Appendix A – Asset Management Plan
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Appendix A – Asset Management Plan
Asset Management Plan
Kempsey Shire Council
Page 2
Introduction
This plan outlines the assets under the care and control of the Council that it manages on
behalf of the community within the Kempsey Local Government Area.
The purpose of the Asset Management Plan is to provide information to assist the
councillors and the community in making decisions on the level of funding of its assets, the
types assets that will be provided and the levels of service to be provided with these assets.
It will also assist the councillors and community in understanding the long term cumulative
impact of the decision that are made, so that it is clear what will happen in the future.
This plan has been written with the target audience of the stakeholders in mind. As such
the plan is designed to be in plain English, avoiding lengthy technical information where
possible. The main concepts and issues affecting the assets and how they impact on the
community is sought to be explained in a manner that will provide you with a strong
understanding of why we manage the assets as we do and the implications of different
ways of managing the assets.
The Council manages a large number of assets and these have varying life spans. This plan
does not seek to set an arbitrary period of time over which it is “managing” the assets.
Instead it takes the true long term approach of seeking to identify what management is
required to provide assets in perpetuity to the community. This will then link in with the
Strategic Plans, Delivery Plans and Operating Plans of the Council to determine what is
required to be done over specific timeframes to achieve the asset provision and service
levels considered appropriate by the community.
Methodology for assessment of priorities
Under any management system there is a need for determination of what works are to be
undertaken in which priority. This system needs to be transparent and clear to the
community and consistently applied. This does not mean that the system should be
followed in all instances. There will always be factors that are not covered in a generalised
system, but any variations from the accepted methodologies should be able to be justified
on clear grounds, showing the factors that are not covered in the prioritisation
methodology. Council will use the same system of assessing its asset management
priorities as it will use to assess its service provision. This will ensure that the decisions of
where resources are allocated are done in an equitable and efficient way.
Within the asset classes there will be a number of factors that need to be taken into
account in relation to the assessment protocols. These will vary for asset classes and within
each asset class there will be a discussion of how the various aspects of the asset will relate
to the overall methodology.
The system is based on assessment of the following factors:
Page 3
Risk:
Risk assesses the danger to the public that exists for the current condition or state of the
asset in question. It is an indicator or the potential negative impacts on the users of assets
should the Council fail to make a change to the existing situation. Risk can relate to social,
economic or environmental factors and as such all of these types of risk need to be
assessed. In determining risk the factors that need to be considered are the level of risk
and the likelihood of the occurrence. These are assessed on a scale of 1 to 5, using the
methodology in the Australian Standard AS4360:2004. This creates a matrix that shows the
resulting level of risk, as follows:
Table 1: Risk assessment matrix
KEY:
Extreme An extreme risk requires immediate action as the potential could be devastating to the local government area.
High A high level of risk requires action, as it has the potential to be damaging to the
local government area. Moderate Allocate specific responsibility to a moderate risk and implement monitoring or
response procedures. Low Treat a low level of risk with routine procedures.
Likelihood
Consequences
Insignificant
1
Minor
2
Moderate
3
Major
4
Catastrophic
5
Almost Certain
A
Moderate
High
High
Extreme
Extreme
Likely
B
Moderate
Moderate
High
High
Extreme
Possible
C
Low
Moderate
High
High
High
Unlikely
D
Low
Low
Moderate
Moderate
High
Rare
E
Low
Low
Moderate
Moderate
High
Page 4
To provide an indication of level of consequences that would trigger an assessment under the various columns above, the following information is provided for each of the triple bottom line classifications. Table 2: Consequence of impacts
Level Environment Social Economic
5 –
Catastrophic Death of animals in
large numbers, destruction of flora
species, air quality requires evacuation,
permanent and
wide spread land/water
contamination.
Fatality Business failure
resulting in six months loss of earnings or
costs. OR Cost impact of over $100,000
4 – Major Death or injury of
individual animals, large scale injury, loss of keystone
species and widespread habitat
destruction, air quality requires
"safe Haven"/evacuation
decision,
remediation of land contamination only
possible by long term program.
Permanent
disability
Business failure
resulting in 3-6 months delay and costs.
OR
Cost impact of 50,000 to $100,000
3 – Moderate Temporary reversible damage, loss of habitat and
migration of animal population. Plants
unable to survive, air quality
constitutes potential
long term health hazard, potential for
damage to aquatic life, pollution
requires physical
removal, land contamination
localised and can be quickly remediated.
Medical treatment required
Business failure resulting in 1-3 months
delay and costs.
OR
Cost impacts of
$10,000 to $50,000
Page 5
Level Environment Social Economic
2 – Minor Slight, quickly
reversible damage to few
species/ecosystem parts, animals
forced to change
living patterns, full natural range of
plants unable to grow, air quality
creates local
nuisance, water pollution exceeds
background levels for short period.
First Aid assistance
required.
Business failure
resulting in less than 1 months delay and
costs.
OR
Cost impacts of $1,000
to $10,000
1 – Insignificant
Some minor adverse affects to
few species
/ecosystem parts that are short term
and immediately reversible.
No significant injury.
Business failure resulting in less than 1 weeks delay and costs.
OR
Cost impacts of less
than $1,000 Once the required work on an asset has been assessed, including the impact of the
proposed works on the risk, Council will then provide a weighting against the risk
component of the project. The following table shows the weighing that applies to each
change in the level of risk.
Table 3: Weighting matrix for risk assessment
Future Current\
Low Moderate High Extreme
Low 0 0 0 0
Moderate 25 0 0 0
High 60 40 0 0
Extreme 100 80 60 0
Nuisance:
The area of nuisance targets the impact a failure to undertake work on the council’s assets
on the quality of life of the people using the asset. While risk focuses on the potential
damage, nuisance focuses on the way a person’s quality of life is impacted by the failure to
undertake works. There are no standard that can be applied in assessing the level of
nuisance, so the following is provided to give an indication of the way in which the
community can expect the Council to assess the level of nuisance in any instance.
Page 6
Table 4: Nuisance factors
Level Description
Extreme Prevents people from being able to live life without significant detrimental damage to their health and wellbeing over a medium
to longer term period.
High Has significant impact on the quality of life of people in a way that
will have a negative impact over a medium period of time.
Moderate Temporary reversible impact on quality of life, localised and can be
quickly remediated.
Low Some minor adverse affects that are short term and do not create
a lasting impact.
The weightings of the changes to the level of nuisance are the same as those used for the
risk factor.
Serviceability:
This factor is looking at how well an asset meets the service that the community needs
from it. It considers whether the work on the asset will provide any improvement to the
level of service it can provide to the users of that asset.
Table 5: Serviceability Factors
Impact Description
Very High Prevents people from being able to live life without significant detrimental damage to their health and wellbeing over a medium
to longer term period.
High Has significant impacts on the quality of life of people in a way that will have a negative impact over a medium period of time.
Moderate Temporary reversible impact on quality of life, localised and can be quickly remediated.
Low Some minor adverse affects that are short term and do not create a lasting impact.
Page 7
The following table records the weightings that will be applied to any change in the
serviceability that is provide to the community as a result of the works undertaken.
Table 6: Serviceability weightings
Future
Current\
Low Moderate High Very High
Low 0 60 80 100
Moderate 0 0 40 60
High 0 0 0 25
Very High 0 0 0 0
Level of Benefit:
The final factor assessed is the number of user benefits that will be provided through the
works on the asset. Council needs to consider the relative valued that the overall
community will receive in assessing projects to ensure that where two projects would
provide the same level of advantage, the one that provides that benefit to the largest part
of the community should be prioritised first. The Council’s system captures the number of
uses and the frequency of the uses to determine the annualised usage rate of the asset.
Usage is weighed in a directionally proportional system, where one point accrues for each
one thousand users. To allow for increased simplicity the levels of usage have been split
within 10 bands. This is to reflect that in most cases the true usage is not known accurately
and as such there will be some degree of uncertainty. Based on this, use of exact usage is
not likely to give a more accurate response, but would significantly increase the cost of
seeking to verify that usage. The weighting of each band is based on the midpoint of that
band. The bands used are:
Level of Usage Factor
<10 0.01
11 – 50 0.03
51 -200 0.1
201 – 500 0.3
501 – 1,000 0.7
1,001 – 5,000 3
5,001 – 10,000 7
10,001 – 15,000 12
15,001 – 20,000 17
> 20,000 25
Page 8
To ensure equity the council’s level of usage is based on annualised usage. Factors allow
conversion of usage on other frequencies into an annualised figure. These conversions are
provided to assist people in determining the annualised usage.
Period of Usage Factor
Daily 365
Weekly 52
Fortnightly 26
Monthly 12
Quarterly 4
Semi-Annual 2
Annual 1
1 – 5 Years 0.4
6 – 10 Years 0.1333
11 – 20 Years 0.06667
21 – 50 Years 0.03333
Greater than 50 Years 0.01428
Calculation of nominal benefit
The calculation of the level of benefit of the works to the community is calculated as
follows:
Multiply the annual recurrent cost/savings (a) from the project by the
number of years that the works will provide the benefit over (b).
o Add : The initial capital costs of the project (c).
This gives the total project cost.
Add: The weighted risk (d), nuisance (e) and serviceability (f) scores to get
the weighted benefit.
Multiply the weighted benefit by the number of time the benefit will be gained
by the community (g) on an annualised basis (h) to get the annualised
benefit.
Divide the total project cost by the annualised benefit to get the cost benefit
figure, which is used to compare the projects.
Cost Benefit = 𝑎 × 𝑏 + 𝑐
𝑑 + 𝑒 + 𝑓 × 𝑔 ×
Page 9
Financial Assessment:
The above benefits are assessed against the estimated costs of the works to determine a
cost benefit result. In determining the financial cost of the project both the initial costs and
any ongoing costs or savings that result from the change need to be taken into account. By
doing so the real long term cost of the asset management task is taken into account,
adjusting for the increased impact of maintenance costs if preventative programs are not
carried out.
New or Additional Assets
Where council plans to implement new assets, an assessment of the asset will be
undertaken within the same framework to determine whether the allocation of funds to that
project are likely to provide a greater benefit to the community that the ongoing
maintenance and retention of other assets.
Page 10
Transport Assets
Roads
Introduction
Roads are the largest asset maintained by the Council, both in sheer size and the cost of
the asset. Equally they are considered to be the most frequently used and one of the most
vital links in daily life.
Roads come in two main types, sealed and unsealed. In both cases, the roads start with a
layer formed of compacted soil and gravel materials (known as the sub-base) built on the
natural surface (the sub-grade), which are supported by drainage networks designed to
move water away from the road structure. The sub-base forms a strong pad on which to
create the road surface at the levels desired and to build strength to compensate for the
sub-grade soil weaknesses.
Constructed on top of this is area a base of gravel, which is compacted to a high degree to
provide the strength as well as the shape of the road surface. While this part of the road is
not directly impacted by traffic, over time the weight of the traffic will reduce the
compaction of the gravel and make it start to shift. Once it starts to shift the road surface
above will start to show signs of dips and what is known as “shoves”. This is where material
is pushed sideways and forms a hump, often following the area most traffics tyres moves
over. This means that every so often this has to be replaced.
For unsealed roads, the base forms the platform that the wearing course is placed upon.
The wearing course is the part of the road that is impacted on by the traffic and is designed
to wear out over time. The gravel that is placed on the road moves under the traffic and
each time a vehicle goes over the road some of the road surface disappears (dust and loose
gravel flicked up). The gravel also is broken up by the repeated vehicle traffic and we lose
some of the surface whenever it rains. While the gravel is compacted when it is put down,
the top is open to the air and soon started to be moved around by cars and trucks. This
leads to the road losing its proper shape and various forms of uneven surface, such as
potholing and corrugations.
Because of this there is a need to:
a) Periodically replace the gravel that has disappeared or broken up, and
b) Move the gravel back to where it should be and re-compacted on a regular basis.
Nearly all of the sealed roads in the area are flexible pavement designs. This means that
the seal is designed to move slightly each time that a vehicle goes over the road. The seal
is made up of a combination of bitumen and aggregate (specific quality and specification
crushed hard rock is used). The bitumen creates the bind holding the gravel in place and
creates a seal over the base, preventing water getting into the aggregate underneath and
giving the base a much better ability to retain its compaction, which leads to it holding its
shape longer.
Page 11
Critical Aspect of Managing This Asset Class
1) Retention of seal on sealed roads: Sealed roads are more costly to construct and the
cost of rectifying damage is considerably higher than proper maintenance. Resealing
a road before it cracks has a cost of $7 per square metre. Once a crack has allowed
the sub-base to be damaged, the cost of repairing that damage properly skyrockets
to $70 per square metre.
2) Retention of gravel wearing course: Unless an unsealed road has a good coverage of
gravel it will not be possible to maintenance grade the road properly and the road
will quickly revert to an uneven and poor condition. Without proper gravel to work
with when doing the maintenance, the material cannot be reshaped and re-
compacted, meaning that the wearing surface will have no real strength.
3) Type of Road: Unsealed roads are the lowest cost option, when looking at to the
total life of the road, up to a certain limit. Under 200 vehicles per day unsealed
roads are the lower cost option. Over 300 vehicles per day, sealed roads become the
lower cost option.
Classification
Roads have been classified based on their usage to allow the Council to determine different
replacement and maintenance levels for the different roads. The individual roads have been
broken up into segments, which are generally from one road intersection to the next, so
that longer roads can be managed for the different levels of traffic on different parts of the
roads.
Where traffic count information is available the number of vehicles travelling over the road
is used from that source. Where traffic data is not available the number of properties
feeding onto that road has been calculated based on:
1) In rural areas the results of traffic studies undertaken to develop the contribution
plans for new development have been used to determine the average usage from
farmland as being one vehicle per day. Rural residential is considered to be more
similar to urban traffic patterns, as the predominant income is from off farm. These
have been assessed as having 6 vehicle movements per day, which is the lower end
of the Roads and Traffic Authority’s guidelines for traffic generating developments.
2) In urban areas the Roads and Traffic Authority’s guidelines for assessing traffic
impacts of new residential developments have been used. The factor identified by
the Roads and Traffic Authority on these roads is 8 movements per day. Comparison
to roads where traffic count data exists indicate that use of this figure would
relatively overstate the traffic movements. Accordingly a movement of 6 vehicles
per day, which is a closer alignment with the actual traffic data has been used.
The cost of undertaking traffic counts on the remaining segments is large as there would be
a need to undertake up to 900 traffic counts. Over time there will be a continuation of the
traffic counting, which will start to fill in some of the gaps in the data. On a number of the
local urban roads, the cost of traffic counts is unlikely to be warranted. In addition the
council will look at undertaking traffic counts in response to community concerns that the
average road use data does not reflect truly the usage. This will have to be prioritised
within the available resource.
Page 12
Asset Register Details
This section includes details of the assets that are under Council’s care and control. The
road length data comes from a condition survey undertaken of the roads currently
maintained by Council. This survey, undertaken in 2008, established the condition of the
road network by measuring the extent of pothole evidence, cracking and deformation of the
road surfaces. This computerised system is considered to provide very accurate data on the
length of the road network.
While there is data on the road network currently not maintained by the Council, it cannot
be assumed that the data is 100% accurate. At this stage it is considered that the cost of
auditing the road length data would outweigh any possible benefits that may come from
having more accurate data on these roads.
The summary of the existing road network is:
Sealed and Maintained: 589.56km
Unsealed and maintained: 577.84km
Total maintained network: 1,167.40km
Unsealed and unmaintained: Approximately 250km
Total road length: 1,417km
From the information available the Council can determine the theoretical condition of the
various road segments and the amount of traffic that is on each segment of the road.
Condition assessment is based on data gathered using the Hawkeye system run by the
Australian Road Research Board. This provides a classification system that provides a
numerical figure to indicate the relative deteriorated condition of the road based on
evidence of potholing, rutting, edge damage and roughness. Descriptive assessments have
been provide to indicate how the Council believe the roads would relate to users
perceptions of quality of service.
This data converts into the matrix below, which shows the current assessed position of the
road network currently maintained by Council.
Table 7: Road Condition Matrix (All Maintained Roads) 2011 Condition/
Vehicle Per Day Total
01 – New
02 –
Near New
03 - Excellent
04 –
Very Good
05 - Good
06 - Fair
07 –
Fair to Poor
08 - Poor
09 –
Very Poor
10 –
Extremely Poor
<10 138.533 0.90 0.03 12.50 48.28 38.66 17.80 6.46 9.29 4.62
11 – 50 310.788 0.96 65.84 81.12 80.68 16.46 16.25 10.33 39.15
51 -200 345.51 3.79 98.57 86.51 52.68 39.51 20.58 6.18 37.69
201 – 500 159.675 19.46 68.36 50.67 20.37 0.32 0.21 0.29 501 – 1,000
70.516 3.78 28.10 21.70 12.89 2.76 1.21 0.08
1,001 – 5,000
127.249 12.62 79.35 28.78 5.50 0.35 0.37 0.27
5,001 – 10,000
8.77 0.29 1.79 2.14 3.04 0.80 0.62 0.10 10,001 –
15,000 2.491 0.18 1.52 0.58 0.21
15,001 – 20,000
3.515 0.07 2.13 0.63 0.58 0.10 > 20,000 0.348 0.07 0.28 Total 1,167.40 0.00 1.44 46.15 356.35 320.67 211.89 77.82 44.96 26.28 81.83
Page 13
Table 8: Road Condition Matrix (Maintained Sealed Roads) 2011 Condition/ Vehicle Per Day
Total 01 – New
02 – Near New
03 – Excellent
04 – Very Good
05 - Good
06 - Fair
07 – Fair to Poor
08 – Poor
09 – Very Poor
10 – Extremely
Poor
<10 11.66 0.03 2.19 3.49 5.04 0.23 0.12 0.57
11 – 50 53.65 0.26 15.80 18.22 9.97 3.08 1.52 0.96 3.85
51 -200 155.75 3.79 71.91 54.32 19.92 7.90 7.83 0.12 0.69
201 – 500 145.27 4.66 68.36 50.67 20.37 0.32 0.21 0.29
501 –
1,000
70.52 3.78 28.10 21.70 12.89 2.76 1.21 0.08
1,001 – 5,000
127.77 12.62 79.35 28.78 5.50 0.35 0.37 0.27
5,001 – 10,000
8.77 0.29 1.79 2.14 3.04 0.80 0.62 0.10
10,001 – 15,000
2.49 0.18 1.52 0.58 0.21
15,001 – 20,000
3.52 0.07 2.13 0.63 0.58 0.10
> 20,000 0.35 0.07 0.28
Total 589.56 0.00 0.54 30.65 269.34 180.79 74.80 15.03 11.25 1.68 5.47
Table 9: Road Condition Matrix (Maintained Unsealed Roads) 2011 Condition/
Vehicle Per Day Total
01 – New
02 – Near New
03 - Excellent
04 – Very Good
05 - Good
06 - Fair
07 – Fair to Poor
08 - Poor
09 – Very Poor
10 – Extremely
Poor
<10 126.87 0.90 10.31 44.79 33.62 17.80 6.24 9.16 4.05
11 – 50 257.14 0.70 50.04 62.90 70.71 13.38 14.73 9.37 35.31
51 -200 179.03 26.67 32.18 32.76 31.61 12.75 6.06 37.00
201 – 500 14.80 14.80 501 –
1,000
1,001 – 5,000
5,001 – 10,000
10,001 – 15,000
15,001 – 20,000
> 20,000 Total 577.84 0.00 0.90 15.50 87.02 139.87 137.09 62.79 33.71 24.59 76.36
Ideally the road network should be maintained to ensure that it remains within the green or
yellow segments of the matrix. To achieve this would take a level of capital replacement
and replenishment works as well as ongoing maintenance of the assets. At this stage it is
important to gain an understanding of how the asset type deteriorates.
While the roads are deteriorating, this is not generally visible until the level of damage is
generally past where it optimally should be. For the first 80% of a well maintained sealed
roads life, the damage should not be visible. From that point it deteriorates quickly.
Previously we have mentioned the three main parts of the asset, being the sub-base, base
and either wearing course or seal. Each of these needs replacing on a regular basis. When a
road is constructed it should be constructed to meet a certain workload of traffic, calculated
using a factor known as the number of Equivalent Standard Axles (ESA) that are expected
to use the road. This design is undertaken to allow the road to last 50 years. In doing this
the calculations assume certain works will be undertaken through the assets life.
Page 14
On sealed roads, this consists of reseals on an eight year basis and as the road moves
towards the later stages of its life heavy patching for the sections of road that have started
to fail due to the traffic use. Maintenance should be undertaken to patch potholes as they
appear to minimise the impact of damage on the remaining part of the road. Due to the
cost of properly fixing damage to a road, failure to undertake the appropriate resealing has
significant financial costs.
The following chart shows the treatment costs of road in different states of repair. The
information shows that as the damage starts to impact the costs escalate dramatically.
Chart 1: Cost of works (condition of roads shown in brackets)
Depending on at what stage the works are undertaken, it can be expected that there will be
certain costs involved. These costs can be estimated based on a formula which shows the
degradation of the road surface. But to determine this it is necessary to determine the level
of service that will be provided through this asset class. In reality, the service level will be
driven by the level of cash that the community is willing to invest in the assets. Once this is
established it will be possible to determine the optimal method of investing these funds in
the asset to determine the level of service that can be sustainably provided.
Costing of works has indicated that an increase of over $5million is required to fund the
existing maintained road network at the ideal level. The current funding levels for this asset
are:
Table 10: Ideal and current workloads
Current Ideal
Quantity Value Quantity Value
Resealing 5.1km $180,000 54km $2.1m
Sealed Reconstruction 6km $1.5m 9km $2.2m
Gravel Re-sheeting 10km $550,000 96km $2.4m
Maintenance $2.67m $3.48m
Total $4.9m $10.2m
$-
$50,000.00
$100,000.00
$150,000.00
$200,000.00
$250,000.00
$24,000.00
$72,000.00
$120,000.00
$168,000.00
$250,000.00
$20,000.00
$55,000.00
Cost of Various Types of Work (per km)
Page 15
As can be seen there is a considerable gap between the ideal management of the asset
group and the currently funded position. At this stage this is leading to a gradual
deterioration of the asset class. To provide an indication of the ongoing effect of this
deterioration an assessment has been undertaken using the data gathered in 2008 on the
condition of the road network. This allowed the determination of the average condition for
each segment of the maintained road network and this to be shown graphically. As the
deterioration curve for roads is known it is possible to estimate the equivalent condition at
the end of the next ten years.
The following graph shows four curves for the road network condition. They show the
percentage of the road network within each condition category. The actual condition from
2008 shows the current base case. For 2020, two models are shown, one includes the
addition of increased funding towards dealing with the backlog of works (2020 Proposed).
The other shows the estimated situation without a change in current processes and
resources (2020 Current).
Chart 2: Sealed road segments - Network condition for 2008 (actual), 2011
(estimated) and 2020 (estimated)
36%
13%
47%
5%
54%
-10%
0%
10%
20%
30%
40%
50%
60%
2008 Now 2020 Proposed 2020 Current
Page 16
Chart 3: Unsealed road segments - Network condition for 2008 (actual) and 2020
(estimated)
Under the current asset management it can be seen that there is a significant deterioration
in the average condition of the road network over the period of time shown. As the council
is unable to keep pace with the rate the roads are breaking down, more road segments fall
into the lower condition ratings. As the focus is on trying to offset the areas of greatest
complaint the poor condition roads are kept a similar level. But here also, the council will be
unable to keep pace, meaning that the level of complaints required before the council will
take action will increase and more road segments will move into the failed section.
Based on the statistical analysis of the condition rating scales, the above will mean for the
sealed road network:
88% more of the road will be rough in some form or other,
The ride will be 26% rougher,
32% more of the road edge will have broken away
40% of more of the road surface will be cracked,
This last will mean that when it rains, there will be 44% more potholing occurring.
The failure to replace the gravel wearing surface of the unsealed roads will mean that roads
will increasingly be unable to be maintained.
Future Asset Management Process
Council has to develop a process whereby the management of the assets in this class is
undertaken on a basis that will be able to be sustained over the longer term. The asset
management system needs to ensure that the funds expended achieve the greatest value
for the community as well as meet the community’s expectations.
Studies undertaken by Austroads in 2002 indicated that the maximum acceptable
roughness of sealed roads was seen generally by the community to be a roughness
equivalent to a rating of 3.3 on the road condition index used. For unsealed roads a rating
of 4.7 was found. To achieve this Council would need to maintain the overall network with
an average rating halfway between the ideal road and these ratings. For sealed roads this
would require a target of 1.65 and for unsealed roads this would require a target of 2.85.
This provided the optimal scenario for asset management within this class.
-5%
0%
5%
10%
15%
20%
25%
30%
35%
2008 2020
Page 17
Currently the average for the two road types is 3.11 for sealed roads and is not available
for unsealed roads. However it should be noted that at the current level of funding, this is
not sustainable. From the surface condition assessments undertaken by Council and the
existing level of works able to be undertaken the condition of the road network will continue
to deteriorate.
From community consultation the current level of standard on the roads is considered
below acceptable by many people. However, maintaining the current standard has been
adopted as the lowest level of acceptable sustainability scenario.
Sealed Roads Capital Management Plan
The Austroads project undertaken in 2002 determined that there was an increased cost in
continuing to maintain a road network with a higher roughness. This is supported by the
other information gathered, and shown above, on the relative per kilometre costs of
resealing due to the impact of more failures. Bringing forward the costs identified in that
report to todays dollars, the cost of the optimal and minimal scenarios can be theoretically
determined.
Maintenance and reconstruction to maintain the current road network with an average
roughness rating of 1.65 equates to an average allocation under the Austroads
determination of necessary funding equating to $8.7million per annum. To maintain the
roads at the current standard of an average roughness equating to the existing average
(2.44), would entail a budget allocation of $4.9million per annum.
To maintain the sealed road network with a roughness rating of 1.65 will require a regular
series of reseals and capital reconstruction. The level of intervention will have to vary
depending on the traffic volumes of the roads to reflect the impacts higher traffic volumes
have on the road network.
In determining the optimal mix between the length of time that the capital investment
should be made to last, the expected level of maintenance costs and the impact on the
replenishment costs of the assets has been assessed. The road deterioration data can be
used to determine points on the scale that an average extent of damage can be determined
for. These points allow for an extrapolation of the degree of damage requiring repair at
various lifetimes in the asset. To improve the accuracy of the forecast, only damage
indicators for the first twenty years of a road’s life have been used to determine the
equations to calculate the likely damage. This is to reflect that under the optimal and
minimum management, this asset class should not be allowed to enter into the later stages
of deterioration.
The following table shows the relative extent of works that will be required at the various
intervention levels of the roads life. Using the unit rates that these works cost it is then
possible to estimate the impact on maintenance costs that increased time between capital
replenishment would have. An assessment of a number of variations on managing the road
network were assessed against the anticipated construction and maintenance costs from
these formulas. The following table shows the annualised equivalent cost for each of the
options assessed. In determining whether the scenarios are likely to meet the requirement
of the public to achieve the desired maximum roughness council has relied on the data
collected for the South Australian Government to develop models that would meet their
desired roughness standard (20 year reconstruction and 11 year reseal treatment). A value
judgement was made from this information on the basis that local roads will have a lower
average level of usage. While this could be determined through consultancies, the overall
cost is not seen as warranted at this time.
Page 18
It is not considered that the models calling for life spans over 50 years would allow the
roughness targets to be achieved. The increased maintenance costs will also lead to higher
annualised costs, these scenarios have been discounted. They are examples of the current
practices, of deferring capital replenishment, which in turn leads to higher long term costs
to the community.
The large capital costs is seen to drive up the annualised cost in the scenarios based on a
20 year reconstruction cycle. It is considered that these scenarios would deliver a higher
level of road quality and could be considered by the community as an option. Indications
from the community are that they are looking to minimise costs. As such these scenarios
have been discounted.
Within the 50 year life models the costing has shown to not display as high degree of
variation. The variation between the lowest service level and the maximum is $133,000 per
annum. In context, this equates to 1.7% increase on the lowest cost option. When factoring
into account the target of having roads with a quality rating no greater than 3.3, it is not
considered that 15 year reseal periods would achieve this. Accordingly, while the cheapest
option, it does not meet the expectations of the community. As the use of 12 year reseals
results in a higher cost and will result in higher roughness, this option can also be
discounted.
Due to the high standard considered acceptable by communities and the minimal cost
variation between options 3 and 4, option 4, with 50 year reconstruction period and 8 year
reseal cycle is considered the best fit with the community’s expectations, and thus gives the
best benefit for the costs.
In light of the relatively close costs of the various options a factor has been calculated to
indicate the impact of the various reseal periods on the cost to the resident. The higher
roughness of the road results in increased maintenance cost on vehicles. The calculated
variation in vehicle operating costs has been compared to the selected option to see
whether the option provided would be offset by increased costs or savings to the wider
community.
Table 11: Calculation of annualised cost of maintain sealed road network.
Scenario (Years) Annualised Lifetime Costs
Average
Roughness
External Impacts
Option Reconstruct Reseal Residents Cost
Impact
Adj Total
1 20 8 9,246,215 1.50 -154,981 9,091,234
2 20 10 8,922,902 1.56 -140,612 8,782,290
3 20 12 8,635,025 1.62 -123,863 8,511,162
4 50 8 7,517,742 2.11 0 7,517,742
5 50 10 7,251,506 2.20 22,373 7,273,879
6 50 12 7,086,012 2.24 34,276 7,120,288
7 50 15 6,783,963 2.50 99,317 6,883,279
8 70 8 8,351,386 2.30 50,276 8,401,662
9 70 10 7,999,729 2.30 50,366 8,050,095
10 70 12 7,717,904 2.46 90,657 7,808,560
11 70 15 7,167,681 2.56 115,045 7,282,726
12 100 8 9,619,284 2.48 94,791 9,714,075
13 100 10 9,001,601 2.57 118,508 9,120,110
14 100 12 8,207,898 2.73 158,729 8,366,627
15 100 15 8,169,790 2.68 146,770 8,316,561
Page 19
Chart 4: Annualised cost of options for sealed road maintenance for each scenario
above
While the above determines the optimal treatment for the overall network, there is
considerable variation in traffic volumes across the network. To meet the expectation of a
consistent level of roughness of the roads the Council has to vary the treatment based on
traffic volumes.
The following outlines the service intervention levels that would be anticipated on the
different asset classes.
Table 12: Estimated yearly timeframes for major intervention (Sealed roads)
Classification Reconstruction Resealing
< 10 N/A N/A
11 – 50 N/A N/A
51 – 200 70 12
201 – 500 60 10
501 – 1,000 50 8
1,001 – 5,000 50 8
5,001 – 10,000 40 7
10,001 -20,000 40 6
> 20,000 20 6
Unsealed Roads Management Plan
Unsealed roads do not have the critical intervention level that exists with the sealed road.
Their condition will generally continue to deteriorate over time as the road is used. As such
the determination of the optimal intervention levels is determined around the workload
required to maintain the roads below the standard identified by communities as being
appropriate. The key determinate is the extent to which gravel is lost, as a road cannot be
properly maintained unless it has a core level of gravel in place.
Information developed by Moorabel Shire Council has provided a good indication of the way
pavement on an unsealed road is affected by the combination of maintenance and
rehabilitation. Below is a copy of the results of the investigation, based on 12 monthly
grading and five year re-sheeting programs. It should be noted that at all times this road
exceeded what was found by the Austroad surveys to be the maximum acceptable
roughness of the community.
7,000,0007,500,0008,000,0008,500,0009,000,0009,500,000
10,000,00010,500,00011,000,000
Page 20
Chart 5: Roughness of Road Surface based on 12 monthly grading
Source:
The data indicated that this level of roughness could be reduced by increasing the
maintenance grading to six monthly treatment as opposed to the 12 monthly scheme
above. The change in treatment resulted in a 13% improvement in the maximum
roughness on low trafficked roads and 18% improvement for heavier trafficked roads.
However, the average roughness shows a much smaller change, of only 4.7% overall.
Based on this information the savings in vehicle maintenance of $94,000 per annum made
by the community is much lower than the cost of the additional grading or $684,000. Any
benefits would be not able to be quantified and thus are not recommended unless
requested by the community, who have indicated a preference for a low cost option.
The local community has expressed a desire for a higher level of road maintenance than
currently exists. At the time the maintained roads were assessed in 2008, the average
surface condition index of the road was 5.56, meaning they were half way between ideal
and failed roads. The surface distress measure within the condition index averaged out at
4.2, indicating issues with crossfall and formation height are also significantly affecting the
road conditions.
The past study into the impact of roughness did not provide any conclusive information on
what level of roughness or surface condition was acceptable by the community. In this area
the community will have to determine the relative improvement in road smoothness against
the cost in rates and charges. I the absence of this it has been assumed that the optimal
performance of the road network would be to have a road network with an average surface
condition no more than half way to the failed surface condition index. As the previous
studies have shown that it is not possible to have a gravel road which would match the
optimal surface condition index, the best result possible is considered a rating of 2. This
would lead to a target average surface condition index of 3.5.
In determining the level of effort to be put into the unsealed roads requires an assessment
of the extent that gravel is lost from the wearing course of the road to determine the length
of time that a road can continue without the gravel being replenished before damage occurs
to the sub base and the base of the road. If the gravel is not replenished, the increased
cost of returning the road to its optimal state will increase. Based on an average traffic use
of 70 vehicles per day the annual gravel loss will be 19mm. Based on this factor the various
lives that will be achieved from different levels of thickness initially placed on the road can
be calculated.
Page 21
Table 13: Various options for maintenance of gravel road network
Scenario (Years) Annualised Costs
Relative Roughness
External Impacts
Option
Resheet Depth (mm)
Resheet Time
(Years)
Grading Freq
Total
Residents Cost
Impact
Adj Total
1 100 3.7 6 5,503,544 7.63 -94,373 5,409,171
2 150 6.3 6 4,425,513 7.63 -94,373 4,331,139
3 180 7.9 6 4,601,006 7.63 -94,373 4,506,633
4 200 8.9 6 5,282,334 7.63 -94,373 5,187,961
5 250 11.6 6 5,127,487 7.63 -94,373 5,033,113
6 100 3.7 12 4,606,002 8 0 4,606,002
7 150 6.3 12 3,527,971 8 0 3,527,971
8 180 7.9 12 3,703,464 8 0 3,703,464
9 200 8.9 12 4,384,792 8 0 4,384,792
10 250 11.6 12 4,229,945 8 0 4,229,945
From the above information it can be seen that the lowest cost option for maintaining the
unsealed network sustainably is option 7.
While this gives the overall average, the level of traffic will determine the timeframe for
each roads need for resheeting. This is caused by the fact that the level of traffic
determines the rate at which gravel is lost from the road’s wearing surface. This has been
calculated for each of the road segments and will be applied as a guide for the frequency of
resheeting needed. The existing backlog will be dealt with through the use of the
prioritisation system, which will lead to a focus on roads with higher usage where all other
factors are equal.
Table 14: Estimated yearly timeframes for major intervention (Unsealed roads)
Classification Resheeting
< 10 10+
11 – 50 8
51 – 200 4
201 – 500 2.5
Bridges
Council manages 37 concrete and 125 timber bridges as part of the transport
infrastructure. Each of the bridges has a design life, at the end of which it requires
replacement. Most of the concrete bridges are considered to have an effective life of 100
years and most timber bridges a 50 year lifespan.
Council has good data on the construction dates of the various bridges and has just
finalised condition assessment of what were considered the worst of the existing timber
structures. The calculated value of the assets in 2010 was $60.7 million dollars.
Critical Aspect of Managing This Asset Class
1) Substructure of the bridge needs to have sufficient strength to take loads.
2) Decking needs to provide a safe crossing surface.
3) The bridge needs to be designed to provide reasonable access.
Page 22
Bridges Capital Management Plan
Priority for the replacement of the assets will be based on condition assessment rating as
the primary information that indicated the suitability for the asset to provide its intended
purpose. This will be linked with the overall assessment process to identify where the most
benefit can be gained from the available resources, which will also consider whether any
particular bridge is the sole, primary or secondary access link.
In undertaking the assessment of the replacement of assets an assessment will be made as
to the benefit of various service levels, such as the degree to which flood free access is
provided. While these factors will have to relate to the particular situation, factors to be
taken into account include:
Whether alternative access exists,
The level of people serviced by the bridge,
The amount of time that a bridge is likely to be inundated,
The advance warning that is available before the bridge is inundated.
The optimal model is considered to be retaining the existing bridge network with bridges
suitable to carry the maximum allowable load for heavy transport on the route. In most
cases this would be an articulated semi trailer. In some instances this would be a B Double.
The minimal model would be only to retain those bridge that no reasonable alternative
access exists for. Other bridges would be removed as they reached an unsatisfactory stage,
generally through a process of reducing load limits as the bridge deteriorated. Further
investigation into bridges that have alternative access is ongoing. Currently identified
bridges with alternative routes provides for a minimal bridge option at a 6.1% reduction in
costs to the community, with an equally corresponding drop in ongoing maintenance costs.
Table 15: Bridge asset summary
Type Asset Value Number Length
(metres)
Deck
Area
(m2)
Annual Replacement
Cost
Optimal Minimal
Concrete $38,155,000 39 2,110 15,262 $664,000 $658,300
Timber $22,566,000 132 2,574 9,023 $370,400 $312,600
Total $60,721,000 171 4,684 24,285 $1,034,600 $970,900
Condition assessment will be undertaken on a five year cycle, with individual assessments
being undertaken where informal assessment indicates that a structure is deteriorating at a
rate other than expected or where indications are that some damage has occurred on the
asset. At this stage condition information only exists on some bridge assets, primarily the
timber bridges. Of Council’s timber bridges 93 (70%) of the 132 bridges have had Bridge
Condition Numbers calculated. None of the 39 concrete bridges have had a formal Bridge
Condition Rating Assessment done, however informal visual inspections indicate that the
timber bridge condition is the greater issue.
Page 23
Chart 5: Bridge condition assessments known
Where funding does not allow for the upgrade of a bridge to take a full weight load (as
compared to the maximum weight load allowed on the adjacent road network, the load limit
on the bridge will be reduced accordingly until such time as the required works can be
funded.
Kerb & Gutter
Council has kerb and gutter in a number of urban locations. Currently there is 146.5
kilometres of kerb and gutter in place in various locations. Well constructed kerb and gutter
has a planned lifespan of 90 years.
In many of the older sections of the road network the kerb and gutter and road shoulder
were constructed on a light base and the impact of heavy vehicles on the edge of the road
is having a significant impact on the alignment of the kerb and gutter. In a number of
instances the kerb and gutter is effectively impassable at this time. Council’s current
approach has been to remove infrastructure where this situation exists or where the risks,
based on the current condition, are considered too high.
Critical Aspect of Managing This Asset Class
Due to the construction method, the main aspects are to ensure that the asset:
retains its ability to remove water, and
that the asset does not create a safety impact on the community any more than
necessary to achieve the purpose.
0
10
20
30
40
50
60
70
80
90
100
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McI
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Page 24
Kerb & Gutter Capital Management Plan
Limited information is known about the age of the infrastructure and as such condition
assessment is the only available method of assessing initial replacement processes. Once
initial backlogs are dealt with the Council will move to a system of regular replacement,
which will lead to infrastructure being replaced prior to the time when the concrete
structures will suffer failures due to age, which may be caused by subsoil movement of
failure of material strength.
Car parks
Council has 13 formal car parks, which consist of sealed parking areas covering 38,841m2
of parking space. These are spread through the main centres of population as shown in the
table below.
Table 16: Car Park Assets
Name Locality Area (m2)
Current Asset Value
Annualised Cost
Begrave Street & Sydney Street Kempsey CBD 3,863 $801,572 $8,100 Sydney Street & Verge Street Kempsey CBD 3,550 $736,625 $7,500 Riverside Park Kempsey CBD 5,129 $1,064,267 $10,800 Forth Street & Stuart Street (West) Kempsey CBD 2,800 $581,000 $5,900 Forth Street & Stuart Street (East) Kempsey CBD 6,200 $1,286,500 $13,000 Clyde Street Kempsey CBD 3,291 $682,882 $6,900 Stuart Street Long Vehicle Area Kempsey CBD 1,024 $212,480 $2,200 Civic Centre West Kemspey 2,698 $559,835 $5,700 Edinburgh Street West Kemspey 2,396 $497,170 $5,0000 Horseshoe Bay Headland SWR 1,993 $413,547 $4,200 Landsborough Street SWR 1,012 $209,990 $2,100 Cresecent Head Reserve Crescent Head 3,615 $750,112 $7,600 Rankine Street Crescent Head 1,270 $263,525 $2,700
Totals 38,841 $8,059,507 $126,700
Critical Aspect of Managing This Asset Class
The traffic in these facilities are travelling at a low traffic level and this leads to the ability
of the seal to retain its sealing characteristics as being the critical aspect of the proper
management over time.
Car Parks Capital Management Plan
Limited information is known about the age of the infrastructure and as such condition
assessment is the only available method of assessing initial replacement processes. Failures
will have less critical impact on the community than a similar level of failure in the road
network, so it is likely that priorities for dealing with these assets may lead to longer
timeframes being in place before this asset groups is effectively managed.
Page 25
Airstrip
Buildings and other aspects of the airport are dealt with in other areas. In this section the
focus is on the actual strip and taxiways used.
Critical Aspect of Managing This Asset Class
Similar to a sealed road, the main aspects are to ensure that the asset retains its ability to
keep water out from the area beneath the sealed surface, as failure will lead to expensive
remediation.
Airstrip Capital Management Plan
As the facility has limited use, it is expected that the life of the asset can be extended
through the use of good preventative maintenance on the strip and taxiway. The existing
facility shows signs of cracking, including crocodile cracking and longitudinal cracking. The
surface also shows signs of oxidisation of the surface in a number of areas. Longitudinal
cracks between the seals have recently been repaired, improving the sealing of the entire
surface.
A regular resealing program is envisaged to ensure a solid surface remains.
Buildings
Council has a range of buildings, which are used for differing purposed. These purposes
range from community halls, to toilet blocks, to council offices and workshops. Despite their
differing uses, the buildings as assets can be managed as a group.
Within this asset group are the following main types of buildings:
Table 17: Summary of Building Assets
Building Type Number Replacement Value Annualised Cost
Community Use (eg halls) 33 $8,300,000 $283,000
Public Toilet/Amenity
Blocks
34 $6,400,000 $196,000
Residential Dwellings 7 $1,180,000 $44,000
Shelters 15 $553,000 $13,000
Sheds and Storage Areas 20 $4,700,000 $215,000
Offices/Kiosks/etc 13 $9,200,000 $344,000
Historic 1 $1,500,000 $60,000
Critical Aspect of Managing This Asset Class
Building components have an effective life and once past this maintenance costs increase
dramatically. The impact of this is seen more pronounced where that component of the
building provides protection from the elements to other components of the building which
are more costly to replace.
As such proper replacement of the main protective components of the buildings is critical to
provision of the service at a reasonable cost.
Page 26
Buildings Capital Management Plan
Each building will have an individual asset management plan prepared that will identify the
main structural components and the preventative maintenance that is periodically required.
Due to the fact that in many cases the period since this form of maintenance has been done
is unknown, priority will be based on the last condition assessment to indicate the potential
damage if left untreated. The general prioritisation system will be used to assess the other
factors in setting the priority for funding required works.
The system developed by IPWEA will be used to guide Council in the effective life of the
various building components, Some of the timeframes for larger components of the various
buildings are reproduced here.
Table 18: Effective life of major components
Component Group
Component Type
Component Useful Lives
Exte
rio
r W
ork
s
Buildings Carport/Garage 50 Shed (Garden / Tool Shed) 20 Verandah - Roof Only 55
Civil works Block Wall 75 Brick Wall 50 Retaining Walls (Concrete) 75 Retaining Walls (Timber) 60
Fencing Corrugated Iron Fence 25 Picket Fence 25 Wire Mesh Fence 25
Misc. Decking 25 Shade Cloth 15
Exte
rna
l F
ab
ric
External Walls
Brick Cladding 75 Hardiplank 50 Plaster 50
Precast Concrete Wall Panels 100 Weatherboard - Timber 75
Roofing Colorbond 30 Tile Roofing - Clay 60 Tile Roofing - Concrete 90
Doors Roller Doors 35 Sliding Doors 55 Timber / Glass Door 55 Timber Framed Windows 55
Inte
rna
l
Internal Walls
Gyprock Lining 50 Insulation 75 Suspended Panel (incl Frame) 40
Floor Finishes
Carpet 15 Ceramic Tiles 50 Floor - Timber T & G 75 Vinyl 15
Doors Doors - Hollow-Core 35 Doors – Solid 50
Page 27
Component Group
Component Type
Component Useful Lives
Sliding Doors 50 Solid Core 50
General Finishes
Paint Finish 10 Wallpaper Finish 11
Stormwater and Drainage
Council has a network of 97 kilometres of drainage pipes, connected to a series of pits and
headwalls. The diameter of the pipes ranges from 100mm to 3000mm in diameter. The
following table outlines the types of drainage infrastructure in place.
Table 19: Summary of stormwater Infrastructure
Description Quantity Length
(metres)
Replacement
Value
Annualised
Inlet Pits 1,101 $6,000,000 $66,200
One Pipe Headwalls 534 $442,000 $5,000
Two Pipe Headwalls 54 $84,000 $1,000
Three Pipe Headwalls 43 $159,000 $1,800
Four Pipe Headwalls 6 $16,500 $200
Five Pipe Headwalls 3 $13,000 $150
Pipe <300mm diameter 5,478 $460,000 $5,100
Pipes 300mm diameter 22,427 $2,640,000 $29,335
Pipes 375mm diameter 29,459 $4,673,000 $52,000
Pipes 400 - 600mm diameter 28,842 $7,143,000 $79,400
Pipes 750 - 900mm diameter 6,565 $3,583,000 $39,800
Pipes Greater than 900mm
diameter
4,180 $2,671,000 $29,700
Council also has a system of open drains, however there is only limited information on
these drain. Council will need to identify the extent of the open drain system to update its
asset data.
Critical Aspect of Managing This Asset Class
Due to its nature, the stormwater system is a fairly stable. Ensuring that blockages are
cleared to ensure the system works as intended is the main form of maintenance, which if
coupled with timely replacement of pipes should minimise flooding issues. Most issues come
as a result of crushing of the main or root system ingress.
Stormwater and Drainage Capital Management Plan
Little knowledge is available on when many aspects of the system were put into place.
Council will respond to blockages to identify areas in which the system is failing. In addition
the Council will use the in pipe camera footage to inspect areas flagged of major concern.
The overall assessment system will be used to determine the allocation of funds for a
regular replacement schedule.
Replacement of components will be undertaken on a 90 year rotating basis. When assets
are due for replacement a review of the capacity required and any flooding issues that have
Page 28
been occurring will be undertaken to ensure that the replacement asset is suitable to meet
potentially changed stormwater demands.
To develop a system of replacing the network, which will allow for a regular replacement
process the Council has identified that the initial focus should be on the larger drainage
pipes within the system. A more detailed assessment of condition will be undertaken on
those assets to determine their remaining effective life and need for replacement. Smaller
pipes will be assessed based on blockage data and reviews of the video camera footage
from the network. These works will be assessed on the impact on the system and the
degree of impact the blockages have on property.
Flood Mitigation Structures
Council operates 173 flood gates connected to a system of 53 drains and 18 levee banks.
Across these drains are 44 bridges to provide uninterrupted access. The drains and level
bank system is designed to have different uses and impacts. The system is designed to
minimise the impact on flooding by providing protection from lower level flood impacts. This
is achieved through levies keeping the water within the river banks above what would
normally occur. In other areas there are series of gates that retain the flood waters within
the river bank up to certain trigger points. Once these are reached, the gates are used to
allow water to spread across the floodplains, increasing the water storage capacity of the
river system and thus increasing the height to which the levy banks will prevent flooding in
other areas.
The system is also used to minimise the impacts of water affected by issues such as acid
sulphate soils on the river environment, reducing the incidences of fish kills.
As there is limited information on a large number of the flood gates, the Council has been
required to determine an estimated value for the assets known of, but for which further
details are not known. This included 108 structures. At this time the Council does not have
the resources to survey all of these structures. Accordingly it has been assumed that the
remaining structures are smaller structures and as such an average assessed
reconstruction value of $20,000 has been attributed. As council is working on this
infrastructure further details will be collected, which will improve the data held.
Table 20: Summary of flood mitigation and drainage infrastructure
Description Quantity Length
(metres)
Lifespan
(Years)
Replacement
Value
Annual
Cost
Flood Gate
Structures
173 1,900 60 $10,000,000 $470,000
Drains 53 89,920 5 $900,000 $180,000
Bridges 44 909 90 $3,661,000 $224,000
Levee 17 34,400 100 $11,880,000 $120,000
Bank Protection
Work
25 37,200 100 $18,400,000 $370,000
Critical Aspect of Managing This Asset Class
Ability of the equipment to function during the high pressure times around an emergency is
critical. In this respected the important aspect is the maintenance of moving parts such as
gates. These items are in a highly corrosive environment and require frequent intervention
as a result.
Page 29
The ability for the system to work as designed is important, with the height of the levy
banks and their structural capacity being the key factors that need monitoring.
Flood Mitigation Capital Management Plan
Flood gates and metal structures exposed to harsh environments will be monitored on an
annual basis and replaced on an as needed basis. It is expected that many of these aspects
of the infrastructure will have relatively short life spans, maybe as low as 20 years.
The concrete portions of the floodgates are often prone to increased deterioration, such as
concrete cancer, due to the harsh environment. These structures will be inspected on a five
yearly basis to ensure a regular condition assessment has been carried out. The results of
these inspections will then feed into the prioritisation system to determine priorities for
replacement.
The levy bank system is potentially subject to slow changes over time. A survey of the levy
bank heights and the structural adequacy of the banks will be carried out every ten years.
It is expected that minimal asset improvement work will be required to maintain the levy
banks without the need for reconstruction.
Siltation and weed clogging will need to be managed within the drainage network. Each
section of the drainage network will need to be assessed to see what value it is providing.
Over time where the drains are not providing a benefit to the wider community, these
drains should be re-converted to their original natural state or taken over by the
landowners gaining the benefit from the structures. Such works will be a lower priority than
the ongoing maintenance of the various infrastructure groups. Where drainage is required
to achieve benefits, these drains should be inspected and subject to a clean out on a
regular five year rotating cycle.
The bridges across the drain systems are in various states of repair. Recent inspections
have indicated that a large number are in poor condition, which will result in increased
maintenance costs in the short to medium term. There is limited data on the age of the
structures and the construction techniques that were used. In many cases these are
inherited assets.
Assessments are currently being carried out on the assets to determine the degree of
dilapidation. Once this data is available the Council will be in a position to determine a
prioritisation list. This list will have to be assessed against other projects, for example
bridges on Council roads, which may limit the ability of the Council to bring all of the asset
class up to desirable levels within a short timeframe. Similar service levels should be taken
as is adopted with the transport infrastructure to ensure equity in service provision.
Related Documents
