Tillegra

Effects on Dungog Council Road network infrastructure

Greg McDonald September 2007 Amended July 2008 1

Pavement Design Basics

Road pavements are designed for a finite life. When the designer needs to determine a design life for the road they typically choose a period of approximately 20 to 30 years. Having a design life, the designer then needs to determine the number of Equivalent Standard Axles (ESAs) that the road is anticipated to carry in that design period, and this figure can then be used to determine a pavement thickness.

A ‘Standard Axle’ is a design equivalent to enable various differently loaded axles to be factored into the pavement design. It takes into effect the load and axle configuration of heavy vehicles.

The standard axle in which all others are related is a single axle load of 8.2 tonnes (80 kN) on dual tyres.

For vehicles that have different axle loadings, the equivalent loading can be calculated from the following formula:

4 NESA = [Pc / PESA)

Where: Pc load on axle group PESA load on standard axle group

For a motor car of approximately 1.6 tonne (standard Falcon or Commodore) the load on each axle group is approximately 800 kg.

4 NESA = (0.9/8.2) = 0.14 = 0.0001

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(or 1 10,000th of an equivalent standard axle)

So 1 car is equivalent to about 10,000 trucks!

Because cars are so insignificant when compared to heavy vehicles, the design method for calculating total ESAs ignores normal traffic and only utilizes the heavy vehicle traffic.

As such, traffic counts are often expressed as Average Annual Daily Traffic (AADT) and a % heavy vehicles. From the AADT and %HV, the ESA for the life of the road can be calculated from the following equation: N = n x c x r x 365 x P x F (formula 1)

Where

n = daily traffic in one direction c = percentage of heavy vehicles r = expected traffic growth rate P = design life (years) F = equivalent number of standard axle groups per heavy vehicle (average of 2.8 for Rural roads)

Typically rural roads will have low HV traffic (somewhere between 3 and 10%) however it is this traffic that has the main effect on the road pavement and still determines the final pavement design.

Effects of increases in heavy vehicle traffic

In determining the effects of increases in heavy vehicle volumes on Council’s road network, consideration needs to be taken in to the haul routes (which roads will be effected), the present condition of those roads, the present heavy vehicle traffic existing on those roads and the likely heavy vehicle increases. Once reasonable assumptions can be made for each of the above, estimates can be made as to the reduction in the original design life of the roads that will be observed as a result of the additional heavy traffic volumes.

Firstly, considering the original formula (formula 1) above you can recognize that a percentage increase in heavy vehicles will have the inverse effect (ie a percentage decrease) in asset life.

Because the increase in additional heavy vehicles is for a period less than the full design life, the effect on the remaining life of the asset can be calculated from the following formula:

P remaining = remaining life of the road asset (yrs) c = percentage of heavy vehicles prior to increase

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P new = new remaining asset life following additional traffic

C increase = increase in heavy vehicles (as % of total traffic) P increase = time of increased heavy vehicle usage (yrs)

Pnew = (P remaining x c – Pincrease x Cincrease ) / (c) (formula 2)

Eg P remaining = 15 yrs c = 3%

C increase = 2% P increase = 2 yrs

Pnew = (15 x 0.03– 2 x .02) / (0.03) = 512.5 / 37.5 = 13.6 years

So reduction in asset life is 15 years – 13.6 years = 1.4 years for the 2 years of additional heavy vehicle loading.

Financial impact

There are two philosophies to be taken here. Council can determine the routes to be utilized by the construction and tourist traffic and simply calculate a replacement rate for these roads or it can take a more detailed analysis into the additional effect that the heavy traffic loading will have on the road network and determine the additional cost to Council. Council has already produced a Roads Access Study that addresses the issues regarding the preferred route that Hunter Water has identified to ingress/egress Plant and Machinery for the construction.

The first method is the simplest but probably overestimates the cost as not all the cost of replacement can be attributed to the developer. The argument that Council would utilize in this position is that the road network is unsafe in its present form and the inclusion of the dam in the shire places undue burden on Council’s resources. The developer is gaining significant benefits from the dam and the cost should not be borne by the community. As such the replacement cost of the roads that are likely to be relied on for both construction and tourist traffic should be improved to a standard that is acceptable prior to completion of the works.

The second method is more detailed and requires not only an estimate for the cost of replacement of the roads, but an estimate of the heavy vehicle loadings, and the time frame for replacement of those roads.

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Knowing the reduction in asset life affected by the increase in heavy vehicles allows Council to determine the increase in financial costs borne by the Council.

This is determined from Net Present Value (NPV) calculations which calculates a comparable figure against different options when there is a time effect on cash flow.

$100 spent in 5 years time only requires me to have $71 now invested at 7% for those 5 years. As such, bringing forward the expenditure by 5 years has cost me $29 in interest. The same analysis can be undertaken on the roads. Bringing forward expenditure on the renewal of the roads will have a cost implication on Council.

The analysis undertaken identified the reduction in road life expected from the traffic loadings assumed. The financial impact of bringing the road works forward can be calculated using the NPV method shown above and as such a dollar figure now, can be assessed against the traffic impact. Due to the difficulty in assessing how many additional heavy vehicles will be utilising the road network, the additional cost on the haul route has been calculated for a number of different heavy vehicle movements to provide a range of costs.

Cost effects by Heavy Vehicles

$1,400,000

$1,200,000

$1,000,000

$800,000

$600,000 Additional cost $400,000

$200,000

$0 0 5000 10000 15000 20000 25000 30000 35000 Increase in Heavy Vehicles

Road Network affected

Dungog Council believes the sections of road network affected by construction traffic during the building of the dam will be the sections of road south of the Dam

Tillegra Dam – Road Improvements 5 wall along Salisbury Road, Chichester Dam Road to Dungog, and roads identified in the Access study which include Hooke Street and Lord Street, MR 101 south of Dungog to Wirrigulla and MR301 to Clarence Town.

Analysis of these road’s lengths, their present condition and hence their expected remaining life have been considered and analysed by spreadsheet to determine the total financial effect on the road network.

In addition to the above roads, it is considered that Council should be making representations to both the State and federal governments for improvements to Glendonbrook Road, Road, Bingleburra Road and Salisbury Gap Road (tourism and link to west) and also for Dungog Main street (footpath improvements and street furniture to stimulate economic activity in town).

Timber bridges affected by the haulage routes include the two timber bridges on MR 301 being (Wallaroo Creek Bridge and Unwarrabin Creek Bridge), however the addition of the timber channel bridge adjacent to the Williams River on MR 101 have also been included in the Access Study.

Tillegra Dam Recreational Facilities Scoping Study

Assumed visitation numbers On the basis of consultations with other dam recreational facility managers that have some similarity to what is proposed at the Tillegra Dam, it is considered that yearly visitor numbers will be in the range of 8,000 to 32,000 for the first few years. After that, visitor numbers will depend, to a large degree, on the perceived attractiveness of the dam for the wider community. This may be determined by such factors as the quality of the freshwater fishing and whether large specialist groups, such as school camps, water skiers and other specialist recreational groups such as canoe clubs are attracted to the dam and the facilities provided. Assuming this does happen, we have, for modelling purposes worked on visitor numbers building to an estimated 48,000 in Year 4 (assuming 2013 is Year 1), which is the benchmark for the development of camping facilities at the site. Table below contains the full 16-year projections.

Table - Estimated Visitation Numbers

Year Date Total Day Use Campers Users 1 2013 8,000 8,000 2 2014 16,000 16,000 3 2015 32,000 32,000 4 2016 48,000 28,000 20,000 5 2017 53,000 32,000 21,400 6 2018 57,245 34,347 22,898 7 2019 61,252 36,751 24,501 8 2020 65,540 39,324 26,216 9 2021 70,128 42,077 28,051 10 2022 75,037 45,022 30,015

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11 2023 80,289 48,173 32,116 12 2024 85,909 51,546 34,364 13 2025 91,923 55,154 36,769 14 2026 98,358 59,015 39,343 15 2027 105,243 63,146 42,097 16 2028 112,610 67,566 45,044

Note – Modelling derived from Burnett River Dam, , Lake Glenbawn and Glennie’s Creek Dams visitation figures and estimates.

Three underlying development philosophies emerge from this finding: ""A staged, incremental approach to recreational development is pursued, preferably market lead, where consumer demand dictates private – or leased supply of facilities. ""Early developments, eg day use facilities, should not preclude the possibility of upgrading or expanding to bigger facilities on the same site, eg a camp ground in the future ""Day use recreation facility infrastructure – eg picnic tables, BBQ’s, toilets etc are essentially a community service rather than a profit making opportunity However, the experience at several other dams in the region is that the time frame and staging of various facilities can be bought forward through the involvement of Hunter Water and Private Developers in the provision of facilities and support infrastructure that has been facilitated through appropriate planning and through successfully securing available funding.

Traffic Issues 1. Traffic Volumes Traffic associated with the recreational areas will comprise generated traffic (i.e. new to the area) and traffic attracted from nearby recreational areas. The attracted traffic could include, for example, fishers who currently visit adjoining areas or visitors to Newcastle, Port Stephens or Great Lakes who are after an inland experience. In the absence of detailed volumes, it is difficult to quantify the potential levels of attracted traffic although these are estimated to be small in comparison to the level of generated traffic. The projected number of visitors to Tillegra Dam in 2028 is 112,610 per year (above). With an average occupancy of 2.5 visitors per vehicle, this corresponds to 90,088 vehicle trips per year (i.e. one trip in and one trip out). The average annual daily traffic (AADT) to the recreational areas is 247 trips per day. It has been assumed that during holiday seasons such as Christmas and Easter the average patronage levels will triple. This equates to 741 trips per day to the recreational areas. Assuming a peak annual event of 10% of visitors over a three-day period, peak traffic is estimated at 3,003 vehicle trips per day to all recreational areas. 2. Vehicle Classification and Maintenance Issues Traffic associated with the recreational areas is expected to be predominantly light vehicles such as sedans, four-wheel drives and utilities. A proportion of these may be towing trailers, caravans or boats and will still be classified as light vehicles. Heavy vehicle traffic associated with the recreational facilities is envisaged to be a small proportion of total traffic and is most likely to include maintenance vehicles and

Tillegra Dam – Road Improvements 7 buses carrying school groups or backpackers and trucks for Primary Production purposes above the dam.

References Alderson/Jacobi Landscape Architect for the Calliope Shire Council, 1994, Recreation Strategy, A Review of the Planning and Management of Recreation Activities at Lake Awoonga and its Environs, Calliope.

Chenoweth Environmental Planning & Landscape Architecture in association with Kinhill Engineers Pty Ltd for -Thuringowa Water Supply Board, January 1997, Dam Recreational Use Preliminary Planning Report, Brisbane.

Chenoweth Environmental Planning & Landscape Architecture, January 1996, Lakes Cooby, Perseverance & Cressbrook – Management Plan Overview and Background Document, City Council.

Chenoweth, A.R.F (1984) Recreational Resources of North Stradbroke Island in Focus on Stradbroke Island, papers for the Royal Society of Symposium 11-12 August, pp. 371-377

Clark RN and Stankey, GH (1979), The Recreation Opportunity Spectrum: A Framework for Planning, Management and Research, Department of Agriculture Forest Services, USA.

EDAW, December 1997, Recreational Use of , Preliminary Planning Report, Townsville Thuringowa Water Supply Board.

Gold Coast Water (Gold Coast City Council), December 2000, Hinze and Little Nerang Dams – Recreation Management Policy, Gold Coast.

Gutteridge Haskins & Davey Pty Ltd, April 1990, Recreation Strategy for , Toowoomba City Council.

Gutteridge Haskins & Davey Pty Ltd, October 1994, Optimising the Recreational Use of Cooby, Perseverance and Cressbrook Storages, Toowoomba City Council.

Queensland Environmental Protection Agency, 2002, Camping in Queensland, 7th Edition.

Richards, G.P. and Heywood, J.L (1999), A Territory-Wide Application of the Opportunity Spectrum Approach using Marketing Techniques, Australian Parks & Leisure, v1 n4, pp11-19.

Sinclair Knight Merz, September 2001, Burnett River Dam Environmental Impact Statement, Burnett Water Pty Ltd

Smith, E. and Lipscombe, N. (1999) An evaluation of Recreation Opportunity Spectrum (ROS) applications in . Johnstone Centre of Parks, Recreation and Heritage Report No. 124.

Stankey, G. and Wood, J. (1982) The Recreation Opportunity Spectrum: An Introduction. Australian Parks and Recreation, February, pp.6-14.

Wide Bay Sport and Recreation Council and Sport Recreation Queensland, no date, Finding Funding.

Conclusion

It is suggested that due to the lack of adequate information regarding the number of truck movements and the increases expected from increased visitation, the estimates required in determining exact dollar values of damage caused and risk exposure to travelers by these additional Vehicle Kilometer Travelled (VKT), that Council simply take the stance that the road infrastructure serving the dam and the surrounding area has significant shortcomings and that this road network should be funded and replaced.

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The following work is recommended:

Glendonbrook Road Upgrade $4,600,000 Allyn River Road Upgrade $6,800,000 Salisbury Road Upgrade $1,100,000 Salisbury Gap Road Upgrade $250,000 Gresford Regional Roads (Rehabilitation) $1,200,000 Chichester Dam Road Upgrade (Dungog to Salisbury Road) $2,600,000 Dungog Urban & Main Streets (Upgrade & Rehabilitation) $1,350,000

Total $17,900,000

Note -: Projects above are listed in priority order.

In addition, Council should be making further representations to the state government regarding the road classification system and suggesting that MR101 from Maitland to Dungog and then Chichester Dam Road and Salisbury road up to and including the section around the dam be classified as a State Road.

Tillegra Dam – Road Improvements