Murray Irrigation

Drainage Review

Project summary



Following the rain events in October and November 2022, where the Murray Irrigation (MIL) footprint received almost 300mm of rain, the company commenced a review into the performance of our drainage system and processes during these unprecedented rainfalls to identify where improvements may exist.


This review was undertaken by an independent Incident Cause Analysis Method (ICAM) investigator, SAFCOM Risk Management, and involved an extensive interview process with customers as well as MIL staff.




Suggestions that arose from the interview process included:


Investigate the practicality of increasing the capacity of drains

Results:

  • The drainage system operated as designed. Given the extensive rain event, increasing the capacity of the drainage system would have had minor, if any impact as a result of the river heights backing up in to the drainage system.
  • A major upgrade would comprise significant construction and maintenance costs, further loss of productive land to provide a minimal increase in the service level benefit.
  • Four high level strategic activities to improve the existing performance were adopted and implemented; their progress can be seen in Table 1 below.


Reviewing MIL's Maintenance Plan, in particular the company's weeds maintenance program

Results:

  • The Asset Management Strategy along with specific asset type management plans continue to be reviewed and redeveloped, where appropriate.
  • Proactive drainage system maintenance tasks are performed during April and May each year. For example, since the 2022 flood, 968 workorders have been completed on both planned maintenance and emergency repairs at a cost of $1.9 million.
  • An additional $500K of capital works have also been completed.


Customers who break the rules should be penalised

Results:

  • Unfortunately, it is extremely difficult for Murray Irrigation to prosecute those customers who did the wrong thing.
  • MIL does have the ability to suspend supply services along with other measures under the Works and Distribution Rules Policy.


Investigate changing the drainage system from a non-regulated system to a regulated system.

Results:

  • The drainage system is designed as a non-regulated system, and redesigning the system to operate as a regulated system similar to the channel system would require significant financial investment.


The key findings of this review were released in a report completed in June 2023, which provided the company with 45 recommendations that could be adopted to further mitigate the risk to MIL and customers should a flood event of this nature reoccur.


A copy of this review is available on the company website, and can be accessed via the button below.

Murray Irrigation Drainage Review - Key findings released

Suggestions that arose from the review included:


The MIL drainage network is designed to drain 50mm of rain over a four-day period. However, due to the unprecedented rain event, the drainage network was inundated and unable to drain the 300mm of rain received. After undertaking an internal assessment of the review, MIL was able to categorise the 45 individual recommendations into the following four main items:



  • Engineering assessment of all MIL assets including all drainage assets in the footprint.
  • The development of business cases, based on the drainage review, to seek approval for works where a positive cost/benefit analysis can be identified.
  • A full internal document control process review
  • Update to the training plan

Current Progress: Table 1

Flood review action Current Progress Next steps
1. Engineering assessment of all MIL assets including all drainage assets in the footprint 92% complete Development of business cases
2. The development of business cases, based on the drainage review, to seek approval for works. Inclusion within the relevant asset management plans where a positive cost benefit result is achieved.
a. Hindley Road pumps Works completed Completed as part of the asset management plan.
b. DC 1000 pump site Engineering feasibility completed Business case development to determine any inclusion to the asset management program.
c. Escapes required to measure height and flow Feasibility study complete Business case development to determine any inclusion to the asset management program.
d. Inability to read drain levels remotely Not commenced Business case development to determine any inclusion to the asset management program.
e. Wakool flood structures Feasibility study complete Business case development to determine any inclusion to the asset management program.
f. Woolami Drain (last few KM) Feasibility study complete Business case development to determine any inclusion to the asset management program.
3. Document control review 30% completed Work in progress.
4. Internal - Update the staff training plan 30% completed Work in progress.

Business as usual

Outside the recommendations provided by SAFCOM, MIL continues to maintain our drainage infrastructure via the company's annual maintenance strategy.



If customers have any questions regarding the drainage review, please contact the Customer Experience team on 1300 138 265 or email customersupport@murrayirrigation.com.au.