Spring runoff two weeks later than ‘usual’ this year — The Pueblo Chieftain

Click on a thumbnail graphic to view a gallery of Basin High/Low graphs for the snow season.

From The Pueblo Chieftain (Chris Woodka) [June 3, 2015]:

Now that the rain, snow and cold temperatures have eased up, at least until the weekend, it’s time for spring runoff.

The runoff is about two weeks later than usual, although “usual” is becoming more difficult to define. National Oceanic and Atmospheric Administration models show that cooler, wetter weather is expected in Southern Colorado through the summer and into next fall.

Rafting companies are anticipating a good season, according to news releases from the Arkansas River Outfitters Association that called current flows “optimal” for every skill level. Flows on the river at Parkdale, west of Canon City, were at 2,300 cubic feet per second and climbing on Tuesday.

“I would say we are in a runoff pattern now,” said Division 2 Water Engineer Steve Witte. “We’re seeing those peaks and valleys in the data. In those years where we have a cool, wet May, it can delay the peak runoff until the end of May.”

Gauges on high-mountain tributaries of the Arkansas River are showing diurnal flows that pick up until about midnight as afternoon snow melts and then drop off during freezing temperatures in the night.

Flows on the Arkansas River are picking up, partly because of the runoff that started in the last week and partly because of the balancing of reservoirs.

The Bureau of Reclamation is making more space in Turquoise Lake and Twin Lakes for anticipated imports, meaning some additional water is moving through the Arkansas River to Lake Pueblo. About 10,000 acre-feet is being moved. An acre-foot is 325,851 gallons.

The Army Corps of Engineers released the last bit of 12,000 acre-feet of stored flood water from Lake Pueblo on Saturday.

Some canal companies are beginning to take water — it was too wet during May for most farmers to start planting, other than some small windows of opportunity.

The result is that John Martin Reservoir has reached its highest point since April 2001, and was storing about 175,000 acre-feet as of Tuesday.

“It looks like we will be in conservation storage for a while at John Martin,” Witte said. “Water is also flowing into the Great Plains Reservoirs (located in Kiowa County and owned by the Amity Canal in Prowers County), which is something of an anomaly.”

Levels at John Martin were just 6,300 acre-feet in November, and had increased to 53,000 acrefeet by the end of winter storage in early April. But those levels dropped to 45,000 acre-feet by May 7. Since then, 3,00010,000 acre-feet daily have been stored in the reservoir.

The snowpack followed a similar pattern. April was a dismal month for accumulation, and it looked like the snowpack would be puny until the first of May.

Because of locally heavy snows in February, however, Reclamation was still forecasting a nearly average year for the Fryingpan-Arkansas Project on May 1. That’s improved considerably.

“Unofficially, we think it’s going to be 20 percent more,” said Roy Vaughan, manager of the Fry-Ark Project. “One of our biggest concerns is that it could come off too fast.”

Snow peaks throughout the state are well above normal, because of additional late snow in May. However, the mid-April peaks that usually occur never came because of the earlier dry conditions.

The Fry-Ark Project brings water from the upper reaches of the Roaring Fork watershed through the Boustead Tunnel into Turquoise Lake, but if snow melts too quickly, the tunnel can’t capture all of the water that might be available.

Meanwhile, Fountain Creek in Pueblo was running at about 830 cfs Tuesday, about 20 times the normal rate.

Meanwhile, managing streamflow to prevent flooding was a balancing act a couple of weeks ago along the Arkansas River. Here’s a report from Chris Woodka writing for The Pueblo Chieftain:

Lake Pueblo is just a couple of weeks from completely filling, if current weather patterns continue.

That could mean water stored in the reservoir could begin spilling — on paper at least, but in reality as well.

Water is being stored to prevent flooding downstream of Pueblo Dam. It boils down to a simple math problem that seeks to keep the Arkansas River flow at Avondale below 6,000 cubic feet per second. That satisfies most downstream direct-flow rights, while protecting downstream Because of high flows on Fountain Creek, unmeasured flooding on Chico Creek and occasional downpours over the St. Charles River, releases from Pueblo Dam have been cut back.

“We have been conservative because we don’t have advance warning of other water that might be coming in,” Steve Witte, Division 2 engineer with the Colorado Division of Water Resources, told the Southeastern Colorado Water Conservancy District Thursday.

Normally, the same amount flows out of Lake Pueblo as flows in. But during this period, about 6,000 cfs has been flowing in each day, too much to add to the Arkansas River below.

The result: About 30,000 acre-feet of water are backed up in Lake Pueblo.

An additional 4,500 acrefeet continues to be stored daily. Flood storage tops off at 90,000 acre-feet, or about 14 more days at the current storage rate, said Roy Vaughan, Fryingpan-Arkansas Project manager for the Bureau of Reclamation.

Lake Pueblo had about 275,000 acre-feet of water stored Thursday. Its physical capacity is about 350,000 acre-feet. (An acrefoot is 325,851 gallons.) “We’re trying to evacuate the water as quickly as possible,” Witte said.

That could take some time, because more water is being stored than released.

Pueblo Dam releases were stepped up Thursday after being cut on Tuesday to accommodate a wall of water moving down Fountain Creek from overnight rain in the Colorado Springs area. That followed a similar cutback a week earlier. About 5,000 cfs can be safely released, if conditions remain dry.

The National Weather Service predicts generally hot, dry weather through at least next Wednesday.

At the same time, spring runoff continues to run full throttle from the mountains in the Upper Arkansas River basin, pushing flows above the 6,000 cfs figure. There still appears to be ample snow in the mountains to prolong the peak.

On top of that, more water is being brought in by the Fry-Ark Project, which is now filling Turquoise Reservoir. Other transmountain diversions, by Twin Lakes, Colorado Springs and the Pueblo Board of Water Works are shut down because there’s no place to put the water.

Even if Pueblo is not completely filled, some non-project water could spill if Reclamation imports more than the 70,000 acre-feet now projected or if its Arkansas River basin water rights come into priority. Right now, there are about 57,000 acre-feet of excesscapacity water and 40,000 acre-feet of winter water that could spill under the right set of circumstances.

Water officials are working to keep the water moving and avoid that scenario, however.

Things are wet in the San Luis Valley also. Here’s a report from Matt Hildner writing for The Pueblo Chieftain:

For the second year in a row, local water officials have seen more water come down the Rio Grande and Conejos River than winter snowpack measurements predicted.

While that made for a pleasant early June as irrigators got more water than they expected for their pastures and crops, the Colorado Office of the State Engineer has since had to increase curtailments to meet the Rio Grande Compact. Under curtailment, a percentage of the river is sent past headgates downstream to New Mexico.

On the Conejos, which had only a 5 percent curtailment in May, it was 43 percent as of June 22.

“Hopefully we’re at the point where we don’t have to do it anymore,” Craig Cotten, division engineer said.

At the beginning of May, streamflow forecasts from the Natural Resources Conservation Service had called for an annual streamflow total of 145,000 acre-feet of water on the Conejos where it enters the San Luis Valley floor.

Now that forecast is 275.000 acre-feet, which raises the bar for how much the state must send down stream to New Mexico for the remainder of the year.

“That really highlights the need to have better forecasting and that’s definitely something that we’re working on,” he said.

This year a pilot project funded by the Colorado Water Conservation Board, has flown a plane with Lidar technology over both the Conejos and Rio Grande basins to determine its effectiveness in measuring in snowpack.

Lidar is a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light.

By flying in both winter and summer months, the difference in distance measured by the Lidar can offer information about the extent of the snowpack.

Cotten said local and state officials are also forming a steering committee that will look at the feasibility of using, Lidar, radar and additional snow gauges.

Cotten said NRCS is also investigating how fire burn scars and beetle-killed trees in the San Juan Mountains may be impacting runoff.

The forecasting hiccups also hit the Rio Grande this year but its 16 percent curtailment is less severe than on the Conejos.

The river is expected to see an annual total of 630,000 acre-feet at the Del Norte gauge, up from a May forecast of 445.000 acre-feet.

Despite the unexpect­ed bumps in flows, this year will likely be the fifth year in a row below the historic average on the Conejos and the seventh on the Rio Grande.

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