The above map depicts depth to groundwater for the assessment year compared to the 10 year long-term range for bores with continuous datasets relevant to the Fitzroy basin. These bores are monitored by the Queensland Government Department of Natural Resources and Mines.
Deepest = between 0 to 20% of levels in the 10 year long-term dataset.
Deep = between 20 to 40% of levels in the 10 year long-term dataset.
Neutral = between 40 to 60% of levels in the 10 year long-term dataset.
Shallow = between 60 to 80% of levels in the 10 year long-term dataset.
Shallowest = between 80 to 100% of groundwater levels in the 10 year long-term dataset.
The results represents the shallowest groundwater level for the reporting period compared to the long-term range. The colours show groundwater levels ranging from 0 to 100 on a standardised index, where 0 is the deepest and 100 is the shallowest
Due to the large scale flooding that occurred across the catchment during the 2010-11 water year, many streams that regularly cease to flow in the second half of the calendar year continued to flow as elevated groundwater tables throughout the catchment provided extended base flows.
The increases in electrical conductivity (EC) observed in the Fitzroy River from October to December 2011 are likely due to geochemical leaching, rising water tables and the seepage of saline groundwater into surface streams of the Fitzroy.
Groundwater usually is harder than surface water. Also, rising water tables were evident. At Emerald, for instance, the large rainfall event of 2010-11 (which followed a similarly large event in 2008) most likely led to recharge of subsurface aquifers. Source: Fitzroy River Catchment 2011-12 Wet Season Report
Nearly all surface-water features (streams, lakes, reservoirs, wetlands, and estuaries) interact with ground water. These interactions take many forms. In many situations, surface-water bodies gain water and solutes from ground-water systems and in others the surface-water body is a source of ground-water recharge and causes changes in ground-water quality.
As a result, withdrawal of water from streams can deplete ground water or conversely, pumpage of ground water can deplete water in streams, lakes, or wetlands. Pollution of surface water can cause degradation of ground-water quality and conversely pollution of ground water can degrade surface water.
Thus, effective land and water management requires a clear understanding of the linkages between ground water and surface water as it applies to any given hydrologic setting