USFS solicits comments on proposed #Aurora dam near Holy Cross — The Aurora Sentinel

A wetland area along Homestake Creek in an area that would be flooded by a potential Whitney Reservoir. The cities of Aurora and Colorado Springs are looking to develop additional water in Eagle County and divert it to the Front Range. Photo credit: Brent Gardner-Smith/Aspen Journalism

From The Aurora Sentinel (Grand Stringer):

The White River National Forest opened a public comment period last week concerning the next phase of a would-be reservoir project dubbed the Whitney Reservoir. Water authorities in Colorado Springs and Aurora plan to divert water near the Vail Valley — normally destined for the Colorado River — to the Front Range by way of pumps and tunnels.

Greg Baker, Aurora Water’s manager of public relations, said in November the Whitney Reservoir could eventually hold between 9,000 acre-feet and 19,000 acre-feet of water.

For comparison, Cherry Creek Reservoir stores more than 134,000 acre-feet.

Aurora Water and its southern counterpart, Colorado Springs Utilities, applied for a Special Use Permit to do so. Geologists would conduct ground-level seismic analyses of the ground below and also drill up to 150 feet below the surface. Currently, the operation proposes ten drilling sites.

The water could help Aurora meet the needs of a rapidly-expanding city while capturing water rights Aurora already holds, Baker said. He estimated the reservoir could be completed in 25 years if key steps were met, including a geological analysis.

The Whitney Reservoir project drew early attention from Colorado River conservationists and a fishing association concerned for the health of local fish habitats and the river system. Prolonged drought and existing diversions have already diminished Colorado River flows in recent decades.

The project could also impact pristine wetland ecosystems and would also require cutting near 500 acres from the Holy Cross Wilderness.

Members of the public can find more information about the project on the U.S. Forest Service website. Comments can be made any time but will be “most helpful” if submitted before June 30, 2020, the Forest Service said in an information release…

To comment on the project, or propose a different course of action, submit a comment online at https://cara.ecosystem-management.org/Public/CommentInput?Project=58221.

Opinion: Don’t hurt farmers to save the #ColoradoRiver — Explore Big Sky #COriver #aridification #DCP

A large irrigation canal in the Grand Valley, which relies on water from the Colorado River to irrigate fields. The state is exploring how a voluntary, temporary and compensated water-use reduction plan, known as demand management, might work. Photo credit: Brent Gardner-Smith/Aspen Journalism

From Explore Big Sky (Andy Mueller):

No one denies it: Overconsumption of water and extreme drought caused by climate change are realities driving the Colorado River into crisis. But some solutions are better than others.

Former Interior Secretary Bruce Babbitt suggested recently in a Writer’s on the Range column that “retiring” 10 percent—some 300,000 acres—of irrigated agriculture would save 1 million acre-feet of the Colorado River. Secretary Babbitt wants the federal government to pay farmers in both the Lower and Upper Colorado River basins to dry up their cropland.

The imbalance on the Colorado River needs to be addressed, and agriculture, as the biggest water user in the basin, needs to be part of a fair solution. But drying up vital food-producing land is a blunt tool. It will damage our local food supply chains and bring decline to rural communities that have developed around irrigated agriculture.

Let’s look at the river’s problems. First, Secretary Babbitt minimizes the challenge as the overuse of the river’s system is even greater than 1 million acre-feet. The flow is so diminished that the end of the line, the Colorado River Delta, hardly receives any water.

The three states that make up the Lower Colorado River Basin—including the former Secretary’s home state of Arizona—have in recent years consumed at least 1.2 million acre-feet more per year than the 8.5 million acre-feet allotted to them under the 1922 Colorado River Compact.

This overuse has been perpetuated because the Lower Basin states and the Bureau of Reclamation fail to account for the losses caused by evaporation from reservoirs and the transit losses during water deliveries. The first step in fixing the imbalance must be elimination of the Lower Basin’s overuse.

Through the Drought Contingency Plan, the Lower Basin is actively reducing its water consumption when Lake Mead hits critically low levels. But while this is a good start, more must be done.

Climate change is a major cause in reducing Colorado River flows, with recent studies putting the reduction between 3-5.2 percent for every 1 degree rise in temperature. Important water-producing parts of our basin, such as Western Colorado, have already seen temperatures rise by as much as 4 degrees since 1895, and predictions for a 2- to 5-degree increase in the foreseeable future will compound the trend.

It might be surprising to learn that the Upper Basin’s annual consumption of Colorado River water—less than 4.5 million acre-feet—is far below the 7.5 million acre-feet allotted to the four Upper Basin states of Colorado, Utah, Wyoming and New Mexico. But this is hardly the time to increase diversions. To sustain the communities and the ecosystems that depend upon the Colorado River, all water users—both Upper and Lower Basin states—will need to consume less water.

The Colorado River District has taken a stand against “buy-and-dry” practices because we recognize the environmental and economic harm of drying up agricultural lands. If the health of the river is balanced solely on the back of agriculture, the 10 percent suggested by Secretary Babbitt today will almost certainly lead to 20 percent tomorrow.

In Western Colorado, most of our agriculture is family owned and operated. These family farms provide a local food supply, form the backbone of our rural communities, and they are already under economic stress. So what can be done to both help the river and keep rural life intact?

Initiatives must be aimed at reducing consumptive losses due to inefficient irrigation systems. At the same time we need to incentivize selective retirement of marginal land, all while providing technical support and funding for growers to switch to higher-value crops. The Lower Basin must reduce the cultivation of highly water consumptive crops in the increasingly hot desert, such as cotton and alfalfa raised solely for export.

Increased funding is better directed to off-farm and on-farm irrigation improvements and growing alternative crops. An example of that kind of effort is the Lower Gunnison Project in Western Colorado, a partnership between agricultural producers, the Colorado River District and the Natural Resources Conservation Service. This project improves diversion structures by piping delivery ditches and modernizing irrigation technology on farms. The producers are also experimenting with new crops such as hemp and hops.

From a purely mathematical standpoint, the Lower Basin has to reduce its 1.2 million acre-feet in overuse. That’s a big start. But in both basins, agriculture must improve the way it uses scarce water taken from the river. We have no time to lose.

Andy Mueller is a contributor to Writers on the Range (writersontherange.org), a nonprofit dedicated to spurring lively conversation about the West. He is general manager of the Colorado River District and spends his time protecting the flows of the Colorado River and its tributaries in Western Colorado.

#Colorado-Big Thompson Project operations update #ColoradoRiver #COriver #aridification

From email from Reclamation (Brittany Jones):

The Bureau of Reclamation will increase diversion of Colorado River water to Horsetooth Reservoir at midnight tonight. The change will require a decrease in the Big Thompson River diverted for power generation at Olympus Dam.

Reclamation is currently releasing 125 cfs to the Big Thompson River from Olympus Dam. The flow will increase to 265 cfs beginning tonight. Our current forecast indicates that runoff into Lake Estes will substantially increase over the next week. It is possible the Olympus Dam required release to the Big Thompson River will exceed 600 cfs.

Aerial view of Lake Estes and Olympus Dam looking west. Photo credit Northern Water.

The delicate dance of Dillon Reservoir during spring #runoff — @AspenJournlism #snowpack

Dillon Reservoir in Summit County is the largest reservoir in the Denver Water system, holding more than 257,000 acre-feet of water when it’s full. With two outlets — the Blue River and Roberts Tunnel — Denver Water officials say it’s complicated to operate. Photo credit: Denver Water via Aspen Journalism

From Aspen Journalism (David O. Williams):

Denver Water officials increased the release of water from Dillon Reservoir into the Blue River to about 400 cubic feet per second in the first week of May as inflow held steady at about 500 cfs through Monday, May 11. The latter number is expected to steadily rise as spring runoff picks up.

The current forecast from the National Oceanic and Atmospheric Administration’s Colorado River Basin Forecast Center estimates as of May 11 that there is 146,000 acre-feet of water — in the form of snowmelt — that will flow into Dillon Reservoir through July 31. There’s currently 17,500 acre-feet of space in the reservoir, according to Denver Water, so about 128,500 acre-feet will flow out of the reservoir either to the Blue River or Roberts Tunnel by July 31, with an estimated 13,000 acre-feet through the tunnel.

All of these complex calculations are the first steps in a delicate dance Denver Water performs each spring to balance public safety with Denver’s water needs, recreation, hydroelectric demands and obligations to downstream senior water-rights holders.

“Dillon is our biggest reservoir and one of our more complicated to operate,” said Nathan Elder, water resources manager for Denver Water. “Most of our other reservoirs only have one outlet, but Dillon’s got both the outlet to the Blue and the outlet to the Roberts Tunnel, which provides water to the East Slope and down the North Fork (of the South Platte River) to Strontia Springs Reservoir and then to our customers.”

The Roberts Tunnel, finished in 1962 about the same time the old town of Dillon was relocated to its current spot and the Dillon Dam was built, is a 23-mile concrete conduit that diverts water from the Blue River basin on the Western Slope to the South Platte Basin on the Front Range to supply more than 1.4 million Denver Water customers.

Colorado transmountain diversions via the State Engineer’s office

This system is what’s known as a transmountain diversion — one of many that bring water from the Colorado River basin on the west side of the Continental Divide to the state’s population center on the Front Range. What it’s not, Elder said, is a way to avoid dangerous spring-runoff flooding.

“We can’t use Roberts Tunnel as a flood-control option,” he said. “So we’re very careful about the amount of water we take from the West Slope over to the East Slope. And when we use the Roberts Tunnel, we can only take it over to the East Slope if it’s put towards the demand. We can’t just dump it over there to prevent flooding or high flows below Dillon.”

The 2014 Colorado River Cooperative Agreement places a 400,000 acre-foot limit on Blue River water stored in existing or future Denver Water storage facilities on the Front Range.

There are more than 1,000 properties in regulatory floodplains in Summit County, according to the Federal Emergency Management Agency, and quite a few of them are along the Blue as it makes its way northwest through Silverthorne and toward its confluence with the Colorado River near Kremmling.

The Blue River travels north-northwest through Dillon Reservoir to its confluence with the Colorado River near Kremmling. Each spring Denver Water performs a delicate balancing act to accommodate flows from snowpack runoff. Photo credit: Denver Water via Aspen Journalism

Snowpack melting

This time of year, as snowpack begins to melt into local tributaries — the Blue, Snake River and Tenmile Creek all feed Dillon Reservoir from the south — Elder and his team closely monitor snowmelt forecasts and weather reports to coordinate with local officials to prevent flooding.

“Denver Water has worked with the town over the years to release water from Dillon Reservoir at rates between 50 cfs and 1,800 cfs,” said Tom Daugherty, Silverthorne’s director of public works. “They have done a very good job of doing that. Denver Water attends our local meetings concerning snowmelt runoff and inform us of what they expect.”

FEMA designates 2,500 cfs as a 10-year flood level just below Dillon Dam, while 3,350 cfs there would be a 100-year flood level. The amount of runoff pouring into the reservoir varies widely, depending on weather conditions and snowpack, from a low inflow of 410 cfs in the drought year of 2012 to a high of 3,408 cfs in 1995.

The amount of snowpack on the Front Range and rate of melting due to high temperatures or rain events also impacts when Denver Water turns on the Roberts Tunnel and how much water it takes out of Dillon Reservoir. The Blue River Decree dictates that Denver Water needs to keep as much water on the Western Slope as possible and can take water only to meet demand.

“Last year was a good example of that,” Denver Water spokesman Todd Hartman said. “We had so much snowpack on the Front Range that we just didn’t need the Roberts Tunnel water and couldn’t take it because of that demand issue.”

That resulted in higher flows on the Blue below the dam last runoff season.

“It got up to around 1,900 cfs, and we didn’t actually turn on the Roberts Tunnel until the second week in August last year,” Elder said. “That’s after everything on the East Slope filled, and we started dipping into that storage and streamflow dropped off on the East Slope.”

This year, there’s a similarly healthy snowpack above the reservoir and also decent snowpack on the Front Range, but temperatures have been higher and the spring runoff season hasn’t been nearly as wet and cool as last year.

“We have a Snotel (snow telemetry) site on top of Hoosier Pass, which is extremely important for monitoring that basin and for forecasting, and it’s still at 121% of normal right now,” Natural Resources Conservation Service hydrologist Karl Wetlaufer said in early May. “It looks like it did actually have a net accumulation through April and is just really just starting to turn around and melt out now over the last few days with this warm weather.”

The Natural Resources Conservation Service produces snowmelt forecasts used by Denver Water, which also taps into the National Oceanic and Atmospheric Administration forecast center.

Based on information from Snotel sites, snowpack above Dillon Reservoir peaked at 127% of normal. The forecast center’s inflow outlook for Dillon Reservoir is 104% of average, and the forecast from the Natural Resources Conservation Service was 107% of average.

The first priority for Denver Water is to fill the reservoir to meet customer needs, but it also tries to minimize high flows out of the reservoir via the Blue River and maintain water levels so that the Frisco and Dillon marinas can operate from June through Labor Day. Elder said the minimum operating level for both Dillon and Frisco marinas is 9,012 feet in elevation.

The goal, Elder said, is to get the reservoir to that level or higher by June 12. On May 11, the surface level of the water in the reservoir was at 9,010 feet. The reservoir is full when the elevation of the water, as measured on the dam, is 9,017 feet, which is 257,304 acre-feet of water. At 9,010 feet, the reservoir is holding about 236,232 acre-feet of water.

Release too much and too early — to avoid high flows and flooding downstream — and Denver Water runs the risk of missing the chance to fill Dillon for use by its customers later in the summer season as well as keep the reservoir full for a long boating season. And then there are the downstream hydroelectric factors and calls by senior water-rights holders.

An inspection team leaving the 23-mile Roberts Tunnel east portal in Park County in 2016. The tunnel, which diverts water from the Blue River to the Front Range is inspected every five years. Photo credit: Denver Water via Aspen Journalism

Senior water rights

While the Blue River Decree does not have a volumetric limit on how much water Denver Water can take out of Dillon Reservoir through the Roberts Tunnel to meet its customer needs, the Roberts Tunnel right is from 1946 and is junior to Green Mountain Reservoir and Shoshone Power Plant rights, which limit the ability of Denver Water to divert. The Roberts Tunnel right is for 788 cfs, which is not a storage right but instead a direct-flow right.

So if Green Mountain gets toward the end of its fill season and hasn’t filled and Dillon has diverted, then Denver Water owes water to Green Mountain. Green Mountain Reservoir, located on the Blue River in northern Summit County, was created specifically to compensate the Western Slope for diversions to the Front Range as part of the Colorado-Big Thompson Project.

Then on the Colorado River in Glenwood Canyon, well downstream from where the Blue feeds the Colorado at Kremmling, there’s Xcel Energy’s Shoshone Generating Station hydroelectric plant — which has one of the most senior water rights on the main stem of the Colorado River. A 1902 right draws 1,250 cfs of water downstream to meet the plant’s needs. During dry times of the year, such as late summer, the power plant often places a “call” on the river, meaning junior diverters upstream — including Denver Water — must stop diverting so that Shoshone can get its full allocation of water.

Elder said Denver Water wants to fill Dillon Reservoir quickly enough each spring before any potential Shoshone call. If a call came before Dillon was full, Denver Water would have to release water from Williams Fork Reservoir in order to keep water in Dillon Reservoir. However, Williams Fork can hold only 96,000 acre-feet of water.

“We want (both reservoirs) to fill quick enough that we fill both before that Shoshone power plant call comes on and before the senior call comes on the river, but not too quick that we fill before peak runoff where we get in those high-flow situations,” Elder said. “So it’s a real balancing act there. You’re balancing elevations for marinas, downstream water rights, filling the reservoir safely and then also any potential releases you may need to make from Roberts Tunnel.”

Aspen Journalism, a 501(c)(3) nonprofit organization supported by its donors and funders, covers water and rivers in collaboration with the Summit Daily News and other Swift Communications newspapers. This story ran in the May 17 edition of the Summit Daily.

Repairs to El Vado Dam Begin Next Year — The #RioGrande Sun

From The Rio Grande Sun (Molly Montgomery):

Beginning in 2021, the Bureau of Reclamation will repair El Vado Dam.

Built in 1935, the dam is one of the only steel faceplated dams in the country. It can store around 200,000 acre-feet of water.

Some of the steel faceplates of the dam have become cracked and bent due to shifts in the land around the dam, wrote Bureau of Reclamation Public Affairs Specialist Mary Carlson in a March 6 email.

The shifts in land have also caused erosion behind the faceplates and cracks and bending in the plates on the dam’s spillway, she wrote.

Bureau of Reclamation Civil Engineer Carolyn Donnelly discussed the potential effects of these changes at the Fifth Annual Rio Chama Congreso Feb. 29.

“The spillway, some of those face plates, if you walk on it, you can hear it’s kind of hollow underneath and they move, so if we started using that at the full capacity, water could get under those plates, take them out, and then there could be failure of the dam,” Donnelly said. “And luckily there’s not a large population downstream, but for those who are there it would not be a good thing.”

El Vado stores water for irrigation in the Middle Rio Grande Conservancy District, which includes six pueblos—Santa Ana, Kewa, Cochiti, San Felipe, Isleta and Sandia.

It also sometimes stores drinking water for cities including Santa Fe and Albuquerque as part of the San Juan-Chama Project.

Carlson wrote that the Bureau of Reclamation is still working out details about how water will be stored and move during the repair, for which the reservoir will be close to empty for at least a year.

New Mexico Lakes, Rivers and Water Resources via Geology.com.

@USBR: Aspinall Unit Spring Operations update

@Northern_Water: Regional Pool Allocation Set at 15,000 Acre-feet

Here’s the release from Northern Water:

The Northern Water Board of Directors allocated 15,000 acre-feet of Regional Pool Program (RPP) water during its May 14, 2020, Board meeting. RPP water is available for lease by eligible Northern Colorado water users, with sealed bids due May 28, 2020. Bid prices per-acre-foot must be greater than or equal to $27.40, a floor price the Board selected based on the 2020 agricultural assessment rate.

Due to the COVID-19 pandemic, interim procedures have been instituted for the May 2020 RPP allocation. The interim procedure and additional Regional Pool information are available at http://northernwater.org/regionalpool.

The following forms are required to submit a bid:

  • Pre-Approval Form – To confirm eligibility, interested bidders must email or mail the Pre-Approval Form to Northern Water. In person delivery will not be accepted in 2020. A new Pre-Approval Form is required each year.
  • Carrier Consent Form – If the RPP water will be delivered by a carrier, such as a ditch or reservoir company, bidders and their carriers must complete the Carrier Consent Form or provide a signed agreement stating that the carrier will deliver the RPP water to the bidder. This form must also be emailed or mailed to Northern Water; in person delivery will not be accepted.
  • Bid Form – Sealed bids will be accepted at Northern Water’s headquarters through a “self-serve” process. Bidders will sign in at a kiosk in the lobby and print a bid label for their sealed bid envelope. The label will identify the bidder name, date and time stamp, and bid number. Secure the label to the bid envelope and place in the drop box. Sealed bids may also be mailed to Northern Water, but must be received before the deadline.
  • Sealed bids are due by 2 p.m. May 28 at Northern Water’s headquarters, 220 Water Ave., Berthoud, CO 80513. As described above, sealed bids can be mailed or hand delivered; email and fax bid forms will not be accepted. RPP leases will be awarded based on highest bids per acre-foot. Sealed bids will be opened during a 9 a.m., June 1 Zoom video conference. The link to the Zoom video conference will be available at http://northernwater.org/RegionalPool.

    Many staff are working remotely due to the COVID-19 pandemic and are not available to answer questions in person. Questions regarding the Regional Pool Program and bid submittal can be emailed to regionalpool@northernwater.org or by calling Sarah Smith at 970-622-2295 or Water Scheduling at 970-292-2500.

    Screenshot of the Colorado-Big Thompson Project boundaries via Northern Water’s interactive mapping tool , June 5, 2019.