Australian Natural Resources Atlas

Groundwater Management Unit

 

Location map of Spring Hill Groundwater Supply Protection Area

Groundwater Management Unit: Spring Hill Groundwater Supply Protection Area

Introduction

The groundwater resource characteristics for the Spring Hill Groundwater Supply Protection Area groundwater managment unit are presented below. This includes technical detail on aquifer properties and water level change for key monitoring bores.

What is the character of Spring Hill Groundwater Supply Protection Area's groundwater resource?

Vital Statistics:

Area253 km2
Total Water Allocated1,500 ML/yr
Total Water Usedno data
Average Salinity1,400 mg/L
Sustainable Yield5,100 ML/yr
Depth to top of aquifer5 m

Aquifer Description:

Unconfined fractured Newer Volcanics basalt aquifer. (explanation of fracture flow and anisotropy)

Method used for determining sustainable yield:

The PAV developed for the Spring Hill GMA has been based on the comparison of a number of aquifer recharge determination methods. The Spring Hill GMA has shown considerable variation between these methods. The method of rainfall infiltration was favoured over hydrograph fluctuation as the available bore hydrographs for analysis were restricted to a small area of the GMA.

Discharge at the margins of the lava flows to the underlying Tertiary sediments and basement rock, as well as to streams, springs and lakes was considered. The limiting effect of well interference on aquifer extraction was found to have little influence on the unconfined basalt aquifer.

The PAV determined for the Ascot GMA was calculated as 5,139 ML/year, based on the rainfall infiltration method. This figure was estimated using limited information and attracts a poor reliability. It should be noted that the PAV specified above applies to a large area and localised intensive extraction is likely to cause local interference effects.

Assumptions used for allocating development categories:

Groundwater categorisation was assessed in terms of the requirements of the audit documentation. Information applied to the categorisation of both abstractions and allocations was based on the best information available from a combination of information supplied by the responsible Rural Water Authority and information from the Groundwater Database.

Forward projections of abstraction were based on a combined surface and groundwater demand evaluation model. This model projected potential demand for water based on predictions of population growth, industry development, agricultural development and water consumption trends.

Are groundwater levels changing?

Technical information on the key groundwater bores and monitoring stations is presented below, including hydrographs where available. Link to a discussion on groundwater levels and trends at a State level as it relates to dryland salinity.

Bore IDStart recordEnd recordDepth of bore (m)Reduced level (m)
VIC9187524-Jun-8724-Sep-9981489
VIC9187630-Jul-8724-Sep-9987415

The following groundwater management units also occur in Lachlan Province:

Further information

Key

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