Ryan Maye Handy):

When the Poudre River surged after a rainy Memorial Day weekend and took the lives of two Greeley residents, it alarmed residents across the state. But even after a wet spring and this year’s heavy snowpack, the Poudre is a long way from causing Fort Collins stormwater managers alarm during this runoff season…

It can be hard to pin down what exactly makes the Poudre’s levels fluctuate — it can be the weather, an irrigator, snow melt or another river, like the North Fork, dumping into it.

The Poudre has been running about twice its normal level since the September 2013 floods, when a year’s worth of rain fell in just days across Colorado. But this year a few other things could be fueling the river’s rise. Spring rains at low elevations, for instance, caused the river to rise during Memorial day weekend. In big snowpack years, snowmelt can drastically change the river’s flow.

Much of Northern Colorado’s snowpack in the mountains west of Fort Collins has yet to melt. The force of snow melt-caused runoff all depends on weather — a steady warming trend will prolong the runoff period, where as a rapid rise in heat over an extended period will fill the river quickly.

Peak runoff flows usually hit the Poudre sometime between late May and mid-June…

Fort Collins has several ways of monitoring the river’s power, one of which is using water gauges in Poudre Park, at the canyon mouth, and at the Lincoln Street bridge.

Fort Collins Utilities has a flood warning engineer and other employees who manage a flood warning system around the clock, said Varella. The city has trigger points — threshold measurements for the water — that trigger flood alerts, exactly the same as those used by the National Weather Service to issue flood alerts…

Several things have to fall into place for the river to seriously flood, and the severity of flooding could depend on when those factors come into play.

But as of Thursday, the Poudre’s level’s were forecast to continue to drop, with a possible spike late Friday due to rain. While the river is moving dangerously fast, and is higher than normal, said Varella, all city stream gauges showed only low warning levels.

From the Summit Daily News (Sebastian Foltz):

River accidents are frequently the result of inexperienced boaters getting into unfamiliar situations. This year, with water flows in rivers already climbing toward peak levels because of rapid snowmelt, there’s some concern among those in the rafting and kayaking industry. While it’s safe for professional guiding companies and experienced boaters, those less familiar with how to read rivers and recognize features may struggle in places where they would be fine during other times of the year.

Stretches of water can change dramatically with higher water flows, making ordinarily tame rivers far more challenging.

With flow levels on some rivers currently as much as 10 times higher than what they might be later in the summer, places like the usually tame Upper Colorado River may be far more technical…

The Upper Colorado, for example, now has flow levels approaching 10,000 cubic feet per second (cfs), when much of the season it runs closer to 500-800 cfs.

From The Denver Post (Tom McGhee):

The Cache la Poudre continues to overflow its banks near Greeley and the National Weather Service has extended a flood warning for the area until further notice.

“That river is expected to stay above flood stage until at least June 3,” NWS meteorologist Todd Dankers said Thursday.

A combination of snow melt, triggered by warm weather, and plentiful rain, has sent water flowing into streams and rivers around the area.

A number of streets, trails and open spaces, are closed near the river, including 71st Avenue, 83rd Avenue and 95th Avenue.

Flood advisories, which are issued when rivers and streams run high, but aren’t in immediate danger of flooding, are in place for the Cache la Poudre at the mouth of the Poudre Canyon, and for the South Platte River near Kersey, which is south of Greeley.

The NWS has also issued flood warnings for Jackson and Grand Counties, Danker said. “Snowmelt and these warming temperatures have things right near the top.”

Flooding in Boulder Creek prompted Sheriff Joe Pelle to close the creek to tubing and single chamber belly flotation devices.

The closure will take effect immediately, and will encompass Boulder Creek from Barker Dam east of Nederland to the Weld County line, north of Erie. The closure includes the section of Boulder Creek that flows through the City of Boulder.

A similar ban on tubing is in effect on the Cache la Poudre in Fort Collins until further notice, the Fort Collins police announced.

Afternoon showers are expected through Saturday, and warm nights, in the high country will assure snow continues to melt, Danker said.

“Emergency mangers are keeping an eye on things and we are going to be watching the radar and when things develop we will issue a warning.”

“The urban corridor stands to have the best chance at rain with storms moving off of the nearby mountains,” according to a Colorado Water Conservation Board flood threat bulletin.

With streams and rivers running high, it won’t take much to trigger more flooding, though major floods like those last year aren’t expected, Danker said.

There is a 30 to 40 percent chance of showers Thursday, a 40 to 50 percent chance on Friday, and 30 percent on Saturday. “Showers are coming up from the south. “The showers on Saturday may have a bit more push to them, but it will depend on where they develop,” Danker said.

From Fox21News (Mark Bullion):

About a year ago, Southern Colorado was mostly under an extreme or exceptional drought, which set the stage for the multiple wildfires that happened.

This year, most of the region is out of a drought status with the exception of the southeastern plains, according to the U.S. Drought Monitor.

“They’ve had a few dust storms, a lot of blowing dirt and not a lot of native grasses to hold that soil down,” said Jennifer Stark, NWS Pueblo Meteorologist.

Southern Colorado has for the most part come out of a drought status because of an above average snow pack this past Winter.

But with the above normal snow amounts some areas of Colorado received, there is a concern of runoff into the Arkansas River as temperatures warm and the snow melts.

“That will be the area from Leadville down to the Pueblo Reservoir depending on how the reservoir is filled,” said Larry Walrod, NWS Pueblo Meteorologist. “Also, some of that water will make it east of Pueblo toward La Junta and Lamar.”

Walrod said as of Thursday morning, Fremont Pass still had a snow pack at 147 percent of average.

“The runoff is just starting to peak and it will be in a state of peak here for the possibly two, three or four weeks,” said Walrod.

Stark said the Climate Prediction Center in Washington D.C. is forecasting above normal amounts of rainfall for the next few months, so she is optimistic Southern Colorado will stay out of a drought or where there is an exceptional drought in the eastern plains, the rain will help saturate the soil resulting in the possibility of some areas being changed to a lower drought status.

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