Marlborough District Council Roading Assets - Activity Management Plan 2015 - 2018 SECTION 1 EXECUTIVE SUMMARY iii. Desired Level: this option would require increasing the renewal budgets in the short-term to remove any bridge restrictions that are undesirable. This would require a modernisation programme primarily targeting older timber bridges. iv. Reduced Level: this option reduces the target LOS to reduce expenditure. This would likely result in accelerated deterioration of structures especially as they approach end of life, with the outcome of a greater number of bridge loading restrictions and or closures, especially in remote areas. The risk of a catastrophic failure would increase with a diminished maintenance and monitoring regime. 1.6.4.4.5 Recent Expenditure The expenditure on bridges and structures for the last five years has been as follows: Activity Equivalent NZTA 2009-10 2010-11 2011-12 2012-13 2013-14 Average Work Category Maintenance 114 134,000 148,000 166,000 169,000 90,000 141,000 Component Replacement 215 318,000 254,000 143,000 247,000 285,000 249,000 Replacement 322 504,000 349,000 0 33,000 590,000 295,000 Table 6.4.4.5: Bridge maintenance expenditure 2009-present The routine maintenance allowance has followed a trend of inflationary increases from 2009 to 2013, excluding the low value in year 2013/14. This expenditure appears to be sufficient to maintain the safe operation of the asset. Component replacement and renewal funding budgets have fluctuated over the last five years due to the irregular requirements of large projects (a large bridge renewal can draw on several years’ worth of funds), but have averaged $249,000 and $295,000 per annum respectively, or 0.2% and 0.25% of asset value respectively. 1.6.4.4.6 Funding Recognised Asset Management practices state that annual renewals should be actioned at a level of 0.45% of the asset value to ensure rolling rejuvenation of the asset. Based on the increased 2014 valuation this would suggest a desirable average annual renewal spend of $540k over and above routine maintenance and component replacement budgets. This desired level of renewal funding is considerably more than the average amount spent over the last five years on renewals, and it could be expected that LOS across the bridge asset would be significantly declining as a result. This result has not been realised to date, however the quantity of bridges waiting for end-of-life intervention is increasing and it appears that a decrease in LOS is inevitable in the near future unless renewal budgets are increased. In terms of LOS strategy, the asset is in a period of high maintenance demand, and the do-nothing-differently response will ultimately result in reduced LOS. Component replacement budgets appear to be adequate however the recent emphasis on timber bridges has seen many timber superstructures replaced with concrete decks using existing abutments. These extensive component replacements have tapped a significant amount of funds that would have generally been used for the replacement of discrete components. This has taken pressure off renewal budgets but as a result preventative maintenance such as bearing and joint renewals have been deferred which will ultimately contribute to deterioration in the long-term. The routine maintenance allowance for 2014/2015 is $172,000 and continues with the strategy of inflationary increase on the previous year’s budget. This amount equates to 0.1% of asset value. 1.6.4.4.7 Funding effects on the asset There are 18 bridges with less than 2 years RUL, of which only 7 are likely to be renewed in the next two years. The other 11 bridges will require either a short-term holding strategy to be actioned to maintain the LOS (augmentation of timber beams can defer renewal by 5 to 10 years), or restrictions placed on bridge use 30 September 2014 Page 74 of Section 1