#ColoradoRiver: Lake Mead Drops But Hoover Dam Powers On — Circle of Blue

Lake Mead turbines photo via <a href="http://corbittsnationalparks.com/sites/lakemead/lakemead.html">CorbittsNationalParks.co&lt;,/a&gt;</a>
Lake Mead turbines photo via CorbittsNationalParks.co<,/a>

From Circle of Blue (Brett Walton):

Six years ago, at the end of the summer of 2010, federal Bureau of Reclamation officials worried that Hoover Dam, the biggest hydropower enterprise in the Southwest, might soon go dark. Water levels in Lake Mead, the dam’s energy source, were falling, and Hoover was moving “into uncharted territory,” the facility manager told Circle of Blue.

Today, the story has a twist. Lake Mead is 10 feet lower, a new record set on May 18 that is re-broken every day now. Yet though water levels continue to decline, Hoover’s hydropower is in a much better spot. Thanks to investment in efficient equipment, managers are confident that they can still wring electricity from the Colorado River even as the surface elevation of Lake Mead drops below 1,050 feet, the uncharted territory that was assumed to be Hoover’s operating limit.

“As far as power goes, we can still operate below 1,050 feet,” Rose Davis, Bureau of Reclamation spokeswoman, told Circle of Blue. Dam operators are revising the lower limit to 950 feet, a boundary that will be confirmed in October once the fifth and final more-efficient turbine is installed, Davis said.

The investments in wide-head turbines, stainless steel wicket gates, and digital controls are emblematic of the types of practices that are necessary for the drying Colorado River Basin. In order to maximize scarce water, authorities must do more with less. Water managers in the lower basin states of Arizona, California, and Nevada, keen to avoid a disastrous downward spiral for Lake Mead that would threaten supplies for tens of millions of people, are spending more than $US 11 million on farm-efficiency and other projects that will conserve water and bank the savings in Lake Mead. Dam managers and power customers are adopting the same ethic for power generation.

Spending to Save Water and Boost Power
Electricity from Hoover is some of the cheapest in the country, at 1.83 cents per kilowatt-hour. Constructions costs for the dam were paid off years ago and the energy source, the water, comes from Mother Nature free of charge.

Customers in Arizona, California, and Nevada, the destination for Hoover’s output, would like to keep the cheap power flowing. That is why they spent $US 14.9 million since 2011 on the turbines and wicket gates.

The problem with Mead’s low water level for power generation is physics. Pressure differences in the water coming into the generators produce air bubbles on the turbine blades. As the water flows across the blades, the bubbles collapse and burst, which causes vibrations that can damage the generating unit. If the vibrations worsen, the unit must be shut down.

Wide-head turbines are designed to avoid these “rough zones” and operate smoothly at low reservoir levels. Four of Hoover’s 17 turbines have been fitted with wide-head models, and a fifth will be installed by October.

The wicket gates, on the other hand, allow for more precise control of water flowing through the turbines. They also reduce water leakage so that every drop that passes through Hoover can generate as much power as possible. Digital controls, which allow for more precise positioning of the wicket gates, have been installed at Hoover as well as at Davis and Parker dams, downstream on the Colorado.

“Any efficiency in hydropower means more power for our customers,” Kara Lamb told Circle of Blue. Lamb is the spokeswoman for the Western Area Power Administration, which markets Hoover’s power.

Though Hoover will not shut down any time soon, low water levels still reduce its output.

Generating capacity — the maximum amount of power that the dam is capable of producing — is down 30 percent from when Mead was full. For every foot that Mead drops, generating capacity decreases by five to six megawatts. Money is power, the old saying goes. So is water.

@OmahaUSACE: The annual sediment flushing exercise will be completed at Cherry Creek Reservoir on Wednesday, June 1, 2016

Cherry Creek Dam looking south
Cherry Creek Dam looking south

Here’s the release from the USACE Omaha office (Katie Seefus):

The annual sediment flushing exercise will be completed at Cherry Creek Reservoir, near Aurora, Colorado on Wednesday, June 1, 2016.

Katie Seefus, water manager in the U.S. Army Corps of Engineers’ Omaha District office, says the exercise involves high releases from each of the five main outlet gates at Cherry Creek Dam, located south of Interstate 225 in Aurora. “When the gates are opened, the high velocity of the water leaving the reservoir scours the area immediately upstream of the gates and transports sediment with the flow,” said Seefus. The sediment flush is required to allow proper operation of the outlet gates.

Cherry Creek Dam will begin releasing 50 cubic feet per second (cfs) at 2:30 p.m. on Tuesday, May 31. The actual flushing exercise will begin at 9 a.m. and end at 12 p.m. on Wednesday, June 1 when the release will be set back to normal levels. The travel time from Cherry Creek Dam to the streamgage located at the Champa Street Bridge, is about 6 hours…

Omaha District Commander Col. John Henderson asks the public to be aware that the high flows will take some time to reach the downtown channel, and flows from the last gate opened will not reach the downtown channel until late afternoon on Wednesday. The high flows will cause higher than normal creek stages and potential flooding of bike paths and stream crossings. “In the interest of public safety, I urge the public to not attempt to cross the stream during this event,” says Henderson.

Boulder County offers water tour of Left Hand Ditch system — the Longmont Times-Call

Above, left: This hand drawn map is one of the original documents of Coffin V Left Hand Ditch, at the Colorado State Archives. A few original documents from the Coffin V Left Hand case can be seen at the Colorado State Archives, filed under case #885, #1103 and #1203.  Above, right: The headgate of the Left Hand Ditch on the South St. Vrain, where the famous confrontation took place.
Above, left: This hand drawn map is one of the original documents of Coffin V Left Hand Ditch, at the Colorado State Archives. A few original documents from the Coffin V Left Hand case can be seen at the Colorado State Archives, filed under case #885, #1103 and #1203. Above, right: The headgate of the Left Hand Ditch on the South St. Vrain, where the famous confrontation took place.

From the Longmont Times-Call (John Fryar):

People can register to participate in a June 11 Boulder County Parks and Open Space water tour that’s to highlight the 150th anniversary of the Left Hand Ditch Company.

The 7:30 a.m. to 2:30 p.m. tour will begin at the Plaza Convention Center, 1850 Industrial Circle, Longmont, and start with presentations on water law, the orientation of the overall Left Hand basin and the history of the Left Hand Ditch.

Tour buses will then visit stops at sites in the Left Hand Ditch system before returning to the Plaza Center. The water tour, which will include a light breakfast and lunch, will cost $20 per participant.

For more information and to register online, visit http://www.bouldercounty.org/os/events/pages/agtours.aspx?utm_source=redirect&utm_medium=redirect&utm_campaign=POSRedirect or contact Vanessa McCracken at vmccracken@bouldercounty.org or 303-678-6181.

The 2016 Water Tour is supported by Boulder County Parks and Open Space, Boulder’s Open Space and Mountain Parks, the St. Vrain and Left Hand Water Conservancy District and Left Hand Water District.

Fountain Creek District board meeting recap

<a href="https://pubs.er.usgs.gov/publication/sir20145019">Report</a>: Remediation Scenarios for Attenuating Peak Flows and Reducing Sediment Transport in Fountain Creek, Colorado, 2013 -- USGS.
Report: Remediation Scenarios for Attenuating Peak Flows and Reducing Sediment Transport in Fountain Creek, Colorado, 2013 — USGS.

From The Pueblo Chieftain (Chris Woodka):

Two projects to improve Fountain Creek will get underway soon after contracts were approved at Friday’s meeting of the Fountain Creek Watershed Flood Control and Greenway District.

A $67,000 contract with MWH Global was approved to evaluate flood control alternatives on Fountain Creek between Colorado Springs and Pueblo.

It’s the next phase of a project to determine the best type and placement of flood control structures on Fountain Creek, which could include a dam or several smaller detention ponds.

The planning started with a U.S. Geological Survey study in 2013 that identified the most effective concepts to protect Pueblo from severe floods and reduce harmful sedimentation. Last year, another study determined flood control projects could be built without harming water rights downstream.

The new study will use $41,800 in grants from the Colorado Water Conservation Board through the roundtable process. It is expected to be complete by Jan. 31, 2017.

A second project, totaling $60,000, was approved to continue a study of Fountain Creek stability and sediment loading by Matrix Design. The project was begun in 2010, and will identify the most critical areas for projects along Fountain Creek.

The district obtained matching funds for the projects through the payment of $125,000 from Colorado Springs Utilities to the district under terms of a recent intergovernmental agreement with Pueblo County that allowed Southern Delivery System to be put into service.

The district board also agreed on a formula to fund routine operation of the district among member governments in Pueblo and El Paso County. The district is looking at $200,000 in funding for next year’s budget. The funding is allocated by population, with Colorado Springs paying half; unincorporated El Paso County, 25 percent; small incorporated cities in El Paso County, 5 percent. The city of Pueblo would pay $26,000, or 13 percent; Pueblo County, $13,000, or 6.5 percent.

Those costs are still subject to approval by each governmental entity.

#Colorado Springs lists 71 stormwater projects to be built in region — The Colorado Springs Gazette

The confluence of Fountain Creek and the Arkansas River in Pueblo County -- photo via the Colorado Springs Business Journal
The confluence of Fountain Creek and the Arkansas River in Pueblo County — photo via the Colorado Springs Business Journal

From The Colorado Springs Gazette (Billie Stanton Anleu):

New detention ponds and detention basins dominate the list of 71 stormwater projects that will be built throughout Colorado Springs over the next 20 years as part of a $460 million intergovernmental agreement.

Topping the list released by the city Wednesday are $2 million worth of projects through the Federal Emergency Management Agency to maintain and repair city stormwater fixtures; a $250,000 King Street detention pond; a $2.5 million detention basin at America the Beautiful Park, and a $3 million detention basin on Sand Creek, surrounded by Forest Meadows housing developments near Woodmen and Black Forest roads.

The projects are intended to stanch the flow of flood waters into Pueblo County, and cut back on sediments and other pollutants entering drainages and going downstream.

Asked why the developers aren’t providing the Sand Creek pond, Public Works Director Travis Easton said he couldn’t recall for certain but thought one of the developers was providing other stormwater work.

The America the Beautiful project calls for a consultant to be hired and to coordinate the work with Kiowa Engineering, designer for the adjacent Olympic Museum, one of three City for Champions projects that all are privately funded.

The city money isn’t being spent to benefit the museum; rather, it’s needed for that entire downtown area, Easton said.

“What we realized is we have open space in that park, with a low-lying area, and needed to route water from downtown into the pond to treat it before it enters Fountain Creek. They didn’t have detention ponds back when that was built, and it just goes straight into Fountain Creek,” he said.

Many of the detention ponds and basins got the nod from Wright Water Engineers Inc., which is representing Pueblo County in its three-way pact with the city and Colorado Springs Utilities.

Other projects throughout Colorado Springs, including many listed by the Pikes Peak Stormwater Task Force in 2013, are lower on the city’s new list.

But, Easton said, “I wouldn’t pay too much attention to the order of things farther down the list because these will change. We’re starting the top nine projects this year. We’re meeting with Pueblo County’s engineers soon to go over the list, which we’ll do every year, and plan the projects for the next five years.”

Big concessions to Pueblo County had to be made in the agreement, or Utilities could have been blocked from launching its $825 million Southern Delivery System last month. The county held a critical permit for the massive water project, and its commissioners demanded extensive stormwater work on Fountain Creek and its tributaries.

The county’s needs were heavy on flood control, sediment loading and channel stabilization, Easton said, “but we agree those are needed.”

The city’s Stormwater Division is spending $7.1 million next year on operating costs alone, primarily personnel and equipment, he said. Three new employees have been brought on board, and five more will be hired over the next three months.

“We need to make sure we have processes in place so these people can hit the ground running and do the job.”

The city has launched a new website to highlight the location of all 71 stormwater projects on an interactive map. Easton said he also plans to combine the city’s new interactive maps so stormwater and roads projects all will be in one place.

“It will be a one-stop shop for citizens to go and see where their money is being spent. This is a tool meant for the citizens, a communication tool.”

City water supply could be tested by climate change — The Aspen Daily News

Smuggler Mine back in the day via GregRulon.com
Smuggler Mine back in the day via GregRulon.com

From The Aspen Daily News (Curtis Wackerle):

If climate change renders the Western Slope warmer and drier, and if historic growth rates keep up, then Aspen’s water utility could have trouble meeting consumer demand without depleting minimum in-stream flows in Castle and Maroon creeks over the next 50 years.

Aspen City Council on Monday heard a presentation from consultants hired to evaluate the adequacy of the municipal water supply. Wilson Water Group put together a report forecasting demand and available supply over a 50-year outlook, and found that in the worst-case climate change scenario, the city could miss in-stream flow targets on Castle and Maroon creeks by between 4 and 9 cubic feet per second during the “irrigation months” of June through September.

The city has committed to a 13 cfs minimum flow in Castle Creek, and 14 cfs in Maroon. Both creeks are tapped to feed municipal needs through diversion structures that send water to Thomas Reservoir, a holding bay for the city’s treatment plant.

Even if the worst-case scenario projections come to pass in terms of climate change and population growth — demands on the city’s water system historically have risen by about 1.2 percent a year, according to special projects utilities engineer Phil Overeynder — the city has other ways to shore up its water supply.

One project that has been on the drawing board for years would pump treated wastewater uphill from the sanitation plant to irrigate the city’s golf course.

The city also controls three wells in town drawing from the local aquifer. If irrigation for city parks increasingly relied on those wells, then more water could be left in Castle and Maroon creeks.

Combined with more water conservation, or restrictions in drought years, depletion of in-stream flows could be avoided, consultants report.

City council agreed to adopt the 2016 Water Supply Availability Study, and continue monitoring hydrologic conditions.

Council also heard a presentation on Monday from another consultant that analyzed threats to the water supply and water quality. Given that Aspen’s water originates in high mountain valleys, wildfire poses perhaps the most imminent and hazardous threat. A bad fire in the Castle or Maroon watersheds could be detrimental to water quality in those streams, and subsequent mudslides could also cause problems.

There is also the abandoned Pitkin Iron Mine above Ashcroft that drains into Copper Creek, a Castle Creek tributary.

The Colorado Rural Water Association conducted a study for the city assessing the best ways to mitigate these threats.

Creating a buffer zone against wildfire near the diversion structures on Castle and Maroon creeks, while continuing to develop plans to limit wildfire debris flow into Thomas Reservoir, were among the study’s top recommendations.

More work to control erosion at the Pitkin Iron Mine site was also recommended. However, the consultant noted that the Pitkin Iron Mine did not make the list of the state’s 200 most pressing mine cleanup needs.

Weld County considers new rules regulating water pipelines — The Greeley Tribune

Weld County courthouse via Wikipedia
Weld County courthouse via Wikipedia

From The Greeley Tribune (Catharine Sweeney):

The new water line regulations would require mostly anyone trying to move water through or out of Weld County to go through the use by special review — or USR — process.

This process gives the county commissioners and surrounding residents a say in the development. The commissioners can give conditional permission — forcing the builder to alter their plans. Usually, officials require more landscaping or other mitigation. The USR process also requires two public hearings — one in front of the planning commission and one in front of the county commissioners. Here, residents get three minutes each to air their grievances.

Because Weld doesn’t require a USR permit now, no one gets to weigh in on the projects. Residents, and perhaps even county officials, can get left in the dark.

“We just need to stay up to speed with the things coming in,” County Commissioner Mike Freeman said. “It comes back to protecting our surface owners.”

It will be the first discussion of at least three before the board can pass the rules. Officials can update or change the rules at any point before they’re passed.

Under the current proposed regulations, some organizations would be exempt from the permitting process.

Only companies or agencies building pipelines 16 inches or thicker will have to apply, said Weld County Attorney Bruce Barker.

“The intent is primarily to deal with the aspects of placing and siting a big water pipeline,” he said.

Weld agencies — such as cities and water districts — get some slack as long as the water is staying in the county.

The rules are gentler now than they were in the early stages, Barker said. County officials had stakeholder meetings with those agencies, and representatives let them know that although Colorado water regulations seem like they can handle a one-size-fits-all approach, they can’t.

“Major concerns in places like the Arkansas Valley don’t really apply here,” Barker said.

There aren’t the same level of power struggles over the water, so commissioners are pumping the breaks on the harsh language against moving water out of the county.

Before, the language had Greeley water officials worried.

“We’re always concerned with things that could affect us,” said Greeley Water and Sewer Director Burt Knight. “We’ve got a connection into Windsor, and Windsor extends outside of Weld County.”

They also have pipelines into other counties in case of natural disasters. The infrastructure is already in place so one can back the other up if water supplies get damaged.

“We’re OK with where they’re heading,” Knight said. “They were receptive to some of our comments.”

Indeed they were.

“There are some municipalities in Weld that get big water pipelines into the county,” Barker said. “Those are exempted.”

Greeley is exempt, but other towns trying to use Greeley’s water aren’t.

The city of Thornton started buying farms in the Eaton and Ault areas decades ago.

“Their goal was and still is to go ahead and dry those properties up,” Barker said.

It’s called buy and dry. Organizations buy farmland with water rights, go to water court and get the use changed. Then they use it for something else — such as municipal water.

Thornton’s water would come out of Weld and get pumped south to the city.

They’re gearing up to apply for the USR later this year, Barker said.

Oil and gas pipelines will see similar regulations, Barker said. But because county officials are already working on USR requirements for that industry, pipeline rules will get wrapped up in those laws.