The SA Government issued salinity advice to River Murray irrigators on 17 and 21 February, in response to the re-opening of the inlet to Lake Bonney.

It was anticipated that as the water enters the main channel a temporary increase in salinity levels would be experienced for two to three weeks in the river downstream of the lake. 

Advice issued 17 February

For irrigators who take water from the main River Murray channel between Lake Bonney and Lock 2: salinity readings on 16 February were at 987 EC at Lock 3, 574 EC at Lock 2 and 437 EC Lock 4.

Advice issued 21 February

Salinity spike has now peaked near Lock 3 and is declining. With Lock 3 back in place the risk of further spikes is reduced.

The Department for Environment and Water (DEW) has received reports of isolated pockets of significantly higher than recorded salinity levels that have pooled near the river bank. These pockets will also be temporary but may occur near irrigation off take points and therefore pose a risk to susceptible crops.

With the hot weather this week, irrigators are advised to monitor their local water conditions. The following advice is provided for consideration:

  • Monitor soil water status and irrigate when the crops need it, do not allow the rootzone to dry out beyond refill point, as this will increase the salt concentration in the rootzone.
  • If using overhead irrigation, irrigate at night to reduce salt uptake through the leaves of the crop. Salt concentration on the leaves, and therefore salt uptake, is increased by evaporation during daylight.
  • If using full cover irrigation (overhead or undertree sprinklers) you may be able to minimise the amount of irrigation required during the peak salinity period by applying a deep irrigation before the salt slug reaches your property.  
  • With drip irrigation systems, however, do not delay irrigating to avoid the salinity peak, as the crop needs frequent water, and slightly salty water is better than no water.
  • Under normal conditions it is recommended that around 10% additional water above the rootzone water holding capacity is applied per irrigation, to flush salt from the rootzone. Do not neglect to provide this flushing during the salinity peak, and you can apply up to 15% extra. Make sure you don’t increase irrigation depth dramatically, as this might bring much saltier back up into the rootzone, especially if clay restricts drainage.

Primary producers impacted by the River Murray Flood are encouraged to access the Primary Producer Recovery Grants and the Primary Production Irrigation Grant along with other services. Information is available through the PIRSA website at or calling 1800 931 314