Aquaculture Groundwater Resource Atlas - West Kimberley Coast – Pardoo to King Sound

Overview

There are two aquifer systems present along the coast from Pardoo to Cape Leveque, the unconfined Cretaceous Broome Sandstone and the confined Jurassic Wallal Sandstone. They are separated by the Jarlemai Siltstone. There are also deeper aquifers in the Permian Grant group, below the Wallal Sandstone, which have not been investigated.

East of King Sound, in the Derby area, the Wallal Sandstone is an unconfined aquifer, overlying the Triassic Erskine Sandstone aquifer. Northeast of Derby, aquifers in the Liveringa Group, Poole Sandstone and Grant Group occur adjacent to Stokes Bay.

Sea water intrusion occurs in the unconfined aquifers along the coast, and large supplies of saline groundwater may be available close to the coast. Fresh or brackish to saline groundwater may also be available from confined aquifers at the coast.

West Kimberley coast - Pardoo to Cape Leveque

Hydrogeological section across western Canning Basin

  Broome Sandstone aquifer

The aquifer system comprises the Broome Sandstone, and relatively thin superficial formations along the coast. The Broome Sandstone includes a variety of named Cretaceous formations overlying the Jarlemai Siltstone. The aquifer extends from Pardoo in the south west near the De Grey River, to Cape Leveque in the north, and inland by approximately 150 kilometres.

The aquifer is a maximum of approximately 300 metres thick. Maximum bore yields are around 10,000 kl/day, but could be greater with appropriate bore construction. Groundwater salinity ranges from less than 0.1 ppt inland to brackish or saline along the coast, with salt water intrusion at the base of the aquifer along the coast. Groundwater Temperature has not been measured, but is likely to be around 30 deg Celsius at the water table, and increasing by 2 deg Celsius per hundred metres depth, ie around 36 deg Celsius at the base of the aquifer.

Groundwater originates by direct recharge from rainfall on the outcrop area of the Broome Sandstone. The water table is deep inland and becomes progressively shallower on to the coastal plain. Discharge from the aquifer occurs at coastal springs in the mud flats.

The aquifer is divided for management purposes into the Pender, Broome and LaGrange sub basins.

Groundwater from the Broome Sandstone is used principally around Broome for town water supply, and for horticultural sub divisions. There is increasing interest in using the resources of LaGrange Basin for large scale cotton development, and in the Pender sub basin for tree crops.

Further information can be obtained from the following reports:

Broome 1:250 000 Hydrogeological Map Explanatory Notes by A. T. Laws, Geological Survey of Western Australia; Broome Groundwater Area Management Plan; Laws (1991); Leech, 1979.

Detailed information on individual water bores can be obtained from the Information Officer, Department of Environment, Water and Catchment Protection, tel. 9278 0580.

Wallal Sandstone aquifer (Pardoo to Cape Leveque)

The Wallal Sandstone and the Alexander Formation together comprise a large aquifer which underlies most of the north west part of the Canning Basin, extending from Cape Leveque to Pardoo. It overlies the Canning Grant and the Canning Liveringa. It is unconfined in the interior of the Great Sandy Desert and underlies the Jarlemai Siltstone and the Broome sandstone aquifer along the coast.

The combined Wallal and Alexander formations are several hundred metres thick. The groundwater level is as much as a hundred metres deep beneath the interior of the Great Sandy Desert. Along the coast and near King Sound bores are artesian. Groundwater salinity ranges from around 0.3 ppt in the south west part of the Canning Basin near Pardoo and Shay Gap, and increases progressively to the north where is around 2.5 ppt at Broome and to the east near King Sound. The salinity inland is unknown but is assumed to be fresh, at least south of Salt Creek. Groundwater temperature depends on depth, and is likely to be a minimum of 32 degrees Celsius at the top of the aquifer around the coast, and increasing by 2 deg Celsius per hundred metres depth, ie as much as 40 degrees Celsius at the base of the aquifer.

Groundwater from the aquifer was formerly used at Shay Gap for town water supply. There are a few artesian bores in the LaGrange area formerly supplying the Talgarno Agriculture Research Station. There are a number of bores at Broome and there are a number of pastoral bores just west of Willare. There is a large development potential particularly in the south west Canning Basin in the Pardoo area where the groundwater is fresh. This area was investigated in the 1970s for groundwater supply to Port Hedland.

Further information can be obtained from the following reports:

Broome 1:250 000 Hydrogeological Map Explanatory Notes by A. T. Laws, Geological Survey of Western Australia; Broome Groundwater Area Management Plan; Laws (1991); Leech (1979).

Wallal Sandstone aquifer (King Sound)

An unconfined part of the Wallal Sandstone occurs at the surface around Derby. It rests unconformably on either the Munkayarra Shale or the Erskine Sandstone, and has a maximum saturated thickness of 77 m. Groundwater in the Derby townsite area is fresh near the watertable, but there is a salt water interface close to King Sound. Groundwater from the Wallal Sandstone is used by shallow bores in Derby and nearby rural subdivisions. The aquifer currently has a low level of use.

Distribution of aquifers in the Derby area

Further information can be obtained from the following reports:

Derby 1:250 000 Hydrogeological Map Explanatory Notes by R. A. Smith, Geological Survey of Western Australia; Derby Groundwater Area Management Plan; Laws (1991); Laws and Smith (1989).

Erskine Sandstone

The Triassic Erskine Sandstone is several hundred metres thick, consisting of interbedded fine grained sandstone and shale, and overlies the Blina Shale. It is overlain in the centre of a syncline extending up to 30 km southeast of Derby by the Munkayarra Shale and in the Derby townsite area, directly by the Wallal Sandstone. Groundwater in the Derby townsite is fresh, but there is a salt water interface to the east, with salt water intrusion around the peninsula.

Groundwater temperatures at the base of the aquifer range from 41 to 49 degrees Celsius, with a geothermal gradient of about 2.8 degrees Celsius per hundred metres.

Current development in the Derby area is for town water supply, at Hamlet Grove for rural and horticultural use, and for minor pastoral use elsewhere. Bore yields range up to 1700 kL/day. The Erskine Sandstone has potential for further development, both inland for fresh water, and north east of Derby where the groundwater is saline.

Further information can be obtained from the following reports:

Derby 1:250 000 Hydrogeological Map Explanatory Notes by R. A. Smith, Geological Survey of Western Australia; Derby Groundwater Area Management Plan, Water Authority of Western Australia (1992). Laws (1991); Laws and Smith (1989).

Liveringa Group, Poole Sandstone and Grant Group

Major aquifers occur in the Permian Liveringa Group, Poole Sandstone and Grant Group adjoining Stokes Bay to the northeast of Derby. These aquifers can be inferred to contain fresh groundwater, with a salt water interface along the coast. Groundwater is currently used only for pastoral purposes, but there is significant development potential.

Further information can be obtained from the following report:

Derby 1:250 000 Hydrogeological Map Explanatory Notes by R. A. Smith, Geological Survey of Western Australia.