Hoover Dam, Metropolitan Water District Line 1, U.S. Highway 93, Boulder City

Source document Quoted word for word from HAER NV-27-P. Not written, edited or summarised by this site.

U.S. Highway 93 Vicinity of Boulder City Clark County Nevada USGS Hoover Dam, Nevada-Arizona 7.5 Minute Provisional USGS Boulder Beach, Nevada-Arizona 7.5 Minute USGS Boulder City, Nevada-Arizona 7.5 Minute UTM Coordinates: 1 (start) (end documented segment) Date of Construction: Engineer: Metropolitan Water District of Southern California Builder: Metropolitan Water District of Southern California U.S. Highway 93 Vicinity of Boulder City Clark County Nevada USGS Hoover Dam, Nevada-Arizona 7.5 Minute Provisional USGS Boulder Beach, Nevada-Arizona 7.5 Minute USGS Boulder City, Nevada-Arizona 7.5 Minute UTM Coordinates: l (start) l l l (end documented segment) Statement of

Source document Quoted word for word from HAER NV-27-P. Not written, edited or summarised by this site.

The Metropolitan Water District Transmission Line 1 (or West Line) was a critical element of the Hoover Dam electrical generation and transmission system. The line provided Hoover Dam power for development of irrigation and municipal water delivery systems in southern California, construction of Parker and Davis dams, and World War II war industries and military training facilities in Arizona and California. Report Prepared by: Associated Cultural Resource Experts (ACRE) Sangre de Cristo Road, STE 202 Littleton, CO Date: April HISTORIC AMERICAN ENGINEERNG RECORD HOOVER DAM, METROPOLITAN WATER DISTRICT LINE 1 HAER NO. (Page 2) The Metropolitan Water District Transmission Line 1 (or West Line) was a critical element of the Hoover Dam electrical generation and transmission system.

The line provided Hoover Dam power for development of irrigation and municipal water delivery systems in southern California, construction of Parker and Davis dams, and World War II war industries and military training facilities in Arizona and California. Description: The Metropolitan Water District Transmission Line 1 (West) consists of large-diameter conductors carried on steel wedge A-frame towers from the MWD Switchyard at Hoover Dam to multiple points in southern Nevada and California. From Hoover Dam, the line courses westward and southwestward across rugged mountains, then southwestward within Eldorado Valley to the east of Boulder City.

The line passes to the east of Mead Substation, and two short transmission lines connect the original line to the substation to allow switching and monitoring at that point. The documented segment of the MWD Transmission Line 1 originates at the MWD Switchyard, near the Nevada rim of Black Canyon, and extends southwestward to east of Mead Substation. The documented segment includes steel towers that are all single-circuit, suspension type. Towers are 27' square at base and up to high. Towers consist of a square leg segment up to 25' high, a square vertical panel 25' high, a standard battered segment either 50' or 60' high, a bridge or cross member 5' high and 50' long, and ground wire extensions 20' high.

Towers vary in height and intervening distance according to topography and cultural features crossed by the transmission line. History: The Metropolitan Water District of Southern California was one of the major contractors for Hoover Dam power, primarily for use in constructing and operating water delivery systems from the Colorado River to southern California.

MWD constructed a 237-mile, transmission line from Hoover Dam to various points in southern Nevada and southern California from December to July The MWD line employed familiar technology that had earlier been developed by Southern California Edison Company (and which would shortly be used by that company for its own lines to Hoover), and steel-wedge, A-frame towers differed from the Y-frame towers used for the Los Angeles BPL transmission lines from Hoover Dam to Los Angeles. Hoover Dam generating units N-5 and N-6 were completed in June and August and commercial delivery of electricity over the MWD line began on November 3, 193 8.

MWD found itself with more power than it could use almost immediately upon completion of its transmission line, and the District sold its excess capacity to the Southern California Edison Company, the City of Los Angeles, and other municipalities in California and Nevada. Some of excess capacity was absorbed by the Basic Magnesium plant at Henderson, Nevada from to The connection of the MWD transmission line to the MWD Switchyard was shifted HOOVER DAM, METRO POLITAN WATER DISTRICT LINE 1 HAER NO. (Page 3) twice: in to accommodate installation of the Basic Magnesium lines; and in to accommodate interchange of power with Davis Dam.

MWD completed a second transmission line in in preparation for the District's absorption of all power from generating unit The second MWD transmission line was virtually identical to the first line, and it was routed parallel to the first line throughout the Hoover Dam-Boulder City area. The Bureau of Reclamation may have begun using at least one of the MWD lines about for power interchange with Davis Dam. Both MWD lines are now used by Western Area Power Administration to transmit power from Hoover Dam to Mead Substation. These transmission lines are unchanged in the vicinity of Hoover Dam and Boulder City, except for replacement of the original conductors, installation of line dampeners and bird guards, and attachment of connecting lines to Mead Substation.

Source document Quoted word for word from HAER NV-27-P. Not written, edited or summarised by this site.

This documentation of features of Hoover Dam and associated structures was accomplished by Associated Cultural Resource Experts (ACRE). ACRE completed documentation of2I features in October Documentation on four linear features was extended and an additional 3 features were newly documented in February Both phases of documentation were conducted as part of the historical/engineering recordation of Hoover Dam-prepared for the Department of Energy, Western Area Power Administration; Bureau of Reclamation; and Federal Highway Administration-that includes a narrative for the Addendum to Hoover Dam and individual documentation of 25 features located at the Hoover Dam facility, photo documentation, and documentation of existing historic photographs and site plans.

The recordation conforms to the standards of the Historic American Engineering Record, U.S. Department of the Interior.

Other reports in the HAER collection completed for these projects are a narrative for the Addendum to Hoover Dam and 24 short forms for individual structures: Hoover Dam, Los Angeles Switchyard (NV-27-A); Hoover Dam, Southern Sierras/CEP/Southern California Edison Switchyard Hoover Dam, Metropolitan Water District Switchyard Hoover Dam, State of Nevada Switchyard Hoover Dam, Southern California Edison Switchyard (NV-27-E); Hoover Dam, Arizona-Nevada Switchyard Hoover Dam, Static Towers and Lines Hoover Dam, Los Angeles Relay Control Building Hoover Dam, Switchyard Fire House Hoover Dam, Promontory Water Tank Hoover Dam, Control Cable Hoist House Hoover Dam, Transformer Circuits Hoover Dam, Los Angeles BPL Lines 1-3 Hoover Dam, Southern California Edison North and South Lines Hoover Dam, Hoover-Basic Magnesium North and South Lines Hoover Dam, Metropolitan Water District Line 1 Hoover Dam, United States Construction Railroad Hoover Dam, U.S.

Highway 93 Nevada Segment Hoover Dam, Lower Portal Access Road Hoover Dam, Kingman Switchyard Hoover Dam, U.S. Highway 93 Arizona Segment (NV-27-U); Hoover Dam, Explosives Magazines Hoover Dam, Nevada Downstream Waste Tailings and Hoover Dam, Nevada Spoils Tunnel Hoover Dam, Henderson-Mead Transmission Line 2

Source document Quoted word for word from HAER NV-27-P. Not written, edited or summarised by this site.

This documentation was prepared for three federal agencies: U.S. Department of Transportation, Federal Highway Administration (FHWA), Central Federal Lands Highway Division, Lakewood, CO; U.S. Department of Energy, Western Area Power Administration (Western), Desert Southwest Customer Support Region, Phoenix, AZ; and U.S. Department of Interior, Bureau of Reclamation (Reclamation), Lower Colorado Region, Boulder City, NV. This documentation records certain transportation and electrical features associated with Hoover Dam before planned removal or alteration of some structures. FHWA plans to construct a bridge over the Black Canyon of the Colorado River about downstream from Hoover Dam. The Hoover Dam Bypass Project would include realignment of U.S.

Highway 93 on the Nevada and HOOVER DAM, METROPOLITAN WATER DISTRICT LINE 1 HAER NO. (Page 4) Arizona sides of Black Canyon. The project would include demolition, relocation, or substantial visual impact to a segment of U.S. Highway 93 on the Nevada approach to Hoover Dam, a segment of a former alignment of U.S. Highway 93 in Arizona, electrical transformer circuits in Arizona and Nevada, two electrical switchyards, a segment of the grade of the U.S. Construction Railroad, a stone gate structure for a dam construction and operations road, and six historic transmission lines. This documentation also records certain structures not directly affected by FHWA's Hoover Dam Bypass Project.

Electrical transmission facilities at Hoover Dam are administered by Western, but these facilities are within a federal reservation administered by Reclamation. Documentation of electrical structures is intended to partially fulfill responsibilities of Western and Reclamation under Section llO of the National Historic Preservation Act (As amended). Some electrical structures addressed by Western and Reclamation would be directly affected by FHWA's Hoover Dam Bypass Project, and all structures addressed by Western and Reclamation are functionally related and geographically near structures addressed by FHWA. Project Manager and historian for the recordation was Kurt P. Schweigert of Associated Cultural Resource Experts. The photographers were Deborah Dobson-Brown and Douglas M.

Edwards of Associated Cultural Resource Experts. This documentation was prepared on the basis of research conducted at Reclamation archives in Denver, CO, and Boulder City, NV; Western archives and files in Denver and Phoenix, AZ; the National Archives and Records Administration in Denver; libraries of the University of Nevada-Las Vegas; and the Western History Collection of the Denver Public Library. This documentation includes information contained in survey reports for the Hoover Dam Bypass Project Environmental Impact Statement, an evaluation of the Western switchyards at Hoover Dam, an evaluation of the Hoover Dam construction railroads, a National Register nomination for Hoover Dam, and other documents.

Source document Quoted word for word from HAER NV-27-P. Not written, edited or summarised by this site.

Kurt P. Schweigert, Associated Cultural Resource Experts, 0 0 ~tJ -~ ~ 0 r ~ ~z tTJ ::E ?O > 0 z ?O51 . tJ < I --l ~~ n ~z : tTJ '-' >-' HOOVER DAM, METRO POLITAN WATER DISTRICT LINE 1 HAER NO. (Page 6) HOOVER DAM, METROPOLITAN WATER DISTRICT LINE 1 HAER NO. (Page 7)