Surface Water Resources of Cape York Peninsula

Home , Annan River, Archer River, Cape York Peninsula, Coen River, Ducie River, Embley River

LAND USE PROGRAM

SURFACE WATER RESOURCES OF CAPE YORK PENINSULA

A.M. Horn Queensland Department of Primary Industries 1995

r .am1, a DEPARTMENT OF, PRIMARY 1NDUSTRIES

CYPLUS is a joint initiative of the Queensland and Commonwealth Governments CAPE YORK PENINSULA LAND USE STRATEGY (CYPLUS)

Land Use Program

SURFACE WATER RESOURCES OF CAPE YORK PENINSULA

A.M.Horn Queensland Department of Primary Industries

CYPLUS is a joint initiative of the Queensland and Commonwealth Governments Recommended citation:

Horn. A. M (1995). 'Surface Water Resources of Cape York Peninsula'. (Cape York Peninsula Land Use Strategy, Office of the Co-ordinator General of Queensland, Brisbane, Department of the Environment, Sport and Territories, Canberra and Queensland Department of Primary Industries.)

Note:

Due to the timing of publication, reports on other CYPLUS projects may not be fully cited in the BIBLIOGRAPHY section. However, they should be able to be located by author, agency or subject.

ISBN 0 7242 623 1 8

@ The State of Queensland and Commonwealth of Australia 1995.

Copyright protects this publication. Except for purposes permitted by the Copyright Act 1968, - no part may be reproduced by any means without the prior written permission of the Office of the Co-ordinator General of Queensland and the Australian Government Publishing Service. Requests and inquiries concerning reproduction and rights should be addressed to:

Office of the Co-ordinator General, Government of Queensland PO Box 185 BRISBANE ALBERT STREET Q 4002

The Manager, Commonwealth Information Services GPO Box 84 CANBERRA ACT 2601 CAPE YORK PENINSULA LAND USE STRATEGY STAGE I

PREFACE TO PROJECT REPORTS

Cape York Peninsula Land Use Strategy (CYPLUS) is an initiative to provide a basis for public participation in planning for the ecologically sustainable development of Cape York Peninsula. It is jointly funded by the Queensland and Commonwealth Governments and is being carried out in three stages:

Stage I - information gathering; Stage I1 - development of principles, policies and processes; and Stage I11 - implementation ind review.

The project dealt with in this report is a part of Stage I of CYPLUS. The main components of Stage I of CYPLUS consist of two data collection programs, the development of a Geographic Information System (GIs) and the establishment of processes for public participation.

The data collection and collation work was conducted within two broad programs, the Natural Resources Analysis Program (NRAP) and the Land Use Program (LUP). The project reported on here forms part of one of these programs.

The objectives of NRAP were to collect and interpret base data on the natural resources of Cape York Peninsula to provide input to:

evaluation of the potential of those resources for a range of activities related to the use and management of land in line with economic, environmental and social values; and formulation of the land use policies, principles and processes of CYPLUS.

Projects examining both physical and biological resources were included in NRAP together with Geographic Information System (GIs) projects. NRAP projects are listed in the following Table.

Physical ResourcelGIS Projects Biological Resource Projects

Bedrock geological data - digitising and Vegetation mapping (NROI) integration (NR05) Airborne geophysical survey (NR 15) Marine plant (seagrass/mangrove) distribution (NR06) Coastal environment geoscience survey Insect fauna survey (NR17) (NR14) Mineral resource inventory (NR04) Fish fauna survey (NR10) Water resource investigation (groundwater) Terrestrial vertebrate fauna survey (NR03) (NR16) Regolith terrain mapping (NR12) Wetland fauna survey (NR09) Physical Resource/GIS Projects Biological Resource Projects

Land resource inventory (NR02) Flora data and modelling (NR18) Environmental region analysis (NR11) Fauna distribution modelling (NR19) CYPLUS data into NRIC database FINDAR Golden-shouldered parrot conservation (NR20) management (NR2 1) Queensland GIs dev$opment and maintenance (NR08)

* These projects are accumulating and storing all Stage I data that is submitted in GIs compatible formats.

Research priorities for the LUP were set through the public participation process with the objectives of:

collecting information on a wide range of social, cultural, economic and environmental issues relevant to Cape York Peninsula; and highlighting interactions between people, land (resource use) and nature sectors.

Projects were undertaken within these sector areas and are listed in the following Table.

People Projects Land Projects Nature Projects

Population Current land use Surface water resources Transport services and Land tenure Fire infrastructure Values, needs and aspirations Indigenous management of land Feral and pest animals and sea Services and infrastructure Pastoral industry Weeds Economic assessment Primary industries (non-pastoral, Land degradation and soil non-forestry) erosion Secondary and tertiary industries Forest resources Conservation and natural heritage assessment Traditional activities Commercial and non commercial Conservation and National Park fisheries management Current administrative structures Mineral resource potential and mining industry Tourism industry ACKNOWLEDGMENTS

This report presents an overview of the surface water resources of Cape York Peninsula. The work was undertaken primarily as a desktop study with a brief field trip to collect river habitat data for two major Peninsula rivers. Consequently this work has drawn heavily on previous studies and personal communications with many Peninsula residents and researchers familiar with this region.

Research work undertaken through the Cape York Peninsula Land Use Strategy (CYPLUS) has been used extensively. In particular river descriptions, field observations and comments by Brett Herbert and the staff at the Walkamin Research Station (CYPLUS Fish Fauna Survey) have been used at length. Also information provided by Andrew Biggs (CYPLUS Land Resource Inventory), John Neldner and Jack Kelly (CYPLUS Vegetation Survey), and Colin Pain (CYPLUS Regolith Terrain Survey) is gratefully acknowledged.

The guidance, assistance and commentary by Andrew Walter (Department of Primary Industries, Water Resources Environmental Section), both in the field and during the write up of this report is greatly appreciated.

Comments and advice by many Department of Primary Industries (DPI) staff including Linda Foster, Greg Hausler, John Hillier, Graham Herbert, Rob Lait and Karen Wilson have been invaluable. Steve Huch and Randy BramweLl undertook the Geographic Information System work including the creation of maps presented in this report. Also Peter Fiedler helped with the DPI Water Resources Database and Sandra Lee Young with the Salinity Trends diagram.

The Cape York Peninsula residents and researchers provided great insight through both local knowledge and personal observations. Many people gave assistance in this way including Bryan Cifuentes, Neil Dahl and Owie, Alan Davy, Graham Harrison, David Hurse, Frank Isenburg, Bill Jakeman, John Lane, Sheril Mehonoshen, Richard Pearson, Bob Pond, Viv Richardson, Bruce Saunders, Fran Segren and Bill Youngman. Apologies must be presented as this list is far from exhaustive.

Several people also made the time available and travelled significantly to attend a focus group meeting to discuss current issues affecting the Peninsula. These include Gary Cotter, Peter Graham, Peter Harris, Brett Herbert, Graham Herbert, Mark Horstman, Rob Lait, John Neldner, John Peeters and Andrew Walter. FOREWORD

In May 1994 contracts were awarded for the provision of project research into various aspects of the natural, social, cultural, infrastructure and administrative aspects of Cape York Peninsula. Funding was provided under the Cape York Peninsula Land Use Strategy (CYPLUS ' Land Use Program. These projects followed up and extended some 16 research projects undertaken under the CYPLUS - Natural Resource Analysis Program.

In all 24 research projects were undertaken under the CYPLUS - Land Use Program with the Department of Primary Industries being awarded the project covering the evaluation of the Peninsula's surface water resources.

This project has involved the collection and analysis of river basin data for surface water resources, assessment of current and future land use in relation to demand for water and a discussion of environmental impacts, in particular environmental flow requirements.

1 a joint initiative of the Queensland and Commonwealth governments TABLE OF CONTENTS

Page No .

EXECUTIVE SUMMARY ...... I

1.0 INTRODUCTION...... 1

2.0 METHODOLOGY ...... 4

3.0 PREVIOUS STUDIES ...... 6

4.0 CLIMATE ...... 8

5.0 NATURAL FEATURES ...... 12

5.1 Physiographic Features...... 12

5.2 Soils ...... 17

5.3 Vegetation ...... 19

5.4 Groundwater ...... 20

5.5 Fire ...... 21

6.0 RIVERINE GEOMORPHOLOGY ...... 23

6.1 East Coast Streams ...... 24

6.2 West Coast Streams ...... 24

6.3 Wetlands ...... 25

6.4 Riparian Vegetation ...... 26

6.5 Hydrology ...... 26 TABLE OF CONTENTS(cont.)

Page No.

WATER QUALITY ...... 37

ENVIRONMENTAL FLOW REQUIREMENTS ...... 44

Environmental Value ...... -44

State of Knowledge Concerning Environmental Flow ...... 45

Peninsula Issues ...... -46

Field Data .Pascoe and Wenlock Rivers ...... 47

8.4.1 Wenlock River ...... -47

8.4.2 Pascoe River ...... 48

8.4.3 Lagoons ...... 49

Habitat Types ...... 49

Environmental Flow Requirements of Peninsula Rivers ...... 50

8.6.1 Flowvariability ...... 50

8.6.2 Overbank Flows ...... 51

8.6.3 High Flows ...... 51

8.6.4 Low Flows ...... 52

Impingements on Natural Flows ...... -52

Review of Methods of Estimating Environmental Flow Requirements ...... 53

8.8.1 Rule of Thumb Method ...... 53

8.8.2 The Species Specific Method ...... 53

8.8.3 Transect Analyses ...... -53 TABLE OF CONTENTS(cont.1

Page No .

8.8.4 Panel of Experts ...... 53

8.8.5 Holistic Method ...... 54

8.9 Management Directions ...... 54

8.10 Discussion ...... 55

9.0 RESOURCE DEMAND...... 58

9.1 Groundwater ...... 58

9.2 Surface Water ...... 58

9.2.1 Present Demand ...... 58

9.2.2 Future Demand ...... 59

10.0 CURRENT GOVERNMENT POLICY ...... 61

11.0 MANAGEMENT ISSUES ...... 63

11.1 Feral Animals ...... 64

11.2 Cattle ...... 65

11.3 Exotic Vegetation ...... 65

11.4 Increasing Population ...... 65

11.5 Water Storages...... 66

11.6 Riparian Zone ...... 67

11.7 Pollution ...... 67

11.8 Sedimentation/Erosion...... 67 TABLE OF CONTENTS(cont.)

Page No.

12.0 CONCLUSION ...... -69

13.0 BIBLIOGRAPHY ...... 70

APPENDICES

1 Basin Characteristics ...... 75

Basin 101 Jacky Jacky Basin 102 Olive Pascoe Basin 103 Pascoe Basin 104 Stewart Basin 105 Normanby Basin 106 Jeannie Basin 107 Endeavour Basin 108 Daintree Basin 9 19 Mitchell Basin 920 Coleman Basin 921 Holroyd Basin 922 Archer Basin 923 Watson Basin 924 Embley Basin 925 Wenlock Basin 926 Ducie Basin 927 Jardine Basin 928 Torres Strait Islands

2 River Discharges at Hydrographic Stations ...... 95

3 Water Quality ...... 104

4 Habitat Characteristics...... 115 Page No .

1.1 Locality Plan ...... 2 1.2 River Basins ...... 3

4.1 Climatic Data ...... 9 4.2 Five Year Average Rainfall ...... 10

5.1 Physiographic Units ...... 13

6.1 Gauging Station Locations ...... 30 6.2 Annual Discharges ...... 33 6.3 No Flow Periods ...... 35

7.1 Surface Water Conductivity ...... 41 7.2 Surface Water Hardness ...... 42 7.3 Conductivity Trends ...... 43

4.1 Average Rainfall Category ...... 10 4.2 Pluviograph Station Locations ...... 11

5.1 Description of Physiographic Units ...... 14 5.2 Regolith Type ...... 15 5.3 Regolith Type Descriptions...... 16 5.4 Soil Type ...... 17 5.5 Soil Type Descriptions ...... 18 5.6 Vegetation Communities ...... 19

6.1 Basin Discharges ...... 28-29 6.2 Gauging Station .Depth of Runoff and Peak Annual Discharges ...... 3 1-32 6.3 Gauging Station .No Flow Periods ...... 34 6.4 Gauging Station .Percentile Exceedence Flows ...... 36

7.1 Conductivity and Hardness Values ...... 40

8.1 Initial Procedure for Developing Environmental Flow Requirements ...... 55

EXECUTIVE SUMMARY

This report presents an overview of the nature of the surface water resources of Cape York Peninsula, including an assessment of the reliability and the existing and projected demands, along with comment on related environmental and social issues. Comment is also made on issues that are likely to effect the quality, availability and ecological diversity of these resources. This work identities specific issues that will affect the longer term management of the Peninsula's surface water and related resources. It is beyond the scope of this report to be able to identifjr all of the issues or present a management plan for this resource.

The area covered in this report includes the entire mainland Cape York Peninsula north of approximately Cooktown. The region covers some 132 500 km2 of northern tropical Queensland and includes 16 river basins and sections of a hrther 2 basins. The area has a small sparsely settled population of around 10 000 (1986 census). The principle land uses are rangeland grazing, mining and tourism.

On the Peninsula about 80% of the annual average rain falls during the four months between December and March, with April to October being a significantly drier period. The climate varies fiom humid tropical (i.e. hot and wet) along the eastern coastal strip to semi arid in the central western Peninsula area. The area also experiences high evaporation rates with the greatest average rates occurring in October, November and December and the lowest generally in February, May, June and July. These monsoonal weather patterns have a particularly pronounced effect on the nature and availability of the surface water resources.

Cape York Peninsula contains some of Australia's most significant rivers including, the Mitchell, which probably has the highest river discharge, the Wenlock, which probably has the greatest fish species diversity (Herbert et al., 1995) and the Jardine, which has the highest baseflow of any river in Queensland. The area is of high wilderness value with several watercourses and wetlands being nearly pristine. However most areas are suffering fiom some form of minor degradation. Isolated areas occur that are suffering severe degradation.

In the Peninsula, there is a variety of river landform types including upland streams, valley streams, high bankedherraced floodplain rivers, low banked wide floodplain rivers, estuaries and others. Riparian vegetation is well developed along most of the major waterbodies in the Peninsula. Riparian zones along the alluvial plains are composed commonly of Melaleuca viridtjlora and stringybark (Eucalyptus tetradonta) with some areas of riverine vine (gallery) forest (Lesslie et al., 1992).

The Peninsula has a wide range of waterbody types with differing ecological requirements including different flow regimes. Waterbodies include permanent and temporary rivers, lakes, billabongs, lagoons, wetlands, estuaries, rainpools, aquifers, springs and others.

The wetlands and lagoons of Cape York Peninsula are extensive and are relatively undisturbed. Wetlands on the western Peninsula occur in major watercourses, as lagoons, outflow channels and in numerous oval depressions on the floodplains of the central and south western drainage basins. The number and size of lagoons and wetlands tend to increase towards the coast. Floodplain lagoons are seasonally inundated with many surviving the dry season as permanent waterbodies. These waterbodies can be quite distant from the main river channels.

In the watercourses, there is a large variation in hydrology and physio-chemical conditions. This variation affects the predictability, frequency of occurrence, length and size of flows as well as the current velocity, temperature, dissolved oxygen, salinity, organic matter and other features.

Gauging station records were used extensively in this work. These are located on key rivers and creeks and collect data for water resource management including streamflow estimation and river hydraulics. Automatic recorders have been installed at the gauging stations and these are essential because of the large spatial and temporal variation in rainfall and runoff, and the fast flowing nature of many of the tropical streams. Annual flow volumes, annual runoff depths, and no flow periods are presented for each gauging station.

River flow is usually ephemeral (intermittent) with only the Jardine and the Wenlock on the west coast, the Pa~coeRiver and several smaller east coast waterways and the Hann River being perennial. These ephemeral rivers can cease to flow for several months during the winter and spring and, depending on the particular season, into the early summer. Rivers in the Peninsula can be subject to extreme, cyclonically influenced floods and monsoonal rains in the summer.

Flow rates can vary from no flow conditions to floods of a large magnitude. In much of the Peninsula, particularly the dryland areas, floods are a major factor driving the riverine ecosystem, with the duration, timing, magnitude and rates of rise and fall important in determining the ecological significance of each flood event.

The relationship between groundwater and surface water is not well understood. However, groundwater is critical for maintaining dry season flows (baseflows). Groundwater is also critical for maintaining the hyporheic (subsurface river channel flow) flow which is important for maintaining the riparian zones, billabongs and ox bow lakes during the extended dry periods.

Water quality data for the Peninsula are sparse with many of the major watercourses having had, at best, extremely limited sampling undertaken. Most of the available data relate to the chemical and physical quality parameters with even less data available on the biological (i.e. levels of biotic contaminants) quality.

Chemical data are presented only for one high and one low flow event at each gauging station and this may limit its representativeness. This procedure was necessarily adopted as limited data were available, and comparison of data from differing flow conditions requires a detailed analysis beyond the resources of this project.

Given these constraints on data availability, water quality in the Peninsula is generally very high with isolated locations such as the West Caludie River (Herbert et al., 1995), containing more marginal quality water. Significant issues and potential issues relating to water quality in the study area include: cyanide leach pads draining into the Coen and other rivers; tailings dam failures; potential for mine dewatering; downstream effects of the Mareeba sewerage outfall; septic system leakage; defecation by stock, feral animals and people close to (and in) the watercourses; urban runoffl, drainage fiom rubbish tips; industrial waste; fertiliser usage; mitigation works reducing flow volumes; increasing levels of turbidity fiom accelerated erosion levels, including sediment fiom road works and other earthmoving activities; increasing turbidity levels and supply of detergents fiom people and vehicle washing into watercourses.

Environmental flows relate to the nature of water required in a waterway to maintain the normal hnctioning of natural ecosystems. Defining environmental flow requirements for the Peninsula is difficult because of the great variability of waterbody types, the wide diversity of life forms depending on the waterways for part or all of their life cycle and the common unpredictability of hydrological flows.

The time available for this work, the technology shortfalls and the complexity of the task has precluded quantitative assessment of environmental flow requirements for the Peninsula's waterways. It has been possible only to partly identify the scope of the task, look at some of the key components of the system and report on the present level of understanding in this area.

Some specific field work was conducted on the Peninsula ecosystems and was limited to determining the variability of habitat types present and gaining an appreciation of local environmental issues. Habitats along the Pascoe and Wenlock Rivers were surveyed. These rivers were considered to be reasonably representative of each of the two drainage divisions in the Peninsula and could, between them, give a preliminary indication of habitat diversity.

The survey conducted was a preliminary qualitative analyses of the habitat structure characteristics of some of the key sites along these rivers. Data were collected on key features of the major habitats such as pools, riffles, runlglides and rapids/falls (including location, size, depth, channel form, aquatic plants, and fish passage disturbance). Additional information was obtained on the river land formation type, riparian zones (height, species composition, understorey and shading), channel banks (nature, size and terracing), substrate (sediment composition, algal growth and abundance of large woody debris), floodplain features (morphology, size, topography and vegetation) and incidence of disturbance (by stock, feral animals, exotic vegetation, pollution and human activity).

In the Peninsula, at present, surface water supplies are extensive and demand for human activities is reasonably low. Limited use of surface water resources occurs throughout the Peninsula for mining, agricultural, town and private domestic supplies, stock watering, construction, road maintenance and aquaculture. The available supplies are not used extensively, principally because of the small population, lack of assurity of supply in most locations between September and December, and lack of large scale industrial, mining and irrigation development.

Groundwater contributions to streamflow and wetlands is important in some areas. These areas may be of cultural significance and of interest for tourism. Management of wetlands may be a concern, particularly if there is a significant reduction in size and quality of these natural discharge sites.

Groundwater is generally a more reliable year-round source of water for most of the Peninsula. As a resource it is also generally more widely available than surface water supplies. Within the Cape York Peninsula study area, groundwater resources provide 90% of the water supplies. All of the major communities, except Bamaga and Wujal Wujal which depend solely on surface water supplies, rely on groundwater for at least part of their domestic water supplies.

Increases in size and development of sewerage plants are likely to proceed at Cooktown, Weipa, Schreger Air Force Base and possibly at Hopevale. Ayton, Bloomfield, Rossville, Laura and Wujal Wujal have future requirements for a reticulated water supply and there is current planning for an extension of the township area at Portland Roads. The only major dam is on the Annan River west of Cooktown, with other minor storages occurring in the Cooktown, Hopevale and Lakeland Downs areas. Some isolated storages exist in other areas.

Tourist numbers appear to be increasing and this may require small infrastructure developments such as toilets and wash basins and associated water supplies at river crossings. Additional water demands are likely to occur from potential larger scale tourist developments. There is potential for hrther mineral exploration and possibly mine development in this region. Demand for irrigation water is occurring in the Endeavour Valley, Lakeland Downs, Bamaga and Sudley Park near Weipa. These factors have the potential to create significant firther demands on the water resources of the area.

The increasing demands on surface water resources and the waterways themselves require overall management strategies with specific objectives. These strategies need to address a balance between the competing aspects and diversity of needs for the water resources. Specific issues that need to be considered include; salinity, sedimentation, nutrient enrichment and eutrophication, downstream effects of agricultural practices, chemical and possible bacterial contamination, feral animals, exotic species, effects of fire, alteration to flow regimes, intensive rural industries and instream water needs.

Much of the Peninsula is comparatively pristine, resulting from a relatively small population, comparatively little industry and low levels of infrastructure. These factors have allowed an opportunity to preserve an ecologically important region in a relatively natural state.

Maintenance of this condition will require a coordinated approach to planning and management of the surface water resources to achieve an overall balanced use of resources. This will require consultation between landholders, community groups and governmental agencies and a thorough knowledge of the base issues. Any overall objectives and strategies may need to be modified to incorporate local knowledge and experience. 1.0 INTRODUCTION

The study area includes the entire mainland Cape York Peninsula and adjacent coastal islands and is bounded to the south by approximately the 16"s latitude and the southern boundary of the Cook Shire (Figure 1.1). The region covers some 132 500 km2 of northern tropical Queensland and includes 16 river basins and sections of 2 further basins.

This report presents an overview of the nature of the surface water resources including location, size, reliability and existing and projected demands, along with comment on environmental and social issues. It also comments on related issues that are likely to effect the quality, availability and ecological diversity of these resources. Information in this report is current to July 1994.

This work provides an initial description of the current situation and specific issues that will confront the region's planners in the long term management of the Peninsula's sudace water and related resources. General summaries are based on specific data and incorporate local knowledge and experience of the processes operating in the Peninsula. Current problems have been identified and potential management issues discussed. It is beyond the scope of this report to be able to identie all of the issues or present a management plan for this resource.

The region presently is experiencing some population growth principally due at present to the tourist industry which has capitalised on the climate and natural attractions of the region (tropical rainforests, Great Barrier Reef, etc.). The other major industries of the region are mining and the pastoral industry. A small but expanding irrigation industry has also been established. Additionally, there is considerable potential for further mineral exploration and possibly mine development in this region, which has the potential to create significant further demands on the water resources of the area.

Data on the 17 mainland River Basins that occur in the Peninsula study area appear in Appendix 1. Basins are named after the major river in each area and the river basin locations appear in Figure 1.2. Lack of active management through the issuing of water licenses in the area by the Department of Primary Industries @PI) makes it difficult to determine actual demand though some qualitative estimates are provided. CAPE YORK PENINSULA . LAND USE STRATEGY

THURSDAY I. CYPLUS is a joint initiative between the Queensland and Commonwealth Governments.

LOCALITY PLAN

The information shown bn this map has been supplied by the Department of Primary Industries. / Initial enquiries regarding the information should be directed to Water Resources Division.

Topographic information shown on this map is current to 1989. COOKTOWN

!'%- 1- ;; \. 6 '-. 1 \,..-/ , NORMANTON i\> j I i\ LEGEND i I h 'i TOWNSVILLE I bA.d$ 0 CYPLUS Study Area i > '\Q -> "L, j MT ISA ,A i '\- ' "! 'Li i. P, I >$ \;-., ! "c i \, Cc'\ i \+. !.< !.< '. j <.I I ;'-, :'; /? . . . -. .- - , $/ 3, i / *,~RISBANE :u

/'"-S ------?= b ,,--. 1 E ./ S Transverse Mercator Projection Zone 54 : Australian Map Grid I 7 3om'm Prepared and produced by the Department of Primary Industries, June 1994.

,,,, , EDITION NO 1 FIGURE 1.1 .,,,,, 4e8&1day Wand '- DRAINAGE DIVISIONS KEY I North East Coast IX . Gulf RIVER BASINS CYPLUS is a joint initiative between the Queensland and Commonwealth Governments. 101 Jaw Jaw 102 Olive - Pascoe 103 Lockhart 104 Stewart RIVER BASINS 105 Normanby 106 Jeannie The information shown on this map has' been 107 Endeavour 108 Daintree supplied by the Department of Primary 'lndus@es. Initial enquiries regarding the information 91 9 Mitchell should be directed to Water Resources Diiion. 920 Coleman 921 Holroyd 922 Archer Topographic information shown on this map 923 Watson is current to 1989. 924 Embley 925 Wenlock 926 Ducie 927 Jardine 928 Torres Strait Islands LEGEND

Roads

Rivers

1:250 000 Geology $ Sheet Boundaries Drainage Division Boundary GULF CORAL -

---- River Basin Boundary SEA Drainage DMsion Number

901 Basin Number

CYPLUS Study Area

CARPENT

Transvers8 Mercator'~ojectionZane 54 : AusWian Map Grid

P- P- and produced by the Deparbnent of Primsvy Industries, June 1994.

wight 0 The State of Queensland, Department of Primaly Industries, 1994.

30 No, 1994 EDITION NO 1 FIGURE 1.2 mm The report has been written for a diverse audience including the Cape York Peninsula Land Use Strategy (CYPLUS) organisation, the residents of Cape York Peninsula, researchers, planners and others interested either through working in this region or in this particular field. This report was originally intended as a more technical dissertation but initiaI feedback from the CYPLUS - Nature Working Group%dicated a more general document for wider distribution would be more appropriate.

This report has drawn heady on previous reports and data sources. A sigdicant source of material has been the CYPLUS - Natural Resource Analysis Program round of projects that have provided Geographic Information System (GIs) coverages, text and additional expertise to draw on for natural resource information. These features have included data on regolith, soils, groundwater, vegetation and land usage.

A key feature of the analysis was the use of hydrographic gauging stations records. These stations are located on key rivers and creeks and collect data for water resource management including streamflow estimation and river hydraulics. Most of these stations are equipped with recording equipment to continuously monitor water quality over a range of flow conditions ranging fiom low flows to flood flows. The use of automatic recorders is essential because of the large spatial and temporal variation in rainfall and runoff and the fast flowing nature of many tropical coastal streams. These stations are also used as reference points for continuity in water sample collection for a range of chemical parameters and physical attribute measurements such as flow velocity and turbidity etc.

The stream£low and water quality data are stored on the DPI's HYDSYS database. Annual flow volumes, annual runoff depths and no flow periods were calculated for each hydrographic station using this system Chemical data are presented for one high flow and one low flow event at each hydrographic station and this may limit its representativeness. This procedure was necessarily adopted as limited data were available and comparison of data from differing flow conditions requires a detailed analysis beyond the resources of this project.

Throughout Queensland the DPI operates a network of some 440 hydrographic gauging stations. In the study area there are 17 gauging stations in operation, with 31 stations having been closed down as a result of a review of the gauging station network in 1988. Several of the basins in the study area have no gauging station records.

Environmental flow information was determined from an extensive literature review, personal cornrnunications with local residents and other researchers and from the collection of original habitat data. This data helped establish the issues relating to the water and other requirements of . certain aquatic habitats at diierent locations and was used in establishing a broad idea of environmental flow requirements. This field survey was limited to two rivers with the Wenlock

'2 am org,misation of Peninsula residents, researchers and other stakeholders convened to oversee and review this and other related projects md act as ,m avenue for public participation in the CYPLUS process River being used as more representative of the western rivers (Drainage Division IX) and the Pascoe River being more representative of the eastern rivers (Drainage Division I), see Figure 1.2.

The growing awareness of water issues within the community has focused on the need for increased community consultation as an integral part of the planning process. Insight into the current and potential surface water issues were gained through one on one interviews with local residents and others with expertise on the area (an informal public consultation program) and through a focus group session3 involving nine researchers who were familiar with the region. Both techniques were found to be very successfhl in gaining cost effective and quality general knowledge on current issues in the region.

Data storage, manipulation and presentation has been essentially computer driven. Key components of the system included a principal data storage system, the DPI surface water database, accessed usiig HYDSYS (produced by HYDSYS Pty Ltd) and a Geographic Mormation System (GIs) - ARCLNFO (produced by Environmental Systems Research Inc). The maps contained within this report also occur in digital form in the CYPLUS GIs database, located at the Department of Lands, Cairns.

focus groups usually consist of eight to twelve people with expertise on a topic discussing certain issues in a non-confrontational environment. The technique is effective for establishing conducive group dynamics for in-depth analysis and discussion 3.0 PREVIOUS STUDIES

Comparatively Little research has been done on the surface water resources of Cape York Peninsula compared to other Queensland areas. Most work has appeared more as preliminary assessments than as detailed evaluations. Detailed information is available in few areas, although ongoing data collection and research have been conducted at Weipa and to an extent Cooktown. The following is a summary of some of the work of general significance on the Peninsula's surface water resources.

An assessment of the surface water resources of eastern Cape York Peninsula was undertaken by Loy (1991). The report documents some of the basin characteristics, stream gauging station details, discharges and water qualities. It also briefly describes existing infrastructure and water resource development, and potential future development and storage sites. Potential physically divertible resources are discussed but there is no consideration of instream uses or environmental flows.

The Snowy Mountains Hydro-Electric Authority (1965, 1966, 1969) undertook preliminary investigations on locations for stream gauging networks in the Coleman-Holroyd, Archer-Watson, lower Gilbert and Mitchell River Basins. These reports documented basin characteristics, physical river and tributary descriptions and an assessment of the merits and potential problems of options for hydrographic station locations.

A report on the wilderness quality of Cape York Peninsula (Lesslie et aL, 1992) discussed some of the intrinsic values and pristine nature of some of the Peninsula's surface water features within a broad environmental value context. In particular the wilderness value of some key wetland areas was discussed.

A comprehensive report by Herbert et al. (1995), on the fish fauna of the CYPLUS study area presented general information on basin characteristics and surface water features and occurrences. Specific information was provided on water quality aspects (such as turbidity, temperature, conductivity, etc) at many locations and extensive field work was undertaken and many field observations were incorporated. Many environmental issues affecting the fish fauna and protection of the watercourses and wetlands of the Peninsula were raised.

A review of the wetlands of international significance in the Peninsula was undertaken by Usback and James (1992). Included was an evaluation of the significance of many of the major wetland areas including a brief description of their physical, hydrological and other features as well as their current usage, land tenure, level of disturbance and potential threats.

A desktop study undertaken by the Queensland Water Resources Commission (1985) provided a rigorous assessment of the mean annual discharges and the physicaJly divertible surface water resources of the Peninsula. This study was presented as an engineering focused evaluation of these components of the river hydrology.

An overview study of the groundwater resources of Cape York Peninsula was completed for CYPLUS (Horn et al., 1995). This report looked at the influence of geology, climate, topography and other factors in determining the quantity, quality and location of groundwater. The study briefly discussed the surface water resources of the area and the interaction of groundwater/surface water processes such as recharge mechanisms and discharge features such as maintenance of perennial streams, wetlands and springs. The study area lies exclusively within the tropical region with the climate varying from humid tropical (i.e. hot and wet) dong the eastern coastal strip to semi arid in the central western Peninsula area. About 80% of the annual average rain falls during the four months between December and March, with April to October being a significantly drier period.

The main rainfall iduences are from the north-west monsoons and tropical cyclones, features that are associated with high temperature and humidity which are common in the summer months. Thunderstorm activity is more prevalent in the early summer and cyclone activity is highest in the late summer. Monsoon rains often 'burst' over a few days resulting in intense falls. Runoff from the catchments is high during this period and flooding can commonly occur within the lower portions of the river basins.

Rainfall is more evenly distributed throughout the year along the eastern coastal areas due to the influence of the moist south-easterly trade winds. These winds cause slightly higher rainfall along the ranges in the eastern coastal belt. West of the coastal range, there is a sharp decrease in rainfall and an increase in rainfall seasonality. For particular storm events, the local rainfall distribution of these inland areas is patchy, with some pastoral stations recording high registrations during storm events while adjacent properties receive little or no rainfall. The variable, sporadic and defined geographic extent of tropical cyclones and rain depressions can also result in large variations in rainfall in any season.

Frequent and lengthy droughts occur and result in sparse and unreliable surface water resources (a feature of significant concern to local pastoralists), though in general the annual 'wets7 themselves are usually reliable being more of a question of when and how much. In the last few years the central area of the Peninsula has experienced intense, short wet seasons (monsoonal rains), which have been very large with an abrupt fmish.

Throughout the Peninsula, mean daily temperatures are moderate in winter and high in summer. The area has high evaporation rates aided by persistent winds in most areas. Pan evaporation figures indicate the greatest average evaporation rates are during October, November and December and are the lowest generally in February, May, June and July.

Figure 4.1 (from Horn et al., 1995) displays general climatic data for the study area, with a composite display of rainfall, and an indication of yearly rainfall, temperature and pan evaporation variations and averages. Figure 4.2 (from Horn et al., 1995) shows a five year moving average of rainfall data for Coen, Cooktown and Weipa and was derived from composite data from the stations in these regions. Composite data were used as no specific rainfall station provided a continuous record over a sufficiently long period for this analysis. It should be noted that this composite approach has given a slightly lower rainfall figure for Cooktown than is illustrated in Figure 4.1. Table 4.1' shows the area and percentages of the region that experiences certain rainfall levels (Appendix 1 gives a breakdown by river basin) and Table 4.2 indicates the location of pluviograph (automatic rainfall recording) stations.

4 Table 4.1 includes a slightly extended study area used in the CYPLUS Groundwater Report see Horn et al. (1995).

WElPA Five Year Average Rainfall - - - COEN ----- 'COOKTOWN

2000 -- E s 1500 -- m

500 --

0"""""""""""""""""""" &A&A&A&~&&&&NA&A&A&& mmOO--NcuOc9-t-tm~wwt.r.alm -*22222Z2222Z2?22Z222 Year

Figure 4.2 Five Year Average Rainfall

Table 4.1 Average Rainfall Category

AVERAGE RAINFALL AREA (km2) PERCENTAGE OF CATEGORY (mm) TOTAL STUDY AREA 4000 - 3200 3 4.1 3200 - 2800 57 4.1 2800 - 2400 172 0.1 2400 - 2100 414 0.3 2100 - 1900 140 0.1 1900 - 1700 3007 2.1 1700 - 1500 13992 9.8 1500 - 1300 20955 14.7 1300 - 1100 19449 13.7 1100 - 900 44375 31.1 900 - 400 37932 26.6 < 400 2080 1.5 TOTAL 142576 100 Table 4.2 Pluviograph Station Locations

STATION NO. STATION NAME OPERATOR LATITUDE LONGITUDE OPERATING PERIOD 027006 Coen Aerodrome Bureau of Meteorology 13'45' 143'06' 1950 - present 027029 Weipa No. 1 Comlco 1 2"4 1' 141'54' Jan 1958 - Aug 1967 027042 Weipa (Composite) Comalco 1 2'37' 141'52' Aug 1967 - present 028000 Laura Bureau of Meteorology 15'33' 144'26' 189ypsesent 031016 Cooktown P.O. Bureau of Meteorology 15'28' 145'15' ~0~7965- present 527000 Dulhunty DPI 1 1'50' 142'25' Nov 197 1 - present 527001 Embley River DPI 12'49' 142'1 1' July 1971 - 1986 527004 Leo Mine DPI 13'43' 143'19' 1977 - present 527005 Wolverton DPI 13'19' 142'53' 1978 - I083 527006 Archer River DPI 13'25' 142'55' 1978 - 1986 527007 Watson River DPI 13'07 ' 142'04' 1986 - present Key natural characteristics of the study area including physiographic expression, climate, soil, regolith, vegetation and groundwater are outlined in this chapter. Appendix 1 shows, percentages of, and total area for each river basin (or river basin component) within the study area, for rainfaU, regolith, soil, vegetation, hydrogeological units and recharge features. The hydrogeological unit component indicates the areas of particular groundwater aquifer types in each basin and the recharge area gives an initial indication of the area of potential groundwater vulnerability. A more detailed description of hydrogeological units aid recharge within the study area appears in Horn et al. 1995, similarly for regolith (Payne et al, 1995), soils (Biggs and Philip, 1995) and vegetation (Neldner and Clarkson, 1995).

5.1 Physiographic Features

The study area is of comparatively low relief, with broad plains comprisiing around 75% of the total area. These broad plains dope gently seaward, both to the east and west iiom a ridge of low mountains and hills formed by the Lower Palaeozoic Coen and Yambo Inliers. These Mers are composed mainly of low to high grade metamorphics and Permian intrusives. The ridge formed is generally located closer to the east than the west coast.. The eastern boundary of this central ridge fiom around Laura to the north can be steep, and in some areas forms escarpments. The highest sections of the central Peninsula ridge are around 800 m above sea level in the Coenkon Range areas and in the area south of Laura around Mt Lukin.

This divide extends' fiom the southern study area boundary northward along the section of the eastern coast immediately north of Cooktown and is expressed as a plateau in the south-east of the study area. This plateau and coastal section is composed of rocks of the Devonian to Permian Hodgkinson Province, which consist of deepwater siltstones, arenites, conglomerates and basalts. The Province has undergone low grade metamorphism and the beds are now tightly folded and are usually steeply dipping.

The Weipa Plateau, Holroyd, Clara - Mitchell and Karumba Plains (a map of the physiographic units occur in Figure 5.1 and a description of the units in Table 5.1) are underlain by rocks of the Jurassic/Cretaceous Carpentaria and Laura Basins. These basins are composed principally of two predominantly quartz sandstone formations overlain by an extensive thick argillaceous unit.

The Tertiary Karumba Basin overlies most of the Carpentaria Basin in the south-western and central western study area (in the Weipa Plateau, Merluna, Holroyd, Clara - Mitchell and Karumba Plains areas) and is composed principally of quartz arenites and siltstones.

Quaternary and ongoing erosional and depositional processes have extensively modied the surface geology of the study area. These processes have formed the depositional plains that are currently active along much of the western side of the Peninsula and have initiated scarp retreat processes on the eastern side. Floodplain and alluvial deposits occur over much of the Peninsula. CAPE YORK PENINSULA LAND USE STRATEGY

CYPLUS is a joint initiative between the Queensland and Common- Governments. PHYSIOGRAPHIC UNITS (dassiition from Jennings and Mabbut, 1977)

The information shown on ihis map has'been supplied by the Deparhnent of Primary Industries. Initial enquiries regarding the information should be directed to Water Resources Division.

Topograph'c information shown on this map is cunent to 1989. CORAL LEGEWD

Roads SEA Rivers 1:250 000 Geology + Sheet Boundaries

GULF

Physiographic Unit Boundary

CYPLUS Study Area

CARPENTARI A I

KILOMETRES 0 100 ZOO 250

I , I I I I I I I I I I 1 Ttartsv~~58Mercator Rejection Zone 54 : MiMap Grid

Prepared and produced by the Deparhnent of Primary Industries, June 1994.

(18 Mar 95 EDITION NO 1 FIGURE 5.1 ,,,,, Additionally several barge dunefields occur along the eastern Peninsula seaboard, the most significant being the Olive River, Shelburne Bay and Cape Flattery Dunefields. Beach ridge dunefields also occur near Cape York.

Table 5.1 Description of Physiographic Units (Modified from Jennings and Mabbutt, 1986)

PENINSULA UPLANDS PROVINCE Torres 'High' Isl'mds Islands and low coastal tableland of volcanic rocks and granite, with fringing reefs. Jardine Upl'mds Locally dissected rolling sandstone upland with transgressive coastal dunes along an Eastern Iateritic cliffed margin. Wenlock Upl'mds Complex of tablelands and low plateaux with North-South lowlands, prominent sc'up. and outlying coastal hills on the Eastern side. Coleman Plateau Rolling s'mdy granitic plateau with low ridges of metamorphic rocks, prominent Easterly scarp. Laura Plain Soft-rock lowlands, alluvial plains of centripetal drainage, and littoral plain. CooktownRanges Deeply dissected sandstone plateaux, with mountain ranges of granite and metamorphic rocks to the East, small 'high' islands. P,almerville Hills Granite hills 'and plateaux and sandstone mesas with intervening plains, steeper fall on the Easterly side. Garnet Uplands Hilly uplands, with dissected greywackes and volcanics in the North and undulating country on granite 'and metamorphic rocks in the South. CARPENTARIA LOWLANDS PROVINCE Weipa Plateau Laterite-capped plateau on clayey sand and sandstone. Merluna Plain Undulating clay plains with lateritic rises. Holroyd Plains Slightly dissected sandy plains. partly lateritic. Karumba Plains Littoral plain. Clara-Mitchel.1 Sloping s'mdy plains with minor clay plains along distributary drainage. Plains Bulirnba Plateau Dissected low sandstone plateau.

A feature of the study area that has been extensively modied by surface water processes is the regolith. The regolith can be considered in a general sense as that material occurring between the soil and solid rock material and includes loose unconsolidated cover of alluvium, colluvium, aeolian deposits and rock fragments etc. The significance of this modification process is illustrated, using the data on area of regolith types and their descriptions (in Tables 5.2 & 5.3 ), to indicate that regolith deposits directly formed by surface water processes (alluvial sediments, channel deposits and overbank deposits) account for almost 40% of the Peninsula study area. Regolith types in each river basin appear in Appendix 1.

The geology of the study area is detailed in a number of associated CYPLUS reports, Bedrock Geology (Bain, 1995), Airborne Geophysics (Hone and Almond, 1995), Coastal Environment Geoscience (Burne, 1995), Mineral Resource Inventory (Denaro, 1995), Regolith (Pain et al., 1995) and Groundwater (Horn et al., 1995). Table 5.2 Regolith Type

REGOLITH TYPE AREA (km2) PERCENTAGE OF TOTAL STUDY AREA alluvial sediments* 30605 23.2 channel deposits* 19570 14.8 overbank deposits* 1591 1.2 sheet flow deposits* 5 1 4.1 colluvial sediments* 218 0.2 estuarine sediments* 391 1 3.0 lacustrine sediments* 3 13 0.2 fanglomerate* 1062 0.8 very highly weathered saprolite 2582 2.0 highly weathered saprolite 791 1 6.0 moderately weathered saprolite 24978 19.0 slightly weathered saprolite 10773 8.2 saprolite 62

REGOLITH TERM DEFINITION Very highly weathered Original source material thoroughly decomposed, composed I I completely of earth materials Highly weathered More than 50% earth material, numerous micro-fractures Moderately weathered Up to 50% earth material microfractures throughout Slightly weathered Traces of alteration, slight decay may be present Saprolite Weathering material that has been formed strictly in situ Completely weathered in Composed completely of earth material and contains no situ rock structures of the original rock Soil on bedrock Soil material, commonly less than lm formed directly on I underlying bedrock Alluvial sediments Material deposited by flowing water confined to a channel or valley floor Channel deposits Commonly coarser alluvium deposited in an alluvial channel Overbank deposits Alluvium deposited outside an alluvial channel e.g. levees Sheet flow deposits Colluvium deposited by networked rills or very shallow water flow Colluvial sediments Down slope sediments deposited by gravity Estuarine sediments Sediments deposited in an estuary or lagoon, from transport by tidal currents Lacustrine sediments Sediments deposited in a closed depression of land Beach sediments Sediments deposited by waves or tides on sea or lake shore Coastal sediments Sediments deposited in the coastal zone by coastal processes Aeolian sand Wind blown sediment of sand size Residual sand Sand size material remnant after the removal of finer material Residual clay Clay remnant after weathering of original rock Fanglomerate Colluvium deposited on a colluvial fan Ash Material deposited on land surface after volcanic ejection Scree Loose rock fragments deposited after falling or rolling from I precipitous slopes Summarised from Pain et al, 1991 5.2 Soils

Soil types in the study area are diverse, generally widespread, related to the major physiographic units and usually reflect the underlying geology. The area of soil types for the region is shown in Table 5.4. Soil characteristics are often dependent on surface water processes and drainage factors. Soil types for the study area appear in Table 5.4 and for each basin appear in Appendix 1 (note that the area reported in this table is that covered by Biggs and Philip (1995) and slightly merent to that covered in this report). A more detailed analysis of the study area's soil types appears in Biggs and Philip (1995) and the soil type descriptions (in Table 5.5) are surnmarised fiom Isbell (1993).

Table 5.4 Soil Type

SOIL TYPE AREA (krn2) PERCENTAGE OF TOTAL STUDY AREA Dermosols De 17979 13.6 Ferrosols Fe 424 0.3 Hydrosols Hg 23334 17.7 Kandosols Ka 60282 1 45.6 1 Podosols Po 4045 3.1 Sodosols So 3183 2.4 Vertosols Ve 3318 2.5 I Chromosols Co 1104 0.8 Water W 7 1 0.1 TOTAL 132107 100 Interpreted fiom Biggs and Philip, 1995 CYPLUS GIs data 1 X

Table 5.5 Soil Ty~eDescriptions

SOIL TYPE SOIL TYPE DESCRIPTION Dermosols Soils with structured B horizons and lacking a strong texture contrast between the A and B horizons. Some of these soils have been known as xanthozems and prairie soils while others have been called red and yellow podzolic soils and chocolate soils. Ferrosols Soils with structured B horizons which are high in f?ee iron oxide and lack a strong textural contrast between A and B horizons. These soils are invariably formed either directly or indirectly from basic igneous rocks (e-g. basalts). These soils have been known as krasnozems and euchozems and some have been called reddish chocolate soils. Hydrosols Soils other than organosols (see Isbell, 1993), podsols and vertosols in which the greater part of the profile is saturated for at least several months in most years. These wet soils have variously been called hurnic gleys and gleyed podzolic soils, they include some of the so-called grey earths, and also solonchaks and sometimes alluvial soils. Kandosols Soils which lack strong texture contrast, have massive or only weakly structured B horizons, and are not calcareous throughout. These are soils previously known as red, yellow and grey earths, calcareous red earths, and some red and brown hard pan soils. Podosols Soils with B horizons dominated by the accumulation of compounds of organic matter, aluminium and/or iron. These soils have been widely known as podzols. Sodosoks Soils with a strong texture contrast between A horizons and sodic B horizons which are not strongly acid. Included are most of the soils that have been called solodic soils and solodized-solonetz as well as some soloths and most sodic red-brown earths and desert loarns. Tenosols Soils with generally only weak pedological organisation apart from the A horizon. This group encompasses a rather diverse range of soils and, under particular criteria, can include soils with high amounts of ironstone or bauxitic nodules or concentrations. Vertosols Clay soils with swell-shrink properties that exhibit strong cracking when dry and at depth have slickensides and/or lenticular structural aggregates. These soils are known as black earths and grey, brown and red clays (cracking clays). Chromosols Soils with strong texture contrast between A horizons and B horizons which are not strongly acid and are non-sodic. These soils have been known as red- brown earths, non-calcic brown soils, podzolic soils and many duplex soils fall into this class. 5.3 Vegetation

The study area has a diverse range of vegetation types resulting fiom the large range of soils, rainfall patterns and landforms. The natural vegetation is considered fiagile and vulnerable to rapid change due to human influences. These influences include the introduction of exotic species, overgrazing, changed fire regimes, intensive development on unstable landforms, and diversion of, or interference with, existing hydrological systems (Connel Wagner, 1989).

Along the east coast, particularly in the Iron Range area, dense tropical rainforests (vine forests) occur. The higher altitude sections of the study area, generally on the margins of the Laura Basin and through the Coen Mier (Central Peninsula Ridge and associated uplands), support iron bark and bloodwood.

The far north-western Peninsula contains extensive fieshwater wetlands with associate aquatic plant species and in general the far northern areas contain tropical eucalypt and some rainforests. Vine scrubs (jungle) also tend to occur in the northern Peninsula, and are usually contined to areas of better quality soil.

The majority of the central Peninsula area experiences highly seasonal rainfall and is covered with eucalypt woodlands, open savanna woodlands, grasslands and melaleuca woodlands. The northern inland areas have extensive areas of Recent and Quaternary sand cover, and experience a greater monsoonal influence. In this area, open heathlands dominate. The Laura Basin in the south-east of the study area, is mostly covered by open eucalypt and stringybark woodlands.

A comprehensive report on the vegetation including maps for the study area appears in Neldner and Clarkson (1995) and a comprehensive discussion of the plant communities is provided in Pedley and Isbell (1 970).

Table 5.6 outlines the area and percentage of the major vegetation communities in the study area. Vegetation communities for each basin are described in Appendix 1 (note the area reported in Table 5.6 is that covered by Neldner and Clarkson (1995) and is slightly dierent to that covered in this report). Table 5.6 Vegetation Communities Vegetation Class km2 yo I Rainforest Associations Wet Eucalypt and Wattle Associations Dry Eucalypt Associations Drier Ti Tree Associations Crasslands Heath Communities Wetter Ti Tree Associations Saline Wetlands Bare Areas Total 131 989 100 Interpreted fiom Nelder and Clarkson (1995) CYPLUS GIs data 5.4 Groundwater

With the ~nonsoonalweather patterns having a particularly pronounced effect on surface water resources, groundwater is generally a more reliable year round source of water for most of the Peninsula. As a resource it is also generally more widely available than surface water supplies. Within the Cape York Peninsula study area, groundwater resources provide 90% of the water supplies.

The Karumba Basin (see Horn et al., 1995) is the major water resource of the study area providing water supplies to 60% of the study area's population. This basin provides domestic supplies for Weipa, three major Aboriginal communities and for the region's largest mining and industrial complex at Weipa as well as stockwater for over one third of the Peninsula.

Data on actual groundwater use in the study area are sparse, with only eight locations where bores are metered. Use by the smaller communities, most mines, tourist locations and pastoral holdings can only be estimated. The use of this resource is principally limited by availability and the economics of water reticulation. In general, the area currently has abundant quantities of groundwater. Although difficulties may be encountered in particular areas in obtaining supplies, overall reserves are large.

Quality of groundwater throughout the study area is usually very good, with only some isolated groundwater quality problems. Salinity levels are commonly very low.

Most of the larger rivers in the study area have sandy beds which can provide small water supplies though in a few localities there is some prospect of obtaining high yielding bores (McEniery, 1980). Good water supplies have been found in shallow alluvial sand and gravel deposits that probably represent old channels of the Mitchell River. Additionally there may be prospects for groundwater in the more extensive flood plain deposits of the eastern rivers.

The quantity of groundwater recharge is iduenced by climate, vegetative cover, extent of evapotranspiration, soil depth and composition and geology. In the more arid areas, which include much of the Peninsula, low recharge rates generally occur.

The relationship between groundwater and surface water and instrearn flows is not well understood. However groundwater is critical for maintaining dry season flows (baseflows) in many rivers. Groundwater is critical for maintaining the hyporheic (subsurface river channel flow) flow which is important for maintaining the riparian zones, biibongs and oxbow lakes during the extended dry periods.

Perennial springs (groundwater outflow areas) are important sources of baseflow for several rivers including the Jardine, the upper reaches of the Wenlock, the Pascoe downstream from Hann Creek as well as providing supplies for the Hann River, which is the only perennial river in the Laura Basin. Additionally spring fed waterholes may be important as refuges for the biota of streams and as particular environments for their own special biota. 5.5 Fire

Fie has a significant initial influence on the Peninsula's surface water by altering runoff characteristics and may ultimately have an effect on streamcourse, wetland hydrology: flow rates, aquatic ecosystems and other aspects of this resource. Differing land management practices since the last century have significantly changed the fire management regime. The following appraisal draws on comments from Bryan Cifuentes (Queensland Fire Service) and Frank Isenberg (Weipa).

Fires (especially wild fire, with an actual flame height of 1- 1.5m high at the front of the fire) can have a significant effect on the catchment areas by removing ground cover and reducing soil moisture content. These features can influence soil detachment rates and combined with the increased runoff rates (which are exacerbated by the intense monsoonal rainfalls of the Peninsula) increase erosion. T~JScan significantly increase the sediment yield into watercourses and may effect channel alignment and stability and may also effect billabong morphology.

Wild fires if sufficiently intense can destroy watercourse riparian zones. This has a direct effect on stream bank stability and allows the opportunity for different (and/or exotic?) species to establish and may cause crowding out of the river banks, however hot fires have controlled rubber vine (an exotic pest at Lakefield). Such crowding out may ultimately change the food supplies for sections of the waterway. It is unknown what effects this may have on the aquatic species. Additionally, conflicting views were presented by local residents on the significance of ash and soot fallout on the aquatic ecosystems.

Wetlands in the study area have been significantly affected by fire, with fires having been observed burning well into such areas (Cifuentes pers. cornrn). As a result some grasses, especially reed species such as Bulgru Swamp grasses may not burn completely and may desiccate and laydown upon themselves. This laydown process can allow fire to establish better the next time it comes through the area. Additionally lower watertables in the dry seasons have allowed one peat swamp in the Iron Range area to burn for several months and one peat fire to have occurred underground at Lakefield. The overall effects of these fires on the hydrology and ecology of the areas is unknown.

Fire management strategies have changed significantly. Aborigines used fire for hunting and opening travel routes, as well as for environmental purposes. They tended to use a mosaic bunzing approach (or a series of "mongrel" fires after the first significant wet) which controls the fuel source available for wild fires and helps control subsequent fires.

Such practices are not as widely followed today and the country is now more densely covered than earlier this century and this may be a reflection on present fire management. With this "closing up" a species change is occurring at Iron Range. More broadleaf species are establishing and these can crowd out shade grasses with a resulting change in fuel ignition temperatures causing a change of fire re,ghes.

The potential impact of fire on the surface water resources and aquatic habitats maybe significant and may require a comprehensive and ongoing management strategy (it is worth noting air ignition by aeroplane was used to burn large tracts of land up to 1988189). At present there is a polarisation of management strategies with many freehold properties burning and some burning in national parks as opposed to significant areas that are not actively burnt as a land management process. An integrated strategy that transcends administrative boundaries is required to protect the natural resources. 6.0 RIVERINE GEOMORPHOLOGY

The study area contains a number of large of rivers of seasonally variable flow. Most rivers flow east or west, with only the Kennedy and Normanby Rivers flowing northwards. The Peninsula rivers commonly have extensive floodplains in their lower reaches and in the coastal belt, and meander across broad mudflats. In these areas, the rivers are a dominant landscape feature, though their alluvial deposits are generally relatively thin.

River landform types include upland streams, valley streams, high banked/terraced floodplain rivers, low banked wide floodplain rivers and estuaries.

River flow is usually ephemeral (intermittent) with only the Jardine and the Wenlock on the west coast and the Pascoe River and several smaller east coast waterways and the Hann River being perennial. The ephemeral rivers can cease to flow for several months during the winter and spring and, depending on the particular season, into the early summer. Rivers in the Peninsula can be subject to extreme, cyclonically influenced floods and rain depressions in the summer.

Flooding in the Peninsula is common though distinctly seasonal, with floods restricted to the summer 'wet season' period caused by general monsoonal rains as well as tropical cyclones. Floods resulting from cyclonic activity can occur as large long duration events that thoroughly clean out and alter the river courses. These large events can cut islands in the watercourse and can fill up waterholes, while large log jams can help create waterholes. General monsoonal floods do not usually alter the river courses abruptly.

Generally the first floods of the season occur in late spring or early summer following some time after the early season rains. These first floods cany a large amount of debris down the rivers and also flush out the billabongs and lagoons and to a varying extent the wetlands. Floods in the study area commonly exhibit an extended flow recession. The major rivers reach a peak and then drop to a lower steady state which usually lasts for several months (the Peninsula Development Road has been cut by the Archer River for up to two months continuously). This steady state level is altered a number of times through the wet season by additional peaks. During this period wetlands can be flooded for months and lagoons, depending on the size of the flows, can be filled and/or flushed out.

The beds and banks of the watercourses observed appear to be generally stable. The banks exhibit some localised erosion, slumping and sediment deposition and damage to banks by pigs is common. However this is generally not significantly destabilising the river banks.

The channel morphology of the rivers in their middle and lower sections appears stable with some aggradation of sediment in the channel in the middle and lower sections of the Wenlock River. Various substrate conditions are also generally stable with; outcrop being stable, cobbles being mobile in high flow events and providing a stable bed during low and moderate flows, coarse sand which is very common and generally mobile in moderate or stronger flows. Areas of mobile sand commonly extend for considerable distances resulting in a relatively uniform substrate such as the runs in the mid sections of the Wenlock River. 6.1 East Coat Stream

The eat coast rivers and stream.. can be classified as perennial ramforest streams; Quaternary sand dune country streams; or short, intermittent coastal plain country streams (Herbert et al., 1995). All are relatively short with small catchments (except the Pascoe River) because of the proximity of mountain range source areas to the coast. The east coast rivers contain few permanent lagoons except for the East and West Norrnanby Rivers which have similar features to the west coast rivers.

Intermittent rivers that drain relatively flat, less forested country include the Stewart, Howick, Jeannie and Starcke kvers. These are short rivers with poorly developed lagoon systems and low average annual discharge with periods of no flow (Herbert et al., 1995). It is considered that, based on fish faunal assemblages, the Stewart and probably the Annan were originally west flowing rivers, but through Quaternary uplift now flow towards the east coast (Herbert et aL, 1995).

The Olive River and sections of the north arm of the Endeavour River are typical of streams draining Quaternary sand dune country.

6.2 West Coast Streams

Excluding the Jardine, all of the rivers of the west coast are broadly similar. All are intermittent except for the Wenlock and the Jardine and generally flow through three broad physiographic area types. These rivers rise on the plateau country on and west of the Great Dividing Range, flow through large erosional plain areas and continue through large outwash plains. Several of these rivers continue through a narrow strip of sand ridges, dunes and saline mud flats.

The Jardine river is significantly different from other west coast watercourses in that it drains extensive Quaternary sand deposits as well as an area of the Mesozoic Helby Beds and has a more reliable and perennial flow regime. The Jardine has the greatest baseflow of all Queensland rivers. Extensive wetlands occur along much of the length of this river and additionally the Jardine has aquatic vegetation on its river bed, a feature noted only in this river in the study area and is probably related to the high baseflow and less severe flooding and scouring effects (Herbert et al., 1995). Significantly, the Jardine is regarded as one of the least disturbed of Australia's major river systems (Lesslie et aL, 1992).

The drainage pattern in the Carpentaria (and Laura on the eastern Peninsula) lowlands is widely spaced and appears to be governed by soil type. Sandy soil areas have a denser drainage pattern and radiating distributaries often develop fiom the large alluvial fans that occur on the western Peninsula The black soil areas have a more widely spaced drainage system

The stream channels in the high plateau country form a dendritic pattern &airing many small catchments and generally do not experience overbank flow. These headwater reaches are commonly dry except for a brief period immediately following heavy rainfall activity, where small permanent waterholes occur, or where there are permanent spring flow contributions. The spring fed watercourses tend to become hyporheic (subsurface river channel flow) once it reaches this flatter country (Herbert et aL, 1995). In these headwater areas the greater proportion of rainfall is probably contributed as runoff to the streamcourses while in the lower areas there is a greater retention of water in lagoons and swamps, higher evaporation and possibly greater infiltration.

The central western Cape York Peninsula is dominated by the extensive alluvial plains, tidal flats and estuaries of the Archer, Holroyd and Edward Rivers (Lesslie et aL, 1992). The rivers flow through broad flat central erosion plains and commonly consist of multiple channels that occur as anabranches and breakaway channels leading to other streams. These provide little flood confinement.

Flooding in these areas has caused the development of levees or terraced banks on the main channels though these are more common on the more northerly west coast rivers. Hoods also form sand ridges and islands in the main stream channels as they lose energy and recede. A series of permanent lagoons and seasonal wetlands which are sometimes interconnected with widely spaced and irregular shallow depressions occur.

Floods are exacerbated by the high tides that occur in the Gulf of Carpentaria effectively holding the floodwaters on the very low relief coastal plains. Additionally these tides can inundate many of the coastal saltpans that occur on the western peninsula and create tidal effects up to an observed 80 krns inland along some rivers.

The drainage pattern in the outwash plans that occur downstream from these broad erosion plains (virtually to the coastal area) is more complex containing a greater interlinking of small watercourses.

Rock bars can inhibit the hyporheic flow and direct this subsurface water to rise to the surface and form, commonly, large billabongs. Some of these western rivers have reasonably long sections of exposed lateritised bedrock that can act as such rock bars.

In the more southern west coast rivers a complex interlaced drainage pattern occurs with the main channels repeatedly splitting to form smaller and smaller waterways as well as waterholes in old river channels. These areas contain many lagoons, wetlands and anabranches. These small channels are roughly parallel and have small water holding capacities and low grades and are subject to extensive overbank flooding. As a consequence of the extensive overbank flooding events, dficulties occur measuring stream discharges precisely. Hydrographic stations can only effectively be located upstream of these flood breakout areas. (Snowy Mountains Hydro-Electric Authority,. 1966)..

6.3 Wetlands

The wetlands and lagoons of Cape York Peninsula are extensive and are relatively undisturbed. Significant wetlands were catalogued by Usback and James (1992). This work described the major occurrences of wetlands in the study area on the plains and shores of the Gulf of Carpentaria, Endeavour Strait, Newcastle Bay and Princess Charlotte Bay. Other major occurrences of wetlands are on the Holroyd Plain, on the alluvials and floodplains of the river systems as well as springs and perched swamps on the sandstones in the Laura Basin. Eight wetland areas were identified as being of international significance (under the RAMSAR Convention, see Usback and James, 1'392) including the Archer River Aggregation, Bull Lake, Cape Flattery Dune Lakes, Jardine River Wetlands, Newcastle Bay Complex and the Northern Holroyd Plain Aggregation. Additionally, many less signifcant wetland areas occur within the study area. The major wetland complexes have relatively little disturbance in comparison to other Australian wetland areas, although cattle and wild pigs may cause locally severe degradation.

Wetlands on the western Peninsula occur in major watercourses, in lagoons, outflow channels and in numerous oval depressions on the floodplains in the central and southern western drainage basins. The number and size of lagoons and wetlands tend to increase towards the coast. Floodplain lagoons are seasonally inundated with many surviving the dry season as permanent waterbodies. These waterbodies can be quite distant from the main river channels. The Jardine River drainage basin contains many extensive, permanent and seasonal swamp areas.

The eastern drainage basins also contain extensive wetlands (e.g. sand dune lakes at Cape Flattery) but relatively few actual lagoons, a feature probably attributable to the short length of most of the rivers (Herbert et aL, 1995) and higher stream gradients. Permanent lagoons occur on the Olive, Stewart and Normanby Rivers. Extensive shallow dune lakes occur at Cape Flattery, Shelburne Bay and other areas. Many of these lakes are permanent and are groundwater sourced.

6.4 Riparian Vegetation

Riparian vegetation is well developed along most of the major waterbodies in the Peninsula. Riparian zones along the alluvial planes are composed of Melaleuca viridij7ora and stringybark (Eucalyptus tetradotzta) with some areas of riverine vine (gallery) forest (Lesslie et aL, 1992).

These vine forests are common along all rivers except the Edward and are more extensive along those rivers with terraced banks (Herbert et al, 1995). Semi deciduous vine thickets as well as open woodland species occur around lagoons and wetlands (Lesslie et al., 1992). In areas of extensive rock bars, riparian vegetation, particularly gallery forest, is absent or very limited.

Filamentous algae (principally brown with some green algae) is the only common plant type observed in streams, whereas lagoons commonly have abundant submerged and or floating aquatic flora.

6.5 Hydrology

The physical characteristics of the major watercourses with gauging station records are outlined in the following tabless. The area of each river basin, hydrographic station locations and operating periods and the mean annual discharge is presented in Table 6.1. These locations also appear in Figure 6.1. Histograms showing stream discharges at each gauging station for the past thirty years is presented in Appendix 2.

5 Original gauging stations are suffixed by "Aand replacement stations by "B" etc. stations are replaced because of flood d'mage or shifted slightly to a more appropriate location. Cornposited data from A and B locations art: presented without suffix e.g. 927001 contuns &ita from 927001A and 927001B. The annual flow and the average of the highest discharges for each year ((mean annual peak discharge) is presented in Table 6.2. The area drained at each gauging station, the percentage of the total basin this area represents and the annual runoff depth in this area for each gauging station is also presented in this table. Annual discharges also appear in Figure 6.2. The percentage of no flow periods and the period over which this percentage has been calculated is shown in Table 6.3 and in Figure 6.3.

Percentile flows appear in Table 6.4 for each hydrographic station. The 10% percentile flow column indicates the flow volume that is likely to be exceeded 10% of the time. SirniIariy the 90% column shows the flow volume that is likely to be exceeded 90% of the time Table 6.1 Basin Discharges

I MEAN ANNUAL BASIN BASIN NAME BASIN AREA DISCHARGE GAUGING GAUGING STATION NAME LATITUDE LONGITUDE PERIOD OF NO. (KM~) FROM BASIN STATION NO. RECORD MLX~O~*

101 Jacky Jacky 2,770 1,926 Creek

102 Oke-Pascoe 4,350 4,248 102101A Pascoe River at Falls Creek Crossing 12"52'56" 142'58'54"" 01110167 present River 102102A Pascoe River at Garraway Creek Junction 12'39'37" 143"02'53" 2011 1170 - present

103 Lockhart River 2,825 1,631

104 Stewart River 2,795 1,162 104001A Stewart River at Telegraph Road 14'10'26" 143'23'48" 18101170 - present

105 Normanby River 24,605 5,954 105001A Hann River at Kalinga Homestead 15'1 2'08" 143'51'23" 10107158 - 11/03/71 105001B Hann River at Sandy Creek 15'13'36" 143'50'50" 01/10168 - present 105001 Hann River at Sandy Creek 10/02/58 - present 105002A Jungle Creek at Kaiinga Station 15'20'57" 143'46'25" 2111 1170 - 30109188 105101A Normanby River at Battle Camp Crossing 15'16'56" 144'50'1 6" 1411 2/67 present 105102A Laura River at Coalseam Creek 15"37'02" 144'29'05" 27103168 - present 105103A Kennedy River at Fairlight 15'33'55" 144'10'07" 17/02/68 . 30109188 105104A Deighton River at Deighton 15'29'35" 144'31'38" 29105169 - 30109188 105105A East Normanby River at Developmental Road 15'46'25 145°00'52" 24/02/69 - present 105106A West Normanby River at Mt. Sellheim 15'45'32" 144'58'29" 1611 2/70 - 30109189 106 Jeannie River 3,755 2,417 106001A Mclvor River at Elderslie 15'08'09" 145'05'05" 26\02/69 . 1411 2/88 106002A Jeannie River at Wakooka Road 14'45'36" 144'51'19" 15101170 30109188 106003A Starcke River at Causeway 14'49'05 144"58'11" 15101170 - 30109188 107 Endeavour River 2,200 1,783 107001A Endeavour River at Flaggy 15'25'28" 145'04'31" 22/10/58 - 11/12/67 107001B Endeavour River at Flaggy 15'25'31" 145'03'49" 01110167 - present 107002A Annan River at Mt. Simon 15'38'45" 145'1 1'31" 25/02/69 . 08110192 107003A Annan River at Main Road 15'4 1'22 145'12'24" 09/03/90 - present 108 Daintree River 2,125 3,560 None present in study area (N.B. for total (N.B. for total basin area) basin discharge)

919 Mitchell River 71,795 1 1.998 919009A Mitchell River at Koolatah 15'56'54" 142'22'36" 07/07/72 - present 919010A Lagoon Creek at Rutland Plains 15'38'21" 141'49'19" 13108174-17110188 919201A Palmer River at Goldfields 16'06'00 144°46'00 11/12/67 - present 9 19202A Palmer River at Maytown 16'05'00" 144'1 9'43" 1611 2/68 - 30109188

I .; CYPLUS is a joint initiative between the Queensland and Commonwealth Governments. GAUGING STATION LOCATIONS

The information shown on this map h& been supplied by the Department of pri& Industries. Initial enquiries regarding Uie information should be directed to Water Resources Division.

Topographic information shown on this map is curtent to 1989.

LEGEND

Roads

Rivers 1:250 000 Geology + Sheet Boundaries

GULF CORAL a Gauging Station Location - Operating Gauging Station Location - Closed SEA - Basin Boundaries

CYPLUS Study Area

Transverse Mecator Projection Zone 54 : Atstdim Map Grid

Prepared and produced by the Department of Primary Industries, June 1994.

30 Nw 1994 EDITION NO 1 FIGURE 6.1 ,,,, Table 6.2 Gauging Station - Depth of Runoff and Peak Annual Discharge

Station Catchment Percentage Annual Flow Volun~e Annual Runoff Mean Peak Annual Station Nun~ber Station Name Area (kln2) of Total (megalitres) Depth Discllarge CUIIICCS(~n'lsec) Basin Area (a~illlnietres)

102101A l'ascoe River at Falls Creek Crossing 635 15 603099 950 1008 102102A Pascoe River at Garraway Creek Junction 1335 3 1 1490066 11 16 1493 lO40OlA Stewart River at Telegraph Road 480 17 249740 520 670 105001A Hann River at Kalinga Homestead 1035 4.2 128133 123 117 105001B Hann River at Sandy Creek 1010 4. I 183 167 181 216 105001 Hann River at Sandy Creek 1010 4.1 170327 - . 168 186 105002A Jungle Creek at Kalinga Station 310 1.3 59147 190 57.7 105101A Normanby River at Battle Station Camp Crossing 2270 9.2 93 1403 410 1585 105 102A Laura River at Coalseam Creek 1425 5.8 385378 27 0 86 4 105 103A Kennedy River at Fairlight 1115 4.5 273612 245 485 105104A Deighton River at Deighton 595 2.4 142856 240 226 105105A East Nom~anbyRiver at Developmental Rd 300 1.2 141933 473 314 105106A West Normanby River at Mt. Sellheim 850 3.5 307017 36 1 793 106001A Mclvor River at Elderslie 194 5.2 119214 614 206 106002A Jeannie River at Wakooka Road 335 8.9 150844 450 297 106003A Starcke River at Causeway 181 4.8 138976 768 ?h8 107001A Endeavour River at Flaggy 315 1 4 154101 489 326 107001B Endeavour River at Flaggy 310 I 4 159270 514 334 107002A Annan River at Mt. Simon 375 17 432994 1155 1037 9 19009A Mitchell River at Koolauh 46050 6 4 13013901 282 4162 919201A Palmer River at Goldfields 530 0.7 192300 363 43 7 919202A Palmer River at Maytown 2210 3.1 645353 29 2 1074 919203A Palmer River at Strathleven 7070 9.8 1543846 218 1636 919204A Palmer River at Drumduff 7750 1 I 2042 123 263 2036 919205A North Palmer River at AMTD 4.8 km 430 0.6 94760 220 228 920001A Lukin River at Old Bamboo 1205 9.2 667716 554 1008 920002A Coleman River at King Junction 1645 12 701714 426 1015 920003A Coleman River at Bass Yards 4900 37 519786 106 133 921001A Holroyd River at Ebagoola 365 3.5 198280 543 598 92 1002A Holroyd River at Strathgordon 4310 4 1 1797308 417 492 92200 1A Archer River at Telegraph Crossing 2950 22 1706773 578 232 1 922101 Coen River at Racecourse 166 1.2 90432 545 236 922101A Coen River at Coen 165 1.2 55307 335 104 922101B Coen River at Racecourse 166 1.2 105486 635 29 3 923001A Watson River above Jackin Creek 995 21 590576 59 3 472 924001A Enlblq River at Kui~acooCreek 365 7.7 27 1945 745 27 11 92J101A Mission River at York Downs 555 12 29794 1 537 175 d Table 6.2 Gauging Station - Depth of Runoff and Peak Annual Discharge (cont)

Station Catchn~et~t Percentage Annual Flow Volun~e A1111ualRul~off hlean Peak An~~ual Station Number Station Name Area (km2) of Total (n~egalitres) Depth Discharge Cu~accs(mJlsec) Basin Area (n~illin~etres) 925001A Wenlock River at Moreton Telegraph St. 3330 44 1408830 423 562 925002A Wenlock River at Wenlock 725 9.6 468679 646 817 925003A Wenlock River at Jacks Camp 5670 75 3197539 564 86 1 926001A Ducie River at Bertiehaugh 635 9.5 4 12069 649 408 926002A Dulhunty River at Dougs Pad 325 4.9 247862 763 114 926003A Rertie Creek at Swordgrass Swamp 130 2.0 107610 828 41.5 927001 Jardine River at Monwnent 2505 77 2 153987 860 360 927001A Jardine River at Telegraph Line 2500 77 2436918 975 432 9270018 Jardine River at Monument 2505 77 2153987 747 289 CAPE YORK PENINSULA LAND USE STRATEGY

CYPLUS is a joint initiative between the Queensland and Commonwealth Governments. ANNUAL DISCHARGE

The information shown on this map has been supplied by the Deparbnent of Primary Industries. Initial enquiries regarding the information should be directed to Water Resources Division.

Topographic information shown on this map is cunent to 1989.

LEGEND

ANNUAL DISCHARGE (annual discharge volume in megalii x 1000) A

Rivers SEA 1:250 000 Geology + Sheet Boundaries

0 CYPLUS Study Area

CARPENTARZ A

KILO METRES 0 1m 2m 250

I t I 1 I I I I I I I I Ttmsver~eMemator Rejection Zone 54 : &&dim Map Gd

Prepared and produced by the Depamnt of Primary Industries, June 1994.

30 Nw 1994 EDITION NO 1 FIGURE 6.2 ,,,, 34

Table 6.3 Gauging Station - No Flow Periods

Period Record Cumulative Percentage Station Loration of Length Length of No of No Flow Number Record (years) Flow Periods Periods I 102lOlA Pnrcoe River at Falls Creek Crossing 1967-93 26 0.81 years 3.1 102102A Pascoe River at Garraway Creek Junction 1970-93 23 0 0 104001A Stewart River at Telegraph Road 1970-93 23 5.3 years 23 105001 Hann River at Sandy Creek 1958-91 33 0 0 105001A Hann River at Kalinga Homestead 1958-71 13 0 0 105001B Hann River at Sandy Creek 1968-91 23 0 0 105002A Jungle Creek at Kalinga Street 1970-88 18 20 days 0.3 105 101A Normanby River at Battle Camp Crossing 1967-93 26 3.6 years 13.8 105 102A Laura River at Coalseam Creek 1968-93 25 7.8 years 31.2 105 103A Kennedy River at Fairlight 1968-88 20 4.5 years 22.5 105 104A Deighton River at Deighton 1969-88 19 9.4 years 49.5 105 105A East Normanby River at Developmental Rd 1969-92 23 3.3 years 14.3 105106A West Normanby River at Mt Sellheim 1970-89 19 6.7 years 35.3 106001A McIvor River at Elderslie 1969-88 19 30 days 0.4 106002A Jeannie River at Wakooka Road 1970-88 18 7.6 years 42.2 106003A Starcke River at Causeway 1970-88 18 4.3 years 23.9 107001A Endeavour River at Flaggy 1958-90 32 1.7 years 5.3 107001B Endeavour River at Flaggy 1967-91 24 2 years 8.3 107002A Annan River at Mt. Simon 1969-91 22 0 0 919009A Mitchell River at Koolatah 1972-93 21 27 days 0.4 919201A Palmer River at Goldfields 1967-94 27 5.5 years 20.4 919202A Palmer River at Maytown 1968-88 20 8 years 40.0 91920314 Palmer River at Strathleven 1969-88 19 44 days 0.6 919204A Palmer River at Drumduff 1972-88 16 0 0 919205A North Palmer River at AMTD 4.8 km 1973-88 15 7.8 years 52 920001A Lukin River at Old Bamboo 1967-88 21 10 years 47.6 920002A Coleman River at King Junction 1970-91 21 10.3 years 49 920003A Coleman River at Bass Yards 1975-89 14 6.2 years 44.3 921001A Holroyd River at Ebagoola 1970-88 18 9.7 years 53.9 921002A Holroyd River at Strathgordon 1972-89 17 4.0 years 23.5 922001A Archer River at Telegraph Crossing 1968-93 25 3.4 years 13.6 922101 Coen River at Racecourse 1957-92 35 5.4 years 15.4 922101A Coen River at Coen 1957-67 10 2.1 years 21 922101B Coen River at Racecourse 1967-92 25 3.3 years 13.2 923001A Watson River above Jackin Creek 1972-91 19 5.4 years 28.4 924001A Embley River at Kurracoo Creek 1971-86 15 6.1 years 40.7 924101A Mission River at York Downs 1972-91 16 6.9 years 43.1 925001A Wenlock River at Moreton Telegraph St 1958-90 32 0 0 925002A Wenlock River at Wenlock 1969-91 22 2.8 years 12.7 925003A Wenlock River at Jacks Camp 1971-88 17 0 0 926001A Ducie River at Bertiehaugh 1968-88 . 20 6.6 years 33.0 926002A Dulhunty River at Dougs Pad 1970-92 22 0 0 926003A Bertie Creek at Swordgrass Swamp 1972-90 18 0 0 927001 Jardine River at Monument 1968-92 24 0 0 927001A Jardine River at Telegraph Line 1968-78 10 0 0 927001B Jardint: River at Monument 1978-92 14 0 0

Table 6.4 Gauging Station - Percentile Exceedence Flows

Station Percentile Exceedence Flows in Number Station Description Megalitreslday

10% 50 % 90 %

102101A Pascoe River at Falls Creek Crossing 41.8 1.52 0.026 102102A Pascoe River at Garraway Creek Junction 112.4 4.76 1.307 104001A Stewart River at Telegraph Road 15.6 0.09 0.000 105001 Hann River at Sandy Creek 8.1 0.63 0.239 105001A Hann River at Kalinga Homestead 7.03 0.51 0.231 105001B Hann River at Sandy Creek 9.40 0.67 0.218 105002A Jungle Creek at Kalinga Street 3.9 0.56 0.321 105101A Normanby River at Battle Station Camp Crossing 39.4 0.92 0.000 105 102A Laura River at Coalseam Creek 11.5 0.07 0.000 105 103A Kennedy River at Fairlight 13.9 0.17 0.000 105104A Deighton River at Deighton 7.005 0.002 0.000 105105A East Normanby River at Developmental Rd 6.4 0.38 0.000 105106A West Normanby River at Mt. Sellheim 9.7 0.08 0.000 106001A McIvor River at Elderslie 7.8 0.47 0.079 106002A Jeannie River at Wakooka Road 10.03 0.015 0.000 106003A Starcke River at Causeway 10.5 0.19 0.000 107001A Endeavour River at Flaggy 8.2 0.34 0.000 107001B Endeavour River at Flaggy 1.2 0.6 0.003 107002A Annan River at Mr. Simon 26.04 2.88 0.363 919009A Mitchell River at Koolatah 1107.7 15.13 0.821

919201A ' Palmer River at Goldfields 9.2 0.20 0.000 919202A Palmer River at Maytown 28.8 0.16 0.000 919203A Palmer River at Strathleven 92.6 1.01 0.073 919204A Palmer River at Drumduff 72.8 2.18 0.462 919205A North Palrner River at AMTD 4.8 km 4.8 0.000 0.000 920001A Lukin River at Old Bamboo 49.6 0.02 0.000 920002A Coleman River at King Junction 47.2 0.00 0.000 920003A Coleman River at Bass Yards 67.2 0.09 0.000 921001A Holroyd River at Ebagoola 15.1 0.00 0.000 921002A Holroyd River at Strathgordon 223.9 0.53 0.000 922001A Archer River at Telegraph Crossing 137.1 1.80 0.000 922101 Coen River at Racecourse 7.2 0.35 0.000 922101A Coen River at Coen 3.8 0.26 0.000 922101B Coen River at Racecourse 8.8 0.39 0.000 923001A Watson River above Jackin Creek 45.5 0.03 0.000 924001A Embley River at Kurracoo Creek 24.2 0.01 0.000 924101A Mission River at York Downs 29.6 0.004 0.000 925001A Wenlock River at Moreton Telegraph St 136.3 3.62 0.867 925002A Wenlock River at Wenlock 38.5 0.48 0.000 925003A Wenlock River at Jacks Camp 39.2 5.70 1.224 926001A Ducie River at Bertiehaugh 40.0 0.25 0.000 926002A Dulhunty River at Dougs Pad 20.4 3.21 1.079 926003A Bertie Creek at Swordgrass Swamp 7.6 1.82 0.704 927001 Jardine River at Monument 177.9 37.65 15.967 927001A Jardine River at Telegraph Line 195.0 45.19 17.059 927001B Jardine River at Monument 155.5 32.20 15.731 7.0 WATER QUALITY Water quality data for the Peninsula are sparse with myof major watercourses having had, at best, extremely limited sampling undertaken. Most of the available data relate to the chemical and physical quality parameters with even less data available on the biological quality(ie. levels of biotic contaminants including pathogens).

The hydrographic stations which are used as a consistent location for ongoing sampling progm have been operating at the most for a little over thirty years with water samples being taken for analysis (as a guide) two to four times per year during maintenance visits. As a result there is a limited historical record of water quality trends. An adequate understanding of water quality is also hampered by the sporadic location of sample sites and the varied timing of sampling. Localised pollution and other water quality problems may be suffciently diluted upon reaching hydrographic station sample sites to no longer register as significant. Similarly, significant occasional pollution discharges may be flushed from the system before samples are taken.

Given these constraints on data availability, water quality in the Peninsula is generally very high, with isolated locations such as the West Claudie River (Herbert et aL, 1995), containing more marginal quality water.

Water quality data are presented in Appendix 3 and include samples taken during a high flow event and during a low flow period at each hydrographic station where possible, and include information on; hydrographic station number, date, discharge, conductivity, total soluble salts, total dissolved ions, total dissolved solids, pH, total alkalinity, colour, turbidity, hardness, Sia, sodium, potassium, calcium, magnesium, chloride, fluoride, nitrate, sulphate, iron, manganese, zinc, aluminium, boron, copper, carbonate and bicarbonate. All of the tested parameters are in maexcept colour (Hazens), turbidity (NTU's), conductivity (p~cm-')and pH (pH units). It should be noted that some of these parameters such as pH and some trace metals may have questionable values as concentrations can change over time if. the samples were not appropriately preserved.

Additionally, it should be noted that these samples were not all collected at the same time, or under the same flow conditions, and only one high flow and one low flow sample have been reported on in Appendix 3 (with the flow rates at the time of sampling).

Surface water chemical analyses can be significantly complicated by stream dynamics. High discharge rates (flood conditions) can lower ionic values and raise nutrient concentrations. This may occur through quicker catchment runoff, giving a lower than normal dissolved ionic return to the stream and a general dilution of ionic concentrations. Additionally, the high evaporation rates experienced in the tropical conditions and the component of groundwater effluent can elevate ionic concentrations at low stream discharges. Further influences on the consistency and comparab'ity of sample results can be caused by the timing of the sampling in relation to river discharges. Samples taken at the beginning of a flood event after a dry period tend to have higher ionic concentrations from a "flushing" effect of the catchment.

Conductivity and hardness values presented in Table 7.1 represent the average value for samples collected between the 10th and 90th percentile flows. This method was used to delete outlying values that may occur as a result of very high cjf very low flow conditions and obtain more representative conductivity and hardness averages.

Average conductivity values appear in Figure 7.1 and hardness in Figure 7.2. Conductivity trends for selected hydrographic stations appear in Figure 7.3. The historical conductivity values presented in this figure were analysed to determine if any conductivity trend was apparent over the time of record. For this purpose a Kendall Tau test was used where the net difference between all data points at each gauging station was determined to calculate whether there is a positive or negative slope to the data trend.

It should be noted that trends have been determined for at most a 30 year period and this period may not be representative of longer term climatic and hydrological iduences. An inspection of the results of this test indicated that five gauging stations may have a falling conductivity value (102101, 102101, 107002,92200 1 and 922101), while the other 15 stations (as shown in Figure 7.3) either had generally steady conductivity levels or the data were too scattered to permit any conclusion to be drawn.

The water samples used in Appendix 3 meet the National Health and Medical Research Council (NHMRC) guidelines for all health guideline levels, however, some of the aesthetic guidelines are exceeded. These include turbidity at some sites, which can be a reflection on flow conditions at the time of sampling. pH is slightly outside the NHMRC aesthetic range of 6.5 to 8.5 at some locations (although this figure may not be reliable as pH readings can change during storage). Aluminium exceeded the aesthetic criteria (of 0.2 mg/L) at the Archer, Normanby and Wenlock Rivers. Additionally, iron values exceeded the aesthetic criteria (of 0.3 ma)at the Normanby, Jeannie and Palmer Rivers.

The sodium adsorption ratio (SAR) is an expression of the sodium hazard of a water in relation to its likely effects on soils and plants. The SAR values of surface waters are generally suitable for all crops including very sensitive horticultural tree crops.

Significant issues and potential issues relating to water quality in the study area include:

cyanide leach pads draining into the Coen and other rivers; tailings dam failures; potential for mine dewatering; downstream effects of the Mareeba sewerage outfall; septic system leakage; defecation by stock, feral animals and people close to (and in) the watercourses; urban runoff; drainage from rubbish tips; industrial waste; fertilizer usage: mitigation works reducing flow volumes; increasing levels of turbidity from accelerated erosion levels, including sediment from roadworks and other earthmoving activities; increasing turbidity levels and supply of detergents from people and vehicle washing in watercourses; bogging and near-shore eutrophication of waterholes, billabongs and wetlands by stock and feral animals; land clearing.

Generally surface water quality in the CYPLUS study area appears to be good with no conclusive evidence of water quality deterioration. However, it should be noted that a paucity of data may significantly limit the reliability of water quality interpretations. 40

Table 7.1 Conductivity and Hardness Values

Hydrographic Station No. Conductivity in pS/cm Hardness in mg/L CaC03 102101A 90 8 102102A 100 10 104001A 100 20 105001 40 3 105001A 50 3 105001B 50 3 105002A 40 2 105101A 150 20 105102A 150 30 105103A 150 20 105104A 60 20 105105A 90 10 105106A 200 30 106001A 200 50 106002A 100 20 106003A 150 15 107001A 100 20 107001B 100 15 107002A 70 8 919009A 100 20 919201A 70 20 9 19202A 90 40 919203A 150 50 9 19204A 150 30 9 19205A 100 20 92000 1A 50 9 920002A Insufficient data Insufficient data 920003A 80 8 921001A 70 9 921002A 60 6 92290 1A 110 15 922101 90 8 922101A 90 8 922101B 90 8 92300 1A 100 20 92400 1A 110 30 924101A 70 20 92500 1A 80 9 925002A 120 15 925003A 90 8 926001A 65 5 926002A 40 3 926003A 30 2 92700 1 30 3 92700 1A 45 3 927001B 30 3 CAPE YORK'. ,.....,, LAND USE STRATEC..

CYPLUS is a joint initiative between the Queensland and Commonwealth Governments.

SURFACE WATER CONDUCTIVITY

The information shown on this map has been supplied by the Department of Primary Industries. Initial enquiries regarding the information should be directed to Water Resources Division.

Topographic information shown on this map is current to 1989.

LEGEND

SURFACE WATER CONDUCTIVITY (rnilligrarnrnes per litre Total Dissolved Ions) + 0 to 50 -W- >50to100

---f-- > 100 to 150 + > 150 to 200 Unclassified NOTES: Values determined under normal flow conditions. Updated 1993.

1:250 000 Geology Sheet Boundaries

CYPLUS Study Area

Conductivity information modified from DPI Water Quality Atlas 1994.

Transverse Mercator Projection Zone 54 : Ausbalian Map Grid

Prepared and produced by the Department of Primary Industries, June 1994.

G.S. 1112101 Fall Creek Crossing G.S.104001 Telegraph Road G.S. 105001 Sandy Creek G.S. 105002 Kalinga Stason GS. 105101 Battle Camp Crossing Pascoe R AMTD i7.2 km. Stewart R AMTD 37.8 krn. Hann R AMTD 73.2 krn Jungle Ck. AMTD 8.9 km Mrmsnby R AMTD 173.9 km

1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 YEAR YEAR YEAR YEAR YEAR

G.S. 105102 Coalseam Creek G.S. 105105 Developmental Road G.S. 106001 Elderslie G.S. 106003 Causevray GS. 107Wn Flaggy Laura R. AMTD 48.3 krn East Normanby R AMTD 19.3 km Mc lvor R AMTD 24.1 km Starcke R. AMTD 7.2 km Endeavour R AMTD 29.3 Inn moo 200 250 MKI 200

1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 YEAR YEAR YEAR YEAR YEAR

G.S. 107002 Mt Simon G.S. 919009 Koolatah G.S. 91 9201 Goldfields G.S. 919203 Strathleven G.S. 919204 Drumduff Annan R AMTD 28.1 krn Mitchell R AMTD 141.6 km Palmer R AMTD 299.3 km Palmer R. AMTD 85.3 krn Palmer R AMTD 39.4 krn

150 300 700 400 250

1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 YEAR YEAR YEAR YEAR YEAR

G.S. 922001 Telegraph Crossing G.S. 922101 Racecourse G.S 925001 Mweton Telegraph Station G.S. 925002 wenlock G.S. 925003 Jacks Camp Archer R AMTD 203.3 km Coen R AMTD 154.5 krn Wenlock R AMTD 156.1 km Wenlock R AMTD 263.6 km 'Nenlock R AMTD 101.9 km

1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 1965 1970 1975 1980 1985 1990 1995 YEAR YEAR YEAR YEAR YEAR

LEGEND CONDUCTIVITY TRENDS (Selected Gauging Stations) Conductivity in @/cm at 25" C cvPLu5CAPE YORK PENINSULA G.S. = Gauging Station AMTD = Adopted Middle Thread Distance LAND USE STRATEGY (approx. distance from river mouth) 8.0 ENVIRONMENTAL FLOW REQUIREMENTS

Environmental flows relate to the nature of water required in a waterway to maintain the normal functioning of natural ecosystems. In a general sense a number of factors need to be considered such as the volume, timing, duration and quality of the flows and the definition and criteria used to determine the normal functioning of the natural ecosystems. The idea can and should be further extended to include the maintenance of stream morphology, erosion, deposition and other "natural" processes. Further complexities relating to providing appropriate environmental flows are discussed

Environmental flows as an area of study is a fairly recent concept. As a result little work has been done in this area, with major directions, techniques and objectives still being defined (see Fitzgerald et al., 1994; Cullen, 1994). The environmental flow concept can be considered under the umbrella of sustainability and in this, key points such as the determination of what we would like to sustain and in what condition were still being debated at a recent w'brkshop on this issue (see Fitzgerald et al., Nov. 1994). There are a large number of objectives and interests that need to be considered in this issue. These include the broader environmental maintenance needs as well as the requirements of urban communities, stock, industry, mining, aesthetic considerations, agriculture and the needs of many other stakeholders. Additionally there are a variety of ecological, physical, hydrological and management parameters that need to be considered (Cross et al., 1994).

8.1 Environmental Value

A preliminary look at the broader concept of environmental flow requirements in Cape York Peninsula is timely for two major reasons.

Firstly, the intrinsic value of the area, with Queensland having the highest level of biodiversity of all Australian states (Roberts, 1992) and the Peninsula being one of the most diverse areas in this state. Each river system in the Peninsula is 'unique' in terms of the particular combination of hydrology, its catchment geology, topography, vegetation, and soils as well as riverine flora and fauna and habitat types.

Secondly, there is the relatively pristine nature of much of the Peninsula resulting from the small population, comparatively little industry and low levels of infrastructure. These points together imply that there is a great opportunity to preserve an ecologically important region in relatively natural state (notwithstanding some of the management issues identified elsewhere' in this report).

Additionally, the impact of these waterways extends beyond the coastline. As an example, river flows and river water quality has a large effect on estuarine wetlands. These areas are the breeding and nursery grounds for many marine organisms, with prawn and oyster breeding being almost entirely estuarine dependent (Hutchings & WiUcinson, 1980). These features significantly affect the offshore fishing industry. In NSW, commercial fishing organisations are becoming concerned about the issue of environmental flows. Conversely, disregarding the environmental flow requirements of stream ecosystems can lead to major environmental problems including algal outbreaks and reduced biotic diversity (Bluhdorn & Arthington, 1994), loss of some wildlife species (Roberts. 1992) and lowered water quality.

8.2 State of Knowledge Concerning Environmental Flow

Our current level of knowledge limits our ability to determine the environmental flow requirements of rivers. Our basic understandings of complex aquatic ecosystems is imperfect and we lack detailed data on the water requirements of riverine ecosystems and particularly lack the detailed understanding of the wide range of biological responses in floodplain/wetland/riparian zones to the highly variable climatic and physical conditions such as those that occur on the Peninsula (Arthington et al., 1991, Jensen, 1994, Knights and Fitzgerald et al., 1994).

While we are aware that the environment needs its water in unpredictable and varied packages, we lack specific data on the environmental value of specific flow characteristics for example of low, medium and high flows and of flow volume, frequency, variability or seasonality etc. (Jensen, 1994). The extent of the problem is illustrated when we consider that it is not just water flows in rivers and streams that are the issue but the total interaction and impacts on wetlands, groundwater, nutrient loads and the other components of the broader ecosystem (Malcolm, 1991).

There are many issues relating to environmental flows where the lack of knowledge makes development of appropriate management strategies difficult and uncertain. While these issues are still being currently identified it is probably worthwhile to flag some of these to indicate the size and scope of the research task ahead.

There is currently a lack of knowledge in understanding the range of biological responses in the channel riparian zone and floodplain areas to the highly variable climatic conditions in the Peninsula and the flow requirements of key native species (Cullen, 1994, Jensen, 1994). We need to be able to set benchmark indicators for ecological, hydrologic, sedimentalogical and other processes. Further work needs to be initiated to determine how much variation from natural flows is appropriate, what is the most effective use of the available water, the effects of different processes at different scales and the effects of multiple use.

One of the key requirements in determining environmental flows is identifying what we want to maintain and at what level compared with a purely natural state. Little has been done on defining our considered goals. These have been invariably left as an all encompassing statement relating to "maintenance of the environment" or similar, though from time to time the term environmental flow has been used for many specific objectives as documented in Cullen (1994). The question of who determines the goal of delivering environmental flows also needs to be resolved.

Specifically at a basic level we need a thorough understanding of what elements of the flow regime are critical or at least most important. Instream environmental flow needs vary in volume, duration, frequency, peak height, etc. and at different places along a watercourse, to ensure the protection and encouragement of regeneration and reproduction processes (Jensen, 1994, Bluhdorn & Arthington, 1994). This level of understanding of the flow regime is essential to determine the least damaging ways of extracting water.

A number of methods for determining environmental flows have been used however there is no agreement to date on an appropriate method. All of the current methods either address only components of the issue and/or are in other ways deficient. Many of the methods used are reviewed in Arthington and Pusey (1993) and a brief discussion of several of these methods appears later in this report.

8.3 Peninsula Issues

The problem of defining environmental flow requirements for the Peninsula is substantially compounded by the great variability of waterbody types, the characteristic unpredxtability of hydrological flows in this region, and the high habitat and biological diversity.

The surface water resources in this area are more varied than in most other regions. In the Peninsula there is a large variation in hydrology and physiochemical conditions, both in general and over time, which affect the predictability, frequency of occurrence, length and size of flows as well as the current velocity, water temperature, levels of dissolved oxygen, salinity, organic matter, and other features. These variations are influenced by topography and climatic features and can have important effects on ecological conditions (Williams, 1994).

Waterbodies and their biota in Australia (in particular in the Peninsula) have evolved under extreme climatic variability as well as having adapted to hydrological characteristics that can differ significantly over short lengths along many of the rivers. The biota have developed a wide range of adaptations to the various natural environmental "stresses" occurring in the habitats that are commonly temporary e.g. river runs as well as the more permanent habitats of the Peninsula. These natural occurrences have resulted in a rich diversity of species and have been instrumental in determining the biological nature of the waterbodies (Cullen, 1994, Williams, 1994).

The Peninsula has a wide range of waterbody types with differing ecosystem and other water requirements. These include permanent and temporary rivers, lakes, billabongs, lagoons, wetlands, estuaries, rainpools, aquifers, springs and others. Consideration of the broader water requirements should also include the associated areas, for example, source areas, riparian zones, floodplain (including its gradient, topography and width) and hyporheos (subsurface river channel flow) zone. Such waterbody types are discussed elsewhere in this report as well as in DPI, -(1993), Arthington and Pusey, (1994) and Herbert et al., (1995).

Bodies of permanent freshwater are restricted in occurrence in the region and any desiccation of these areas would have important consequences for any biota lacking resistant stages and with poor dispersal abilities (Williams, 1994). Temporary bodies of freshwater are more characteristic of the Peninsula. These temporary water resource ecosystems have some differing characteristics compared with permanent waterbodies, including the tendency to be shallower, more readily effected by wind action (which influences water circulation patterns), have different nutrient dynamics and production processes and have marked fluctuations in turbidity and temperature. These points together can contribute to a reduced capacity to buffer adverse environmental effects (Her'bert et al., 1995, Williams, 1994).

More specifically numerous individual wetland areas exist in the Peninsula and there have been few systematic scientific studies on the water needs of wetland plants, leaving us unable to specify the water requirements for all individual wetlands (Bennett and McCosker, 1994, Jensen, 1994). Additionally, the freshwater flow from rivers (as well as flows influenced by ocean tides) is a prime factor in controlling the salinity structure of estuarine areas. Any significant change to the river flows may effect this salinity structure and cause a permanent change to the estuarine biota (Hutchings and Wilkinson, 1980). Further we have little knowledge of the minimum flow requirements of most native fish, though many of the indigenous species of the Peninsula are adapted to a seasonal lack of water and great variations in river flow (Tanner, 1991, Cullen, 1994).

While this is only an indication of the diversity of waterbody types and their natural requirements the scope can be extended by mentioning springs (sourced from groundwater). These are intrinsically linked with surface water supplies, admittedly with a time lag, through groundwater recharge mechanisms and as a consequence groundwater protection may in some ways be an essential component in maintaining aquatic ecosystems.

8.4 Field Data - Pascoe and Wenlock Rivers

An appreciation of the diversity of waterbodies and their differing characteristics and water needs is necessary to understand the complexity of environmental flow requirements.

Specific field work was conducted to investigate some Peninsula ecosystems. This was limited to determining the variability of habitat types present and gaining an appreciation of local environmental issues. Habitats along the Pascoe and Wenlock Rivers were surveyed as these rivers were considered to be reasonably representative of each of the two drainage divisions in the Peninsula and could between them give a preliminary indication of the habitat diversity.

Field data were collected at 16 sites, with the location of these sites and data appearing in Appendix 4. A summary of the characteristics of these watercourses follows.

8.4.1 Wenlock River

The Wenlock River has its headwaters in the Great Dividing Range and flows north westwards into the Gulf of Carpentaria. The river is around 300 km long and is intermittent for the first 110 krn or so from the source. The river channel is consistently 20-40 m wide, containing a small meandering stream during the dry season for most of its length. The river has extensive floodplains containing numerous lagoons, ephemeral wetlands and flood channels which are irregularly developed in the mid and lower sections of the river. The river has high banks up to 20 m above the watermark except in the lower flood plain estuary reaches. These terraced banks are of variable width up to 50 m from the main river channel. The substrate is principally sandy and contains extensive waterholes and numerous outcrops of lateritic bedrock with a small number of waterfalls. The water quality is good and the Wenlock probably has the highest fish species diversity of any river in Australia (Herbert et al., 1995).

Major restrictions on the watercourse occur at rapids in the mid section of the river. Fish passage past these structures at low flows would be restricted, though these structures would be passable at moderate to high flows. ?'he Wenlock Falls are a permanent barrier to in- channel migration. However, this obstacle is probably bypassed in significant (annual?) high flow events through floodplain flood channel flow, lagoons and possibly general overbank flow. These high flows overtopping river banks are needed to provide passage for aquatic fauna to and from the main channel for lifecycle requirements. The high flows reaching the lagoons are critical for the maintenance of many species in the lagoons and the main river channel, wetlands and the riparian zone.

Additional restrictions to fish passage occur as the river stops flowing in its middle sections toward the end of each year although waterholes remain as refuges for the aquatic fauna and flora.

The riparian zones are generally open with variable vegetation, medium to tall trees of 10 - 30 m height in the tallest stratum. Generally development of the riparian vegetation extends only about 10 m onto the floodplain. Melaleuca species commonly dominate in the riparian zone and there is significant callistemon and a variable abundance of species of rainforest affinity, particularly in the lower/estuarine sections of the river.

Instream sections where there is outcrop in the stream banks, such as rapids or falls, or where there is poor soil development, the riparian zone is usually poorly developed. Influencing this is seasonal droughting or a general lack of subsurface moisture in stream banks or beds. This contrasts with the well developed riparian zones adjacent to pools and sandy runs which may occur in the same stream reach.

8.4.2 Pascoe River

The Pascoe River has its source in rainforest and dense woodland country in the Great Dividing Range and flows north eastwards into the Coral Sea. The river is approximately 125 km long, is incised in its valley for most of its length and has steep banks generally greater than 10 metres above the watermark.

The river has limited floodplain development, except for those reaches very close to the coast, and a virtual absence of associated lagoons.

Some local restrictions in the watercourse occur but these would be overtopped in moderate to high flows. The peak wet season high flows probably overtop these high banks for short periods. There is generally good to unresmcted fish passage in the middle and lower reaches of the Pascoe River and this passage would still be available at flows significantly less than watermark flows. The water quality of the Pascoe is generally very high.

The river has extensive gallery forests containing abundant 'rainforest' species with callisternon close to the water. The tallest stratum generally consists of tall trees of commonly greater than 30 m height with a dense understorey that exposes little bare ground. The riparian zone is generally of variable width, depending on the topography and soil conditions, but is generally greater than 15 rn wide.

8.4.3 Lagoons

Lagoons are more common on the western Peninsula rivers, where extensive floodplains have developed, than the eastern rivers. These lagoons are generally less than 10 m wide and commonly less than 5 m, though some have been observed at up to 50 m wide and over 500 m in length.

The lagoons generally have moderate to high levels of algal and aquatic vegetation with plants providing around 20% to greater than 50% cover and algae commonly providing greater than 20% cover.

The riparian communities are narrower and less diverse than river zones in the same area. These communities are commonly dominated by reedhedge species that are not found in the streams, with melaleuca species (paperbarks) often bordering the lagoon.

8.5 Habitat Types

The habitat types identified in these two rivers are diverse and include pools, falls, runslglides, riffles/rapids, oxbows/billabongs, waterholes, backwaters, lagoons and feeder streams. A range of micro-habitats occur in each habitat type e.g. in pools, snags, tree roots, overhanging vegetation, substrate variants and undercut banks occur. All of these habitats need a diversity of flows to maintain their physical and ecological integrity. The flow diversity needed commonly requires an annual variation including major high flow (including overbank flow), wet season flood events as well as low flood-flow events.

The survey conducted was a preliminary qualitative analyses of the habitat structure characteristics of some of the key sites along the Wenlock and Pascoe Rivers and their associated floodplains. Data were collected on key features of the major habitats such as pools, riffles, runlglides and rapidslfalls (including location, size, depth, channel form, aquatic .plants, and fish passage disturbance). Additional information was obtained on the river land formation type, riparian zones (height, species composition, understorey and shading), channel banks (nature, size and terracing), substrate (sediment composition, algal growth and abundance of large woody debris), floodplain features (morphology, size, topography and vegetation), incidence of disturbance (by stock, feral animals, exotic vegetation, pollution and human activity). Site locations and descriptions appear in Appendix 4 and key observations have been included throughout this report. This survey work highlighted the large variations between habitat types along two of the Peninsula's rivers and helps illustrate the great complexity of flow types that is needed to adequately maintain the ecosystems in these areas. This work is a preliminary survey and would need to be extended considerably before even a rudimentary determination of essential flow rates, flood heights, frequency, duration, rates of rise and fall etc. could be made to adequately address environmental flow issues.

8.6 Environmental Flow Requirements of Peninsula Rivers

8.6.1 Flow Variability

A greater understanding of the environmental flow requirements of watercourses can be gained by considering the requirements of parts of the system. The maintenance of a well functioning system requires flows for the maintenance of habitats and channel stability and possibly for the maintenance of groundwater recharge and flow. Habitat preservation also requires a range of flow types with different species having different flow requirements for maintenance and may have different vulnerabilities.

The types and character of instream habitats and their ecological functions change with changes in flow rates. A range of flow types is important in maintaining the diversity and function of instream habitats. Major high flow events may be an important part of instream habitat maintenance. These flushing flows may be critical for removing large woody debris and cleaning out the channel. Low flow and 'no flow' periods may be important for the maintenance of water quality and water levels (including the hyporheos or subsurface river channel flow) in disconnected pools, and in runs which commonly have small areas of permanent water (e.g. near obstacles and close to overhanging banks). Removal of subsurface flows or extending the period of habitat dependence on the hyporheos may have adverse effects on water levels and water quality with consequent effects on fauna and the health of waterholes and small pools.

The natural variabilities of river flows are an essential component of instream environmental flow requirements. Some rivers have predictable flows while other rivers have short flow durations following major storm events. These events effect the ecosystems directly by supplying water, and by determining the physical morphology of the watercourses, the nature of the watercourse bed and the composition and quantities of dissolved matter (Williams, 1994). The hyporheos may also be critical in maintaining ecosystems in ephemeral watercourses.

Flow rates can vary from no flow conditions to floods of a large magnitude. As an example the lower Coleman River can spread laterally over 20 km when it is in flood. In much of the Peninsula, particularly the dryland areas, floods are a major factor driving the riverine ecosystem, with the duration, timing, magnitude and rates of rise and fall important in determining the ecological significance of each flood event. The estimated mean annual sediment contributions from the north eastern Cape York Peninsula catchments total 2,096,000 tonnes with most sediment exports occurring during extended high intensity storms and associated major flooding (Moss et al., 1992).

Significantly changed flow regimes would probably alter sedimentldeposition regimes in the main channel with significant ramifications for instream habitat maintenance. In sections with cobbles and outcrop, high flow events are required to maintain substrate diversity and prevent sand filling. These areas commonly appear to be the locus of relatively intense macro-invertebrate activity. The watercourse channels tend to become clogged with sandylpebbly sediments in 'drier' wet seasons. Major high flow events are needed to clean out river channels and pools and to maintain the diversity of substrates and instream habitats.

8.6.2 Overbank Flows

Regular inundation, through overbank flows of the floodplains is important to river systems for the maintenance of nutrient inputs, for the life cycle needs of a range of offstream and instream biota (plant and animal) and for soil regeneration. Such overbank flows are critical for replenishing lagoons, restoring water quality and for providing access for aquatic fauna for breeding etc. Access to the main river channel through these overbank flows needs to be maintained for a period of weeks to allow some species to complete life cycle stages and then return to the river (unless possibly a second high flow occurs to allow such return to the river). Such flows may be essential for the maintenance of the riparian zone by assisting in seed dispersal, nutrient cycling, fire protection and maintenance of diversity. These overbank flows can cause tree and shrub loss on banks as well as the removal of leaf Litter usually without replacement.

8.6.3 High Flows

Periods of higher river flows (but lower than overbank flows) such as those experienced over the wet season are needed to rejuvenate micro-habitats and maintain water quality (which deteriorates over the dry season) and allow resident fauna and flora to regeneratelreproduce.

These higher flows, such as low flood flows, also allow recruitment of species to the no flow, or commonly dry sections of the stream and provide upstream passage for migrating and spawning requirements. These flows also probably help ameliorate the impact of trampling, foraging and grazing by feral animals and cattle and generally aid in the physical and biotic rejuvenation of the riparian zones. Such maintenance requirements of the riparian zone may be different for areas adjacent to pools and runs as opposed to areas adjacent to riffles and rapids.

These higher flows are important for the maintenance of stream habitats and micro-habitats by supplying logs, leaf litter and nutrients into the stream and maintaining substrate stability and diversity. These higher flows are also important for periodic cleaning out of accumulated sediments, leaf litter, logs etc. and the cleaning out of idling sediments in backwaters. Additionally moderate flood flows can provide some of the annual inflow and outflow needed by billabongs, oxbow lakes and lagoons through flood channels and such flows are essential for changing bars and low-flow channel meanders. 8-64 Low Flows

Periods of river low flows that isolate lagoons and oxbow lakes etc may be important for the life cycle requirements of certain species. These periods may also by important for the maintenance of species that have adapted to these conditions by providing an advantage over those species that have not. In more stable hydrological conditions particular species tend to dominate with commonly less biodiversity. These flow conditions are also important in allowing a period for the riparian vegetation to regenerate, after modification by floodwaters.

8.7 Impingements on Natural Flows

Having outlined some of the various flow requirements of the Peninsula streams, it is possible to identify some of the existing modifications to natural flows. With our present knowledge it is not possible to quantify the effect on ecosystems of such changes to the flow regime. Possible modifications to the natural flow regime include:

Impoundments effecting the flow regime, particularly low flows, and reducing the duration of streamflow. This appears to be occurring on the Laura River. Similarly offstream storages may also be reducing streamflow around Lakeland Downs.

Abstraction of groundwater from the upper aquifers of the Karumba Basin or from alluvial deposits may reduce baseflow and hyporheos (subsurface river channel flow) zone. The extent of such effects is unknown but is probably minor at present.

Abstraction of surface water for supplies to major communities such as Bamaga and Wujal Wujal and other users will have an effect on natural flows. However, these effects at present are probably minor.

Extensive erosion in some areas through mining, earthworks and grazing, is providing additional sediments to watercourses. This process has a likely effect of changing the morphology of the watercourse by infilling waterholes and altering the low flow watercourse and consequently having an effect on flow regimes.

Changing vegetation species in the riparian zone (in particular Rubber Vine (Cryptostegia grandflora) infestation along the lower Mitchell River) may alter stream bank stability and effect the supply of debris to the watercourses which may effect the nature of some flows.

Changing fire management strategies, which has the ability to cause species changes may have an effect on runoff rates and volumes which may alter the peaks, duration, and timing of streamflows. 8.8 Review of Methods of Estimating Environmental Flow Requirements

Several methods have been used in attempting to determine environmental flow requirements for various watercourses. The following outlines some of these methods and their shortcomings.

8.8.1 Rule of Thumb Method

This approach is used to assign an environmental flow requirement to a proportion of natural discharge based on, for example, fixed percentages of mean annual flow for minimum and maximum requirements, or, alternatively a nominated monthly percentile figure. For this approach two techniques have been used the Montana Method and the Flow Duration Curve Analysis Method. These methods do not address the complexities of the ecosystem discussed previously and do not consider the critical flows needed for the maintenance of ecosystem biodiversity.

8.8.2 The Species Specific Method

In this method target species are identified and the flow required to meet their needs is determined by detailed study. This method may have some merit in protecting individual species. The method makes allowance for the points that different flow environments will favour different groups of invertebrates in a stream (Cullen, 1994) and a change of water conditions can result in an encroachment of species (Jensen, 1994). Additionally, knowledge of plant species environmental tolerances are usually based on observation rather than rigorous scientific experimentation (Bennett and McCosker, 1994). There is a need to look at protecting ecosystems rather than just an individual organism or species.

8.8.3 Transect Analyses

This method measures hydraulic and habitat features across stream transects to establish the effects of flow regimes on the stream habitats and biota. This method combined with flow probability curves is used in the Instream Flow Lncremental method. While this technique can provide useful information on the minimal flow requirements for a particular species it tends to neglect processes relating to refuge elements like woody debris, undercut banks and river shading (Cullen, 1994) and other features (see Arthington & Pusey, 1993). In practice it would be exceedingly complex to implement, because of the variety of species, and range of stream cross section types. It appears to be more suited to regular streams.

8.8.4 Panel of Experts

The expert panel approach developed by NSW Fisheries Department uses an assessment by scientists (a fish biologist, an invertebrate ecologist and a fluvial geomorphologist) with relevant experience to best determine the flow requirements for various species and habitats and has had some success in understanding components of environmental flows downstream of a water storage. This method is limited by current knowledge and understanding of biological processes (Cross et al., 1994), though has been used with reasonable success in other Queensland waterways (discussed later). 8.8.5 Holistic Method

The holistic method (Arthington et al., 1992) attempts to define natural hydrological regimes and identify the critical components of these regimes to maintain ecosystems and other natural waterbody processes. It attempts to define certain critical flows and apply an incremental or trial and error approach to fine tune the initial assessments.

The method attempts to address intrinsic knowledge shortfalls on habitat structures and species requirements etc. through this incremental approach and other techniques. However the method does not at present allow in its current applications e.g. the Barker-Barambah study (Arthington et al., 1992) for all hydrological inputs. The method is still in development.

A more appropriate method may lie in using a hybrid of some of the above methods feeding into a water balance model (eg. Bennett & McCosker, 1994) possibly guided by the broader holistic method concept or the "panel of experts" approach. The habitat structure data collected (while principally helping to identify the scope and complexity of the environmental flow question in the Peninsula) could be used in conjunction with hydrographic records presented and data obtained through other methods, as part of such a hybrid approach to determining environmental flow requirements of Peninsula rivers.

8.9 Management Directions

The 'Panel of Experts' approach has been trialed by the DPI for the Dawson and Boyne Rivers in central Queensland and was found to have merit as an interim decision making process until more appropriate and detailed knowledge is developed.

The panel should ideally be widely sourced from government, academia, industry and include local residents, farmers and interest groups. Such a broad base would facilitate codunity acceptance of recommendations and ensure a widespread range of skills and knowledge is incorporated. However care needs to be taken to limit the number of participants to ensure effective group dynamics can be achieved. An appropriate mix of skills for such a workshop based on the DPI's experience as an initial guide may be: a fisheries biologist, a stream ecologist, an environmental engineer, a hydrologist/surface water modeller, a hydrographer and a fluvial geomorphologist and possibly a person with significant planning experience. At the Boyne River 'Panel of Experts' workshop conducted by the DPI a series of steps was undertaken that develop initial environmental flow requirements. Table 8.1 outlines the procedure developed in Vanderbyl(1994). Table 8.1 Procedure for Developing Initial Environmental Flow Requirements (from Vanderbyll, 1994)

PROCESS DISCUSSION 1. Identification of habitats e.g. waterholes, rapids, lagoons, riparian areas. These have been very broadly identified for the study area in this work. 2.Identification of key ecological e.g. dissolved oxygen level, flow velocity nutrient level, characteristics and requirements bank and substrate type and stability. Some of these features have been qualitatively defined for the study area though more precise quantitative information is needed. 3.Identification of critical This can be outlined as a table with the requirement of requirements of observed habitats each habitat type e.g. backwaters, riffles and runs being determined in relation to criteria such as dissolved oxygen, temperature, depth, flow velocity, nutrient level, sedimentbank type and stability, instredriparian vegetation and cover etc. Insufficient data were able to be collected for the Peninsula's waterways in this study to define these requirements. 4.Determination of broad This process includes outlining desirable objectives e.g. management principles to mimicking natural events, maintaining specified water maintain environmental depths, maintaining acceptable levels of dissolved oxygen requirements and specifying key considerations (and management strategies) relating to these objectives e.g. releases from top layer of storage, depth in waterholes greater than 2m etc. 5.Monitoring strategy Includes the identification of key ecosystem health flags and appropriate monitoring and review procedures.

This procedure would give a general idea of objectives for the maintenance of environmental flows and broad strategies for the maintenance of ecosystem health. This technique has the advantage of being reasonably easy to set up and fairly inexpensive, and may serve as an interim technique until a more sophisticated and effective management process can be established.

8.10 Discussion

The time available for this work, the knowledge shortfalls described and the complexity of the task has precluded quantitative assessment of environmental flow requirements for the Peninsula's waterways. It has been possible only to partly identify the complexity of the task, look at some of the key components of the system and report on the present level of understanding in this area. It is not possible to give rigorous scientific specifications for what are appropriate environmental flows for the overall requirements of ecosystems (Cross et al., 1994) though it is considered we can arrive at reasonable estimates as to what are appropriate flows to maintain particular species (Cullen, 1994). From this incomplete rundown it becomes apparent that while the field of science is the most likely to come up with further information on many of these points there will still be shortfalls that will need to be addressed by other disciplines and/or may never be adequately answered. Given this, innovative. original and as yet unknown approaches may need to be considered (such as the idea of trade-offs currently being considered by NSW Water Resources).

An initial step is to appreciate that there are competing attitudes on management philosophy in the scientific community even without considering the many other stakeholders. At the risk of quoting out of context, Cooney et al. (1994), as a general comment considers 'It is important that the inundation of wetlands is not further impacted until the effects of extraction and regulation are better understood' while Bluhdorn and Arthington (1994) consider 'some parts of the flood regime (e.g. the fust major flood of the wet season) will be needed by the environment while others may be harvested without major environmental impact.'. In the determination of management strategies there is the real possibility that competing arguments may be inappropriately weighted. Planners may be influenced by the comparative quality of hydrological data over the more rudimentary ecosystem process data available at present. Additionally developers with strong economic arguments may have a stronger case than the present lack of scientific data can provide.

Ultimately, the decisions will need to be made using the best available information from and the best mix of, our environmental, technological, economic, social and political knowledge (Bluhdorn and Arthington, 1994, Knights and Fitzgerald, 1994). The lack of complete knowledge requires that some value judgements be made and this may be, for example, on which species we are going to use as indicators to manage the system (Cullen, 1994). This rnay lead to the need for a range of management options, the need to determine the cost benefit of these options and the need to periodically update and review these options.

Any changes to the natural flow regime will cause some change to the ecosystem. Consequently decisions about flow management will be concerned with the degree of damage and risk, and this environmental risk will vary according to the level of scientific information and to economic and social sensitivities (Knights and Fitzgerald, 1994). Further, this risk assessment will not only effect the instream users but also the reliability of supply for other users (such as pastoralists, mining etc.) that the water may be allocated to. In an assessment of risk, the following are some points that may need to be considered: relative priorities for water use; reliability needs; existing use versus future growth; and the ability of particular users to overcome restrictions on use (Fitzgerald et al., 1994). This risk assessment may be critical as it is difficult once water has been allocated to make widespread changes and reallocate it for environmental purposes. Additionally, irreversible damage will probably occur while it is being realised the management strategies are inappropriate. It appears in the Cape York Peninsula region we currently have a window of opportunity to determine and initiate appropriate environmental flow management practices.

Implementation of appropriate management strategies will require consideration of differing community values and the need for community involvement, financial aspects, educational processes, and the different time scales under which the environment and economic processes occur. Additionally research is needed on appropriate grazing regimes and appropriate species and structures and landholder management strategies and adoption processes.

At this stage it is not possible to realistically and adequately determine the environmental flow requirements for the Peninsula waterways. This work has illustrated the complexity of the related ecological and other processes, discussed the lower knowledge level in this field and considered in a very general sense how these knowledge shortfalls may be addressed to anive at a stage where reasonable and effective management decisions can be made. 9.0 RESOURCE DEMAND

In the Peninsula groundwater is used more extensively than surface water supplies for industrial (including mining), agricultural purposes and for human consumption. Surface water resources are used for the supply of Cooktown, Wujal Wujal and Bamaga. Surface waters commonly have high asethetic and recreational values.

9.1 Groundwater

With the monsoonal weather patterns having a particularly pronounced effect on surface water resources, groundwater is generally a more reliable year round source of water for most of the Peninsula. Groundwater as a resource is also generally more widely available than surface water. In general, the area currently has abundant quantities of groundwater. Although difficulties may be encountered in some areas in obtaining supplies, overall reserves are large.

Within the Cape York Peninsula study area, groundwater resources provide 90% of the water supplies. All of the major communities except Bamaga and Wujal Wujal rely on groundwater for at least part of their domestic water supplies. Groundwater is the major source of water supply for agricultural purposes, particularly stockwatering, and for bauxite mining at Weipa. Data on actual groundwater use in the study area are sparse, with only eight locations where bores are metered. Use by the smaller communities, most mines, tourist locations and pastoral holdings can only be estimated. The use of this resource is principally limited by availability and the economics of water reticulation.

The Karumba Basin, (which covers the Holryd, Clara-Mitchell, Karumba Plains and a substantial portion of the Merluna Plain and Weipa Plateau - see Figure 5.1) is the major water resource of the study area providing water supplies to 60% of the study area's population. This resource provides domestic supplies for Weipa, three Aboriginal communities and for the region's largest mining anci industrial complex as well as for stock water to over one third of the Peninsula.

9.2 Surface Water

9.2.1 Present Demand

Limited use of surface water resources occurs throughout the Peninsula for mining, agricultural. town and private domestic supplies, stock watering, construction, road maintenance and aquaculture. The available supplies are not used extensively principally because of the small population, lack of assurity of supply in most locations between September and December and relative lack of large scale industrial, mining and ifrigation development. Bamaga, Cooktown and Wujal Wujal are the only major communities using surface water.

Surface water supplies are extensive. On the eastern Peninsula, potential major divertible supplies are 4,600.000 megalitres per year of which less than 6,000 megalitres are currently being used, with 34 possible dams sites having been identified (Loy, 1991). These sites were identified in a preliminary desktop study and field investigation alone would significantly reduce the number of sites. The feasibility of development of any of these sites is unknown. Si~nilarfigures are not available for the western Peninsula, however the geology is likely to preclude the construction of any major dams in this area.

On the eastern Peninsula there are 18 licensed dams, 76 waterworks licenses and irrigation licenses over 3,158 hectares (Loy, 199 1). Large scale irrigation is presently occurring in the Lakeland area, an area along McIvor Road towards Hopevale, at Bamaga and Sudley Park near Weipa. The only major dam is a high level reservoir on the Annan River which is used for the town water supply for Cooktown. There is also a high level reservoir at Firebridge Hill at Hopevale. The Cook Shire Council is currently negotiating the purchase of a private darn on the Lankelly River at Coen for assurity of the town's supply.

Some investigations of a dam site on Eveline Creek and a weir on the right arm of the Endeavour River are being undertaken for the DPI. Additionally, there is a dam located at Horn Island and a gold mining company dam at Byerstown. At Lakeland Downs there are approximately 10 dams located on gully systems with Honey and Cattle Dams located on major watercourses. The Department of Transport has constructed two small dams at Wolverton and two dams have been constructed at the Schreger Air Force Base (Weipa), though groundwater will probably provide the main water supply for this establishment.

Surface water is also used by the many tourists principally at roadside campsites. The major campsites are located along the Peninsula Development Road but tourists tend to access many sections of the Peninsula rivers. Tourist numbers appear to be increasing and this may require small infrastructure developments such as toilets and wash basins. Additional demands are likely to occur from potential larger scale tourist developments.

Small gold mining enterprises on the Palmer River and tributaries, tin mining ventures along the Annan River, and the Cape Flattery Silica mine also use surface water supplies. Stock also use small quantities throughout the Peninsula both on pastoral properties and along stock routes. Minor aquaculture farms and professional and recreational fishermen are also users of this resource.

9.2.2 Future Demand

Mining development appears to have the greatest likely demand with each proposal requiring differing amounts of water (the potential surface water needs of these possible projects has not been assessed). Some of these projects iflwhen they eventuate may conjunctively use surface and groundwater. -

These potential projects include an alumina refinery under consideration at Weipa, a kaolin mine at Skardon River, extensions to Cape Flattery silica mine (which may require additional supplies from perched lakes), dredging for gravel extraction at Helenvale, increase of production of the Aman River tin fields including the possible development of the Collingwood Joint Venture Project, development of the extensive coal reserves at Bathurst Range, the development of base and precious metal mining in the Coen Mier and an increase in alluvial mining activity in the Palmer and other rivers. Increases in size and development of sewerage plants are likely to proceed at Cooktown, Weipa, Schreger Air Force Base and possibly at Hopevale. Ayton, Bloomfield, Rossville, Laura and Wujal Wujal have future requirements for a reticulated water supply and there is current planning for an extension of the township area at Portland Roads.

Residential development at Cooktown is Likely to continue and extensions to Weipa are under way particularly if normalisation from company ownership and control proceeds. Such normalisation would most likely lead to an increase in tourism. Major tourism developments are periodically proposed for the Peninsula usually in areas where surface water would be the most likely water supply source.

Additionally Aboriginal communities are expressing a desire to live on the land and establish low key resorts and other commercial developments such as the crocodile farm at KOwanyama.

Demand for irrigation water is occurring in the Endeavour Valley and at Lakeland where there is currently some break up of properties to 405 ha (1000 acre) lots. At Lakeland there is presently four centre point irrigation systems operating, a lateral move irrigator operating at Sudley Park near Weipa and a new irrigation system has been recently installed at Bamaga. Additionally some of the Peninsula's farmers believe irrigation is becoming increasingly necessary to maintain their viability particularly in the current (drier) seasonal conditions (David Hurse pers. comm.).

Additional use of surface water resources through offstream development such as flood harvesting is likely to occur. At present the DPI is not recommending ponded pastures development in north Queensland as some grass species have been found to escape from such developments and block waterways. The DPI is currently reviewing the effect of such establishment and the viability of ponded pastures in north Queensland. 10.0 CURRENT COVERNMENT POLICY

In Queensiand the DPI has the responsibility (under the Water Resources Act, 1989) for assessing, planning, managing, and developing Queensland's non-tidal water resources, while the Department of Environment and Heritage has responsibility for tidal waters.

The DPI is attempting to take an integrated approach to water resources planning and management in consultation with the community through the development and implementation of catchment management plans.

New Natural Resource Management legislation is in preparation which will enable a more integrated and planned approach to the allocation and management of Queensland's natural resources. Water resources legislation in Queensland is currently being amended to separate co~nrnercialactivities from the natural resource management aspects. Natural Resource Management legislation is being drafted with the objective of incorporating the goals of the National Strategy for Ecologically Sustainable Development (ESD).

Integrated Catchment Management and ESD are the two major elements which underpin the natural resource management policy of the DPI. The key elements of the ESD initiative are: integrating economic and environmental goals in policies and activities, ensuring that environmental assets are appropriately valued, providing for equity within and between generations and dealing cautiously with risk and irreversibility.

In this the ESD initiative recognises the needs of environmental users as well as the needs of consumptive and other traditional users. ESD considers the need for security and reliability of supply and the complexities of increasing competition for water within and between user groups, with future users and with wetland and instream needs.

The State Water Conservation Strategy provides an overall framework and on-going mechanism for the future planning development and management of the water resources of the state. This strategy forms an essential part of an on-going planning process of investigation, analysis and review and forms part of a regular re-examination and reporting process to reflect cunent needs and opportunities and prevailing economic and social circumstances.

Also being addressed in the legislation under review are the protection of aquatic habitats and riverine vegetation and rninimise National Water Quality Management Strategy principles. These principles relate to the the impact of mining and agricultural runoff. Additional issues being considered for the legislation include reform of water resource administration charges and procedures, establish property rights in water and extended community consultation and participation.

The DPI through the Water Resources Act (1989) regulates the use of surface and groundwater resources and associated environment by issuing licenses and permits.

Certain requirements and obligations effect all local governments, companies, irrigators and other landholders. These users require licences to divert water and construct water facilities on their land for private water supply, drainage or flood mitigation purposes. AU riparian owners have the right to use water for domestic and stock purposes though a permit is required for any works installed for this purpose.

Catchment areas around storages may be declared to enable land use and the quality of discharge of water to be controlled by DPI. Private dams can only be constructed on a watercourse of greater than a certain size with prior approval from the DPI. The DPI also manages watercourse sand and gravel extraction operations. 11.0 MANAGEMENT ISSUES

Cape York Peninsula at present has several watercourses and wetlands that are near pristine. However most areas are suffering from some form of degradation though generally this is slight. Isolated areas occur that are suffering severe degradation. Overall, the study area has extensive tracts that have had little disturbance, are unique and warrant concerted efforts to ensure the protection of their environmental and resource values.

The increasing demands on surface water resources and the waterways themselves require overall management strategies with specific objectives. These strategies need to address a balance between competing aspects and diversity of needs for the water resources, including a balance between the multi sectoral consumptive demands such as agricultural, tourism, urban and mining and the non consumptive uses such as the environmental flow requirements, scenic, recreation~andwilderness values.

Specific issues of significance which need to be addressed in management strategies include salinity, sedimentation, nutrient enrichment and euttophication, downstream effects of agricultural practices, chemical and possible bacterial contamination, alteration to flow regimes, intensive rural industries and instream water needs.

There are specific procedures that should be employed in detailed appraisals of any water resource development. These include economic evaluation, environmental impact assessment, hydrologic assessment, engineering design, and community consultation processes. Additionally, it should be considered that effective water resource management is dependent on other natural resources in the basin and the premise that this generation is merely the custodian of these resources for future generations.

Such goals will require a coordinated approach to planning and management of the surface water resources to achieve a balanced use of these resources and this will need to involve landholders, community groups and government agencies. This will require a thorough knowledge of the base issues with the idea that overall objectives and strategies may need to be mitigated with local knowledge and experience.

There are still many aspects of the Peninsula water resources that are unknown and compound the problems of effectively managing these resources. The main shortfall is in the surface water monitoring network which now comprises only 18 stations, mainly on large rivers. These shortfalls also include for example, a thorough knowledge of the variability of rainfall, such as the spacing and intensity of events. This extreme variability is not accommodated in the temperate Australia focused river models that are presently available. Other shortfalls include the fact -that no aquatic invertebrate inventory has been done. Such information could be useful in monitoring the condition of surface water resources and could be an important guide to river health through assessing the integrity of the food web.

The significance of this lack of information is compounded when considering it is usually a combination of issues that effects the health of the watercourses. Compounding effects are caused by feral pigs, domestic cattle, large wild fires and vehicular tracks etc that can multiply the effect of single or isolated threats. There are many potential threats of varying significance to the water systems of the Peninsula some of which include:

11.1 Feral Animals

Feral pigs are probably at present the greatest environmental concern to the water systems of the Peninsula with virtually every pocket of water having evidence of pig activity. Pigs have the effect of reducing bank stability by interfering with the riparian understorey growth (by undermining and felling small trees and shrubs) and digging in and wallowing in the waterholes. This has the effect of increasing turbidity and affecting the aquatic vegetation by trampling.

Pigs destroy Pandanus (Pandanus spiralis) as well as lotus, lily and possibly other rhizomes, and bulbs and fruits (Mitchell, 1994). The occurrence of the red lotus of the lower floodplains of the Mitchell River is considered endangered, attributable to destruction or disturbance by pigs to rhyzomes or seeds (Herbert 1993). Pigs also have the effect of removing animal food sources and interfering with animal microhabitats by removing logs and disturbing leaf litter, rocks and other refuges.

The recent extended dry seasons encourage pigs to establish near streams, waterholes and swamps sooner than normal, during wetter periods pigs probably spend less time near the watercourses. Additionally pigs can help in the propagation of noxious weeds. There is also a compounded effect from the direct damage caused by people who follow pigs into these areas for hunting.

Herbert et al. (1995) flagged the effect of pigs, and to an extent cattle and horses in lagoons, particularly their eating of aquatic vegetation; as well as there stirring up of water and causing turbidity, principally because of the importance of the lagoons in maintaining fish populations and as nursery grounds for juvenile fish.

Mitchell (1994) considers there is a general perception that the pig damage in coastal lowland streams and marine habitats causes extensive erosional problems during flooding.

Cane toads are also of concern as they now occur throughout the Peninsula (cane toads arrived at Weipa in 1985 - Saunders, pers. comrn) and are omnivorous and voracious eaters of insects and small frogs. Their effects on the aquatic ecosystems are not well understood but is probably significant.

Additionally, populations of feral exotic fish species occur in irrigation channels that drain into the Walsh River in the upper reaches of the Mitchell River catchment (Herbert, 1993). The ability of these species to migrate into the study area and their effect through competition with native species is unknown. Goldfish have been observed in drainage works at Weipa; at present they do not appear to have migrated into natural watercourses but it is unclear if they may in the future. 11.2 Cattle

Cattle numbers are relatively low in the Peninsula, though any plans to increase the intensity of grazing are of concern. Large areas of Cape York Peninsula such as National Parks and rugged sections of many of the pastoral leases and other areas have no cattle (including feral or scrub) management plans. Cattle (both domestic and scrub) cause compaction of the soil around watercourses and destruction of the understorey, including tufted grasses. This can reduce protection for trees, which can result in tree death. Cattle can also damage the underbank habitat and can spread weeds by breaking off branches and seeds which can float downstream and germinate. Disturbance by cattle appears to favour rubber vine (Cryptostegza grandzjlora) colonisation in the riparian zone in the Mitchell River (Herbert, 1993).

Further problems are caused by trampling, compacting and stirring up river banks and beds. Water quality problems can occur from significant nutrient additions to the banks and within watercourses leading to near shore eutrophication (overgrowth of aquatic plants) in waterholes and wetlands.

11.3 Exotic Vegetation

Significant effects of exotic vegetation on water resources do not appear to be widespread throughout the Peninsula, however significant local effects do exist.

Rubber vine (Cryptostegia grandzjlora) is extensively established in the Mitchell River and is present in the Normanby, Coen and Archer Rivers. Heavy rubber vine infestation appears to prevent the regeneration of large riverine trees and this may have an effect on the aquatic habitats by reducing the replenishment of logs to form snags (which produce a unique sheltered habitat) as well reducing the shading of the waterways (which has an effect on water temperature).

Some species compositions are changing, with sedges and reeds reducing in places (this may be occurring at Willum Swamp, near Weipa). This is allowing the invasion of native grasses which are a good &el for fire which can change the local fire regime. Additionally the spread of wild passionfruit by birds, and farmer introduced species, i.e. improved pasture species are of concern.

The native fauna is adapted to local conditions and such vegetation changes may cause species changes down the food chain. There is a strong possibility the above changes may be compounded by the potential widespread application of fertiliser in agricultural areas (as farming may potentially become more intense) which could also promote rapid algal and other growth in streams.

11.4 Increasing Population

Population increases would have compounding effects on many of the issues discussed. Better roads allow more people into the area and encourage small businesses to set up. This sediment loads add to the infilling of lagoons and waterholes and can result in a deterioration of aquatic ecosystems and reduced habitat diversity. This is a potential issue that may be of significant concern in lower energy environments such as wetlands and smaller creeks.

Local changes can be attributed to human and introduced animal activity. In a flyover of the Mitchell fiver, Herbert (1993) considered heavily grazed areas (as evidenced by numerous cattle tracks) accounted for most of the areas with extensive erosion problems. Also in the Mitchell River the effect of clearing below Quaid's Dam near Mareeba may have a significant effect on natural sediment fluxes.

Mining activities have turned over the bed sediments of the Palmer River several times. The bed of significant sections of this river is now rock, while similar rivers have sand beds. This feature may be related to mining disturbance allowing significant sediment loads to be washed downstream.

Roads and other construction works show evidence of erosion contributing further sediment loads into the watercourses. Offroad 4WD and trail bike activity also increases sedimentation and turbidity. Sources of sediment through such activities can be from erosion of the stream bed, banks and from the lower and upper catchment.

It is difficult to determine the effects of this increased sedimentation on the larger features such as river courses and coastal sand bars. Sand bars off Weipa and at the mouth of the Stewart fiver have changed significantly in the last twenty years. However, it is unknown how much of this change is due to accelerated catchment erosion. 12.0 CONCLUSION

In the study area there is a lack of data relating to surface water resources and a lack of detailed interpretation of the available data. This report has collected new field information on aquatic habitats and degradation issues and presented some interpretations on basin characteristics, river discharges, no flow periods and other information. One of the key points from this work is that information is so sparse in location, in time and in detail that -significantprocesses, such as point source pollution discharges, may be unknown.

The Peninsula's waterways are virtually pristine in several areas and in many locations have a high wilderness value. This feature presents an opportunity for proactive management to ensure an appropriate mix of protection and development is achieved to preserve the key areas. Given the constraints of limited data, overall the surface water quality is good with some local exceptions including the West Claudie River.

River discharges can be very high with the Jardine having the highest baseflow of any river in Queensland and the Mitchell possibly having the highest peak discharge of any river in Australia. However, flow rates are seasonally variable and the duration of flow, in the predominantly temporary watercourses, in each year may be critical for the natural ecosystems. Significant hrther work should be done on these environmental requirements before any fbrther modifications to streams are undertaken.

Additionally, several issues have been flagged that appear to have substantially affected the "health" of various sections of the watercourses. These include the impact of alluvial mining, feral and domestic animals, accelerated erosion supplying high sediment loads, exotic vegetation, and destruction of the riparian zone.

There is some increasing pressure on the surface water resources from irrigation, mining and residential development, increasing population, tourism and road construction. However, the overall consumptive use of the surface water resources is at present minimal (eg. on the east coast drainage area less than 0.2% of the mean annual flow). At this stage there is an opportunity to identifjr those areas that are suitable for further development and those areas for which development would cause irreparable damage. It is also an ideal time, ahead of any major development, to develop effective and sustainable management policies, and to collect information required for management of the surface water resources of the area. 13.0 BIBLIOGRAPHY

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APPENDIX 1 CATCHMENT CHARACTERISTICS RIVER BASIN 101 - JACKY JACKY

Average Rainfall Category (mml ...... Total = 2863 knr2, 10affh

km' % km' % km' % km' %

4000 - 3200 2400 . 2100 1700 1500 1828 63.8 1100 . 900 3200 . 2800 2100 . 1900 1500 1300 354 12.4 900 . 400 2800 - 2400 1900 . 1700 681 23.8 1300 1100 400 - 0 Regolith Type ...... -...... Total = 2841 knt, 100.ffh -km' km' % km' % Very highly weathered saprolite Soil on bedrock 53 Estuarine sediments 247 8.7 Residual sand Highly weathered saprolite Alluvial sediments Lacustrine sediments Residual clay Moderately weathered saprolite Channel deposits Beach sediments 21 0.7 Fa~~glon~erate Slightly weathered saprolite Overbank deposits 64 Coastal sediments Ash Saprolite Sheet flow deposits Aeolian sand Scree Completely weathered in situ rock Colluvial sediments

Soil Type ...... Total = 2842 kml, 100.0%

km' % km' % km' % km' %

Dermosols 4 0.1 Ka~tdasols 1431 50.4 Tenosols 407 14.3 Cl~ro~nosols Ferrosols Podosols 770 27.1 Vertosols 5 0.2 Water Hydrosols 225 7.9 Sodosols

Vegetation Class ...... Total = 2837 knrl, 100.0%

km' % km' % km' % km' Oio

Rainforest associations 254 9.0 Drier Ti Tree associations 5 0.2 Heal111 co~n~nunities 1336 47.0 Saline wetlands 220 7.8 Wet eucalypt and wattle associations 40 1.4 Grasslands 12 0.4 Welter Ti Tree 26 0.9 Bare areas 182 6.4 Dry eucalypt associations 763 26.9

Hydrogeological Unit ...... Total = 2865 knrl, 100.0%

km' % km' % km' % km' %

Alluvial aquifers 168 5.9 Regional sedia~eataryaquifers 58 2.0 Potential local sedimentary aquifers 9 0.3 Crystalline material, salt palls, 0 0.0 Potential dune aquifers 722 25.2 Potential local sedimentary aquifers 966 33.7 (often sali11e1 shales, etc Other possible unconsolidated aquifers 917 32.0 Potential fractured rock aquifers 0 0.0 Water 25 0.9

Potential Recharge Area (Aquifer Ty~e)...... Total = 2865 knr2, 100.ffh

km' % km' % km' % km' %

Non-recharge 1141 39.8 Dune 717 25.0 Bulin~ba Wyaaba Fractured rock Mesozoic 1007 35.2 RIVER BASIN 102 - OLIVE PASCOE Average Rainfall Category lmml ...... Total = 4153 k/ti2, 100.m

- km' % km' % km' % km' % 4000 - 3200 2400 . 2100 1700 . 1500 1910 46.0 1100 . 900 3200 . 2800 2100 . 1900 1 <0.1 1500 . 1300 1874 45.1 900 . 400 2800 - 2400 1900 . 1700 367 8.9 1300 . 1100 1

Very highly weathered saprolite Soil on bedrock 759 18.3 Estuarine sedi~nents 30 Residual sand Highly weathered saprolite 743 17.9 Alluvial sedin~ents 102 2.5 Lacustrine sediments Residual clay Moderately weathered saprolite 575 13.9 Channel deposits Beach sedin~ents 2 Fangloleerate Slightly weathered saprolile 1607 38.7 Overbank deposits 25 0.6 Coastal sediments 3 Saprolite Sheet flow deposits Aeolian sand 108 2.6 Scree Colluvial sediments 1

SoilType ...... Total=

km' % km' % km' %

Dermosols 180 4.3 Kandasols 2057 49.5 Tenosols 1259 30.3 Chro~nosols Ferrosols Podosols 355 8.6 Vertosols Water Hydrosols 149 3.6 Sodosols 48 1.2

Vegetation Class ...... Total = 4151 kd, 100.Ph

km' % km' % km' % km' %

Rainforest associations 512 12.3 Drier Ti Tree associations 242 5.8 Heal111 communities 1057 25.5 Saline wetlands 38 0.9 Wet eucalypt and wattle associations 8 0.1 Grasslands 8 0.2 Wetter Ti Tree 9 0.2 Bare areas 63 1.5 Dry eucalypt associations 2218 53.5

Hydrogeological Unit ...... Total = 4153 km2, 100.0%

km' % km' % km' % km2 Sb

Alluvial aquifers 222 5.3 Regional sedimentary aquifers 1215 29.3 Potential local sedimentary aquifers 681 16.4 Crystalline material, salt pans, 0 0.0 Potential dune aquifers 111 2.7 Potential local sedimentary aquilers 311 7.5 [often saline) sl~ales, etc Other possible unconsolidated aquifers 414 10.0 Potential fractured rock aquifers 1193 28.7 Water 6 0.1

Potential Recharge Area [Aquifer Tyml ...... Total = 4153 kmz, log&%

km2 % kmZ % km' % km' %

Noa.recharge 1282 30.9 Dune 158 3.8 Buli~nba Wyaaba Fractured rock 1193 28.7 Mesozoic 1520 36.8 RIVER BASIN 103 - PASCOE Average Rainfall Category (mm) ...... Total = 2838 kmz, 1OO.ffh

km' % km' % km' % km' %

4000 - 3200 2400 - 2100 1700 . 1500 854 30.1 1100 . 900 3200 . 2800 2100 . 1900 1500 1300 1507 53.1 900 . 400 2800 . 2400 1900 . 1700 127 4.5 1300 . 1100 350 12.3 400 . 0

Regolith Type ...... Total = 2809 kntz, 1Ollffh

km' % km' % km' % km' %

Very highly weathered saprolite 115 4.1 Soil on bedrock 310 11.0 Estuarine sediments 134 4.8 Residual sand 25 0.9 Highly weathered saprolite 173 6.2 Alluvial sediments 539 19.2 Lacustrine sedin~ents Residual clay Moderately weathered saprolite 1049 37.3 Channel deposits Beach sediments 124 4.4 Fanglo~nerate Slightly weathered saprolite 228 8.0 Overbank deposits 13 0.5 Coastal sediments 5 0:2 Ash Saprolite 54 1.9 Sheet flow deposits Aeolian sand 40 1.4 Scree Completely weathered in situ rock Colluvial sediments

Soil Type ...... Total = 2810 knt', 1OO.Ph

km' % km' % km' % ktn' %

Dern~osols 210 7.5 Kandasols 866 30.8 Tenosols 345 12.3 Cl~romosols 286 10.2 Ferrosols Podosols 237 8.4 Vertasols Water Hydrosols 584 20.8 Sodosols 282 10.0

Vegetation Class ...... Total = 2809 kntz, 1OLlPh

km' % km' % km' % km' %

Rainforest associations 1287 45.8 Drier Ti Tree associations 432 15.4 Health corn~nunities 165 5.9 Saline wetla~~ds 102 3.6 Wet eucalypt and wattle associations 297 10.6 Grassla~~ds 56 2.0 Wetter Ti Tree 5 0.2 Bare areas 26 0.9 Dry eucalypt associations 439 15.8

Hydrogeological Ullit ...... -.- Total = 2838 kntz, 1OO.ffh

km' % km' % km' % km' %

Alluvial aquifers 6 0.2 Regional sedimentary aquifers 486 17:1 Potential local sedinlentary aquifers 0 0 Crystalline nlaterial, salt palls. 0 0.0 Potential dune aquifers 177 6.2 Potential local sedilt~entaryaquifers 181 6.4 (often saline) sl~ales, etc Other possible unconsolidated aquifers 530 18.9 Potential fractured rock aquifers 1430 50.4 Water 22 0.8

-. - . 1 Potential Recharge Area (Aquifer Ty~e)...... ~ota/=ZUJU kntz, IUU,~

km' % km' % km' % kn~' %

Non.recharge 1216 42.8 Dune 223 7.9 Bulinlba Wyaaba Fractured rock 1399 49.3 Mesozoic - RIVER BASIN 104 - STEWART Average Rainfall Category imm) ...... Total = 2715 knj2,

km' % km' % km' % km' % 4000 - 3200 2400 - 2100 1700 . 1500 136 5.0 1100 . 900 169 6.2 3200 - 2800 2100 1900 5 0.2 1500 . 1300 593 21.8 900 . 400

2800 . 2400 1900 + 1700 26 1.0 1300 - 1100 1786 65.8 400 - 0 Regolith Type ...... Total = 2688 kd, loam

km' % km' % km' % km' %

Very highly weathered saprolite 236 8.9 Soil on bedrock 48 1.8 Estuarine sediments 67 2.5 Residual sand 160 6.0 Highly weathered saprolite 753 28.0 Alluvial sediments 1172 43.6 Lacustrine sediments Residual clay Moderately weathered saprolite 184 6.8 Channel deposits 3 0.1 Beach sediments 45 1.7 Fanglornerate Slightly weathered saprolite Overbank deposits Coastal sediments 16 0.6 Ash Saprolite Sheet flow deposits Aeolian sand 4 0.1 Scree Coinpletely weathered in situ rock Colluvial sediments

SoilType ...... rota/=268gkn~~, 100.Ph

km' % km' % km' % km' %

Derinosols Kandasols 1386 51.6 Tenosols 107 4.0 Cl~ro~nosols 1

Vegetation Class ...... Total .: 2692 kn#, 10OR4 - km' % km' % km2 % k~n' %

Rainforest associations 406 15 Drier Ti Tree associations 615 22.9 Health co~nn~unities 16 0.6 Saline wetlal~ds 75 2.8 Wet eucalypt and wattle associations 51 1.9 Grasslands 19 0.7 Wetter Ti Tree 88 3.3 Bare areas 0 0 Dry eucalypt associations 1422 52.8

Hydrogenlogical Unit ...... ,- Total = 2715 kn?, lOO,ff!% km' % timl % km' % km' %

Alluvial aquifers 0 0 Regional sedimentary aquifers 171 (3.3 Potential local sedin~entary aquifers 0 0.0 Crystalline niaterial, salt pans, 0 0.0 Potential dune aquifers 70 2.6 Potential local sedimentary aquifers 3 0.1 (often saline) sliales, etc Other possible unconsolidated aquifers 1622 59.7 Potential fractured rock aquifers 822 30.3 Water 27 1.0

r ? ann m, Potential Recharge Area (Aquifer Type) ...... ~ora~.. = ~113"....- Knr,. IUU.~

km' % km' % km' % kml %

Nonrecharge 1619 59.6 Dune 106 3.9 Bulirnba Wyaaba Fractured rock 822 30.3 Mesozoic 168 6.2 s 9'9 ss szz -gsx2 r- "2 s Ur.0 3 -.- ZXZ -=as.-r 2 2 Q)mN 2 5 -4 -4 It 11 .a .8 g t2 C --'D mM gg7 .---aa- - U - V)- a gss -=(0 -2I3 aVI -.- -(0 tV) 0

ern2 ..sz2 1 -LO.- -

1-kk5O .: -.3 :$$

g LI .-= =a m g 2- a-5 000 - 000 5; 2 LO C? -7-- E m -0 GV)? ... a== >. 000 cer : 000 -"1 0 z. hES! Egg e: 2 - -a .- : . -C z0. = 2 'Y 0 z : 0 5 . . L YI' -.0 : . *7=? : s E- 000 zz cn- u : m. I :a 2 SEE 2 C? 2: a.

ff 2 .--a I =aw = 000 > .E 000 -ah -$LIz-= N--... 23%e a 000 .- 000 =sz u-m NN- -"'a .- a - .-E 5 zz CT

7 :s 0 : s " 2 zzzw

LO : .: g wz "E3 ZgE-

E - L E rn E '3- - z 2 " -.i m 000 z O-FI 0 0 0 = m= - hlwu .-- m C? N N C f U ... 3 - 0 0 0 - .-xu 2 m 000 m >x= ONW -C .- 3 .= (Y UC?N .- m = a=- Cr:m P- - -0 cn 0 5 0V) D1m a L e (Y f u> 5 2 x 0 RIVER BASIN 106 JEANNIE

Average Rainfall Category (mm) ...... Total = 3851 kn~', 1000%

km' % km' % km2 % kn~' O;o

4000 . 3200 2400 . 2100 1700 . 1500 1778 46.1 1100 . 900 3200 . 2800 2100 . 1900 75 2.0 1500 1300 1451 37.7 900 . 400 2800 . 2400 1900 . 1700 305 7.9 1300 . 1100 242 6.3 400 . 0 Regolith Type ...... Total = 3819 knt, loo.&

km' % km' % km' % km' %

Very highly weathered saprolite 1 <0.1 Soil on bedrock 1072 28.1 Estuarine sediments 170 4.5 Residual sand 218 5.7 Highly weathered saprolite 45 1.2 Alluvial sediments 589 15.4 Lacustrine sediments Residual clay 76 2.0 Moderately weathered saprolite 123 3.2 Channel deposits Beach sed~nlents 19 0.5 Fanglonlerate 893 23.4 Slightly weathered saprolite Overbank deposits Coastal sediments Ash 2 <0.1 Saprolite Slleet flow deposits Aeolian sand 603 15.8 Scree 8 0.2 Completely weathered in situ rock Colluvial sedinients

Soil Type ...... Total = 3820 knt, 100.W0

km' % km' % km' % kml %

Dermosols 1255 32.9 Kandasols 388 10.2 Tenosols 957 25.0 Cl~ro~~~osols 22 0.6 Ferrosols 102 2.7 Podosols 739 19.3 Vertosols Water 5 0.1 Hydrosols 219 5.7 Sodosols 133 3.5

Vegetation Class ...... Total= 3814knr2, 1OO.ffh

km' % km' % km2 % knl' %

Rainforest associations 295 7.7 Drier Ti Tree associations 353 9.3 Health con~niunities 5544 14.5 Salinc wellands 174 4.6 Wet eucalypt and wattle associations 141 3.7 Grasslands 10 0.3 Wetter Ti Tree 89 1.8 Bare areds 85 2.2 Dry eucalypt associations 2133 55.9

Hydrogeological Unit ...... Total = 3852 knr', loo.&%

km' % km' % km' % km' %

Alluvial aquifers 323 8.4 Regional sedimentary aquifers 583 15.1 Potential local sedimentary aquifers 0 0.0 Crystalline material, salt pans, 0 0.0 Potential dune aquifers 927 24.0 Polenlial local sedimentary aquifers 0 0.0 loften saline) sl~ales, etc Other possible unconsolidated aquifers 1324 34.5 Potential fractured rock aquifers 656 17.0 Water 39 1.0

.- . . .- .. - Potential Recharge Area (Aquifer Ty9e) ...... Total = 3852 kn!', 100m

km' % km' % km' % km' %

Non.recharge 1766 45.9 Dune 859 22.3 Bulimba Wyaaba Fractured rock 644 16.7 Mesozoic 583 15.1 RIVER BASIN 107 . ENDEAVOUR

Average Rainlall Category (mm) ...... Total = 2126 kn12, 100.0%

km' % km' % km' % km' %

4000 . 3200 3 0.1 2400 . 2100 262 12.3 1700 . 1500 748 35.0 1100 . 900 3200 . 2800 34 0.1 2100 . 1900 1500 . 1300 555 26.1 900 . 400 2800 . 2400 104 4.9 1900 . 1700 256 12.0 1300 . 1100 169 8.0 400 . 0

RegolithType ...... Total=2101kn#, 1OaPh

km' % km' % km' % km' Yo

Very highly weathered saprolite 113 5.4 Soil on bedrock 244 11.6 Estuarine sediments 29 1.4 Residual sand Highly weathered saprolite 492 23.5 Alluvial sediments 482 23.0 Lacustrine sedin~ents Residual clay 46 2.2 Moderately weathered saprolite 523 24.9 Channel deposits Beach sediments 4 0.2 Fanglomerate 4 0.2 Slightly weathered saprolite Overbank deposits Coastal sediments 8 0;4 Ash 2

Soil Type ...... Total = 2103 km2, 100.0

km' % km' % km' % km' %

Dermosols 1467 69.7 Kandasols 163 7.8 Tenosols 153 7.3 Chro~~iosols 7 0.3 Ferrosols 54 2.6 Podosols 141 6.7 Vertosols Water Hydrosols 34 1.6 Sodosols 84 4.0

Vegetation Class ...... rota1 = 2098 kn12, 100,m

km2 % km' % km' % km' %

Rainforest associations 446 21.2 Drier Ti Tree associations 4 0.2 Healtll conlnlunities 95 4.5 Saline wetlands 27 1.3 Wet eucalypt and wattle associations 250 11.9 Grasslands 10 0.5 Wetter Ti Tree 10 0.5 Bare areas 18 0.9 Dry eucalypt associations 1238 59

Hydrogeological Unit ...... Total = 2126 ktr,', lOO.L?%

D km' % km' % km2 % k~n' A

Alluvial aquifers . 231 10.9 Regio~~alsedimentary aquifers 175 8.2 Potential local sedinientary aquifers 0 0.0 Crystalline material, salt pans, 0 0.0 Potential dune aquifers 123 5.8 Potential local sedimentary aquifers 0 0.0 (often saline) sl~ales,etc Other possible unconsolidated aquifers 650 30.6 Potential fractured rock aquifers 921 43.3 Water 2G 1.2

Potential Recharge Area (Aquifer Type) ...... rota1 = 2126 kn#, 100,m

km' % km' % km' % kill1 X

Nonrecharge 893 42.0 Dune 141 6.1 Bulimba Wyaaha Fractured rock 917 43.1 Mesozoic 175 8.2 RIVER BASIN 108 - DAINTREE Auerage Rainfall Category (md ...... Total = 132 knjz, 1OO.ffh - km' % km' % kml % km' % 4000 . 3200 2400 . 2100 68 51.5 1700 . 1500 1100 . 900 3200 - 2800 2100 . 1900 1500 . 1300 900 . 400 2800 . 2400 24 18.2 1900 . 1700 25 18.9 1300 . 1100 400 . 0 Regolith Type ...... -..... -'8 kni'. I km' km' km' I I I I - - Very highly weathered saprolite Soil on bedrock Estuarine sedi~ne~~ts 2 Residual sand Highly weathered saprolite Alluvial sediments Lacustrine sediments Residual clay Moderately weathered saprolite Channel deposits Beach sediments 3 Fanglo~nerate Slightly weathered saprolite Overbank deposits Coastal sedi~nents Ash Saprolite Sheet flow deposits Aeolian sand 2 Scree Completely weathered in situ rock Colluvial sedin~ents

Soil Type ...... Total = 127 knt2, 1OO.ffh

km' % km' % kml % kml %

Dermosols 94 73.9 Kandasols 2 1.6 Tenosols 26 20.5 Cl~ro~nosols Ferrosols Podosols 2 1.6 Vertosols Water Hydrosols 3 2.4 Sodosols

Vegetation Class ...... Total = 128 kni2, 100,w - km' % km' % km' % km' Oh Rainforest associations 95 74.9 Drier Ti Tree associations 0 0.0 Health comn~unities 0 0.0 Saline wetla~~ds 2. 1.6 Wet eucalypt and wattle associations 29 22.9 Grasslands 0 0.0 Wetter Ti Tree 2 1.6 Bare areas 0 0.0 Dry eucalypt associations 0 0.0

Hydrogeological Unit ...... Total = 132 knt, lOO.G%

km' % km' % km' % km' %

Alluvial aquifers 28 22.0 Regional sedimentary aquifers 0 0.0 Potential local sedimentary aquifers 84 63.6 Crystalline material, sall pans, 0 0.0 Potential dune aquifers 0 0.0 Potential local sedimentary aquifers 0 0.0 [often saline) shales, etc Other possible unconsolidated aquifers 15 11.4 Potential fractured rock aquifers 0 0.0 Water 4 3.0

Potential Recharge Area (Aquifer Typel ...... Total = 132 knj2, 100.a

km' % km2 % km' % km2 %

Non.recharge 48 36.4 Dune Buli~nba Wyaaba Fractured rock 84 63.6 Mesozoic

RIVER BASIN 920 - COLEMAN

Average Rainfall Category (mml ...... Total = 12961 knr2, 100.wi

km' % km' % km' % km' %

4000 - 3200 2400 . 2100 1700 . 1500 14 0.1 1100 . 900 5217 40.3 3200 - 2800 2100 . 1900 1500 . 1300 889 6.9 900 . 400 5100 39.3 2800 . 2400 1900 . 1700 1300 1100 1741 13.4 400 . 0 ...... Total = 12912 knr2, 100.0% km' % km'

Very highly weathered saprolite 1505 11.7 Soil on bedrock 149 "i- 19.0 LacustrineEstuarine sedimentssediments Residual sand Highly weathered saprolite 1002 7.8 Alluvial sediments 2450 Residual clay Moderately weathered saprolite 1617 12.5 Channel deposits 4196 32.5 Beach sediments 342 Fanglon~erate Slightly weathered saprolite 1 <0.1 Overbank deposits 334 2.6 Coastal sediments Saprolite Sheet flow deposits Aeolian sand Scree Completely weathered in situ rock 167 1.3 Colluvial sediments 39 0.3 SoilType ...... Total= t2912knr2, 100.Ph

km' % km' % km' % kn~' %

Dermosols 106 0.8 Kandasols 7528 73.8 Tenosols 2112 16.4 Cl~ro~~~osols 86 0.7 Ferrosols Podosols 9 <0.1 Verlosols 414 3.2 Water Hydrosols 3255 25.2 Sodosols 115 0.9

Vegetation Class ...... Total = 12905 knr2, 1OO.m 1 1 km' I % km' % km' % km' % I I I Rainforest associations 27 0.2 Drier Ti Tree associations 2619 20.3 Heal111 co~n~nunities 212 1.6 Saline wetla~~ds 164 1.3 Wet eucalypt and wattle assaciations 1 <0.1 Grasslands 928 7.2 Wetter Ti Tree 245 1.9 Bare areas 1

Hydrogeological Unit ...... Total=12961kn~,IO0.0~

km' % km' % km' % km' % I I I Alluvial aquifers 2751 21.2 Regional sedin~entaryaquifers 5613 43.3 Potential local sedin~entaryaquifers 241 1.9 Crystallir~e~nalcrial, salt pans. 53 0.4 Potential dune aquifers 294 2.3 Potential local sedimentary aquifers 0 0.0 [often saline) sl~ales, elc Other possible unconsolidated aquifers 1440 11.1 Potential fractured rock aquifers 2506 19.3 Water 63 0.5 - . .... -. Potential Recharge Area [Aquifer Type) ...... Total = 12961 knr', 100.0%

km' % km' % km' %

Non.recharge 6349 49.0 Dune 268 2.2 Bulin~ba 96 0.7 Wyaaba Fractured rock 2508 19.4 Mesozoic vi .3 m1- - 2 mM -- ma--o .- . -"G; gG3- : -.-gw -w (0 5 0

zz:UN.

gE; .-- a ==.a. 0. 2.O. ma* . Egg : .- : 0z=& we5 : "'Yo . -zzz . -0 - - m. .m .% : --w. 'Yo.- - OR - P

LD w 0

VI L -.-" g 3- z 2 000 000 -mh N--... 5 $ 000 .- z 000 5 u-m g = NN- -m 2 e - .=m .=- w= = 'Y e

m-m-0- *

I= LI, m = C VI= s -8$ g 5 m .g= zs-u = z.""=: m -m-=E 5 =g

0- - 0-0 .-a -c - B 0 2 - % .--- zz s eY CI -2 - * -E $5 - LD* 2 - .It 8 2

00 88: sm m gdE m ==0 1 I

- : * 22: 7 - 2 - 0h P. h0 m0 ggs *u*(I 2 --- 0N -

M .- a 00 0 .-- 000 c 2 LD 0 = + ---- E .- m ... 5: -.- 000 a 0 00 Y m E"71 -=-w - : zs x= ' I 0.. EE u. .: N. N. - 0). z.: s 22 22 22 uV). - - = : -0 0 @a : "E "7z *Lno L9 NNO) Ln 2 :z a. -

g .-0 .--LO 00 0 000 aY " -oh M vC .-0 N-- 'rn a 0 ... a s f 000 - 0 a 2 000 .-'-a I zT;ZI! + L .-w 0 - - s 22: 22 I- CJ - . . -

.ax,: m(I m : m N 2 WNC- m CY0 - " - .-0C E .--m -E Egg 2 .-0 w '; DI 000 .z :.: 000 ~5 Nm- 5 m - CINN 2% = ULO -e ... z3: 0 va2 - ooa --CI 2 ; LO 000 rn C' ONrn :ma .-- O-L S$ .--c ga z= > -z e 3 L P - RIVER BASIN 923 . WATSON

Average Rainfall Category (mm) ...... Total = 4673 knt2, 100,ffh

km' % km2 % km' % km2 %

4000 . 3200 2400 - 2100 1700 - 1500 1029 22.0 1100 . 900 671 20.8 3200 . 2800 2100 . 1900 1500 - 1300 921 19.7 900 . 400 317 6.8 sann . s~nn 1900 - 1700 1300. 1100 1435 30.7 4nn . fl

Regolith Type ...... Total = 4627 kd, 1OO.ffh

km' % km2 % km' % km' %

Very highly weathered saprolite Soil on bedrock Estuarine sediments 88 1.9 Residual sand 38 0.8 Highly weathered saprolite Alluvial sediments 2773 59.9 Lacustrine sedinlents 17 0.4 Residual clay Moderately weathered saprolite 1373 29.7 Channel deposits 313 6.8 Beach sediments 25 0.5 Fanglolnerate Slightly weathered saprolite Overbank deposits Coastal sediments Ash Saprolite Sheet flow deposits Aeolian sand Scree Completely weathered in situ rock Colluvial sediments

Soil Type ...... Total = 4631 knt2, 1OO.Ph

km' % km' % km2 % km2 %

Dermosols 1610 34.8 Kandasols 2103 45.9 Tenosols 46 1.0 Cl~ro~iiosols Ferrosols Podosols Vertosols 58 1.2 Water 2 <0.1 Hydrosols 181 3.9 Sodosols

Vegetation Class ...... Total=4628knt2,

km2 % km' % km2 % km' %

Rainforest associations 94 2.0 Drier Ti Tree associations 28 0.6 Health co~n~nunities 22 0.5 Saline wetlands 74 1.6 Wet eucalypt and wattle associations 0 0.0 Grasslands 31 0.7 Wetter Ti Tree 107 2.3 Bare areas 0 0.0 Dry eucalypt associations 4272 92.3

Hydrogeological Unit ...... Total = 4674 knt,

km' % km' % km' % km' %

Alluvial aquifers 0 0.0 Regional sedimentary aquifers 2749 58.9 Potential local sedimentary aquifers 1485 31.8 Crystalline ~naterial, salt pans, 0 0.0 Potential dune aquifers 21 0.4 Potential local sedimentary aquifers 0 0.0 (often sali~~e) shales, etc Other possible unconsolidated aquifers 366 7.8 Potential fractured rock aquifers 0 0.0 Water 53 1.1 - ...... Potential Recharge Area (Aquifer Ty~e)...... Total = 4614 knf,

km' % km2 % km' % km' Z

Non.recharge 2441 52.2 Dune 45 1.0 Bulimba 2188 48.8 Wyaaba Fractured rock Mesozoic RIVER BASIN 924 - EMBLEY

Average Rainfall Category (mm) ...... Total = 4678 ktr*, 1OLlffh

km' % km' % km' % km' %

4000 . 3200 2400 . 2100 1700 - 1500 1211 25.9 1100 . 900 447 9.5 3200 . 2800 2100 1900 1500 . 1300 1804 36.6 900 . 400 2800 . 2400 1900 . 1700 1300 1100 1216 26.6 400 . 0

Regolith Type ...... Total = 4566 knr2, 1OO.Ph

km' % km' % km' % km' %

Very highly weathered saprolite Soil on bedrock Estuarine sediments 433 9.5 Residual sand 1574 34.5 Highly weathered saprolite Alluvial sediments 294 6.5 Lacustrine sediments 37 0.8 Residual clay Moderately weathered saprolite 21 11 46.2 Channel deposits Beach sediments 52 1.1 Fanglomerate Slightly weathered saprolite Overbank deposits 15 0.3 Coastal sediments Ash Saprolite Sheet flow deposits Aeolian sand 50 1.1 Scree Completely weathered in situ rock Colluvial sediments

SoilType ...... Total= 4580knra, 100,ffh

km' % km' % km7 % km7 %

Oermosols 1738 37.9 Kandasols 2942 39.7 Tenosols 246 5.4 Cl~roi~~osols Ferrosols Podosols 8 0.2 Vertosols 118 2.6 Water 5 0.1 Hydrosols 367 8.0 Sodosols

Vegetation Class ...... Total = 4581 kn~', 100.ffh 1 km' % km' % km' % km' %

Rainforest associations 50 1.3 Drier Ti Tree associations 84 1.8 Heal111 communities 54 1.2 Saline wetlands 296 6.4 Wet eucalypt and wattle associations 0 0.0 Grasslands 78 1.7 Wetter Ti Tree 150 3.3 Bare areas 0 0.0 Dry eucalypt associations 3860 84.3

Hydrogeological Unit ...... Total = 4681 knrl, 1OO.ffh

km' % km' % km' % k~n' YO

Alluvial aquifers 0 0.0 Regional sediliientary aquifers 722 15.4 Poter~tiallocal sedimentary aquifers 1499 32.0 Crystalline ~naterial.salt palls, 0 0.0 Potential dune aquifers 118 2.5 Potential local sedimentary aquifers 0 0.0 (often saline) sl~ales, etc Other possible unconsolidated aquifers 2241 47.9 Potential fractured rock aquifers 0 0.0 Water 101 2.2

. . -...... - . - . 7 Potential Recharge Area [Aquifer Ty'le) ...... Iota1 = 4081 knr-, IUUUJ%

km' % km' % km' % klnl %

Non-recharge 1191 25.4 Dune 245 5.3 Buli~nba 3245 69.3 Wyaaba Fractured rock Mesozoic 6 ;: 2 9 -.- g -=- -a sD-= I1 .C C

-a 0LO - 0 1 = LD 3 U

: S 22-

: Oeo - -%a= UOON

-.z 2 e e s 2 P; e >

: " 2-72

' L1 . E NO- , gz-

2 LO LO 0-- ge", zsz zz'z

: S : 2

:=Z;Z'- Ln .,NU

0 LO2 0 - gLOze !?s -a> &.i=

mP -.-I= CO0 RIVER BASIN 926 - DUClE

Average Rainfall Category (mm) ...... Total = 6789 kn12, 1OO.ffA

km' % km' % km' % km' %

4000 3200 2400 . 2100 1700 1500 1549 22.8 1100 . 900 3200 . 2800 2100 . 1900 1500 . 1300 4562 67.2 900 - 400 2800 . 2400 1900 . 1700 250 3.7 1300 . 1100 428 6.3 400 . 0

Regolith Type ...... Total = 6733 kn?, 100.ff/p

km' % km' % km' % km' %

Very highly weathered saprolite Soil on bedrock Estuarine sediments 329 4.9 Residual sand 2122 31.5 Highly weathered saprolite , 275 4.1 Alluvial sediments 184 2.7 Lacustrine sediments Residual clay Moderately weathered saprolite 197 2.9 Channel deposits Beach sediments 238 3.5 Fa~~glo~liera~e Slightly weatliered saprolile 2994 44.5 Overbank deposits 394 5.9 Coastal sediments As11 Saprolite Sheet flow deposils Aeolian sand Scree Completely weathered in situ rock Colluvial sediments

Soil Type ...... Total = 6734 km2, 100,ffh

km' % km' % km' % km' %

Dermosols 686 10.2 Kandasols 2606 79.7 Tenosols 287 4.3 Cl~ro~~iosols Ferrosols Podosols 546 8.1 Vertosols 37 0.5 Waler Hydrosols 553 8.2 Sodosols

Vegetation Class ...... Total = 6735 kn4, fOO.m

km' % km' % km' % km' %

Rainforest associations 88 1.3 Drier Ti Tree associations 641 9.5 Healtll communities 772 11.5 Saline wetlands 230 3.4 Wet eucalypt and wattle associations 0 0.0 Grasslands 94 1.4 Wetter Ti Tree 118 1.8 Bare areas 413 6.1 Dry eucalypt associations 4379 65.0

Hydrogeological Unit ...... Total = 6791 knt2, 100,m

km' % km' % km' % km' %

Alluvial aquifers 42 0.6 Regional sedimentary aquifers 306 4.5 Potential local sedimentary aquifers 1984 29.2 Crystalline nlaterial. salt palls, 0 0.0 Potential dune aquifers 252 3.7 Potential local sedinientary aquifers 1536 22.6 [often saline) shales, elc Other possibls unconsolidated aquifers 2628 38.8 Potential fractured rock aquifers 0 0.0 Waler 43 0.G

Potential Recharge Area (Aquifer Type) ...... Total = 6791 kn?, 100,0!&

km' % km' % km' % k~i? %

Non.recharge 3280 48.3 Dune 599 8.8 Buli~nba 1376 20.3 Wyaaba Fractured rock Mesozoic 1536 22.6 RIVER BASIN 927 - JARDINE Average Rainfall Category lmm) ...... Total = 3271 knr2,

km' % km' % km' % knl' %

4000 . 3200 2400 . 2100 1700 . 1500 1051 32.1 1100 - 900

3200 - 2800 2100 + 1900 1500 . 1300 1569 48.0 900 . 400 2000 . 2400 1900 - 1700 544 16.6 1300 - 1100 107 3.3 400 . 0 Regolith Type ...... Total = 3268 knt, 100.0%

km' % krn' % km' % krn' %

Very highly weathered saprolite Soil on bedrock 1 <0.1 Estuarine sediments 22 0.7 Residual sa~~d 276 8.9 Highly weathered saprolite Alluvial sediments 40 1 12.3 Lacustrine sediments Residual clay Moderately weathered saprolite 32 1.0 Channel deposits Beach sediments 35 1.0 Fanglomerate Slightly weathered saprolite 2245 68.7 Overbank deposits 186 5.7 Coastal sediments As11 Saprolite Sheet flow deposits 5 1 1.6 Aeolian sand 19 0.6 Scree Completely weathered in situ rock Colluvial sediments

SoilType ...... Total= 326gknt2, 1OaPh

km2 % krn' % km' % km' %

Dermosols Ka~ldasols 166 61.3 Tenosols 32 1.0 Chro~~~osols Ferrosols Podosols 602 18.4 Vertosols 8 0.2 Water Hydrosols 21 0.7 Sodosols 9 3.3

Vegetation Class ...... - Total = 3268 kn? loam km' % km' % km' % km' %

Rainforest associations 409 12.5 Drier Ti Tree associations 13 0.4 Health co~nn~unities 1561 47.8 Saline wetlands 22 0.7 Wet eucalypt and wattle associations 59 1.8 Grasslands 1 <0.1 Wetter Ti Tree 12 0.4 Bare arcas 272 8.3 Dry eucalypt associations 919 28.1

Hydrogeologicalunit ...... T0ta1=3272km~,100,~

km' % km' % km' % km' %

Alluvial aquifers 264 8.1 Regional sedime~~taryaquifers 0 0.0 Potential local sedi~nentaryaquifers 0 0.0 Crystalline material, salt pans. 0 0.0 Potential dune aquifers 53 1.6 Potential local sedimentary aquifers 1867 57.0 (often saline) shales, etc Other possible unconsolidated aquifers 1052 32.2 Potential fractured rock aquifers 19 0.6 Water 17 0.5

- ...... - . Potential Recharge Area [Aquifer Ty'le) ...... Total = 3272 knf, 100,m

km2 % km' % kmZ % km' %

Non.rec11arge 1068 32.6 Dune 324 9.9 Buli~nba Wyaaha Fractured rock 18 0.6 Mesozoic 1862 56.9 RIVER BASIN 928 - TORRES STRAIT ISLANDS Average Rainfall Category (mm) ...... Total = 278 kn?, 100,m

km' % km' % km' % km' @h

4000 . 3200 2400 . 2100 1700 - 1500 197 70.9 1100 , 900 3200 . 2800 2100 . 1900 1500 1300 22 7.9 900 . 400 2800 . 2400 1900 - 1700 59 21.2 1300 . 1100 400 . 0

Regolith Type ......

km' % I I Very highly weathered saprolite Soil on bedrock Highly weathered saprolite Alluvial sediments Moderately weathered saprolite Channel deposits Sliglitly weathered saprolite Overbarik deposits Saprolite Slieet flow deposits Colluvial sedinients

Soil Type ...... Total = 271 kn?, 100,099

km' % km' % km2 % km' %

Der~nosols Kandasols Tenosols 31 11.4 Cliromosols Ferrosols Podosols 45 16.6 Vertosols Water Hydrosols 21 7.4 Sodosols

Vegetation Class ...... Total = 271 knr': 100.0% km' % km' % km' % km' %

Rainforest associations 20 7.4 Drier Ti Tree associations 55 20.3 Health con~munities 2 0.7 Saline wetlalids 20 7.4 Wet eucalypt and wattle associations 2 0.7 Grasslands 1 0.4 Wetter Ti Tree 0 0.0 Bare areas 0 0.0 Dry eucalypt associations 171 63.1

Hydrogeological Unit ...... Total = 27g knr2, 100.0%

km' % km' % km' % km' S'o

Alluvial aquifers 0 0.0 Regional sedi~nentaryaquifers 0 0.0 Potential local sedinientary aquifers 0 0 Crystalline n~aterial,salt pans. 0 0.0 Potential dune aquifers 8 2.9 Potential local sedilnelitary aquifers 0 0.0 loften saline) sliales, etc

Olher possible unconsolidated aquifers 75 ' 26.9 Potential fractured rock aquifers 184 65.9 Water 12 4.3

Potential Recharge Area (Aquifer Ty~e)...... Iota/ = ZfY ki~r,lUU.m

km' % km' % km' % km' %

No~~.recliarge 95 34.1 Dune Buli~nba Wyaaba Fractured rock 184 65.9 Mesozoic 95

APPENDIX 2 RIVER DISCHARGES AT HYDROGRAPHIC STATIONS Water Resources Period 30 Year Plot Start 00:00~01/01/I 965 Interval 1 Month Plot End 00:00~01/01/I 995 1000000 102101A Pascoe R O Foll Ck X 151 .OO Total Discharge (MI) 800000 600000

2000000 102102A Pascoe R O Gorraway 151 .OO Total Discharge [MI) 1600000 1 200000

200000 - 104001 A Stewart R Q Telegrap 151 .OO Totol Dischorge (MI) 104001A 160000 : 120000 : 80000 I 40000 J J J J 0: 3 3 + J 500000 105001 Honn R Q Sandy Ck 151 .OO Total Discharge (MI) 400000 300000

50000 - 105002A Jungle Ck @ Kolingo 151 .OO Total 105002A 40000 : 30000 : 20000 : 10000 : I I,, A, I 5 0. I 5 165 166167 168 169 I70 81 182 183 184 185 186 187 188-

000000000000000000000000000000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 OWN^^ ooooo ooooo ocomw~ ooooz CV-7 OONCOt C)3NWy 7 lnbMm CV--

104

APPENDIX 3 WATER QUALITY Water Quality Drainage Division I (examples of water quality from comparatively higher and lower flow conditions)

Gauging Date Discharge Conductlvlty Total Total Total pH Total Colour Turbidity Hardness SIO, Na K Ca Station (m31s) (plcm) Soluble Dissolved Dissolved Alkalinity (Hazens) (NTU's) (mglL) (mg1L) (mglL) (mg/L) (mglL) Salts Ions (mglL) Solids (mglL) (mg/L) (mglL)

106002A ( 91011881 0.0221 170.00) l0.00l 103.401 96.001 7.51 36.001 70 1 7 1 39.001 16.001 16.501 2.701 5.10

106003A 1 31031871 3.4601 93.001 l0.00l 57.601 63.001 7.51 12.001 101 7 1 11.001 13.001 12.501 0.701 1.20 106003A 1 211051881 0.3851 1l0.00l 5.001 55.901 60.001 7.51 12.001 51 2 1 15.001 11.001 13.001 0.501 1.70

1070018 1 14/02/91( 37.3001 46.001 26.001 24.501 31.001 6.61 6.001 60 1 331 5.001 10.601 7.001 1.001 0.70 1070018 1 151091931 0.0701 116.001 3.001 70.301 68.001 7.21 22.001 30 1 1I 24.001 12.601 13.20) 0.701 3.30

107002A 1 15/02/911 56.0001 63.001 52.001 39.201 44.001 6.81 ll.00l 30 ( 38 1 10.001 12.201 11.601 1.401 1.20 107002A ) 9/08/91 ( 1.2901 73.001 9.001 44.501 48.001 6.51 12.001 5 1 1I 7.00) 11.301 9.001 1.601 0.90 NB. 0 values are below detectable limits and blanks denote that no analysis was undertaken for that attribute eInq!Jue 1ew lob ueyelJepun seM sisl~eueou leyl qouep syuelq pus q!w!l elqeloelep Moleq eJe senleh o .EIN

OO'OL IOE'OI (ZO'O I I I I I I I 100'91 109'9 1110'0 1881401~1 1 VEOl901 00'91 1 I I I (09'0 1 (01'8 109'1 IOSZ'P~~81€0/01 I VEOLSOL

OZ'EE 100'0 10'0 €0'0 I 108'0 1 9P'O 02'1 1 (08'~ 66P'O (16111181 1 VZOLSOL 09'8E 101'0 10'0 €0'0 (€0'0 IOZ'OI 09'El IOP'P 00P'ZP IE6~0161 I VZO1901

OL'E I I I I I I IZZ'O IOO'E I I 100'91 IOZ'O1191'0 ~881111OL ( VZOO901 06'P 160'0 1 I I0P.8 IOZ'O1061'2 IL8l~lRl I VZOOSOL

OZ'9 100'0 180'0 1 IEO'O I I IEE'O IOS'O / I 109'8 IOL'O P6L'O ~~611111 I 9100S01 OE'L I I I I I 106'0 1 1 100'1 1 IOL'O PZ9'E ~~81~0101I 9100901

09'8P 00'0 10'0 OL'O OP'O 191'0 OE'81 IOFZ 100'0 E6160lE VlOOPOL 00'61 LE'O 101'0 08'9 ~OL'O OOP'ZP L8IEOIE VLOOPOL

OZ'ZZ 00"O LC0 20'0 10'0 2E'O 00'1 91.0 09'PZ 00'1 €11'0 1618019 VlOLZOl 00'0 10'0 10'0 P1'0 10'0 1Z'O OS'l 10.0 OP'P1 OP'l OOZ'Ol 16lEOlOZ VlOlZOl

(116~) (116~) (-116~) (116~) (-116~) (116~) (-116~) (116~) (116~) (116~) (116~) (116~) (116~) (sl,~) uollals '03~ '03 n3 0 IV ut UW ad '0s 'ON d 13 6w afi~stpsla awa 6u16neo

(suo!l!puo~MOIJ JaMol put?~ayB!y Ala~!te~edluoa luo~~ Al!lenb JateM JO saldluexa) I uo!s!A!a a6eule~aAt!leny) JaleM Water Quality Drainage Division I (examples of water quality from comparatively higher and lower flow conditions)

Gauging Date Discharge Mg Ci F No3 SO4 Fe Mn Zn Al @. Cu CO3 HC03 Station (m31s) (mglL) (mglL) (mglL) (mglL) (mglL) (mglL) (mglL) (mgll-1 (mglL) (mglL) (mglL) (mglL) (mglL)

105105A 6/06/90 22.900 1.30 9.00 0.90 0.25 0.01 0.62 0.03 0.04 0.00 10.6C 105105A 31105193 0.520 1.80 14.40 0.01 0.60 0.28 0.01 0.01 0.00 14.4C

NB. 0 values are below detectable limits and blanks denote that no analysis was undertaken for that attribute Water Quality Drainage Division IX (examples of water quality from comparatively higher and lower flow conditions)

Gauging Date Discharge Conductlvlty Total Total Total pH Total Colour Turbidity Hardness SIO, Na K Ca Station (rn31s) , (pslcm) Soluble Dissolved Dlssolved Alkalinity (Hazens) (NTU's) (mglL) (mglL) (mglL) (mglL) (mg1L) Salts Ions (mglL) Solids (mg/L) (mglL) (mglL) 919009A 15103188 53.618 85.00 28.00 59.40 59.00 7.7 31 .OO 30 22 23.00 19.00 6.60 2.00 5.50 919009A 23109193 1.380 99.00 3.00 68.80 64.00 7.5 31 .OO 24.00 15.30 9.90 1.60 4.70

921001A 1 211051861 0.0681 61.001 5.001 23.801 38.00) 7.51 1.001 101 1I 7.00) 15.001 9.001 0.901 1.30 921001A 1 10/031871 8.6901 43.001 55.001 27.101 33.00) 7.01 9.001 30 1 44 1 4.001 12.001 6.701 1.00) 0.80 NB. 0 values are below detectable limits and blanks denote that no analysis was undertaken for that attribute elnq!lue ley JO~uayelJapun seM s!slleue ou py]elouep syuelq pue q!u!i elqaoqep Moleq ale senpA o '8N 0 09'0 09'01 IOP'PI 00'8 I00'11 8'9 00'09 OL'ZP OO'P OO'PL 1089'0 1~611LIP V100926 01'1 00'1 OL'OI 101'91 00'8 6 91 100'01 O'L 00'8P OZ'6E 00'8 00'ZL 1008' 1 1 / 0619010~ V 100926

OL'Z 02'0 OP'L 00'8 I00'11 Z 101 00'2 1 9'L 100'9~ OP'9E 00'9 100'99 1 190'0 18819018 1 VlOlPZ6 00'0 1 100'8~ 1099'0 I98190162 09'1 OP'O 08'9 00'9 100'9 9 1'2 00'2 1 2'L 100'61 0 1'EE VlOlPZ6

.- ~. ~.. . I I I I I I I I - OL'Z IoP'~ IOO'PI100'61 100'91 IP 19 100'12 IE'L 100'1~ IOZ'SS100'0 1 100'01 1 10~9'9 ~98190102 I VZOOZZ6

09'1 08'0 01'6 OO'OZ 00'01 9 OO'P 1 I"! 00'19 OO'OP 00'9 00'29 980'0 68180102 VZOOCZ6 08'0 06'0 0 00'21 OO'E 6E OL 00'9 6'9 OO'lE Ol'EZ 00'92 OO'OP 109'81 88lE019 1 VZOOlZ6 (116~) (116~) (116ru) SPIIOS (-116~)suol slles (116~) (116~) (116~) (116~) (i161u) (s,nl~) (suaze~) ~(I!U!I~YIV peAlossla peAlossla elqnlos (ruelstl) (sI~) UOII~IS e3 n e~ Z~!~SS~UPJ~H All~lqrnl .in0103 lelol ~d lelol lei01 lei01 htl~lwnpuo3 e61etpsla elea 6ul6ne0

(suo!l!puoa ~oljJaMol pue ~ay6!yr(la~!je~edluoa wo~j r(~!lenb JaleM jo saldurexa) XI uo!s!A!a a6eu!e~a~l!~en~ JaieM Water Quality Drainage Division IX (examples of water quality from comparatively higher and lower flow conditions)

Gauging Date Discharge Conductlvlty Total Total Total pH Total Colour Turbidity Hardness SIOz Na K Ca Station (m3/s) (pslcm) Soluble Dlssolved Dissolved Alkalinity (Hazens) (NTU's) (mglL) (mglL) (mglL) (mglL) (mglL) Salts Ions (mglL) Solids (mglL) (mglL) (mglL) 925002A 4103187 34.700 83.00 93.00 45.00 50.00 7.6 14.00 15 4 1 14.00 14.00 8.80 1.30 2.60

9270018 1 181051941 61 6001 45.001 2.001 24.301 29.001 6.1 1 2.001 151 I 3.001 7.501 6.501 0.301 0.10 927001B 1 291091941 15.3001 42.001 I 20.601 27.001 6.01 3.001 I 3.001 5.901 0.~~1 0.20 NB. 0 values are below detectable limits and blanks denote that no analysis was undertaken for that attribute elnq!Jue le~JOJueyellepun seM s!sAteue ou leu1 elouep syueiq pue q!w!l etqq3eiep Moleq eJF?sanieh o 'RN

16'01 00'0 €0'0 EO'O 6L'O Ll'O 00'8 08'0 P9L'O 0619011E 1 WOO086 1O'E 1 61'0 OS'L Ot'O 009'61 L8/E0/01 1 WOO026

)0'09 I 20.0 I 01'0 00'9 OZ'E 91 1'0 88190102 1 VEOZ6lE 19'1E 01'0 ( 10'0 92.0 I 00'9 00'2 910'EL L8lE0181 1 VEOZ6lE

11'8E 00'0 10'0 00'1 01'0 90'0 OE'Ol OO'E 08E'l E6160lEZ V60061E )B'LE 01'0 80'0 01'0 OE'9 O2'Z 819'ES 88IEOlS 1 V60061E

(116~) (116~~)(116~) (-116~) (116~) (116~) (116~) (116~) (116~) (116~) (116~) (116~) (116~) (s/,4 uo!tets E03~ c03 n3 8 Itl UZ Ulnl ad OOS ,ON d 13 6yy a6~e~losla etea Bu!6ne~ ejnq!lne ley JOJ ueyejlapun seM s!sAleue ou ley1 elouep syuelq pue q!w!l elqaoelep Moleq eJesenleA o 'gN OS'El 100'0 11'0 I lGOO'O I I 121'0 I09'0 I I 106'~~109'1 1089'0 IE6/111P 1 VlOOPZ6 08'11 100'0 PO'O IZO'O 119'0 /10'0 I IOP'O I I IOE'Z~IOE'1 1008' 11 106/90/0E I VLOO9Z6

09'Pl I 1 I I I I 190'0 I I I 109'6 100'1 I190'0 1881~0181 I VlOlPZ6 oaw I 1ro.o I 1ro.o ILO'O 100.z 109'0 101'0 IOI'L 109.0 IOSP'O 1~8/~0/6z1 VLOIPZG

09'91 101'0 I I I I 1 101.9 00'29 OE'P 180'0 I98/90/ 1E VlOOPZ6 OE'L 100'0 I 08'0 00'9 09'0 1lE'91 1~~1~0191 VlOOPZ6

06'9P 101'0 120'0 1 I 160'0 IOE'O IOL'O I IE6/901El 1 VlOOE26

(l/fiW (11fi~) (11Bw) (1/61u) (i/fi~) (i~fiw) (116~) (116~1) (116~) (11fi~) (116~) (IIBUI) (11fiu1) (61~~1 uo~~ets E03~ E03 n3 8 IV UZ UW a9 '0s 'ON 9 13 fi~ afi~aqosla atsa fiu1fina0

(suo!l!puoa MOIJ JaMol pue raqfjiy Ala~!le~edwo:,~OAJ Alyenb AaleM lo saldwexa) XI uo!s!A!a a6eu!e~aAl!leno JaleM Water Quality Drainage Division IX (examples of water quality from comparatively higher and lower flow conditions)

Gauging . Date Discharge Mg CI F NO, SO4 Fe Mn Zn A1 B Cu C03 HCOI Station (m31s) (mglL) (mg/L) (mglL) (mglL) (mglL) (mglL) (mgll-1 (mgll-1 (mglL) (mg/L) (mglL) (mgl~) (mgl~)

925002A 4/03/87 34.700 1.90 11.50 1.20 0.19 17.50 925002A 26/05/92 0.378 2.00 21.00 0.01 0.74 0.01 0.03 0.00 15.60

925003A 1 8/03/861 121.0001 0.201 8.001 I I 1 0.161 I I 9.80 925003A 1 2/10/871 1.060l l.10l 18.001 0.101 0.501 2.001 0.291 I 1 0.041 1 I 11.00

I I I 926001A 6/03/86 22.800 0.10 7.00 1 0.061 4.90 926001A 12/08/87 0.01 1 1.40 20.00 0.10 1 0.301 I' I I 6.10

926002A 19/03/911 11.7001 0.501 6.401 1 0.701 0.031 I 0.01 I 0.021 0.001 2.40 926002A 511 11931 0.6081 0.901 9.301 1 0.501 0.021 I 0.051 I 0.001 4.90

926003A 1 19/03/911 4.1901 0.501 7.001 1 1.001 0.05 1 0.021 I 0.01 1 0.01 1 0.001 2.40 926003A 1 21/11/911 0.4541 0.701 7.001 I 1 0.04 I I 0.01 1 0.011 1 0.001 3.50

927001A 14/07/78 34.950 1.20 10.00 I 1.OO I 1 0.10 36.00 927001A 310819 1 20.400 0.70 8.70 1.70 0.02 0.021 0.00 4.70

9270018 1 18/05/94) 61.600) 0.701 12.401 I 1 0.501 0.031 1 0.021 0.021 1 0.051 I 3.60 9270018 1 291091941 15.3001 0.801 9.501 I I 0.011 1 0.021 I 1 0.051 3.80 NB. 0 values are below detectable limits and blanks denote that no analysis was undertaken for that attribute 115

APPENDIX 4 HABI7AI' CH.ARACTERISTICS LOCATION DESCRIPTION CAPE YORK PENINSULA 1 Lagoon on Wenlock R. Floodplain UIS of ~mnRange Rd Crossing. LAND USE STRATEGY 2 Wenlodc R. at Iron Range Rd. 3 Pascoe R. at Iron Range Rd. 4 Fyfe's Lagoon adjacent to Pasme Rd. CYPLUS is a joint initiative between the 5 Pascoe R. at 'Wattle Hills' Homestead. Queenstand and Commonweallti Governments. 6 Pasax? R. at 'Frenchman's Rd" Crossing near 'Wattle Hills". 7 Wenlodc R. at Frenchman's Rd. HABITAT SURVEY LOCATIONS 8 Brown Lagoon, Wenlock R. Flaodplain near Frenchman's Rd. 9 Wenlock R, 2km ds of Frenchman's Rd. The information shown on this map has'been 10 Nimrod Ck Waterhole. supplied by the Department of Primary Industries. 11 Wenlock R. at Moreton Telegraph Station. Initial enquiries regarding the information 12 Wenlock R. at Wenlock Falls. should be directed to Water Resources Dim. 13 Wenlock R. a. lOkm u/s of Wenlock Falls. 14 Willum Swamp, Weipa. 15 Wenlock R. Estuary. Topographic information shown on this map 16 Wetland on Wenlock R. Floodplain. is current to 1989. 17 Wenlock R. at Stone's Crossing.

LEGEND

Rivers

Wenlock River

Pascoe River

1:250 000 Geology GULF CORAL + Sheet Boundaries Habitat Survey Location SEA

CYPLUS Study Area

CARPENTARI A

KlLOMETRES 0 1m 2111 a0 1 1, I , I I I I 1 I I I I Tramverse Mercatw Projection Zone 54 : MianMap Grid -

Prepared and produced by the Department of Primary Industries, June 1994.

30 Nov 1994 EDITION NO 1 A?407299 Site

D -m m - 2 0) C f " a, -c r. -f: C m z? g 3 0 -" 5 u m -0 z I": 5 LL Ca, Y 5 z -c c -E" .-0 a cnE 3 .-C

L u x0

Habitatcharacteristics ~nie

RAPIDIRIFFLE: IIIIIIIIIIIIIII I I Bed Seds: Bedrock

Coarse Sand Branches/Logs/Tree Roots Aquatic Plants excluding Algae

Area Permanent Water > 1m Deep

LEGEND River landform type Channel Form Understorey Cover BranchlLogslFree Roots 1. Upland 1. Mildly sinuous D Dense H > 10% bed cover 2. Valley-no floodplain 2. Irregular M Moderate M 5 - 10% bed cover 3. Valley - floodplain 3. Regularmeanders L Low L < 5% bed cover 4. Extensive 1. Irregular meanders N None 5. Estuary 5. Tomous Channel Substrate Stability Aquatic Plants, excl Algae Disturbance Floodplain Features S Stable HH > 50% cover ofwerted P Pristine L Lagoons M Mobile are3 L Low C Flood cha~els E Eroding H 37 -50% M Moderate A Aggrading M 23-37% H High % Bare Ground L 10 -23% HH > 50% bare Fish Passage at Water LL < 10% H abitats H 37 -50% Mark N Absent Y Habitat feature exists M 23-37% U Unrestricted, > 1.0m N H abitat fearure does not L 10-23% G Good. 0.5 - l.Om Algaelcover exist LL c 10 % bare M Moderately restricted. E Extensive. > 30% cova 0.1- 0.3m M Moderate. 10 -30 % VB AU measuremenuarein Maximum Tree Height R Restricted,< O.lm S Slight,< 10 % nekes T Tall, > 30m high N None N Absent M Medium. 10 - 30m high L Low.< lorn high Site

0 m u' m -.- 0: 0) L m m -=a, C C c 2 m 2 P 0 - - d 0 tii 9 m LL a: Y E 0 tii -2 0 6, C - 2 C .- C m Q V) P -0 .-c -C -m

u Y0 0 c

gm-lmmo 5$5$gzm ppszsss Habitat Characteristics :$ N ti + i 6.ficji~$cv POOL: Bed Seds: Bedrock

Coarse Sand BranchesILogsTTree Roots Aquatic Plants excluding Algae

Area Permanent Water > lm Deep

Bed Seds: Bedrock

Coarse Sand Branches/LogsTTree Roots Aquatic Plants excluding Algae

Area Permanent Water z Im Deep Site

u d m -U) a C3) .- C I " m -m -c 2z 2 C r 2 f 0 -" -0 d m 0 E C Y C 0 -C

P ..-5 51 0

0 L I Y

Habitatcharacteristics 119 APPENDIX 5 TERMS OF REFERENCE

Terms of Reference for the Surface Water Resources of Cape York Peninsula project.

1. Provide the following data in ArcIInfo GIs and hard copy formats:

(a) characteristics of main river basins, related to yield and wetlandlaquatic habitats (ie. area, soils, vegetation, fish habitat, wetland habitat, land use, rainfall isohyets)

2. Provide the following data in ArcIInfo GIs and hard copy formats:

(a) calculated mean annual river and average monthly hydrographic station discharges; (b) calculated average depth of runoff to river basins by interlinking topography, soil types, rock outcrop characteristics, rainfall isohyets and variability, and interpret seasonality of runoff; (c) water quality data and surface water quality constraints.

3. Using information from NRAP and Tasks 1 & 2:

(a) estimate the quantity, quality and frequency of water flows required to maintain ecosystems; (b) estimate the likely sustainable water use levels for the major basins.

4. Integrate information from Tasks 1, 2 & 3 and input from Nature Working Group, and produce draft final report.

5. Produce final report.