FortisBC Inc. (FortisBC) Application for a Certificate of Public ...

future will follow a similar dispersion as that witnessed over the last number of years. As
such the Iowa 50-R3 selected for this account provides a good fit to the historical retirement
patterns and is considered to be reflective of the future retirements in this account.
Account 355.00 – Transmission Poles, Towers and Fixtures, represents 6% of the
depreciable plant studied. The retirements, additions and other plant transactions for the
period 1960 through 2009 were analyzed by the retirement rate method. This account
consists of the transmission, towers, poles, insulators and attachments, such as guy wires
and anchors. In 2004, 380 km of 60Kv transmission lines was removed. Discussions with
operating staff indicate that the account did experience a significant level of plant
retirements over past few years due to required system improvements and upgrades of
aging plant. Management has indicated future builds and retirements will occur as needed
but are not expected to be similar in number or significance as the past 3 years.
Therefore, the Iowa curve has shifted from 45-S2 to 50-R3 and is considered to be
reflective of the estimated future retirement patterns.
Appendix BCUC IR1 69.4
Account 356.00 - Transmission Conductors and Devices, represents 6% of the
depreciable plant studied. The retirements, additions and other plant transactions for the
period 1960 through 2009 were analyzed by the retirement rate method. This account
consists mainly of the Transmission conductor, and related material required for the electric
transmission of electricity. As indicated in the original survivor curve as plotted at page IV-
32, this account has witnessed a significant amount of retirement activity within the
experience band analyzed. Retirements in this account have begun at a relatively early
age and significantly increased in frequency at age 30 and continued at a high frequency
through to age 50. Discussions with management and company staff indicate that further