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
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illard E. Dunham, Mayor
AYES: Valdatta, Smith, Keil, Shafer, Casagranda, Dunham
NOES: None
ABSENT: Bardarson
ABSTAIN: None
ATTEST:
ohanna Kinney
City Clerk
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Agenda Statement
Meeting Date: Monday, June 27, 2011
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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
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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.
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