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Safety Modification Study for Cherry Creek Dam: Public Meetings scheduled for January

Published Jan. 7, 2015
Cherry Creek Dam provides several benefits to the Denver community including Flood Risk reduction and serves as a local recreation area. However, in an extremely rare maximum precipitation event, there is potential for overtopping at the dam. This graphic depicts benefits of the dam as well as areas of potential inundation if the dam were to fail under these extreme conditions. The probability of such an event is extremely rare. However, it is important to improve the public's awareness of these risks. Actual flooding is dependent upon runoff and flow from the dam.

Cherry Creek Dam provides several benefits to the Denver community including Flood Risk reduction and serves as a local recreation area. However, in an extremely rare maximum precipitation event, there is potential for overtopping at the dam. This graphic depicts benefits of the dam as well as areas of potential inundation if the dam were to fail under these extreme conditions. The probability of such an event is extremely rare. However, it is important to improve the public's awareness of these risks. Actual flooding is dependent upon runoff and flow from the dam.

Map depicting tributaries flowing into Cherry Creek Reservoir and the Sand Creek watershed that would be impacted by the maximum conceivable precipitation event related to the Dam Safety Modification Study. The probability of such an event is extremely rare. However, it is important to improve the public's awareness of these risks. Actual flooding is dependent upon runoff and flow from the dam.

Map depicting tributaries flowing into Cherry Creek Reservoir and the Sand Creek watershed that would be impacted by the maximum conceivable precipitation event related to the Dam Safety Modification Study. The probability of such an event is extremely rare. However, it is important to improve the public's awareness of these risks. Actual flooding is dependent upon runoff and flow from the dam.

Timeline associated with the Cherry Creek Dam Safety Modification Study and developing a report that outlines the feasibility of recommended modifications at Cherry Creek Dam. It is important to improve the public's awareness of these risks. Actual flooding is dependent upon runoff and flow from the dam.

Timeline associated with the Cherry Creek Dam Safety Modification Study and developing a report that outlines the feasibility of recommended modifications at Cherry Creek Dam. It is important to improve the public's awareness of these risks. Actual flooding is dependent upon runoff and flow from the dam.

Cherry Creek Dam and Reservoir Project near Aurora, Colo.

Cherry Creek Dam and Reservoir Project near Aurora, Colo.

A system of 14 relief wells was installed along the downstream toe of Cherry Creek Dam in 2012. A new project will install a 2,200-foot-long underground outfall pipe system for the relief wells.

A system of 14 relief wells was installed along the downstream toe of Cherry Creek Dam in 2012. A new project will install a 2,200-foot-long underground outfall pipe system for the relief wells.

A round of storms Sept. 14, 2013, impacted the Cherry Creek basin causing pool elevations at Cherry Creek reservoir to enter the flood control pool. Cherry Creek peaked at a pool elevation of 5553.4 ft on Sept. 25, more than 12 feet below the record pool of 5565.8 feet in 1973. Major transportation routes and a large population, which makes up the Denver metropolitan area are located downstream from Cherry Creek Dam.

A round of storms Sept. 14, 2013, impacted the Cherry Creek basin causing pool elevations at Cherry Creek reservoir to enter the flood control pool. Cherry Creek peaked at a pool elevation of 5553.4 ft on Sept. 25, more than 12 feet below the record pool of 5565.8 feet in 1973. Major transportation routes and a large population, which makes up the Denver metropolitan area are located downstream from Cherry Creek Dam.

OMAHA, Neb. — Cherry Creek Dam in Aurora, Colorado, is undergoing a Dam Safety Modification Study and an incorporated Environmental Impact Statement being conducted by the U.S. Army Corps of Engineers, Omaha District.

Two public scoping meetings are scheduled and residents are invited to attend and participate:

  • Thursday, January 22, 6-8 p.m.
  • Cherry Creek High School lecture center
  • 9300 East Union Avenue, Greenwood Village, Colorado
  • Saturday January 24, 10 am – Noon
  • Campus Middle School cafeteria
  • 4785 S. Dayton Street, Englewood, Colorado

The presentation and some handouts will also be available in Spanish.

The study is designed to determine appropriate Federal actions to remediate dam safety concerns at Cherry Creek Dam. A Notice of Intent to prepare an EIS was published in the Federal Register dated December 17, 2013.

USACE engineers will be considering possible structural and non-structural measures to address the risk drivers at Cherry Creek Dam. A variety of structural measures may be considered including raising the dam, modifying the existing spillway, creating a secondary spillway, storing water in upstream structures, adding additional relief wells and subsurface cut-off structures. Non-structural measures may include altering operating procedures, preparing warning systems and evacuation plans and conducting community outreach.

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

Previous dam safety studies of Cherry Creek include efforts in 1999 which were later terminated. In 2005, (post-Katrina) USACE began screening its dams (approximately 694 across the U.S.) to determine each dam’s risk level. Cherry Creek Dam received an elevated risk rating primarily because of the dam’s large downstream population and the potential for overtopping or seepage issues during an extremely rare precipitation event (probability of 1/40,000).

The study is being conducted in accordance with USACE policy as described in Engineering Regulation 1110-2-1156 “Safety of Dams – Policy and Procedures,” and the EIS is being prepared pursuant to the National Environmental Policy Act of 1969, as amended.


Contact
Eileen Williamson
402-995-2417
eileen.l.williamson@usace.army.mil
or
Cynthia Upah
402-995-2672
cynthia.s.upah@usace.army.mil

Release no. 150107-001