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HomeMy WebLinkAboutRes2011-055 Sponsored by: Oates CITY OF SEWARD, ALASKA RESOLUTION 2011 -055 A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF SEWARD, ALASKA, ADOPTING THE CLIMATIC DESIGN CRITERIA FOR THE ELECTRIC UTILITY OF ALL DISTRIBUTION UTILITY POLES SOUTH OF NASH ROAD FOR THE PURPOSE OF CONSTRUCTION AND ATTACHMENT WHEREAS, the climatic design criteria have a direct impact on the safety and reliability of the electrical system; and WHEREAS, the reliability of the electrical system has a direct impact on the health and welfare of the community of Seward; and WHEREAS, the recommended engineered climatic design criteria from Dryden and LaRue engineering firm is an extreme wind load of 100mph with the associated NESC 250C factors for an extreme wind and the NESC 250B heavy loading; and WHEREAS, this climatic design criteria shall dictate the design, construction and attachments for all distribution utility poles in the downtown Seward area South of Nash Road; and WHEREAS, the NESC states in section 1.012.0 "For all particulars not specified in these rules, construction and maintenance should be done in accordance with accepted good practice for the given local conditions known at the time by those responsible for the construction or maintenance of the communication or supply lines and equipment "; and WHEREAS, the known standards for the two closest utilities to Seward (Homer Electric Association and Chugach Electric Association) have more stringent attachment conditions than the NESC 250B heavy conditions for some distribution poles; and WHEREAS, all communication carriers joint use agreements in Article III.a. state, "Minimum requirements for jointly used poles covered by this agreement together with all attachments on such poles shall be at all times placed and maintained in conformity with the National Electric Safety Code, current edition, except where modified by authority of the State of Alaska and such other specifications as may be mutually agreed upon and approved in writing: except where the lawful requirements of the public authorities may be more stringent, in which case the latter shall govern "; and WHEREAS, the current city standard established by the electric department for all distribution poles south of Nash Road is set at NESC heavy (40 mph with ' /2" ice), 70 mph with ' /2" of ice at 30 degrees Fahrenheit, and 115 mph with no ice. CITY OF SEWARD, ALASKA RESOLUTION 2011 -055 NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF SEWARD, ALASKA that: Section 1. The City of Seward adopts an extreme wind load of 100mph with the associated NESC 250C factors and the NESC 250B heavy loading. Section 2. This resolution shall take affect immediately upon its adoption. PASSED AND APPROVED by the City Council of the City of Seward, Alaska, this 27 day of June, 2011. THE CITY 0 SEWARD, ALASKA ..eor illard E. Dunham, Mayor AYES: Valdatta, Smith, Keil, Shafer, Casagranda, Dunham NOES: None ABSENT: Bardarson ABSTAIN: None ATTEST: ohanna Kinney City Clerk (Cit�f� q ., • +r`1' . • 'a i .. - ® _ _. : • • Agenda Statement Meeting Date: Monday, June 27, 2011 4 o SFk To: City Council Through: Phillip Oates, City Manager q P From: John Foutz, Electric Utility Manager Agenda Item: To Enact the Climatic Design Criteria for Construction and Attachment on the Electric Utility Poles in Downtown Seward, South of Nash Road. BACKGROUND & JUSTIFICATION: The Climatic Design Criteria are determined by the City of Seward for construction of the electric utility system to keep the people, businesses and community of Seward safe and energized during the projected life of the individual poles. These Criteria are based on sound engineering practices, local weather conditions, and conservative assumptions. The wind loading criteria are meant to reduce the risk to life, limb and property in the community of Seward while still allowing safe and practical additions of conductor (wire). The wind loading criteria are the basic design standards the electric department shall use to construct the system that supplies power to the businesses and residents of Seward. These criteria are also used for additional attachments by, not only the electric department, but communication companies. Dryden and LaRue recommend the climatic design criteria to be extreme wind load of 100mph with the associated NESC 250C factors and the NESC 250B heavy loading for the downtown electric utility system. The electric department recommends the city council adopt this as the standard for the downtown Seward, south of Nash Road, for construction and attachment purposes. The electric department is of the opinion that adopting anything less than the recommended engineering minimum would make it more likely that the City of Seward will suffer failure of one or more utility poles during periods of extreme wind conditions. INTENT: To adopt the recommended extreme wind load of 100mph with the associated NESC 250C factors and the NESC 250B heavy loading of all distribution poles south of Nash Road for the purpose of construction and attachment. CONSISTENCY CHECKLIST: Where applicable, this agenda statement is consistent with the Seward City Code, Charter, Comprehensive Plans, Land Use Plans, Strategic Plan and City Council Rules of Procedures or Other Plans or Policies. FISCAL NOTE: This fiscal note relies on calculations performed by Dryden & LaRue as presented to Council in a recent work session, utilizing actual wind load calculations from a subset of existing City poles. The overall cost of replacing poles will depend in large part on the specific wind load criteria adopted by the City, as well as on the final engineering calculations for the 34 poles in question. For example, utilizing a wind loading standard of 115 mph results in the necessity to replace twenty percent (or eight poles) of the 34 poles which GCI is requesting to attach to. The estimated cost of replacing eight poles is approximately $160,000. This cost would be borne by the electric utility. Utilizing a wind loading standard of 100 mph results in the necessity to replace ten percent of the poles (or four of the 34 poles), at an estimated cost of $80,000. These figures are estimated, and the actual number I o of poles required to be replaced will be determined once final engineering calculations are available, indicating the specific poles to be replaced. It is not possible to estimate the financial risk associated with poles which might pass initial wind load requirements but subsequently fail after adding attachments. We would expect to bill GCI to recover the costs associated with pole failures subsequent to the placement of attachments. Approved by Finance Department: !1 4,a,- euL�e., ATTORNEY REVIEW: Yes X No It should be noted that Seward City Code, Section 14.15.610(a) provides that the City could be liable for an interruption of electric utility service if any "injury, loss or damage results from the sole negligence of the city." RECOMMENDATION: Approve Council Resolution 2011 -055, adopting the climatic design criteria for the electric utility of all distribution utility poles south of Nash Road for the purpose of construction and attachment, as recommended by Dryden & LaRue. \d'3\