Asset Management Plan for Drainage

1. Introduction and Overview

Introduction - BRC's Asset Management Plans are based on the minimum requirements for Asset Management Plans in Queensland as detailed in the Asset Management Advancement Program.

1.1 Scope

1.2 Drainage Hierarchy

Drainage Hierarchy - In the case of drainage assets BRC has adopted a fairly flat hierarchy with Stormwater Drains being classified as either Trunk or Non-Trunk and the other sub-classes considered to be of equal importance.

1.3 Quantitative Data

1.3.1 Drainage Inventory Summary

Drainage Inventory Summary - Council is responsible for the following drainage assets.

1.4 Links to Other Documents

The following documents have been referred to in developing this plan.

General Documents

NOTE: The BRC Asset Management Policy is a Draft version and will be set up to be adopted by Management /Council and incorporated into the LTAMP

Drainage Specific Documents

  • None

1.5 Legislative and Regulatory Requirements

Legislative and Regulatory Requirements - The principal relevant statutes regulating the asset management practices of Councils are:

The Department of Infrastructure and Planning requirements for asset management plans include:

  • description of the maintenance program
  • timing of program
  • maintenance expense per asset class and sub-class

2. Service Levels

A Customer Satisfaction Survey is conducted annually to gauge community expectations. The results of these surveys are taken into account when setting service levels.

2.1 Strategic/Community Service Levels

Service Level Performance Measure
The drainage network and all activities associated with management, maintenance and operation of the network comply with all relevant Acts and Regulations. Full compliance with relevant Acts & Regulations
To provide and maintain a safe drainage network. Incident reports trending in right direction
To provide a service that reflects the priorities of its users User input to regular customer satisfaction surveys aligns with Council priorities.

2.2 Technical/Maintenance Service Levels

Problem Intervention Level Remedy Response Time
Blocked Drain TBA Remove Rubbish TBA
Damaged Pit Lid TBA Replace Lid TBA
Long grass in open channel TBA Slash Grass TBA

3. Future Demand

3.1 Future requirements associated with corporate plans or operational plans

Future Requirements for Drainage - No future requirements associated with the corporate plan or the operational plan have been identified.

3.2 Known or possible areas for expansion

Expansion - There are several factors that may affect the demand for and on Council assets.

3.2.1 New Subdivisions

New Subdivisions - Council is gifted infrastructure on a regular basis, with a significant number of new subdivisions coming off maintenance each year.

3.2.2 Population Growth

Population Growth - According to the OESR Queensland Regional Database & Google Public Data Explorer Bundaberg Regional Council's estimated population has increased from 78,943 in 2001 to 95,132 in 2009.

Year Population % Increase
2001 78,943 -
2002 80,369 1.81%
2003 81,579 1.51%
2004 83,238 2.03%
2005 85,522 2.74%
2006 87,898 2.78%
2007 90,302 2.73%
2008 92,651 2.60%
2009 95,132 3.00%

3.2.3 Changes in Land Use

Changes in Land Use - Bundaberg Regional Council has yet to finalise a consolidated Planning Scheme for the amalgamated Council. If any changes in land use affecting future demand are included in the new scheme they will be identified here.

3.2.4 Changes to Government Policy & Regulations

Government Policy & Regulations (Drainage) - No changes to government policy or regulations have been identified in this plan.

3.3 Asset classes and potential acquisition dates

New Asset Classes - It is not anticipated that any new asset classes will be acquired within the time frame of this plan.

3.4 Cost estimates

The costs of changes in the future demand on drainage have yet to be calculated.

3.5 Impact of future demand on service levels, asset lifecycle and financial considerations

The impact of future demand on service levels, asset lifecycle and financial considerations has yet to be ascertained.

3.6 Technological Change Forecast

Technological Change Forecast - The past few centuries have seen enormous technological advances, and in computing, nanotechnology & biological science the current rate of advancement is exponential. (e.g. Moore's Law.) If this trend continues the impact on Local Government is potentially enormous, and obsolescence could become the main factor in determining the useful lives of many asset classes.

There are a number of key areas in which this rapid technological advancement could affect the way assets are constructed and maintained.

3.6.1 Energy

Energy - The availability or lack of availability of relatively cheap energy will have a huge impact on the cost of and need for infrastructure assets into the future.

Oil reserves are a finite resource, and transport systems will almost certainly become more and more dependent on synthetic fuels, bio-fuels and/or electrical power in the medium to long term.

If the cost of transport increases the cost of constructing infrastructure assets is likely to increase commensurately.

On the other hand, there are a couple of possible reasons that energy might actually become cheaper in the medium term which would drive construction costs down.

The amount of solar power being generated is increasing exponentially, and there are number of reasons to suspect the efficiency of solar power generation will improve markedly in the short to medium term.

Commercial fusion power is not expected to be available until at least 2040, but its impact if and when it does become a reality could be enormous, given that there is enough heavy hydrogen in the oceans to satisfy mankind's energy needs for millions of years.

3.6.2 New Materials & Construction Techniques

New Materials & Construction Techniques - It is possible that Automated Construction Techniques like D-Shape & Contour Crafting will have a significant impact on the construction of civil assets in the not-to-distant future. Given the long lives of some civil assets it is feasible that by the time they are due to be replaced automated construction techniques will enable them to be replaced for considerably less than their current replacement cost.

High tech materials like carbon nanotubes could result in decreased construction costs.

3.6.3 Increased Collaboration & Knowledge Sharing

Collaboration & Knowledge Sharing - Increased collaboration & knowledge sharing via the internet has the potential to reduce overhead costs significantly by reducing the amount of duplication of effort between Councils.

3.6.4 Artificial Intelligence & Expert Systems

Artificial Intelligence & Expert Systems - Some observers believe that human level general artificial intelligence could be a reality as soon as 2030.

4. Lifecycle Management and Financial Considerations

4.1 Useful Life

Drainage Asset Useful Lives - The useful life of most stormwater drainage assets will depend on a range of environmental factors. The estimated useful lives given below which have been extracted from the Assetic Asset Management System are best guess averages.

Asset Sub-classpixel.png Useful Life Average RUL Annual Depreciation
Absorption Trenches 80 years 62.4 years $4,819.00
Causeways 80 years 44.8 years $31.34
Gravity Pipes 80 years 51.4 years $1,053,550.41
Lagoons 80 years 20 years $3.00
Low Flow Pipes 80 years 28.2 years $1,314.00
Natural Channels 80 years 35 years $160.00
Open Channels 80 years 60.4 years $17,784.88
Retention Basins 80 years 62 years $115,049.41
Road Culverts 80 years 50.2 years $91,076.35
Asset Sub-classpixel.png Useful Life Average RUL Annual Depreciation
Stormwater Pits 80 years 65.0 years $251,790
Headwalls 80 years 46.0 years $62,734.21
GPTs 80 years 72.5 years $776.2
Channels 80 years 53.4 years $1,674.40
Flood Devices 80 years 72.0 years $7,908.75

4.2 Valuation

4.2.1 Drainage System Valuation

Drainage Valuation - The figures below were extracted from the Assetic Asset Management System on 30 September 2009.

Asset Sub-classpixel.png Replacement Cost Written Down Replacement Cost
Natural Channels $12,800 $5,440
Open Channels $1,422,790.62 $1,100,590.61
Causeways $2,507.46 $1,372.83
Lagoons $240 $57
Retention Basins $9,203,952.65 $8,137,065.75
Absorption Trenches $385,520 $296,139.4
Gravity Pipes $84,284,033.04 $48,225,517.39
Low Flow Pipes $105,120 $35,828.4
Road Culverts $7,286,108.46 $5,044,407.78
Asset Sub-classpixel.png Replacement Cost Written Down Replacement Cost
Stormwater Pits $22,381,383.12 $18,412,900.65
Headwalls $5,576,375.11 $3,196,384.03
GPTs $69,000 $60,306
Channels $148,836 $101,738.80
Flood Devices $703,000 $639,730

The 2010 Drainage Network Valuation figures below were extracted from the June 2010 Financial Reconciliation Report.

Asset Sub-classpixel.png Replacement Cost Written Down Replacement Cost Annual Depreciation
Stormwater Pits $29,514,900.19 $22,953,602.89 $6,561,297.31
Stormwater Pipes & Channels $141,055,586.21 $89,747,240.52 $51,308,345.70
Total $170,570,486.40 $112,700,843.41 $57,869,643.01

4.2.2 Unit Rates

Drainage Unit Rates - The unit rates below were used in the 1 July 2009 Revaluation.

Asset Type Unit Rate
Absorption Trench $79.00/m
Box Culvert (1200mm x 1200mm) $2,014.40/m
Box Culvert (1200mm x 2000mm) $2,950.44/m
Box Culvert (1200mm x 300mm) $881.60/m
Box Culvert (1200mm x 450mm) $1,083.82/m
Box Culvert (1200mm x 600mm) $1,277.88/m
Box Culvert (1200mm x 750mm) $1,466.74/m
Box Culvert (1200mm x 900mm) $1,651.90/m
Box Culvert (225mm x 450mm) $557.05/m
Box Culvert (300mm x 1500mm) $984.02/m
Box Culvert (300mm x 150mm) $469.25/m
Box Culvert (300mm x 1800mm) $1,083.82/m
Box Culvert (300mm x 225mm) $506.39/m
Box Culvert (300mm x 400mm) $583.57/m
Box Culvert (300mm x 450mm) $604.18/m
Box Culvert (300mm x 750mm) $720.50/m
Box Culvert (300mm x 900mm) $775.50/m
Box Culvert (3600mm x 3600mm) $12,557.60/m
Box Culvert (375mm x 150mm) $488.28/m
Box Culvert (375mm x 225mm) $532.29/m
Box Culvert (375mm x 300mm) $573.07/m
Box Culvert (375mm x 600mm) $720.50/m
Box Culvert (450mm x 1200mm) $1,083.82/m
Box Culvert (450mm x 1800mm) $1,372.85/m
Box Culvert (450mm x 225mm) $557.05/m
Box Culvert (450mm x 300mm) $604.18/m
Box Culvert (450mm x 450mm) $692.34/m
Box Culvert (600mm x 225mm) $604.18/m
Box Culvert (600mm x 300mm) $663.64/m
Box Culvert (600mm x 450mm) $775.50/m
Box Culvert (750mm x 300mm) $701.78/m
Box Culvert (900mm x 3000mm) $3,237.12/m
Box Culvert (900mm x 300mm) $775.50/m
Box Culvert (900mm x 450mm) $933.19/m
Box Culvert (900mm x 600mm) $1,083.82/m
Box Culvert (900mm x 900mm) $1,372.85/m
Causeway $52.90/m
Causeway (375mm) $52.90/m
Causeway (450mm) $52.90/m
Causeway (450mm) $52.90/m
Causeway (600mm) $52.90/m
Lagoon $10.00/m
Low Flow Pipe $146.00/m
Natural Channel $10.00/m
Open Channel $53.00/m
Open Channel (2m) $53.00/m
Retention Basin $1,000.00/m
Retention Basin (35m) $1,000.00/m
Stormwater Pipe (100mm) $186.24/m
Stormwater Pipe (1050mm) $831.83/m
Stormwater Pipe (1200mm) $1,040.17/m
Stormwater Pipe (1350mm) $1,277.54/m
Stormwater Pipe (1500mm) $1,543.92/m
Stormwater Pipe (150mm) $191.19/m
Stormwater Pipe (1650mm) $1,839.33/m
Stormwater Pipe (1800mm) $2,163.76/m
Stormwater Pipe (1950mm) $2,517.22/m
Stormwater Pipe (2100mm) $2,899.68/m
Stormwater Pipe (225mm) $204.68/m
Stormwater Pipe (3000mm) $5,803.95/m
Stormwater Pipe (300mm) $225.41/m
Stormwater Pipe (375mm) $253.41/m
Stormwater Pipe (450mm) $288.65/m
Stormwater Pipe (525mm) $331.16/m
Stormwater Pipe (600mm) $380.92/m
Stormwater Pipe (675mm) $437.93/m
Stormwater Pipe (750mm) $502.20/m
Stormwater Pipe (825mm) $573.72/m
Stormwater Pipe (900mm) $652.50/m
Stormwater Pipe (975mm) $738.54/m

The unit rates are based on the cost of a small number of BRC drainage projects, the standard rates used by ACEAM to value the drainage network post amalgamation, and unit rates developed by Fraser Coast Regional Council. To try and smooth out inconsistencies that may have resulted from the infrequent use of the larger Box Culvert sizes, first cut unit rates were plotted against culvert area, and a best fit curve plotted.

The equation adopted was: Unit Rate = 0.000835 x Area² + 0.385 x Area + 350

In the graph below the blue dots represent individual unit rate data points, and the green line is the above equation.

Box-Culvert-Graph.png

A similar technique was used to smooth out variations in the unit costs of stormwater pipes. This yielded the equation.

Unit Rate = 0.000645*Diameter² -0.062*Diameter +186

1-July-2009-Stormwater-Pipe-Unit-Rates.png

4.3 Maintenace

4.3.1 Maintenance Activities

Drainage Maintenance Activities - Council performs a number of maintenance activities in relation to drainage assets, including:

There are eight drainage maintenance activities in BARS.

  • Maintain & repairs to culverts, pipes
  • Drainage Miscellaneous
  • Open Drains Concrete Repairs
  • Culvert Repairs
  • Catchpit Repairs
  • Manhole Repairs
  • Access Repairs
  • Aquifer Maintenance
  • Clean culverts pipe pits (mjr)
  • Drain Cleaning (Open Drains) - Bobcat, wheel barrow - cleaning schedule exists
  • Clean Culverts, Pipes & Pits - Major - known high risk sites checked prior to storm season. (List exists) - pits? - GPTs done on an irregular basis
  • Drain Repairs - from inspections shotcrete or stone pitching or concrete repairs

4.3.2 Maintenance Expenditure

Drainage Maintenance Expenditure - Maintenance Expenditure is detailed in the table below.

Asset Sub-class Annual Maintenance Expenditure
Drain Cleaning $400,000
Drain Maintenance & Repairs $240,000

4.4 Asset Renewal & Replacement

Drainage Renewal & Replacement - The table below shows the overall amounts set aside for capital works on drainage assets in Council's Ten Year Capital Expenditure Forecast, and the estimated proportion of those amounts that will be spent on renewal works. The exact split between new and renewal is unknown, but historically at least 90% of capital expenditure on drainage has been for new works.

Planned Capital Expenditure on Drainage
Year Total Expenditure Renewal Expenditure
2010-2011 $2,455,000 $245,500
2011-2012 $2,279,000 $227,900
2012-2013 $2,415,740 $241,574
2013-2014 $2,560,684 $256,068
2014-2015 $2,714,325 $271,432
2015-2016 $2,877,185 $287,718
2016-2017 $3,049,816 $304,982
2017-2018 $3,232,805 $323,280
2018-2019 $3,426,773 $342,677
2019-2020
2020-2021

More work needs to be done matching these figures to specific projects, but a number of first cut renewal programs are under development. (You must be logged on to BRC Intranet to view the links below)

4.5 Asset Creation & Acquisition

New Drainage Works - The table below shows the overall amounts set aside for capital works on drainage assets in Council's Ten Year Capital Expenditure Forecast, and the estimated proportion of those amounts that will be spent on new works. The exact split between new and renewal is unknown, but historically at least 90% of capital expenditure on drainage has been for new works.

Planned Capital Expenditure on Drainage
Year Total Expenditure New Expenditure
2010-2011 $2,455,000 $2,209,500
2011-2012 $2,279,000 $2,051,100
2012-2013 $2,415,740 $2,174,166
2013-2014 $2,560,684 $2,304,616
2014-2015 $2,714,325 $2,442,893
2015-2016 $2,877,185 $2,589,467
2016-2017 $3,049,816 $2,744,834
2017-2018 $3,232,805 $2,909,525
2018-2019 $3,426,773 $3,084,096
2019-2020
2020-2021

4.6 Asset Disposal

Bundaberg Regional Council has no plans to dispose of any of the assets identified in this plan in the next ten years.

4.7 Risk Management

Risk Management - Council recognises 4 levels of risk, low, medium, high and extreme. These risk associated with a given hazard is calculated in accordance with Council's Risk Management Policy using the following risk matrix.

Risk-Matrix.png

All identified risks are recorded in Council's Risk Management System. The system contains a hazard register and a rectification action plan.

Council typically adopts one or more of the following risk handling options when risks are identified.

  • accepting risk;
  • reducing likelihood of event;
  • reducing the consequences of event;
  • transferring the risk;
  • sharing the risk;

Risks

Hosting the plan online and backing it up locally should ensure that the plan content is safe even in the case of a server failure.
Internet outages can restrict access to the live version of the plan from time to time, but the data itself should be very safe.
Backups of the plan are made regularly and stored in the directory: S:\Support Services\Assets\Asset Management Plans.

5. Asset Management Practices

5.1 Asset Management Systems

Asset Management Systems - Bundaberg Regional Council uses a the following software systems & databases to manage various asset management related tasks.

Software System Interaction Diagram
Software-System-Map4.png

5.2 Standards & Guidelines

Standards & Guidelines - BRC has referred to a wide range of standards and guidelines in developing its asset management practices, including those listed below;

Drainage Standards & Guidelines - BRC has referred to the following drainage related standards & guidelines in developing its asset management practices.

6. Improvement and Monitoring

6.1 Known data quality issues

Drainage Data Quality Issues - The following drainage data quality issues have been identified.

  • A number of pipe diameters appear to have been altered when the databases of the four former Councils were amalgamated. (This problem has been substantially rectified.)

6.2 Drainage Data Quality Improvement Plan

Drainage Data Quality Improvement Plan - It is planned to improve the quality of the drainage data in the asset management system, by carrying out the following actions:

  • All pipe diameters are being checked against the databases they were extracted from and will be corrected, and a revaluation applied to drainage table prior to new drainage assets being inserted into the database in the 2009-1010 financial year. (Done)
  • The Drainage Section (Ian Stitt) maintains hard copy plans of modifications to the drainage system carried out by Council. Incorporation if this information into the asset management system proper should further improve the accuracy of the data.
  • Publishing as much existing data about drainage infrastructure both here and on the internal BRC Wiki, and encouraging the readers and users of the AMP/wiki to advise the Assets Section of any errors or inconsistencies.

6.3 Estimate of Reliability

Estimate of Reliability - The majority of the figures used in BRC's Asset Management Plans are generated from Council's Assetic Asset Management System. The Assetic database was compiled from numerous databases and spreadsheets used by the former Councils of Bundaberg, Burnett, Isis & Kolan. The quality of the data available varied from Council to Council and asset class to asset class, and in some cases has been further degraded as a result of the aggregation process.

Council is in the early stages of developing and implementing long term management systems and as such expects the Long Term Asset Management Plan, incorporating this Asset Management Plan and associated expenditure programs, to change significantly over the next five years as these systems mature and better information becomes available.

It should be noted that Council has made significant advances in the reliability of the base data (quantity, location, condition and value) since amalgamation.

7. References

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