#Snowpack, #runoff and the #ColoradoRiver Basin — @MountainTownNew #COriver

Water rushes through scenic Glenwood Canyon. Photo/Colorado River Water Conservation District via The Mountain Town News -- Allen Best.
Water rushes through scenic Glenwood Canyon. Photo/Colorado River Water Conservation District via The Mountain Town News — Allen Best.

From The Mountain Town News (Allen Best):

Eric Kuhn paints a big picture of changing realities in the Southwest

rom his office in Glenwood Springs overlooking the Colorado River, Eric Kuhn has become one of the West’s most prominent thinkers about the intersection of water, climate change, and allocations for farms, factories and cities, including ski towns.

He joined the Colorado River Water Conservation District as an engineer after working in the private sector as a nuclear engineer. He has been manager of the water district since 1996. The district encompasses all of the Colorado River drainage in Colorado upstream from Fruita. As such, the district is a primary source of water not just for the bulk of Colorado ski towns and Front Range cities but also downstream farms and cities, including Phoenix, Los Angeles, and San Diego.

Mountain Town News collaborated with Kuhn on a reader-friendly Q&A to probe the growing evidence that warming temperatures have started upsetting the apple cart of Colorado River operations.

Eric Kuhn along the banks of the Colorado River in Glenwood Springs, general manager of the Colorado River District. Photo via the Grand Junction Daily Sentinel.
Eric Kuhn along the banks of the Colorado River in Glenwood Springs, general manager of the Colorado River District. Photo via the Grand Junction Daily Sentinel.

Was it a good snow year in the upper Colorado River Basin? It varied, of course, but generally it was average to a little above average in the Gunnison, Yampa, Green and other basins of the upper Colorado River.

Does that mean the reservoirs in the Colorado River Basin are filling? We’ve been hearing a lot about declining levels of Lake Powell and Lake Mead, the two giant reservoirs on the Colorado River. Water runoff is a more complicated story than snowpack. This year, for example, the runoff reached about 94 percent of average. So, average or above-average snowpack but below-average runoff.

The best way to understand snowmelt is to study the inflow into Lake Powell. You can call this reservoir the savings account for the Upper Colorado River Basin. It is this savings account that allows the upper division states of Colorado, Utah, Wyoming and New Mexico to consistently meet water supply obligations to the Lower Basin at Lake Mead as spelled out by the Colorado River Compact of 1922. The lower division states are California, Nevada, and Arizona.

There is no such thing as an average snow year—nowhere, no place. Snowpack varies wildly from year to year. That said, in an average water year, about 10.7 million acre-feet flows into Powell. Three-fourths of that occurs during April through July.

Colorado River Basin, USBR May 2015
Colorado River Basin, USBR May 2015

Average snowpack but below-average runoff? That poses an obvious question. But first, would you explain this savings account more? The 1922 compact requires the upper division states to not deplete the flows downstream to Lake Mead below a certain volume. Powell most often releases 8.23 to 9 million acre-feet, as required by the 2007 interim agreement among the seven basin states and the federal government, a side agreement to the compact. But ordinarily, because of evaporation, that means the effective demand on Powell is 8.6 to 9.4 million acre-feet.

What this means is that in any year with an 85 percent of average runoff, Lake Powell just about breaks even. In other words, water levels are not gaining but neither are they declining.

For local supply reservoirs in most of Colorado, we can get by with an 85 percent or better inflow year without too many concerns.

So nothing to worry about in the upper basin? We’re meeting our obligations, end of story? We are OK for now and probably for the immediate future, but if the current conditions transition into a drought over the next several years, as happened after the 1998 El Niño event, we could be in serious trouble because unlike in 1998-99 when system reservoirs were plumb full, today they’re only about half full.

How much of the water in Lake Powell and Lake Mead comes from upstream of Grand Junction (or Moab)? And how much of that originates as snow in places like Steamboat Springs, the Eagle Valley, and the San Juan Mountains? Most of the run-off in the upper basin originates from about 20 percent of the land: those watersheds above about 9,000 feet in elevation, where snowpack accumulates and sticks through the snow season.

The Green River drainage contributes 36 percent of the flow into Lake Powell, the Colorado mainstream 36 percent, the San Juan 24 percent, and the others 4 percent, according to the U.S. Bureau of Reclamation. This is the long-term average.

We’ve heard a lot about drought in the 21st century. Are we still in drought? Colorado as a whole is definitely not in a drought. From the entire Colorado River Basin perspective, it depends on the period one looks at. From 1906 through 2015, the mean annual flow at Lee’s Ferry (between Lake Powell and the Grand Canyon was 14.8 million acre-feet (maf). From 1930 forward, it’s been less, 13.9 maf, according to the National Flow Data Base kept by the U.S. Bureau of Reclamation (available on its website)

For the period of 2000 though 2015, the mean natural flow was 12.4 maf. That’s well below average. During the first part of the century, from 2000 through 2004, it was even less, just 9.4 maf.

Bottom line here: Nearly all the water in the Colorado River comes from upstream of the Grand Canyon, and the average in the 21st century has lagged below the longer-term averages of the 20th century.

Why are Lake Powell and Lake Mead continuing to decline? The recent declines in Mead have been caused by annual demand levels that exceed supply. By the end of 2016, I expect that total storage in Lake Powell and Lake Mead will be close to what it was at the end of 2005. Keep in mind that the major decline in runoff and hence storage was from 2000 through 2004.

Lake Powell via Aspen Journalism
Lake Powell via Aspen Journalism

That’s scary. Some decent snow years in the Rocky Mountains, where most of the Colorado River water comes from, but yet the storage in Mead is declining. Why the decline in Lake Powell?Lake Powell has actually gained a little bit of storage since 2013 and is well above the low point it reached in the winter of 2005. But because of obligations to deliver a little extra water to Lake Mead and because of OK-but-not-great inflows of 90 to 95 percent, the storage is not going up as rapidly as the snowfall in the Rocky Mountains suggests it should.

People talk about a “structural deficit.” What do they mean by that? The structural deficit is the difference between inflow to Lake Mead and demands at Lake Mead when Lake Powell is delivering a “normal” 8.23 maf/year. The math works this way: 8.23 maf from Powell plus native inflow between Powell and Mead of about 700,000 acre feet gives a total inflow of about 9 maf. Demands are 7.5 maf for the three Lower Basin states plus 1.5 maf for Mexico plus about 1.2 maf of evaporation and system losses for a total of 10.2 maf. Thus, the structural deficit is about 1.2 maf. Evaporation varies based on Lake Mead levels. When Lake Mead is fuller, evaporation plus system losses can be as high as 1.5-1.6 maf.

In a recent paper, you cited evidence that warming regional temperatures have turned above-average or abundant precipitation into just average runoff, kind of a reverse alchemy. How can this happen, turning more into less? Temperature is a major variable in the hydrologic cycle. As temperatures go up, evaporation goes up, crops and native vegetation consume more water (transpiration), and the runoff occurs earlier, which exposes native vegetation earlier. The net result is lower stream flows for the same precipitation levels. Brad Udall suggests that about one-half of the reduction in flows we’ve seen since 2000 in the Colorado may be due to temperature alone.

Good snow years means so-so water years in the Colorado River? Wow, that seems to have a lot of so-what! What do you think are the most important so-whats? For water supply purposes, it’s more than a so-what. If temperatures continue their upward trajectory (with year to year variability, of course), we may be in for a new normal. That normal may not have a ground floor.

I like statistics. Does one statistic leap to mind that illustrates what’s going on in the Colorado River Basin? Yes, the number is 1.2 million acre-feet, the amount that the Lower Basin (and Mexico) must reduce their demands if they are to stabilize levels in Lake Mead—at least for the moment. If temperatures continue to warm, they may have to reduce their demands even more.

Spray irrigation on a field in the Imperial Valley in southern California. This type of irrigation is a lot better than the extremely water inefficient type of flood irrigation that is popular in this region. Still, in the high temperatures of this desert region a lot of the water evaporates, leaving the salts, that are dissolved in the colorado River water that is used, on the soil.
Spray irrigation on a field in the Imperial Valley in southern California. This type of irrigation is a lot better than the extremely water inefficient type of flood irrigation that is popular in this region. Still, in the high temperatures of this desert region a lot of the water evaporates, leaving the salts, that are dissolved in the Colorado River water that is used, on the soil.

Why do California, Arizona and Nevada have to cut back—and we in the headwaters area don’t. The 1922 Colorado River Compact gave the upper basin states 7.5 million acre-feet, and the lower-basin states 8.5 maf. It was always assumed that California, in particular, but also Arizona would develop more rapidly, and they did, while the upper-basin states would be slower to put their allocated water to use. But, by the 1970s California was using far more than its 4.4 million acre-foot allocation. Since then, they have been reducing their diversions, but they remain above their allocation.

What are the implications for the headwaters in Colorado and Wyoming? We could continue to see good snow years and decent regional water supply conditions, but due to increasing regional temperatures and system-wide demands that exceed supplies, the Colorado as a whole may continue to be in crisis. There is an old saying that water flows uphill toward money. My biggest concern is that the continuing supply deficit may trigger efforts that will impact our quality of life, especially upper basin agriculture, which may be seen as the “low-hanging fruit.”

In your recent paper, you issue a warning. What is that warning—and is more than just one exclamation mark justified? My warning is that often, but not always, after we’ve had big El Niño years, in the next year, or two (or even three), we end up with drought in Colorado. 1997-98 and 1957-58 are good examples.

In Colorado, we need to quit talking about continuing drought and acknowledge that conditions in much of the state since the fall of 2013 have been wet (the Southwest and Rio Grande have not been as lucky). This means we need to be prepared for the NEXT drought. As (Colorado Water Conservation Board director) James Eklund says “wishing for the drought to end is not a successful strategy.”

For the basin as a whole, we need to be prepared to survive another 2000-2004 period. The difference is that in 1999 reservoirs were full to the brim. Now, they’re at levels of 40 to 50 percent of capacity.

It sounds like we will really need to rethink our use of water from Colorado and Wyoming to Arizona and California. Who’s in charge of this Plan B? The good news is that many entities are actively engaged in seeking solutions. The State of Colorado has just issued a water plan, for the first time ever. The lower division states appear to be on track to implement significant additional water savings if Mead levels continue to decline. Nobody is really in charge. The U.S. Secretary of the Interior has a significant role because of her authority over the operation of the major projects, but the states, affected water users, environmental groups, and the Native American tribes are all at the table.

The latest “Water Matters” newsletter is hot off the presses from the #Colorado Water Trust

On July 7th, we closed our headgate that takes water from the Little Cimarron for irrigation. The water in the above photo will now bypass our headgate and return to the river. Photo via the Colorado Water Trust.
On July 7th, we closed our headgate that takes water from the Little Cimarron for irrigation. The water in the above photo will now bypass our headgate and return to the river. Photo via the Colorado Water Trust.

Click here to read the newsletter. Here’s an excerpt:

The Little Cimarron and McKinley Ditch

Exciting news from the Gunnison Basin this month! A few weeks ago, the Water Trust implemented a unique project aimed at exploring the effectiveness of water conservation tools and voluntary measures to protect Colorado River Compact entitlements.

You may recall that in 2014, the Colorado Water Trust purchased a portion (5.8 cfs) of the McKinley Ditch to restore late summer flows to the Little Cimarron, while keeping agricultural land in production. Earlier this year, the Water Trust received approval from the Upper Colorado River Commission for a Pilot Program project for our water.

Under the project, McKinley Ditch water was used to irrigate approximately 195 acres of pasture grass from April through July 6th. We’re pleased to report that the pilot project was implemented as planned, and on July 7th, we ceased irrigation for the rest of the season. Water is now being returned to the river for the remainder of the irrigation season.

Water conserved by this pilot project will help improve habitat conditions, and ultimately will benefit both the Little Cimarron and Colorado Rivers. We are excited to be a part of this Pilot Program and are hopeful the study results will lead to a more secure future for Colorado’s rivers.

Arkansas River Basin: “Those releases help keep the rafting industry afloat” — Alan Ward

Twin Lakes collection system
Twin Lakes collection system

From The Pueblo Chieftain (Chris Woodka):

After a wet spring, summer has been relatively dry, and drought conditions are creeping back into Colorado, particularly over the Rocky Mountains in the center of the state and the Rio Grande basin.

River flows have dropped, so Reclamation and Pueblo Water are running water from accounts in upper reservoirs to Lake Pueblo. This serves two purposes: Creating space for imports next spring and providing water for the voluntary flow program that extends the commercial rafting season.

Finding the additional space in Clear Creek, Twin Lakes and Turquoise reservoirs was problematic this year, because reservoirs still were full from a very wet 2015. Twin Lakes filled early with native water and delayed imports from the Western Slope.

The Fryingpan-Arkansas Project has delivered more than 58,760 acre-feet so far, about 90 percent of what had been expected when allocations were made in May.

The Southeastern District, which determines allocations, will adjust agricultural deliveries, because cities already had requested less water than they were entitled to receive.

Pueblo Water imported about 13,500 acre-feet of water, about 92 percent of normal. Part of the reason was the lack of free space at Twin Lakes, and part was due to maintaining long-term limits since storage space was scarce anyway, said Alan Ward, water resources manager.

Pueblo Water will lease more than 21,700 acre-feet of water this year because of the potential storage crunch earlier this year.

Even so, Pueblo Water had 49,133 acre-feet of water in storage at the end of June, which was down from last year, but 17,600 acre-feet more than was in storage at the end of May. Most of the gain came in the upper reservoirs, and is now being sent to Lake Pueblo, where it is needed for leases and to make space, Ward said.

“Those releases help keep the rafting industry afloat,” Ward said.

@USBR Releases Draft Environmental Assessment for Tri-Districts Long-Term Excess Capacity Contracts

Colorado-Big Thompson Project east slope facilities
Colorado-Big Thompson Project east slope facilities

Here’s the release from Reclamation (Buck Feist):

The Bureau of Reclamation has released the Draft Environmental Assessment (EA) for the proposed Tri-Districts Long-Term Excess Capacity Contracts for public review and comment.

The Draft EA evaluates environmental impacts associated with Reclamation’s proposed approval of 40-year excess capacity storage, exchange, and conveyance contracts between Reclamation and East Larimer County Water District, Fort Collins-Loveland Water District, North Weld County Water District (collectively referred to as Tri-Districts).

“Excess capacity contracts are very important,” said Eastern-Colorado Area Manager, Signe Snortland. “These provide a needed benefit of water management flexibility, so Districts are better equipped to address drought, changes in municipal demand, and temporary changes in the watershed affecting water quality.”

Tri-Districts have annually requested annual excess capacity contracts to mitigate poor water quality conditions in the Cache La Poudre River due to increased particulate matter due to the High Park and Hewlett wildfires in 2012. The long-term contracts would allow Tri-Districts to utilize excess capacity in Horsetooth Reservoir for storage, exchange and conveyance of the Tri-Districts’ water supplies for delivery to the Soldier Canyon Water Treatment Plant. Each district would execute a separate contract with combined total exchange and storage contract volumes not to exceed 3,000 acre-feet (af).

The Draft EA is electronically available at http://www.usbr.gov/gp/ecao/nepa/cbt_tridistricts.html.

Comments on the Draft EA can be sent to: tstroh@usbr.gov; Terence Stroh, Bureau of Reclamation, 11056 West County Road 18E, Loveland, CO 80537; or faxed to 970-663-3212. For additional information or to receive a printed copy of the Draft EA, please contact Terence Stroh at 970-962-4369 or tstroh@usbr.gov. Reclamation requests comments on the Draft EA on or before August 5, 2016.

Denver Water digs into Vasquez Canal Project — The Sky-Hi Daily News

The south portal of the Vasquez Tunnel is shown in this 1957 photo. Via Denver Water.
The south portal of the Vasquez Tunnel is shown in this 1957 photo. Via Denver Water.

From the Sky-Hi Daily News (Lance Maggart):

The Vasquez Canal Project is a multi-year multi-million dollar project that continues efforts by Denver Water to improve existing water diversion infrastructure. Work on the Vasquez Canal Project focuses on removing sections of the existing Vasquez Canal and replacing removed sections with a 114-inch diameter concrete reinforced pipe.

Work on the project has occurred in previous year with Denver Water replacing between 5,000 and 6,000 feet of the Vasquez Canal over the past two decades. Officials from Denver Water say they plan to replace about 2,000 feet of the Vasquez Canal in 2016, leaving roughly 15,000 feet to be replaced in the future.

Officials from Denver Water did not provide an overall projected cost on the project pointing out that, “funding allocation for this project is reassessed annually”. In previous year the project averaged around $750,000 per year in costs. Future projected cost estimates on the Vasquez Canal Project total between two to three million dollars annually.

Monies used for the project come directly from Denver Water which is funding operation, as it does all operational and capital projects, through water rate fees, bond sales, cash reserves, hydropower sales and system development charges for new services.

Work on the Vasquez Canal Project consists primarily of excavation and earth moving to facilitate the canal upgrade. “Crews will demolish the old concrete liner and covers, excavate the area and install the new 114-inch pipe, piece by piece,” stated Denver Water Communication Specialist Jimmy Luthye. Luthye explained Denver Water plans to, “work aggressively to complete this project in the next few years in an effort to replace aging infrastructure and improve the safety and strength of the entire water system.”

Ames Construction is the contractor of record for the project. For the past 20 years though, as previous sections of the Vasquez Canal have been replaced, employees of Denver Water performed the upgrade work. According to Denver Water this is the first year work on the project has been contracted out.

The Arapaho National Forest prepared an environmental assessment of the Vasquez Canal Project. All construction work on the project is being conducted entirely on National Forest System Lands. According to Denver Water that environmental assessment determined, “there would be no significant environmental impacts.” Officials from Denver Water went on to state, “They approved the project along with required best management practices, design criteria and monitoring designed to protect the area during construction.”

The Vasquez Canal is part of Denver Water’s historic water diversion network that brings mountain runoff to the Front Range and Denver Metro area. The original canal was completed in the late 1930s. According to Denver Water, information on the original construction of the canal is fairly limited but officials from the municipal water supplier stated, “we suspect that some of it (Vasquez Canal) was originally dug by hand because the canal had to be cut into the side of a steep mountain… making it difficult for machines to access.”

In the late 1950s Denver Water covered the originally open Vasquez Canal, effectively creating a tunnel. A drought during the early 1950s prompted the action, which was intended to mitigate evaporation as water traveled through the diversion system.

Water utilized by the Denver Water’s diversion system follows a zigzagging path of infrastructure as it descends from snowmelt in the high Rockies to homes along the Front Range.

Diversion structures in the Upper Williams Fork River send water through the Gumlick Tunnel, formerly known as the Jones Pass Tunnel, where the water passes under the Continental Divide. From there water travels through the Vasquez Tunnel, which brings the water back through to the other side of the Continental Divide, where it enters into Grand County and Vasquez Creek. The water is then diverted through the Moffat Tunnel back under the Continental Divide for a final time and into South Boulder Creek, feeding into Gross Reservoir, a major water storage reservoir for Denver Water.

Colorado transmountain diversions via the University of Colorado
Colorado transmountain diversions via the University of Colorado

New measures could reduce Glen Canyon Dam’s impact on the Grand Canyon — a bit — The High Country News

Before and after photos of results of the high flow experiment in 2008 via USGS
Before and after photos of results of the high flow experiment in 2008 via USGS

Here’s a report from Cally Carswell writing for The High Country News. Click through and read the whole article, here’s an excerpt:

If the San Juan River were a freeway, Glen Canyon Dam would be a 50-car pile-up. It forces the river to back up and spread out for dozens of miles. As the river morphs into Lake Powell, the sand in its current settles out. A rock overhang at Grand Gulch where boaters once lounged is now buried more than 30 feet deep.

Before the dam killed the current, the San Juan carried all of this silt to the Colorado, which spit much of it through the Grand Canyon, replenishing hundreds of sandbars. These expansive blonde beaches, which form in eddies, are river runners’ favorite campsites, and they provide backwater habitat for fish. But today, about 95 percent of the sediment that once washed through the canyon sits at the bottom of Lake Powell, and the sandbars have shrunk: The Colorado erodes them, but doesn’t build them back up.

This is one of the problems the 1992 Grand Canyon Protection Act was supposed to correct. It directed federal officials to figure out how to manage the dam in a way that did less harm and even protected the national park’s assets. In addition to threatened sandbars, three of eight fish species native to the Grand Canyon have disappeared since the dam went up, and two are endangered.

But can altering dam operations really help the river when the dam itself imperils it? Scientists have explored this question since 1992, and their research informs the Bureau of Reclamation’s draft management plan for the dam’s next 20 years, released earlier this year. Conservationists are optimistic that it will yield improvements downstream, but only small ones. “You’re really just trying to make the best of a bad deal,” says Utah State University watershed sciences professor Jack Schmidt…

But there might be other ways to help fish, Kennedy says. Chub spawn almost exclusively in the toasty Little Colorado, then move into nearby parts of the mainstem Colorado, where their growth is inhibited by chilly water. The water does warm as the river twists further from the dam, but though it should be good habitat, few chub live in these downstream reaches.

Scientists think that could be because there aren’t enough bugs to eat there. Aquatic insects lay their eggs at river’s edge, and when the water level drops, as it does daily when water releases fluctuate with hydropower demand, the stranded eggs shrivel and die.

The plan proposes to eliminate flow fluctuations on spring and summer weekends, when electricity demand isn’t quite as high, in hopes of keeping eggs wet and boosting insect numbers. More food might help chub populations colonize and prosper in the river’s lower reaches.

Upper Colorado River Endangered Fish Recovery Program
Upper Colorado River Endangered Fish Recovery Program

Open house for #Colorado Springs’ new SDS pipeline draws 1,200 — The Colorado Springs Gazette

Southern Delivery System map via Colorado Springs Utilities
Southern Delivery System map via Colorado Springs Utilities

From The Colorado Springs Gazette (Matt Steiner):

More than 1,200 people endured 90-degree temperatures Saturday in eastern Colorado Springs to learn more about Colorado Springs Utilities’ new Southern Delivery System.

During the SDS Waterfest at the Edward W. Bailey Water Treatment Plant on Marksheffel Road, kids and adults interacted with community volunteers at hands-on educational booths. And most of those on hand were treated to a guided tour of the state-of-the art facility…

David Schara, 42, said he is a Colorado Springs native and has watched as CSU and city officials spent more than 20 years planning the Southern Delivery System which began piping water north out of Pueblo Reservoir in late April.

“It’s much needed,” David Schara said. “As the city grows, they had to do something.”

David Schara said he and others have been skeptical over the years since CSU introduced the SDS in the Colorado Springs Water Plan of 1996. According to Schara, the biggest concern was about the capacity of Pueblo Reservoir, which he said has been “pretty low at times.”

The Southern Delivery System cost $825 million. Forte said that presently the SDS takes care of about 5 percent of the Colorado Springs Utilities customers and produces about 5 million gallons of water each day.

During Saturday’s event, CSU handed out free water bottles and had refill stations throughout the event where visitors could rehydrate with water from the Pueblo Reservoir. The hands-on exhibits allowed kids to make snow, touch a cloud, shoot water from a fire hose, and learn more about how CSU uses water supplied by the SDS…

Forte said the Waterfest was designed to thank customers “for their patience” over the last couple of decades while the SDS became reality.

“Our citizen-owners have come out to see what we’ve been talking about for the last 20 years,” Forte said. “It’s just a fun day.”