Howard Springs Nature Park: Synthesis of What We Know
How the Spring Functions
The Howard spring discharges from the Lower Proterozoic Koolpinyah Dolomite (2000 million years old). The dolomite is overlain by 65 metres of Cretaceous aged claystone and clayey sandstone. It is located near the margin of the dolomite aquifer and is in a sinkhole whose northern wall has been breached. The collapsed rock beneath the sinkhole provides a pathway for the deep groundwater to find its way through the overlying claystone. Faulting may have influenced the location of the sinkhole and thus of the spring. The dolomite forms a fractured and cavernous aquifer. The upper ten metres or so is often very porous due to very abundant fine solution cavities.
A rock wall has been constructed around the spring outlet to divert stream flows and runoff from other parts of the catchment around the spring minimising silting of the spring outlet. Howard Springs and springs in Melacca Creek, are direct windows to the dolomite aquifer.
Figure 1 : Local geology at Horward Springs (Tickell unpublished)
Spring flowing
Spring ceased
