Marlborough District Council Roading Assets - Activity Management Plan 2015 - 2018 SECTION 1 EXECUTIVE SUMMARY may require to be reverted to fords if they are not economically viable to replace the bridge structure. Council does have some structures insured for loss. Appendix B lists all structures (including ‘off-RAMM’ and footbridges) and their assessed remaining useful life (RUL) based on the NZ Infrastructure Asset Valuation and Depreciation Manual - Ed 2.0, 2006. The minimum remaining useful life is 2 years by default, therefore those bridges with a RUL of 2 are highest priority for replacement or an alternative intervention. 1.6.4.3 Asset Valuation The value of the asset has been derived from replacement cost. The costs to replace structures on the network have been based on square metre rates for bridges and lineal metre rates for culverts. The rates used are based on local experience as well as comparison with outturn costs from recent replacements carried out by other South Island Local Authorities. The average replacement cost for a bridge is just under $3,000/m2 of bridge deck. Bridges have been assumed to be replaced like-for-like in terms of dimensions, i.e. a single lane bridge will be replaced with a single lane bridge, so there is no allowance for an increase in level of service. The exception to this is where existing bridge width is too narrow to meet current bridge design standards, in which case a slightly wider bridge has been allowed for. Bridges have been assigned a replacement type which aims to be the most economical replacement for the site, for example a stone arch would be typically replaced by a steel or concrete culvert, or a short span bridge in a gentle waterway would be replaced with a box culvert, etc. The previous valuation undertaken in 2011 has been reviewed and updated. It is considered that previously reported replacement costs have been significantly undervalued due to an underestimation of complexity in the physical work of replacement. This undervaluation has been across the entire asset but most reflected in the valuation of high value assets, i.e. large rural bridges and high-use urban structures. The 2014 valuation of Total Gross Replacement Cost is $120 million, a roughly 75% increase from the previous valuation of $68M. The latest valuation is broken down by structure type and number of lanes is shown in Table 6.4.3.1., and the full results of the valuation exercise are attached as Appendix B-2. Type Lanes No. Structures Length (m) Gross Replacement Cost 1 21 294.2 $5,251,839 A $7,604,170 2 25 174.0 1 104 1972.3 $32,425,975 B $17,430,345 2 23 483.6 C 1 14 559.8 $8,367,548 2 5 99.7 $3,592,191 1 15 671.8 $12,304,007 D $1,769,491 2 4 59.7 1 9 193.5 $2,539,304 E $94,847 2 1 3.2 F 1 1 15.0 $106,037 G 1 6 35.1 $710,903 2 7 21.7 $677,779 H 1 51 872.3 $14,745,478 I 1 45 295.4 $4,942,480 J 1 14 350.9 $3,814,674 K 1 22 213.6 $3,504,579 Total 367 6315.5 $119,881,646 Table 6.4.3: Bridge replacement value by structure type 30 September 2014 Page 72 of Section 1