@OmahaUSACE: Annual sediment flushing exercise scheduled at Cherry Creek Reservoir

Release at Cherry Creek dam during a low flush year. (Photo by USACE)

Here’s the release from the US Army Corps of Engineers Omaha office (Katie Seefus):

The annual sediment flushing exercise will be conducted at Cherry Creek Reservoir on Wednesday, May 24, 2017.

Katie Seefus, water manager in the Corps’ 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, Colo. “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. This 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 23. The actual flushing exercise will begin at 9 a.m. and end at 11:10 a.m. on Wednesday, May 24 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. The following table shows a schedule of the planned releases:

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 not to attempt to cross the stream during this event,” says Henderson.

2017 River Sweep recap — The Greenway Foundation

Photo credit The Greenway Foundation.

Here’s the release from The Greenway Foundation:

Volunteers donated over 1,000 hours to 6 parks along the South Platte River. We were able to spread over 70 yards mulch to protect existing trees and plants. Volunteers collected 20 cubic yards of pant debris and 10 cubic yards of trash. Originateve, another local non-profit, sorted through the collected trash and sorted out 400 gallons of recyclable materials!

Over 30 families joined The Greenway Foundation SPREE Education team for the Publication Printers Family Event at City of Cuernavaca Park. We started the morning with a trash clean up along the South Platte River and removed invasive plants under the guidance of Arborforce staff. Families then came up to the pavilion for lawn games and fun guided nature crafts. We made butterflies out of coffee filters, clay stamps using natural materials, planted seeds, and drew with chalk. Thanks again to everyone who helped us clean up this beautiful park!

The Greenway Leadership Corp (GLC) team picked up trash along the road and river in City of Cuernavaca Park. We had a great crew helping clean up the park, with a bunch of new faces and some familiar ones as well! We all spent a couple of hours diligently removing trash, and then some of us hung around to eat food and try our hand at giant Jenga.

Check out the pictures from both events!

Final decision made for Cherry Creek Dam Water Control Plan Modification Study

Cherry Creek Dam looking south

Here’s the release from the Army Corps of Engineers (Katie Seefus):

In October 2015, the U.S. Army Corps of Engineers Omaha District began studying modifications to the Cherry Creek Dam Water Control Plan. A water control plan outlines predetermined regulation requirements for federally authorized project purposes.

Historically, Cherry Creek Dam has been regulated as a system with Bear Creek Dam and Chatfield Dam targeting a maximum flow of 5,000 cfs at the South Platte River at Denver, Colorado streamgage to mitigate flood risk in Denver, Colorado.

The purpose of the Cherry Creek Dam Water Control Plan Modification Study (WCPMS) was to reduce the potential risk of overtopping and failure of Cherry Creek Dam during extreme flooding events by releasing more water from the dam while limiting exposure to potential downstream damages.

The Cherry Creek Dam WCPMS analyzed the impacts due to six release alternatives and recommended an alternative that requires Cherry Creek Dam releases of 7,000 cfs if the reservoir reaches elevation 5590 feet Project Datum (PD), which is 24 feet higher than the record pool set in 1973.

Evacuating flood water from Cherry Creek Reservoir at an accelerated rate reduced the risk of overtopping and failure during an extreme rain event and resulted in minimal incremental downstream damage following single rain events that have limited rainfall downstream of the dam. Some risk of additional downstream damage is possible if releasing during subsequent storm events, however, due to the uncertainty in forecasting a thunderstorm’s intensity, duration, and location, the risk is outweighed by the need to release flood water and reduce the risk of Cherry Creek Dam’s overtopping and failure.

Public and agency meetings were held in January 2016 and again in September 2016 to collect and discuss comments from agencies and the public. All comments were resolved by December 2016 following a comment extension in November 2016. The environmental analysis resulted in a Finding of No Significant Impact (FONSI) in March 2017.

Effective April 2017, the Cherry Creek Dam, Chatfield Dam, and Bear Creek Dam water control plans were modified to reflect a 7,000 cfs release from Cherry Creek Dam if the reservoir reaches elevation 5590 feet. Releases from Chatfield Dam and Bear Creek Dam were not increased in the updated water control plans.

Background: The Cherry Creek Dam project was authorized in the 1940s for the primary purpose of mitigating flood risk to the downstream city of Denver from floods originating on Cherry Creek above Cherry Creek Dam. Cherry Creek Dam and Reservoir is located on Cherry Creek, 11.4 miles southeast of its confluence with the South Platte River in Aurora, Colo.

The final Cherry Creek Dam WCPMS report and the updated Cherry Creek Dam, Chatfield Dam, and Bear Creek Dam Water Control Plans are available below:

http://www.nwo.usace.army.mil/Missions/Water-Information/Water-Control/Cherry-Creek-WCPM/

Douglas County to developers: Focus more on a renewable supply

Denver Basin aquifer map
Denver Basin aquifer map

From The Golden Transcript (Jessica Gibbs):

The county held a late afternoon public workshop on Nov. 14 for proposed changes to the county’s water zoning plan.

Conversation was diligent and thorough, despite a sparsely attended meeting of six people in addition to county staff.

The exact portion of the plan under review is Section 18A, which helps determine if a proposed development has an adequate water supply, particularly in terms of quality, quantity and dependability. Douglas County’s Board of Commissioners first adopted 18A in 1998, but it has been revised in 2002, 2005, 2007 and 2013.

County experts said the regulations are primarily for new housing developments or properties seeking to rezone for reasons like expansion. Additionally, they mostly pertain to unincorporated Douglas County, as most municipalities or other water districts have their own regulations.

The main changes in Section 18A were to remove about 15 pages of repetitive sections and more clearly explain if a developer would qualify.

But staff also has proposed Section 18B, an entirely new set of regulations that will act as an alternative to Section 18A.

As the resolution stands, developers must meet a water demand standard of .75 acre-feet per residence per year.

A demand standard is an estimate of how much water a household or development will need, said Kati Rider, a planning resource supervisor with Douglas County.

An acre-foot is how water is measured. One way to think of it, Rider said, is to imagine it as the equivalent to the amount of water that woud spread across an acre of land at one foot deep.

However, county staff said, the average household uses closer to .40 or .45 acre-feet. The .75 standard is costly for developers and may require them to source more water than necessary.

“This revision may matter to residents as it may be a way to encourage new development to utilize renewable water resources, rather than groundwater, in all areas of the county,” Rider said.

Under 18B, developers could propose higher-density developments if they also promise to use less groundwater, rely on more renewable water sources and prove they can accomplish that goal.

Not more than 50 percent of the water supply could come from non-renewable sources. Although the overall amount of water use might be greater, the hope is to encourage a more environmental approach.

If the amendments continue to gain traction, they would pass before the Planning Commission and the Board of Commissioners for final approval.

Public comment is accepted at http://www.douglas.co.us through Nov. 23. Information aboutthe amendments may be found through the county’s Project Records Online (PRO) online tool.

Commissioners will schedule a work session to review the input after public comment closes.

douglascounty

@OmahaUSACE: Public meetings scheduled to discuss Cherry Creek Dam studies

Cherry Creek Dam looking south
Cherry Creek Dam looking south

Here’s the release from the US Army Corps of Engineers (Eileen Williamson):

Three public meetings to provide an update on the status of two studies taking place at Cherry Creek Dam are scheduled for the week of September 20.

The U.S. Army Corps of Engineers will host meetings to provide a status update on alternatives under consideration to address risks from extreme storm events associated with Cherry Creek Dam including a study to modify the dam’s water control plan.
The meetings will be held at the following times and locations:

  • Tuesday, Sept. 20 from 6 – 8 p.m.
    Cherry Creek Presbyterian Church
    Rooms 112/113 (Main Building)
    10150 E. Belleview Avenue
    Englewood, CO 80111
  • Wednesday, Sept. 21 from 5:30 – 7:30 p.m.
    Virginia Village Library
    1500 S. Dahlia Street
    Denver, CO 80222
  • Thursday, Sept. 22 from 5:30 – 7:30 p.m.
    Aurora Municipal Center
    City Café
    15151 E. Alameda Parkway
    Aurora, CO 80012
  • The public meetings will include a presentation and an open house to provide the public an opportunity to ask questions about Cherry Creek Dam and the alternatives being presented and considered as part of the Dam Safety Modification Study and Water Control Plan Modification Study.

    Meeting materials will be made available online following the meetings at http://go.usa.gov/cQ7hP.

    Background: Cherry Creek Dam and Reservoir is located in the southeast Denver metropolitan area on Cherry Creek, 11.4 miles upstream of its confluence with the South Platte River.

    In 2005, (post-Katrina) USACE began screening its dams (approximately 700 across the U.S.) to determine each dam’s risk level. Cherry Creek Dam received an elevated risk rating primarily because of the large downstream population and the potential for overtopping during an extremely rare precipitation event.

    A dam safety modification study began in 2013 and is being conducted in accordance with USACE policy as described in Engineering Regulation 1110-2-1156 “Safety of Dams – Policy and Procedures.” An Environmental Impact Statement is also being prepared pursuant to the National Environmental Policy Act of 1969, as amended.

    Urban Water Conservation Through Native Landscaping. A Colorado River Day Webinar — Audubon

    Photo via Audubon (Abby Burke).
    Photo via Audubon (Abby Burke).

    Click here for all the inside skinny and to register. From the website:

    You Can Help Rivers: Create Habitat!

    Urban Water Conservation Through Native Landscaping. A Colorado River Day Webinar.
    Thursday, July 21, Noon – 1 p.m. MT
    Register here.

    Co-presented by:
    Abby Burk, Western Rivers Program Lead, Audubon Rockies
    Don Ireland, Habitat Hero Award Winner and Volunteer HOA President, Cherry Creek 3

    Did you know native landscaping can save both significant water and money? When we say significant, we mean it! Find out how a neighborhood in southeast Denver saved 15 million gallons of water and $100,000 annually by transforming to native landscaping and incorporating water efficiency into everyday life.

    The Cherry Creek 3 Homeowner’s Association (HOA) won the 2015 Colorado WaterWise Conservation Award for their efforts! HOA Volunteer President Don Ireland will talk about how he and fellow volunteers led this 251-condo development into a new era of water conservation while simultaneously establishing a new landscaping plan that has attracted many new birds and pollinators into the neighborhood. This HOA, without formal training in water conservation but with a burning desire to “do the right thing,” has been a poster child for water conservation and Audubon Rockies’ Habitat Hero program around the Front Range and beyond.

    Register for this webinar today.

    You may also be interested in these upcoming webinars from Audubon’s Western Rivers Action Network:

  • Wednesday, July 20, 1 – 2 p.m. MT: Lake Mead Structural Deficit and Why it Matters
    Presented by Kevin Moran, Senior Director of Water Programs, Environmental Defense Fund
  • Wednesday, August 7, 1 – 2 p.m. MT: Diversity and Inclusion in Conservation and Advocacy
    Presented by Chandra Taylor Smith, Vice President of Diversity and Inclusion, National Audubon Society
  • Wednesday, September 21, 1 – 2 p.m. MT: River Funding and Restoration Efforts
    Presented by Jennifer Pitt, Director – Colorado River Project, National Audubon Society and Scott Deeny, Arizona Water Program Lead, The Nature Conservancy
  • High Line Canal Conservancy Launches New Public Planning Initiative to Re-imagine the 71-Mile Trail Corridor

    Highline Canal Denver
    Highline Canal Denver

    Here’s the release from the High Line Canal Conservancy (Suzanna Jones):

    The High Line Canal Conservancy, which is dedicated to preserving the recreational and environmental future of the High Line Canal, today announced the launch of the High Line Canal public planning initiative. The public planning initiative is part of a large-scale planning program to ensure the well-loved Canal trail reaches its potential as an economic, environmental, recreational and social asset along all of its 71 miles. The goal of the public outreach and visioning phase, called “Adventure on the Canal: Charting our course for the next century,” is to develop a shared vision for the Canal that will guide the future planning process.

    “Today begins a region-wide conversation led by the High Line Canal Conservancy to rehabilitate this beloved corridor into a legacy greenway that unifies and celebrates the distinct communities it intersects,” said Gov. John Hickenlooper. “This project joins a statewide effort to get people outdoors and connect with the beauty of Colorado.”

    Gov. John Hickenlooper will help kick off the public planning initiative at the High Line Canal and Triple Creek Trail connection ribbon cutting and bike ride in Aurora on Tuesday, May 31 at 12:10 p.m. Following the press conference, the Governor will begin a bike ride along the Canal with local children from Environmental Learning for Kids (ELK), assisted by Bicycle Colorado, and continue with a small select group of riders for a portion of the trail. The Governor will have an opportunity to see some of the challenges presenting the Canal currently.

    “The High Line Canal Conservancy is thrilled to work with the Governor and other leaders throughout the region to preserve and transform this outmoded water delivery corridor into a legacy greenway that unifies and celebrates the distinct communities along the High Line Canal,” said Harriet Crittenden LaMair, Executive Director of the High Line Canal Conservancy. “We’re thrilled to have Governor Hickenlooper’s help launching the public outreach phase of this project, asking the public to consider how they view the long-term purpose of the Canal.”

    Following the kickoff event, the Conservancy will launch its summer outreach “Adventure on the High Line Canal,” which will include a series of community open houses, events and other engaging activities in various locations across the region. These gatherings will be interactive, fun opportunities where participants can share the reasons they love the Canal and help write a new chapter for the Canal’s future.

    Each series of community open houses includes 3 identical gatherings in various locations along the Canal’s reach and represents an important chapter in the mission to chart the High Line Canal’s course for the next century. Together, the four series follow the arc of a typical story. Chapter One – “Our Journey Begins” will kick off the week of June 6 at Aurora Central Library, the Lowry Town Center and Goodson Recreation Center. At these introductory open house events, we’ll take a journey together along all 71 miles of the Canal, from the foothills to the plains, and you’ll be able to share your ideas and feedback every step of the way.

    Chapter Two – “A Fork in the Road” will be held the week of July 18 at Expo Recreation Center, Eloise May Library and Eisenhower Recreation Center. This set of community open houses will be the second chapter of the story, bringing residents together to focus on the Canal’s future opportunities and challenges. We’ll explore how each of these ideas could impact the Canal’s narrative in the years to come and ask for your feedback.

    Chapter 3 – “Our Story” will be held the week of September 5 at locations to be set in the future. This third chapter will focus on presenting the initial vision reached by residents, the draft shared vision for the Canal, asking the public to share their feedback and input on the shared vision for the Canal.

    Chapter 4 – “Looking Ahead” will be held the week of October 16 at locations to be set in the future. This fourth set of open houses represents the final chapter, the draft action plan, determined by feedback from the public. It will be focused on implementation and next steps, and will continue to rely on feedback from the public about the final preferred vision for the Canal.

    In addition, online surveys will be available in June and July, providing additional opportunities for input. Visit highlinecanal.org.

    Anyone can participate throughout the launch and subsequent events on social media by following @COHighLineCanal and using the hashtag #71Miles.

    Here’s how to stay updated on High Line Canal project updates:

    The High Line Canal newsletter.

    High Line Canal’s social media channels (Facebook, Twitter, and Instagram).

    Participate in public meetings: http://highlinecanal.org/community

    Take online surveys, which will be active throughout the summer by visiting http://highlinecanal.org/surveys

    Help us spread the word: Please invite your friends and neighbors to participate too!

    ABOUT THE HIGH LINE CANAL CONSERVANCY

    The High Line Canal Conservancy was formed in 2014 by a passionate coalition of private citizens to provide leadership and harness the region’s commitment to protecting the future of the High Line Canal. With support from each jurisdiction and in partnership with Denver Water, the Conservancy is connecting stakeholders in support of comprehensive planning to ensure that the Canal is protected and enhanced for future generations. For more information, please visit http://www.highlinecanal.org.