NORTHWEST TASMANIA GROUNDWATER MAP · Penguin Pt Cooee Pt Mersey Bluff TABLE CAPE THE NUT CIRCULAR...
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Talus and windblown sands are usually in elevated locations on the side of slopes and groundwater prospects are usually low. Till has low prospects as a result of its usually limited thickness and the fine grained nature of the material between the boulders. 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 cases the material underlying these deposits will be the same as that surrounding this unit at the surface. Aquifers are unconfined to confined. and conglomerate) are likely to have some intergranular storage. In most cases the transmission is probably through fractures and bedding planes. 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. 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 around Spreyton where artesian water can be obtained from the base of the Permian (gravel/tillite) at about 120-150 metres. MODERATE- HIGH HIGH FRACTURED ROCK FRACTURED ROCK FRACTURED ROCK (Intergranular on some horizons) POROUS (INTERGRANULAR) POROUS (INTERGRANULAR) LOW - MODERATE The talus consists of boulders, usually with a moderate to high clay content. Minor windblown sand on sloping bedrock. Tertiary limestone, often loose to semiconsolidated (Redpa). Marine origin. Ordovician sediments. Ordovician limestone. Dolomite. Tertiary basalt. 40 42.9 7.6 2.06 (14) 122 2.43 (80) 65 - 1000 41 30.3 35.0 207 2.35 (175) 82 - 1000 18.95 41.1 25.33 61 - 3700 2.75 (834) 1086 1700 25.27 80 - 950 32.7 33.3 1.90 ( 1417) 87.2 82.7 70.5 88.9 High. Deep clay soils may give some protection e.g. at Northdown. reduced to low to moderate if these overlying materials are thick. clay and silty clay, will give some protection and vulnerability may be High. Vulnerability can be very high in karst areas. Where thick clayey soil overlies these aquifers vulnerability will be reduced. some protection to underlying aquifers, some locations and in these situations, vulnerability is high. e.g. Sheffield - Devonport area. Low to high. Clay sediments at the surface will give High. Low permeability layers at the surface - depth. Coarse grained aquifers without such protection are highly vulnerable, as are aquifers underlying such materials. Low to high. Clayey material overlying aquifers will offer protection to groundwater at 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 Precambrian rocks occur throughout the region. 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. Aquifers are semiconfined to confined and occasionally unconfined. 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 yields have been reported. Aquifers are often confined and occasionally unconfined. Aquifers are unconfined to confined. Some high yielding bores have been established around the coast line near Devonport and Burnie where some coarse sediments occur. POROUS (INTERGRANULAR) 54 15.2 33.3 2.19 (24) 51.9 Quality of water in these aquifers is usually good enough for a wide range of uses. Aquifers are mostly unconfined. River and Peggs Beach have proved to have potential for useful supplies. POROUS (INTERGRANULAR) 0 High. NUMBER OF BORES PERCENTAGE SUCCESSFUL (YIELD >0.03) ROCK GROUPS AQUIFER TYPE VULNERABILITY TO POLLUTION 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. There are many spear bores installed for investigation and production purposes in coastal sand deposits in the region. Bores often extend through these materials and draw water from underlying strata. 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. Intensive farm production activities are predominantly on the basalt derived soils. 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 Quaternary coastal plain deposits consisting of sand, clayey sand, gravel and shelly deposits. Probable marine origin. The alluvium consists of clay, sand and gravel with variable clay content. Quaternary alluvium, talus and till. Tertiary sediments consisting of clay, sand and gravel of non marine origin, usually interbedded with or underlying basalt. HIGH MODERATE - HIGH HIGH PROSPECTIVITY (Whole of Tasmania) Extensive areas of these deposits occur in the Smithton area and on King Island. 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. 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 Cambrian sediments and Neoproterozoic sediments. MODERATE FRACTURED ROCK FRACTURED ROCK Jurassic dolerite. Peridotite (no bores in this unit). Devonian and Precambrian granite. 11.1 1.52 1.12 (9) 56.3 16 38.7 1.01 770 0 0.50 (11) 31 fractures can be less open, causing lower permeability and storage capacity. Aquifers are often unconfined, semiconfined to confined. Precambrian granite on King Island has been drilled at several locations. Bore success rates in granite of both ages is relatively poor and this is probably largely due to the sparse nature of the jointing. Peridotite and serpentinite outside the agricultural areas are untested and little is known of their potential. Aquifers are unconfined to confined. Aquifers are mainly confined to unconfined locally. 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. Devonian granite occurs in areas adjacent to agricultural areas or outside them and only a few bores have penetrated the granite. LOW - MODERATE Water quality is likely to be good at most locations in north west Tasmania. Quality of the groundwater in the basalt is generally very good. Slightly higher salinity is possible in water from bores near the coastline. 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. Moderate. As a result of the probable lower intensity of fracturing at most locations and tighter joints, vulnerability at most locations will be only moderate. The development of clay soils will aid in protection. Low to moderate. This unit has low prospectivity and as a result vulnerability to pollution can be expected to be low to moderate. Deep clayey soils developed on the granite will add to this protection. Tertiary limestone in the Redpa - Woolnorth area occurs at the surface at GENERAL AQUIFER CHARACTERISTICS 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. (High on this map) Triassic sediments (no bores in this unit). Mainly marine origin, deposited under glacial conditions. Permian mudstone, siltstone, sandstone and tillite. Precambrian mudstone slate and quartzite. 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 (Low on this map) 60 95 0.65 (11) 1.3 Quaternary aeolian deposits marginal to the coast consisting of fine to medium grain size sand. 4. There are many spear bores installed for investigation and production purposes in coastal sand deposits in Tasmania. Salinity 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 270 - 980 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 underlying basalt. Tertiary limestone occurs at the surface or underlying basalt at Redpa - Woolnorth. 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 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 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 holes). LOW - HIGH 187 - 2420 SALINITY RANGE (mg/L) PERCENT IRRIGATION SUCCESSFUL (YIELD >=1.5) MAXIMUM YIELD (L/s) AVERAGE YIELD (L/s) # 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 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, A very saline zone (17500 mg/L) occurs in limestone at Woolnorth. 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 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. 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 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. 5. Small elevated areas of any hydrogeolgical unit will usually have lower prospectivity because of limited storage and high drainage rates. ranges for some of the Quaternary aquifers have been obtained from these borehole records and included in the legend (marked with a star ). 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). 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 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). 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 Moderate to high. Depends on whether low permeability material (e.g. clay) overlies the aquifer. 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 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. The till comprises boulders with a higher content of fine-grained material. 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 While every care has been taken in the preparation of this data, 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 advisers. As a result the Crown in Right of the State of Tasmania and its employees, contractors and agents expressly disclaim all and any liability (including all liability from or attributable to any negligent or wrongful act or omission) to any persons whatsoever in respect of anything done or omitted to be done by any such person in reliance whether in whole or in part upon any of the material in this data. Crown copyright reserved. The rainfall map shows the mean annual rainfall over Tasmania for the standard 30-year period from 1961 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 Centre. The analysis system blends measured rainfall with topography to give estimates of rainfall for each area. The results will be less accurate in mountainous or data-sparse regions, and may differ from the observations at individual locations. NORTHEAST SOUTHEAST SOUTHWEST NORTHWEST LOCATION DIAGRAM MEAN ANNUAL RAINFALL WARNING: INKS ARE LIGHT SENSITIVE Plotfile for this map generated from digital data: 05-OCT-2006 /covers/project/tas_gw_pros/amls/gw250_nw_out yield
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Albatross Island
ISLAND
HUMMOCK
ISLAND
THREE
HUNTER
ROBBINS ISLAND
WALKERISLAND
ISLANDPERKINS
Bay
Bay
Ann
PERKINS BAYBig Bay
Duck Bay
BAY
SAWYER
CoulombBay
Cave Bay
Bay
Kenneth
Bay
Hazard Bay
NelsonBay
Mawson
ROBBINS
PASSAGE
Bay
WALKERRansonnet
Bay
HU
N
TER
B A S S S T R A I T
BOULLANGER
BAY
PAS
SA
GE
Emu
Half MoonBay
CHANN
EL
HO
PE
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AN
NE
L
Studland
Penguin Pt
Cooee Pt
Mersey Bluff
TABLE CAPE
THE NUT
CIRCULAR HEAD
Guyton Pt
CAPE ROCHON
CAPE ADAMSON
CAPE ELIE
CAPE KERAUDREN
Picnic Pt
Rupert Pt
Pieman Head
SANDY CAPE
CAPE GRIM
NORTH WESTCAPE
Wallaby Pt
CAPE BUACHE
Shipwreck Pt
NORTH POINT
ROCKY CAPE
Anniversary Pt
Bluff Pt
WEST POINT
Green Pt
Bluff HillPoint
Sundown Pt
Richardson Pt
Conical Rocks Pt
Hardwicke Bay
PENGUIN
Sulphur Creek
Heybridge
Boat Harbour
Boat Harbour Beach
Forest
Stanley
Roland
Wilmot WestKentish
Gawler
Stowport
Redpa
ULVERSTONE
Chudleigh
RockyCape
MyallaWYNYARD
DEVONPORT
Barrington
Forth
BURNIE
Yolla
Ridgley
Sheffield
Kimberley
Weegena
Marrawah
Christmas Hills
Trowutta
Irishtown
RIVERSAVAGE
Luina
BeachSisters
SMITHTON
Balfour
SOMERSET
Wesley Vale
LATROBE
Spreyton
LowerBarrington
Railton
Kindred
Sprent
South Riana
Riana
Lileah
Edith Creek
LEVEN
RIVERSava
ge
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r
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MERSEY
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is
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MackintoshLake
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L Parangana
L Cethana
L Lea
L Barrington
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EY
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Mole Creek
River
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River
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WESTERNBLUFF
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MT BERTHA
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MT SUNDAY
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E
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DECEPTION PT
MT CLAUDE
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FURYRIVER
PEAKST VALENTINES
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RAMSAY
BLACK
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North Black Cuvier Pt
CuvierBay
Rock
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300000mE 350000mE 400000mE 450000mE
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5450000mN
5500000mN
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300000mE 350000mE 400000mE 450000mE
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Christmas Is
KING
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PHOQUES
BAY
BayFitzmaurice
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BAY
Surprise Bay
DisappointmentBay
Bay
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Seal
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Cataraqui Pt
Whistler Pt
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FraserBluff
Cowper Pt
CAPE WICKHAM
Lavinia Pt
New Year Is
SE
AEL
EPHAN
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Tasmania
MINERAL RESOURCESTASMANIA
NORTHWEST TASMANIAGROUNDWATER MAP
DEPARTMENT of INFRASTRUCTUREENERGY and RESOURCES
These aquifers are contained in surface deposits, usually of limited thickness.
Talus and windblown sands are usually in elevated locations on the side of slopes and groundwater prospects are usually low.Till has low prospects as a result of its usually limited thickness and the fine grained nature of the material between the boulders.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 manycases the material underlying these deposits will be the same as that surrounding this unit at the surface.
Aquifers are unconfined to confined.
and conglomerate) are likely to have some intergranular storage. In most cases the transmission is probably through fractures and bedding planes.
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.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 zonearound Spreyton where artesian water can be obtained from the base of the Permian (gravel/tillite) at about 120-150 metres.
MODERATE-HIGH
HIGHFRACTURED ROCK
FRACTURED ROCK
FRACTURED ROCK(Intergranular onsome horizons)
POROUS(INTERGRANULAR)
POROUS(INTERGRANULAR)
LOW -MODERATE
The talus consists of boulders, usually with a moderateto high clay content.
Minor windblown sand on sloping bedrock.
Tertiary limestone, often loose to semiconsolidated(Redpa). Marine origin.
Ordovician sediments.Ordovician limestone.
Dolomite.
Tertiary basalt.
40 42.97.62.06 (14)
122 2.43 (80) 65 - 10004130.3
35.0
207 2.35 (175) 82 - 100018.95 41.1
25.33 61 - 37002.75 (834)1086
1700 25.27 80 - 95032.7
33.3
1.90 ( 1417)87.2
82.7
70.5
88.9
High.Deep clay soils may give someprotection e.g. at Northdown.
reduced to low to moderate if theseoverlying materials are thick.
clay and silty clay, will give someprotection and vulnerability may be
High.Vulnerability can be very high in karstareas. Where thick clayey soil overliesthese aquifers vulnerability will bereduced.
some protection to underlying aquifers,
some locations and in these situations,vulnerability is high.
e.g. Sheffield - Devonport area.
Low to high.Clay sediments at the surface will give
High.Low permeability layers at the surface -
depth. Coarse grained aquifers withoutsuch protection are highly vulnerable, asare aquifers underlying such materials.
Low to high.Clayey material overlying aquifers willoffer protection to groundwater at
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 andPrecambrian rocks occur throughout the region.
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.Aquifers are semiconfined to confined and occasionally unconfined.
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 whereyields have been reported.
Aquifers are often confined and occasionally unconfined.
Aquifers are unconfined to confined.
Some high yielding bores have been established around the coast line near Devonport and Burnie where some coarse sediments occur.POROUS(INTERGRANULAR)
54 15.2 33.32.19 (24)51.9
Quality of water in these aquifers is usually good enough for a wide range of uses.
Aquifers are mostly unconfined.
River and Peggs Beach have proved to have potential for useful supplies.
POROUS(INTERGRANULAR)
0 High.
NUMBEROF BORES
PERCENTAGESUCCESSFUL(YIELD >0.03)
ROCK GROUPSAQUIFER TYPE VULNERABILITY TO POLLUTION
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.
There are many spear bores installed for investigation and production purposes in coastal sand deposits in the region.
Bores often extend through these materials and draw water from underlying strata.
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.
Intensive farm production activities are predominantly on the basalt derived soils.
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
Quaternary coastal plain deposits consisting of sand,clayey sand, gravel and shelly deposits.Probable marine origin.
The alluvium consists of clay, sand and gravel withvariable clay content.
Quaternary alluvium, talus and till.
Tertiary sediments consisting of clay, sand andgravel of non marine origin, usuallyinterbedded with or underlying basalt.
HIGH
MODERATE -HIGH
HIGH
PROSPECTIVITY(Whole of Tasmania)
Extensive areas of these deposits occur in the Smithton area and on King Island.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.
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
Cambrian sediments and Neoproterozoic sediments.
MODERATEFRACTURED ROCK
FRACTURED ROCK
Jurassic dolerite.
Peridotite (no bores in this unit).Devonian and Precambrian granite.
11.11.521.12 (9)56.316
38.7 1.01 77000.50 (11)31
fractures can be less open, causing lower permeability and storage capacity.
Aquifers are often unconfined, semiconfined to confined.
Precambrian granite on King Island has been drilled at several locations.Bore success rates in granite of both ages is relatively poor and this is probably largely due to the sparse nature of the jointing.Peridotite and serpentinite outside the agricultural areas are untested and little is known of their potential.Aquifers are unconfined to confined.
Aquifers are mainly confined to unconfined locally.
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.
Devonian granite occurs in areas adjacent to agricultural areas or outside them and only a few bores have penetrated the granite.LOW -MODERATE
Water quality is likely to be good at most locations in north west Tasmania.
Quality of the groundwater in the basalt is generally very good. Slightly higher salinity is possible in water from bores near the coastline.
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.
Moderate.As a result of the probable lower intensityof fracturing at most locations and tighterjoints, vulnerability at most locationswill be only moderate. The developmentof clay soils will aid in protection.Low to moderate.This unit has low prospectivity and as aresult vulnerability to pollution can beexpected to be low to moderate.Deep clayey soils developed on thegranite will add to this protection.
Tertiary limestone in the Redpa -Woolnorth area occurs at the surface at
GENERAL AQUIFER CHARACTERISTICS
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.
(High on this map)
Triassic sediments (no bores in this unit).
Mainly marine origin, deposited under glacial conditions.Permian mudstone, siltstone, sandstone and tillite.
Precambrian mudstone slate and quartzite.
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
(Low on this map)
60 95 0.65 (11) 1.3Quaternary aeolian deposits marginal to the coastconsisting of fine to medium grain size sand.
4. There are many spear bores installed for investigation and production purposes in coastal sand deposits in Tasmania. Salinity
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 spear270 - 980
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 stabiliseunderlying basalt. Tertiary limestone occurs at the surface or underlying basalt at Redpa - Woolnorth.
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
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
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 (gasholes).
LOW - HIGH
187 - 2420
SALINITY RANGE (mg/L)
PERCENTIRRIGATIONSUCCESSFUL(YIELD >=1.5)
MAXIMUMYIELD (L/s)
AVERAGEYIELD (L/s) #
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, Arthuruse. 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,
A very saline zone (17500 mg/L) occurs in limestone at Woolnorth.
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
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.
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
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.
5. Small elevated areas of any hydrogeolgical unit will usually have lower prospectivity because of limited storage and high drainage rates.ranges for some of the Quaternary aquifers have been obtained from these borehole records and included in the legend (marked with a star ).
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).
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
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).
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
Moderate to high.Depends on whether low permeabilitymaterial (e.g. clay) overlies the aquifer.
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
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.
The till comprises boulders with a higher content offine-grained material.
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
While every care has been taken in the preparation of this data,no warranty is given as to the correctness of the information andno liability is accepted for any statement or opinion or for anyerror or omission. No reader should act or fail to act on the basisof any material contained herein. Readers should consult professionaladvisers. As a result the Crown in Right of the State of Tasmaniaand its employees, contractors and agents expressly disclaim all andany liability (including all liability from or attributable to anynegligent or wrongful act or omission) to any persons whatsoever inrespect of anything done or omitted to be done by any such person inreliance whether in whole or in part upon any of the material in this data.Crown copyright reserved.
The rainfall map shows the mean annual rainfall over Tasmania for the standard 30-year period from 1961to 1990. It was derived by the Climate and Consultancy Section in the Tasmania and Antarctica RegionalOffice of the Bureau of Meteorology, from a gridded analysis prepared by the Bureau’s National ClimateCentre. The analysis system blends measured rainfall with topography to give estimates of rainfall foreach area. The results will be less accurate in mountainous or data-sparse regions, and may differfrom the observations at individual locations.
NORTHEAST
SOUTHEASTSOUTHWEST
NORTHWEST
LOCATION DIAGRAM
MEAN ANNUAL RAINFALL
WARNING: INKS ARE LIGHT SENSITIVE Plotfile for this map generated from digital data: 05-OCT-2006
/covers/project/tas_gw_pros/amls/gw250_nw_out yield
