300000mE 350000mE 400000mE 450000mE

MINERAL RESOURCES TASMANIA

CAPE WICKHAM Tasmania Disappointment DEPARTMENT of INFRASTRUCTURE Cape ENERGY and RESOURCES Farewell Bay 5600000mN NORTHWEST TASMANIA 5600000mN GROUNDWATER MAP

PHOQUES

Lavinia Pt BAY New Year Is

Christmas Is PERCENT PERCENTAGE AVERAGE SALINITY PROSPECTIVITY NUMBER MAXIMUM IRRIGATION VULNERABILITY TO POLLUTION AQUIFER TYPE (Whole of Tasmania) ROCK GROUPS SUCCESSFUL YIELD (L/s) RANGE GENERAL AQUIFER CHARACTERISTICS OF BORES YIELD (L/s) SUCCESSFUL (mg/L) (YIELD >0.03) # (YIELD >=1.5) Whistler Pt Quaternary aeolian deposits marginal to the coast 60 95 0.65 (11) 1.3 0 270 - 980 These aquifers are contained in surface sand deposits of limited thickness - usually up to a maximum thickness of 10-15 metres, but often much less. Yields depend on grain High. consisting of fine to medium grain size sand. POROUS size, clay content and the thickness of saturated material. Yields decrease with an increase in the clay content. Groundwater is usually extracted from these aquifers using spear (INTERGRANULAR) HIGH bores installed to a depth of 7-8 metres. A single spear in a prospective area may yield 0.75 L/s (e.g. Currie area) which would be sufficient for domestic, garden, and stock use. A nest of spear bores (10-20) using a central pump may yield irrigation or small town supplies (7-15 L/s). Significant extraction from these deposits takes place at Currie, where the town supply comes from dune sand, and at Stanley where the golf club installed a system to water the course. Other areas including Woolnorth, Stanley, Arthur River and Peggs Beach have proved to have potential for useful supplies. Quality of water in these aquifers is usually good enough for a wide range of uses. There are many spear bores installed for investigation and production purposes in coastal sand deposits in the region. Aquifers are mostly unconfined. Quaternary coastal plain deposits consisting of sand, 54 2.19 (24) 15.2 These aquifers are contained in surface deposits of limited thickness (10-15 metres or less). Yields depend on grain size, clay content and the thickness of saturated material. Moderate to high. POROUS 51.9 33.3 MODERATE - clayey sand, gravel and shelly deposits. Some high yielding bores have been established around the coast line near Devonport and Burnie where some coarse sediments occur. Depends on whether low permeability (INTERGRANULAR) HIGH Probable marine origin. In the far north west, coastal influences appear to sometimes have a bearing on the slightly increased salinity near the shoreline compared to bores remote from the coast line. material (e.g. clay) overlies the aquifer. Extensive areas of these deposits occur in the Smithton area and on King Island. KING RIVER Bores often extend through these materials and draw water from underlying strata. Cowper Pt Aquifers are unconfined to confined. Quaternary alluvium, talus and till. 40 35.0 2.06 (14) 7.6 42.9 These aquifers are contained in surface deposits, usually of limited thickness. Low to high. POROUS LOW - The alluvium consists of clay, sand and gravel with Yields in alluvium are variable, but where coarse sediments occur with a low clay content, outputs from bores can be high (e.g. Railton area). Clayey material overlying aquifers will (INTERGRANULAR) MODERATE variable clay content. Talus and windblown sands are usually in elevated locations on the side of slopes and groundwater prospects are usually low. offer protection to groundwater at Till has low prospects as a result of its usually limited thickness and the fine grained nature of the material between the boulders. depth. Coarse grained aquifers without The talus consists of boulders, usually with a moderate such protection are highly vulnerable, as to high clay content. In many areas where these deposits occur, the potential for obtaining useful bore yields are from bores that extend through these deposits into the underlying material. In many are aquifers underlying such materials. ELEPHANT SEA The till comprises boulders with a higher content of cases the material underlying these deposits will be the same as that surrounding this unit at the surface. fine-grained material. Water quality in the coarse grained sediments will usually be good. Recharge to aquifers in the alluvium may take place from surface streams in some cases. ELEPHANT Minor windblown sand on sloping bedrock. Aquifers are unconfined to confined. Tertiary sediments consisting of clay, sand and 12270.5 2.43 (80) 30.3 41 65 - 1000 Tertiary sediments are exposed at the surface mainly in the Devonport - Sheffield regions, but they occur as under surface horizons in many areas e.g. interbedded with and Low to high. BAY POROUS gravel of non marine origin, usually underlying basalt. Tertiary limestone occurs at the surface or underlying basalt at Redpa - Woolnorth. Clay sediments at the surface will give (INTERGRANULAR) LOW - HIGH interbedded with or underlying basalt. Success rates are moderate to high in most cases where these materials have been drilled. As they are usually unconsolidated, care needs to be taken by drillers to stabilise some protection to underlying aquifers, e.g. Sheffield - Devonport area. (High on this map) Tertiary limestone, often loose to semiconsolidated these aquifers with a screen or slotted casing with appropriate slot size and gravel pack. Small irrigation supplies have been obtained from a large proportion of the bores where ISLAND (Redpa). Marine origin. yields have been reported. Tertiary limestone in the Redpa - Fraser Woolnorth area occurs at the surface at A very saline zone (17500 mg/L) occurs in limestone at Woolnorth. some locations and in these situations, Currie 100 Bluff Aquifers are often confined and occasionally unconfined. vulnerability is high. 100 Permian mudstone, siltstone, sandstone and tillite. 207 88.9 2.35 (175)18.95 41.1 82 - 1000 Permian age rocks occur only in the eastern half of the region and are mainly regarded as fractured rock aquifers, although some of the coarser grained horizons (sandstone High. SEA FRACTURED ROCK 100 Low permeability layers at the surface - (Intergranular on HIGH Mainly marine origin, deposited under glacial conditions. and conglomerate) are likely to have some intergranular storage. In most cases the transmission is probably through fractures and bedding planes. some horizons) In the northwest, the success rates for bores drilled in these rocks is particularly high, with a high proportion of high yielding bores (outputs up to almost 20 L/s). Lower lying clay and silty clay, will give some Triassic sediments (no bores in this unit). protection and vulnerability may be areas are usually more favourable for siting bores than elevated areas such as the slopes of the Great Western Tiers in the southeast of the region. reduced to low to moderate if these In the north west, quality is almost always very good and a wide range of uses are possible. Aquifers are mainly unconfined to confined locally. Of particular interest is a zone overlying materials are thick. around Spreyton where artesian water can be obtained from the base of the Permian (gravel/tillite) at about 120-150 metres.

100 Ordovician sediments. Ordovician rocks occur only in the eastern part of the north west region, while dolomite occurs only in the north west corner near Smithton. Cambrian, Neoproterozoic and High. MODERATE- FRACTURED ROCK Ordovician limestone. Precambrian rocks occur throughout the region. Vulnerability can be very high in karst HIGH In the northwest, the Ordovician rocks are the least prospective, but of those where water was obtained, yields are high with a high proportion giving amounts of > 1.5 L/s or small areas. Where thick clayey soil overlies 100 Cambrian sediments and Neoproterozoic sediments. irrigation quantities. Many bores in cavitied dolomite in the Smithton - Togari - Redpa area are high yielding. Precambrian rocks have a lower proportion of bores yielding small these aquifers vulnerability will be Dolomite. irrigation quantities. Yields are up to 25 L/s and the water is used for domestic, garden, stock and irrigation purposes. Rocks outside the agricultural areas are largely untested. reduced. Precambrian mudstone slate and quartzite. Quality is generally very good and a wide range of uses is often possible. Near coastal areas may have groundwater with slightly higher salinity levels. 1086 82.7 2.75 (834) 25.33 33.3 61 - 3700 Aquifers are semiconfined to confined and occasionally unconfined.

100 Tertiary basalt. 1700 87.2 1.90 ( 1417) 25.27 32.7 80 - 950 In the northwest, basalt has had by far the most bores installed in it of all rock units in the region. The basalt is wide spread. High. Bold Head FRACTURED ROCK HIGH Intensive farm production activities are predominantly on the basalt derived soils. Deep clay soils may give some Fitzmaurice Yields can be high (up to 25 L/s) and the proportion of bores with small irrigation yields is also high. Many of the irrigation bores in the Devonport - Port Sorell area are in basalt. In protection e.g. at Northdown. 5550000mN Grassy Grassy Bay some localised areas, such as the Moriarty Basalt at Northdown (where the basalt has been weathered to clay) and Central Marrawah, basalts have lower success rate. Basalt 5550000mN Bay 100 often has greater storage capacity than other fractured rock aquifers as a result of more extensive and closely spaced jointing and the presence of widespread vesicularity (gas Cataraqui Pt holes). Quality of the groundwater in the basalt is generally very good. Slightly higher salinity is possible in water from bores near the coastline. Aquifers are mainly confined to unconfined locally. 16 56.3 1.12 (9) 1.52 11.1 187 - 2420 Jurassic dolerite in the northwest region is of limited extent and only a few bores have been drilled in it. Success rate is moderate as at most other locations in the State. Moderate. Jurassic dolerite. As a result of the probable lower intensity FRACTURED ROCK MODERATE Average output is moderate to low and only one bore has been recorded with small irrigation quantities. Dolerite often has less fracturing than other fractured rock aquifers and of fracturing at most locations and tighter fractures can be less open, causing lower permeability and storage capacity. joints, vulnerability at most locations Water quality is likely to be good at most locations in north west Tasmania. will be only moderate. The development Seal Pt Aquifers are often unconfined, semiconfined to confined. of clay soils will aid in protection. Bay Devonian granite occurs in areas adjacent to agricultural areas or outside them and only a few bores have penetrated the granite. Low to moderate. Surprise Bay LOW - Devonian and Precambrian granite. 31 38.70.50 (11) 1.01 0 770 This unit has low prospectivity and as a Precambrian granite on King Island has been drilled at several locations. FRACTURED ROCK MODERATE Peridotite (no bores in this unit). result vulnerability to pollution can be Seal Bore success rates in granite of both ages is relatively poor and this is probably largely due to the sparse nature of the jointing. expected to be low to moderate. (Low on this map) Peridotite and serpentinite outside the agricultural areas are untested and little is known of their potential. Deep clayey soils developed on the Aquifers are unconfined to confined. granite will add to this protection. 1. Statistics provided in the legend are based on deep boreholes entered in MRT groundwater database (BORIS) by February 2003. Boreholes shown on the map are those with locations mainly supplied by drillers and from location in the field by MRT staff. STOKES POINT 2. # Boreholes with yields >0.03 L/s have been considered as successful bores. Yield related statistics (average, maximum yield and percent irrigation successful) are based on the number of successful bores (number in brackets in the average yield column). Outputs of bores are those supplied by drillers and are mostly the result of short term pumping measurements. Some bores have been successful but outputs have not been reported. These bores are included in the total percentage of successful bores but have not been used for other statistical calculations. Boreholes reported as dry holes usually have small unreported yield (<0.05 L/s). 3. Successful bores with a reported yield >= 1.5 L/s have potential for small irrigation purposes. Very limited irrigation is possible with lower yields. 4. There are many spear bores installed for investigation and production purposes in coastal sand deposits in Tasmania. Salinity ranges for some of the Quaternary aquifers have been obtained from these borehole records and included in the legend (marked with a star ). 5. Small elevated areas of any hydrogeolgical unit will usually have lower prospectivity because of limited storage and high drainage rates. 6. In areas where there is little or no water bore data, the groundwater prospectivity has been assumed to be similar to that in areas where data are widely available.

MEAN ANNUAL RAINFALL

LOCATION DIAGRAM Albatross Island NORTH WEST CAPE ROCHON CAPE KERAUDREN CAPE

Coulomb Bay NORTHWEST HOPE CHANNEL THREE NORTHEAST HUMMOCK ISLAND CAPE ADAMSON Cuvier 100 Bay North Black Cuvier Pt Rock Black Pyramid

Wallaby Pt HUNTER SOUTHWEST SOUTHEAST ISLAND While every care has been taken in the preparation of this data, Cave Bay no warranty is given as to the correctness of the information and no liability is accepted for any statement or opinion or for any error or omission. No reader should act or fail to act on the basis of any material contained herein. Readers should consult professional The rainfall map shows the mean annual rainfall over Tasmania for the standard 30-year period from 1961 advisers. As a result the Crown in Right of the State of Tasmania to 1990. It was derived by the Climate and Consultancy Section in the Tasmania and Antarctica Regional Office of the Bureau of Meteorology, from a gridded analysis prepared by the Bureau’s National Climate and its employees, contractors and agents expressly disclaim all and Centre. The analysis system blends measured rainfall with topography to give estimates of rainfall for any liability (including all liability from or attributable to any Steep negligent or wrongful act or omission) to any persons whatsoever in Island each area. The results will be less accurate in mountainous or data-sparse regions, and may differ respect of anything done or omitted to be done by any such person in South Black from the observations at individual locations. Rock CAPE BUACHE reliance whether in whole or in part upon any of the material in this data. Crown copyright reserved.

E H G U A L N WALKER S E T S ISLAND ER A N P N A H C 5500000mN 5500000mN Trefoil Island ER ALK W Ransonnet Bay BOULLANGER

BAY Guyton Pt CAPE GRIM ROBBINS ISLAND NORTH POINT CAPE ELIE Half Moon GE SSA Bay PA

100 ROBBINS Shipwreck Pt Big Bay Stanley THE NUT Bluff Pt PERKINS BAY CIRCULAR HEAD Studland PERKINS B A S S Bay ISLAND S T R A I T

Welcome

River Duck Bay SAWYER

BAY

SMITHTON

River

Forest ROCKY CAPE

200 100 Anniversary Pt Ann 200 Rocky Bay Cape Montagu Christmas Hills 100 Green Pt 100 Irishtown Sisters River Beach Boat Harbour Beach 100 100 Marrawah Redpa 200 200 Black 200 Boat Harbour TABLE CAPE

100

WEST POINT 200 100 Lileah 100 Edith Creek 200 River 100 Myalla 100 WYNYARD Duck Mawson 200 100 200 Inglis 100 River 200 200 Bay 100 200 100 200 100 200 Bluff Hill SOMERSET 100 400 Point 100 RANGE Cooee Pt 200 River 200 DIP 500 500 BURNIE Trowutta 100 100 300 Emu Bay 100 Flowerdale Heybridge 200 200 300 100 200

100 300 200 Sulphur Creek 5450000mN 300 5450000mN ARTHUR 100 100 100 200 200 300 PENGUIN 100 300 River 200 200 Stowport 200 Penguin Pt 200 100 200 RIVER 100 200 A 300 R Yolla 200 300 T Sundown Pt H 500 400 Picnic Pt U 300 200 R Frankland 300 Cam 300 Ridgley ULVERSTONE 100 400 100 200 Mersey Bluff 400 300 200 200 400 500 400 Nelson 100 CAMPBELL 100 Rapid Bay 300

DEVONPORT 100 500 Gawler 400 400 100 Wesley Vale River River

200 300 200 RANGE R RIVER 400 200 300 Riana Forth 400 400500 Inglis 200 300 400 100 Spreyton 400 200 400 200 100

500 Emu 500 500 200 200 200 100 200 R 300 400 300 300 400 Kindred LATROBE South Riana MERSEY

500 400

300 400 200 100 200 400

Richardson Pt 500

300 LEVEN 500 500 500 Sprent 200 600

400 200 River Balfour 400 300 400 500 Hazard Bay 300 400 300

400 400 200 100 300 300 500 200 700 Lower 100 400 500 THE RIVER

600 300 Barrington 200 MT BERTHA Blythe 300 L Paloona 300 200 100 700 500 500

BADGERS 300 200 500 RIDGE 400

300 600 100 300 400 200 300 Barrington Hellyer 500 500 600 500 300 Ordnance Pt 500 600 600 RIVER 600 700 400 500 600 400 700 Railton 200 600

900 BARETOP ST VALENTINES800 TIER RIVER 500 600 400 300 300 PEAK MT EVERETT 400 400 500 800 TRACK 100 600 700 300 600 100 100 600 NATIVE 400

500 300 400 Sheffield 300 500 600 600 500 River 500 West300 600 800 Wilmot 500 400 600 Kimberley 300 600 700 River Kentish 600 600 300 Kenneth 600 400 L Barrington 300

600 300 Bay 400 Roland 200

NORFOLK WILMOT 400 500 600 600 200 MT BISCHOFF 400 900 400 500 600 600 400 Talbots MT 300 SANDY CAPE 100 River Lagoon TOR 600 400 500 300 500 800 500 200 500 MT MT Waratah 800 500 CLEVELAND700600 1200 1000900 Weegena NORFOLK 400 500 400

400 500 600 1100 600 700 400 1100 700 600 400 1100 600 Luina 600 500 400 RANGE 700 600 RA 400 MT ROLAND 700 700 FF 400 LU 700 500 B 800

300 1000 600 700 MT 900CLAUDE 400 MT VANDYKE 300 700 800 K 300 300 700 C 300 A 400 GOG RANGE 200 Donaldson SAVAGE L 1000 L Cethana 800 700 300 MT PEARSE B 500 RIVER 800 900 MERSEY 700 700 600 700 200 900 Savage 600 300 700 200 L Lea RIVER

400 500 300 MT SUNDAY 200 1000 200 600 600

500 800 500 600 River 900 500 300 500 600 200 5400000mN 100 5400000mN 200 Chudleigh 900 400 600 300

700 400 400 800 Mole Creek 600 600 River 400 700 500 400 GREAT

300 600 600 1000 MT MEREDITH 800 MT 900

400 500 700 BEECROFT 300 400 200 MT 600 400 700 RAMSAY 600 800 700 600 500 600 1300 300 100 800 FORTH

200

600 1200 200 700 300 WESTERN 1100 900 1200 1100 500 WESTERN 300 BLUFF 1000 100 300 500 200 400 Huskisson MT

REMUS 1100 RIVER Whyte 700 500

600 700 400 L Parangana

300 500 1200 900 100 400 400 900 1100 600 1200 500 500 1100 500 Rupert Pt 100 300 700 RIVER

PIEMAN 200

300 1100 400 700 400 600 1000 200 800 600700 500 L Mackenzie TIERS 200 400 200 400 700

200 500 500 CRADLE Pieman Head 200 MT 1300 200 600 800 MTN LIVINGSTONE 600 200 FURY 1200 100 500 400 600 R Hardwicke Bay 500 IVE R 1000 1300 100 700800 1200 1000 1200 400 500 FISHER BLUFF Conical Rocks Pt 200 800 1200 1300 1300 1300 300 300 1100 1400 Lake 1100 MT EMMETT 600 IRONSTONE MTN 200 700 DECEPTION PT

400 Mackintosh 800 1000 1200 900 200

300000mE 350000mE 400000mE 450000mE

INKS ARE LIGHT SENSITIVE WARNING: Plotfile for this map generated from digital data: 05-OCT-2006

/covers/project/tas_gw_pros/amls/gw250_nw_out yield