The Western Australian Department of Water has declared unrestricted pumping from the Gascoyne River beds for all bores during February.

 

Following a test on Monday, the department found the water level at Nine Mile Bridge was 1.4m and the water quality stable at 393mg/l TDS (total dissolved solids).

 

Subsequent flows have been recorded upstream and the department anticipates the conditions are likely to continue for the following weeks.

 

The conditions are therefore now suitable for unrestricted pumping of groundwater from the Riverbeds Sands aquifer.

 

Since the last flow of the river (December 2010 – September 2011), the department has recorded an increase in salinity in the Riverbed Sands aquifer. In May 2011 the reading was 1008mg/l TDS at Nine Mile Bridge and in July 2011 it increased to 2000mg/l TDS.

 

The first flows of the river this year reached the Carnarvon horticulture area on Monday 30 January.

 

The water salinity of the initial flow was in excess of 1200mg/l TDS. The department has since monitored flow and water quality of the river.  As the flow has progressed the salinity has slowly lowered below 500mg/l TDS.

 

Growers are encouraged to take advantage of the current unrestricted pumping period to help recharge the aquifer with the current flow of good quality water.

 

The more water that is pumped from the Riverbed Sands aquifer the better the infiltration and recharge of the aquifer with the new flow of good quality water.

 

In line with the Lower Gascoyne water allocation plan 2011, growers are encouraged to switch to their bores and spearpoints in the Riverbed Sands aquifer and are reminded that:

  • Unrestricted pumping is encouraged from the Riverbed Sands aquifer
  • Maximum monthly abstraction limits do not apply to eligible properties (those having bores/ spearpoints to take water from the Riverbed Sands aquifer) during periods of unrestricted pumping 
  • Abstraction during unrestricted pumping from properties with access only to the Older Alluvium aquifer (OAA) will count towards their annual entitlement but will not be considered during an assessment of an application for increased entitlement.

People are welcome to contact the regional office in Carnarvon on (08) 99416100 if they require clarification on the rules of unrestricted pumping.