• Crucial Glen Canyon Dam tubes damaged face uncertain Future. By Tony Davis for Arizona Daily Star.
• Glen Canyon Dam's underwater tubes unreliable for water deliveries and low lake levels. By Tony Davis for Arizona Daily Star.
• Possible damage to Glen Canyon Dam tubes could spell trouble for Lake Mead. By Alan Halaly for Las Vegas Review Journal.
• Memo reveals damage to pipes inside Glen Canyon Dam, a threat to Colorado River water supply. By Greg Hass for KLAS-TV in Las Vegas.
• Damage at Glen Canyon Dam raises water risks on the Colorado River. By Ian James for The Los Angeles Times.

Other News

• 1997, June 28 - Power plant at Flaming Gorge Dam churning out electricity again. Deseret News.

General Design Specifications

• The design of the river outlets was based on concrete having a compressive strength of 3,000 pounds per square inch at 28 days for structural concrete and 2,500 pounds per square inch at 28 days for mass concrete.
• The river outlets provide for releases for downstream commitments when the powerplant is not in operation and during the period of final closure of the diversion tunnels. The outlets will also be used to maximum capacity during maximum flood releases.
• More Information

MEMOS AND REPORTS
Federal Agencies

• Memo of April, 2024 - Glen Canyon Dam Outlet Tubes Memo
• Meeting of March 6, 2024 - Arizona Reconsultation Committee and video; marked at 49.40 minutes. Specific to river outlets.
• April 4, 2023 - Long-term Drought and Glen Canyon Dam: Potential effects on water deliveries and hydropower. Congressional Research Service.
• 1990 - Cavitation in chutes and spillways. USBR.
• 1960 - Air and hydraulic model studies of left diversion tunnel outlet works for GC Dam, CRSP. USBR.

REPORTS
Science and History

• Canyon Legacy; Volume 59; Spring 2007. Authors include John Keys and John Weisheit.

DESIGN SPECIFICATIONS OF GLEN CANYON DAM

• Fact Sheet
• 1961 - Design features of Glen Canyon Dam. Bureau of Reclamation.
• 1970 - Glen Canyon Dam technical record of design and construction; searchable doc; for reading the horizontal pages; Chronology; Intro; Geology; Foundation; Dam; Spillways; River Outlets; Penstocks; Powerplant; Switchyard; Visitor Center; Consruction, Appendix. Bureau of Reclamation.

• Opening river outlet tubes for High Flow Experiment in November of 2018. NPS; mp4.

REPAIR PROPOSAL 2022
River Outlet Works Pipe Relining at Glen Canyon Power Plant

• Document: Solicitation 140R4023R0010 Glen Canyon Dam River Outlet Works Pipe Relining
• The Bureau of Reclamation, Upper Colorado Basin, is seeking potential sources to reline the river outlet works pipe at the Glen Canyon Power Plant.
• The Contractor shall provide all the expertise, labor, tools and equipment necessary to reline 4 river outlet tubes at Glen Canyon Power Plant.
• Work is located at Glen Canyon Dam, approximately 2 miles northwest of Page, Arizona, in Coconino County.

Work Details

• Control ponding, seeping, and flowing leakage water in outlet works during relining operations.
• Outlet pipe (4 total) Abrasive blast clean surfaces to remove corrosion and existing linings, create a surface profile, and apply a new lining system on interior surfaces of outlet works pipe  from bell mouth transition to hollow jet valve. Including manhole covers interior and exterior surfaces. Approximately 22,600 square feet of surface preparation and lining.
• To include Interior Drain Line 140 square feet and Exterior Coating of Drain line 20 square feet.
• High pressure water jet clean to remove corrosion and existing lining and apply new surface tolerant lining for drain lines on outlet works pipes.
• Furnish and install cathodic protection if any corrosion is observed in the bell mouth of an outlet works pipe.
• Contain, handle, and dispose of hazardous coating materials.
• Allowable window for work is approximately April through October.
• The contract specialist and point of contact for this request for information is Jennifer Handy. Please submit responses and any other inquiries via email to jhandy@usbr.gov.

THE LITTLE FLOOD OF 1983
(Under construction; come back soon.)

Spillways at Glen Canyon Dam (see the specifications at page 32)

• Original capacity for the volume of a probable maximum snowmelt, from April to July (four-months), is forecasted to be 29,0600,000 acre-feet, and the river flow rate would peak at 380,000 cfs.
• A probable maximum rain event, which is predicted to occur in the fall, would have a peak discharge of 417,000 cfs and a 6-day volume of 2.063,600 acre-feet.
• These engineering specifications are completely useless because in real-time, the spillways at Glen Canyon Dam failed during the snowmelt of 1983 after only one week of emergency operations at 20 percent of capacity.
• The four month snow melt was only 15,000,000 acre-feet; peak flow into Lake Powell was 104,000 cfs.
• The spillway repairs following the snowmelt of 1983 included air injection mechanisms to minimize the cavitation pressures. This modification diminished the total capacity of the spillway discharge by 25 percent.
• Therefore, even if the spillways could avoid failure during a four month snowmelt, such a surge of melt water would of course overtop the dam and destroy the powerplant below and erode the foundation bedrock around the dam.
• Will such a scenario unfold? Paleoflood hydrologists have evidence of four snow melts in the last 2000 years greater than 380,000 acre-feet.
• If it happened in the past, it will happen in the future.

Paleoflood Studies:

• Colorado River
• Green River
• San Juan River
• Dolores River
• Grand Canyon (publication is pending.