Version 1, February 1998

Roads in the Wet Tropics

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Context ofthe Region

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Version 1, February 1998

Roads in the Wet Tropics

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A CONTEXT OF THE REGION FEB 98

A1 Wet Tropics Region A-1

Description of the Region A-1

Wet Tropical Forests in the World A-1

Wet Tropics of Queensland World Heritage Area A-2

Wet Tropics Management Plan A-2

A2 Great Barrier Reef Marine Park A-3

A3 Regional Climate A-4

TABLE OF CONTENTS

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A1 Wet Tropics Region

Description of the Region

The wet tropics region is that area of northernQueensland which receives more than1200mm of annual rainfall. The region isdepicted on the Figure 1.

Note: Throughout this manual, the wet tropicsregion is used to describe this biogeographicregion, the Wet Tropics World Heritage Area isused to describe the Wet Tropics of QueenslandWorld Heritage Area.

The wet tropics region is unique in having twoworld heritage listed areas, the Wet Tropicsand the Great Barrier Reef, within itsconfines. These features, together with a wettropical monsoonal climate (mostly greaterthan 1200 mm annual rainfall), vibranteconomy and good quality of life, have meantit is perceived as a highly desirable place tolive and visit. This is manifest in thesubstantially increased numbers of residentsand visitors over the past decade.

The wet tropics region has three basiclandforms; the coastal plain, the coastalrainforest clad ranges and the tablelands.The coastal plain is a relatively narrowfeature between the Great Barrier Reef andadjoining rainforest clad coastal ranges.

The wet tropics region has Cairns andTownsville as its major urban centres andgenerally extends north to Cooktown, west toHerberton and south to Townsville.

The region's natural resources such as land,water, forests, minerals and fisheries are animportant component of both the regionaleconomy and natural environment. Theregion has substantial areas of good qualityagricultural land which support a range of

agricultural and horticultural industries(predominantly sugar cane on the coast, beefcattle to the west and intensive irrigatedcrops on the tablelands).

Urban growth, including rural residentialdevelopment, is placing considerablepressure on agricultural land and farmingindustries through loss of land, fragmentationof farm holdings and the introduction ofincompatible urban land uses in rural areas.

The region's water resources are used tomeet a number of demands includingirrigation, urban supplies, power generation,recreation and ecological processes. Theregion's coastal waters and wetlands play animportant role in providing habitat for marinelife, which supports important recreationaland commercial fishing and marine basedindustries.

Wet Tropical Forests in theWorld

Tropical rainforests are of tremendousbiological significance. They cover onlyseven per cent of the Earth's surface yetcontain more than half of the Earth's plantand animal species.

Scientific research has highlighted thesignificance of tropical rainforest as the homeof a diverse range of plant and animal life, amajor source of atmospheric oxygen and adriving force behind the world's climate andweather patterns. Rainforest products arealso being actively studied for their medicinalvalues.

The rapid disappearance of the world'stropical rainforest has become a globalconcern. Every year 12 million hectares, oran area the size of Tasmania (about 1.5% of

CONTEXT OFTHE REGION

Figure 1 Wet Tropics Biogeographical Region

Figure 2 Department of Main Roads Northern andPeninsula District Boundaries and RoadNetworks

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the total extent of tropical rainforests globally)is destroyed through large scale clearing andburning (IUCN 1991).

Australia contains less than one-thousandthof the world's tropical rainforests, but it's wettropical rainforest is one of the mostsignificant regional ecosystems in the world.The World Heritage listing of the Wet TropicsWorld Heritage Area demonstrates Australia�scommitment to preserve tropical rainforests.

Australia is well placed to set an example forrainforest management and to demonstratethe economic benefits of protecting therainforest. Australia can also provide ideasand information for the developing nationsthat have minimal funds to spend on thepreservation of World Heritage areas. TheManual may also be relevant to suchcountries.

Wet Tropics of QueenslandWorld Heritage Area

In December 1988 the tropical rainforestareas of north-east Queensland wereinscribed on the World Heritage List by theWorld Heritage Committee. As a result of thelisting, the area is now known as the WetTropics World Heritage Area.

The Area comprises nearly 900 000 hectaresand extends 400 kilometres along the NorthQueensland coastline. The wet tropics regionof Queensland is Australia's most floristicallyrich area at both the family and genera level.A survey of plant records registered with theQueensland Herbarium indicates that theregion's flora of higher plants exceeds 3500species. At least 1160 species of higherplants representing 523 genera of 119families are recorded from the region'srainforests. Seventy-five of these genera areAustralian endemics with 43 of these entirelyrestricted to this region. Some 710 speciesare endemic to Australia, with 500 (or 43% ofthe total regional species) endemic to wettropical closed canopy forests.

Although representing less than one-tenth ofone per cent of the land surface of theAustralian continent, the Area contains theonly habitat for 76 species of animals that areregarded as rare, vulnerable or endangered.

The Area provides an unparalleled livingrecord of the ecological and evolutionaryprocesses that shaped the flora and fauna ofAustralia over the past 415 million yearswhen first it was part of the Pangaeanlandmass, then the ancient continentGondwana (which included India, Antarcticaand parts of Africa and South America inPalaeozoic and Mesozoic times) and for thepast 50 million years an island continent.

Wet Tropics Management Plan

The Wet Tropics Management Plan 1997 wasapproved by Governor in Council on 7 August1997 and takes effect on 1 November.

The Wet Tropics Management Plan 1997sets out a regulatory framework formanagement of the Wet Tropics WorldHeritage Area in accordance with the WetTropics World Heritage Protection andManagement Act 1993.

With regard to roadworks in the Wet TropicsWorld Heritage Area the plan has a numberof implications:

n the Area is divided into four zones whichhave different levels of integrity,remoteness from disturbance, intendedphysical and social setting andmanagement purposes;

n roads are classified (with differentimplications for access and roadmaintenance and building) as:

� State-controlled;

� Community access;

� Presentation (unrestricted);

� Presentation (restricted); and

� Management Roads;

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n various activities are prohibited or aresubject to a permit from the Wet TropicsManagement Authority (or othergovernment agency);

n maintaining a road is prohibited unless apermit is obtained in all zones, buildinga road requires a permit and is onlyallowed subject to a permit in zones Cand D;

n permits are decided in accordance withthe most important consideration, �thelikely impact �on the area�s integrity�,in accordance with the precautionaryprinciple, considering prudent andfeasible alternatives and taking intoaccount World Heritage values andcommunity considerations;

n the plan states that a permit to build aroad may only be issued if there is �nonet adverse impact on the integrity ofthe area or there is no prudent andfeasible alternative� and that roadworksshould be confined to land alreadycleared or otherwise degraded;

n roadworks requiring clearing will onlyreceive a permit if they will reduce theimpact on the integrity of the Area or areneeded for public safety, a communityservice, access to a residence or arerequired to �properly manage the area�.

A document �Protection ThroughPartnerships� has also been published by theWet Tropics Management Authority to set outpolicies for implementing the Wet TropicsManagement Plan 1997. Of particular interestis that the document specifically encouragesthe development of a Code of Practice forRoadworks.

A2 Great Barrier ReefMarine Park

On the 26 October 1981 the Great BarrierReef Marine Park was recognised and listedas a World Heritage Area. The Great BarrierReef Marine Park is a natural treasurestretching more than 2 000 km from CapeYork to just north of Fraser Island. The parkcovers an area of 348 200 km2 and containsa diverse array of natural, cultural andhistorical features. Inscription as a WorldHeritage area is an obligation for theAustralian Government and relevantManagement Authorities to design andimplement policies and managementpractices which aim to preserve and protectthis unique, dynamic ecological system.

The Great Barrier Reef Marine Park isprotected by Australian and QueenslandLegislation and management policies. This isimperative due to the rapidly increasingdemands from tourism, fishing and industry.Whilst diverse and beautiful, the GreatBarrier Reef supports a range of activitiesand industries that stand to adversely impactthe Reef if not managed correctly. Theseinclude:

n tourism;

n fishing;

n shipping and port related activities;

n mariculture; and

n recreational activities eg. game fishing,diving, coral viewing etc.

The coastline which fronts the entirety of theGreat Barrier Reef Marine Park supports arange of land based activities which include:

n urban development;

n cane growing;

n grazing; and

n horticulture.

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These activities need to exercise bestpractice to ensure the sustained well-being ofthe Marine Park and minimise any significant,localised impacts.

Road corridor planning, design,maintenance, construction and operationneeds to reflect the sensitivity andimportance of the Great Barrier Reef as aunique natural resource and natural wonder.

The wet tropics region being an area of rapidgrowth, essentially needs to implement amanagement system that minimises anysignificant adverse impacts which maycompromise the inter-generational equity ofthe reef.

A3 Regional Climate

Many of the distinctive features of the regionrelate to the high rainfall and diverse terrain.Seasonal variations in climate are much lessthan in the southern temperate areas withgenerally two seasons only, "the wet" and"the dry". Rainfall varies markedly throughoutthe biogeographical region and some partsare the wettest in Australia.

The height and orientation of the coastlinewith respect to the prevailing moist south-east to north-east air stream significantlyinfluences rainfall. The highest averageannual rainfall is experienced in the Areabetween Cairns and Tully, inland to the edgeof the Atherton Tablelands.

Rainfall on the Atherton Tableland decreasesrapidly westward. The mean annual rainfallranges from about 1 200 to 8 000 mm.However, Mt. Bellenden Ker, at an altitude of1 561 m, has recorded as much as 10 472mm over an eight month period (January toAugust 1979) and has received 1 140 mm ofrain in a 24 hour period (Tracey 1982).Rainfall intensities at this station are amongstthe highest recorded in the world.

The rainfall is distinctly seasonal with thehighest rainfall registrations in the regionoccurring in the period between November

and April, when 75 to 90 percent of theannual rainfall is recorded. Daily totals inexcess of 250 mm are frequently recorded.Rainfall totals for individual years may varywidely from long-term averages, due largelyto the incidence of cyclones.

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Intense tropical cyclones are a feature of theregion's climate. Cyclones are a major factorshaping the structural and floristicdifferentiation of the vegetation - particularlywith respect to forest mosaics of the coastallowlands.

By comparison with other tropical rainforestareas of the world, the wetter parts of theregion lie at the "extremely wet" end of thehydrological spectrum. The occurrence ofwidespread overland flow also appears to berare in wet tropical rainforests elsewhere.

Temperatures vary throughout the Area dueto the effects of altitude and distance from thecoast. Highest temperatures tend to occur inJanuary and the cooler temperatures duringJune, July and August when frosts may beexperienced in the higher areas, particularlyon the Atherton Tableland. The coastal beltexperiences a mean daily temperature rangeof 25°C to 36°C. The upland/tablelands arecooler with mean daily temperatures rangingfrom 17°C to 28°C with mean daily wintertemperatures ranging from 9°C to 22°C.

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AA3Table 1 Mean Monthly Rainfall for Selected Locations

n