Inquiry into flood mitigation infrastructure in Submission no.6

Lake Boga Vic. 3584

23rd July 2011

The Chairman Inquiry into Flood Mitigation Infrastructure in Victoria

Dear Mr Koch, Herewith, I offer a submission to your enquiry which includes items I hope will be acted upon after you deliver your report. I also hope my submission and remarks give additional information to help you arrive at your conclusions.

Now retired, I once conducted woolgrowing activities in the Tresco – area. I have lived at Tresco over 72 years, have experienced three major floods in that time, and know the Benjeroop, Mystic Park, region well.

It is the Avoca River, terminating in this area, with which I am particularly experienced. All remarks and recommended works for the Avoca Outfall are based on experience and knowledge of the flood characteristics of that area of the river. The latest 2011 flood, considered the greatest since European settlement, was carried by existing infrastructure of the Outfall channel past Mystic Park, but its disposal beyond that township was poor because of much needed works and improved management.

Below, is my resume of the past and present situation of this river and lakes system, followed by a list of works urgently required to safeguard against future damage in the control of floods.

Yours faithfully, John Jobson

The Avoca, Loddon and Murray Rivers in the region north of .

Three rivers in flood (the Avoca, Loddon and Murray Rivers) reach this region and converge in one general area (Benjeroop, Winlaton, Fish Point, Lake Boga) before proceeding past in one river – the Murray. Adjacent to and within this river system, are the Kerang Lakes, which usually are supply lakes for irrigation. In flood times these lakes serve as flood relief and buffer zones in the control of the . Manipulation of Loddon flows usually involves running high volumes through the Kerang Lakes system, in addition to the normal river flow toward Benjeroop to join the .

Managing floods from the Avoca River always adds to the problem of managing Loddon River floods into an already swollen Murray River, because extreme levels reach the region at differing times. The Murray is already running at high levels when a Loddon flood arrives, and from one to three weeks later, Avoca River floodwater emerges from the Mystic Park Marshes. Avoca floodwater then flows along the man-made Avoca Outfall channel toward the . The disposal of Avoca River floodwater beyond Mystic Park can have great bearing upon the local area and management of the Loddon/Murray flood levels.

A major lake (Lake Tutchewop) was taken out of the system in 1968, to become a saline water disposal basin. During the recently experienced major drought, Lake Tutchewop became dry until the 2011 flood, when emergency measures demanded it be used to aid flood control. Before 1968, Tutchewop was used extensively to aid in flood control of the Avoca River; thereby aiding overall control of Loddon River floodwater. Lake Tutchewop should be returned to its original natural use for flood mitigation.

In past floods, flood flows in the Kerang – Swan Hill region were controlled by one authority - the SR&WSC. That water authority has now been superseded by Goulburn-Murray Water. This current water authority should remain as the one authority in control of the flood flows, because of the somewhat juggling act needed to balance the overall problem of three rivers coming together. Outside interference from other government departments attempting to influence flood control by this one authority (Goulburn Murray Water) must be avoided.

The newer generation of local Goulburn-Murray Water senior personnel need to consult much more with local flood wardens and farmers regarding management of floods through the Kerang Lakes. The 2011 flood showed the department’s great ignorance to manage the lakes prior to any floodwater reaching the region. Had a strategy known to flood wardens and farmers been implemented, better Loddon flood control would have resulted and Benjeroop possibly not been subjected to such great inundation. This problem is an example of the newer generation of authority personnel being inexperienced and unwilling to seek sound advice from reliable sources. Government department attitudes need to be changed as well as procedures.

______

To: The Chairman. The Inquiry into Flood Mitigation Infrastructure in Victoria

The Avoca River

Mystic Park Marshes to the Murray River.

Important points needing consideration as a result of January 2011 floods, to safeguard against future floods.

The writer considers points 1, 2, 3, & 5 marked with a red asterisk to be of great importance.

Suggested works.

*1. The levee bank at north end of Mystic Park Marshes.

* This levee bank needs strengthening, 45 cm additional height and regular maintenance. * Immediately close breach in above levee bank caused by ignorant officials during the flood.

Avoca floodwater reaching the marshes from naturally flows in a north- easterly direction toward the Mystic Park forest and Lake Tutchewop, thence to the Murray River. In early times during extreme floods, Avoca River water combined with Loddon River water at the western side of Kangaroo Lake, to create an inland sea about Mystic Park, eastern Tresco, Lake Boga, Winlaton and Fish Point.

Under natural conditions, Avoca floodwater had no defined route to the Murray River beyond Lake Bael Bael and the Mystic Park marshes. The Avoca Outfall channel was constructed in the early 1930’s to stop local flooding and deliver water from the marshes to Lake Tutchewop. The outfall channel is the final route of Avoca floodwater for disposal into Lake Tutchewop or the Murray River via a large water channel.

A levee bank at the north end of the Mystic Park Marshes was placed there many years ago to control the Avoca River and Yassam (Back) Creek. The bank is on privately owned land and was regularly maintained for some 50 years by a former property owner. There has not been a flood in the marshes, and maintenance has not been done on the bank, since about 1996.

This strategically positioned bank acts to contain Avoca River floodwater within the Marshes. It also allows storage of greater quantities of floodwater. Discharge of water from the marshes via the Outfall channel can then be managed in conjunction with the Loddon and Murray rivers. Some form of management control and maintenance needs to be exercised by an authority over this levee bank to safeguard Mystic Park, aid local lake and river flood management, and avoid potential flood threat to the Tresco horticultural district and Lake Boga. Without this levee bank, uncontrolled Avoca water would create havoc in flood management in this area.

A breach was made in this bank during the recent flood, by ignorant authorities, in a mistaken idea to “spread the flood.” Fortunately, the breach was made where water would not flow anywhere, and did not cause damage to anyone. This bank should never be interfered with in future, as it is most important in flood control within this area.

This bank needs to be left where it is and not interfered with in future floods. It only requires improvement and regular maintenance. ______

*2. Remove Lake Tutchewop from Barr Creek salinity interception scheme, and use exclusively for Avoca River flood relief.

Lake Tutchewop was originally the Avoca River terminal lake until 1968, when it was taken over as an evaporative basin for disposal of saline water from the Barr Creek. The Barr Creek changed from being a freshwater creek, to become the largest single source of salinity entering the Murray River, after water authorities made the creek into a drainage channel for the Cohuna district almost a century ago. With the re-arrangement of irrigation in the Murray-Darling basin, high water costs, laser grading and water re-use, and other changes to the system, the Barr Creek will no longer be a great source of salinity in future. Environmental flows should be made available into Barr Creek, to guarantee reduced salinity in the creek and the lower Loddon River. Increased Pyramid Creek flows to the Loddon River released from the Kerang weir into the Lower Loddon would further reduce salinity inflow to the Murray River. This would aid farmers living along the lower Loddon, and improve conditions at Benjeroop for potential tourist trade in future. (The Benjeroop Hall Committee is aiming to establish a working historic pump which is presently being restored).

Under present changed Barr Creek conditions, Lake Tutchewop is not needed. Climate pattern changes with possibly wetter years will create more frequent floods in this area. Management of three flooded rivers in this area is always a problem. When Lake Tutchewop was taken out of flood relief 49 years ago, flood management became a greater problem. The latest flood made it essential to use Tutchewop as part of management to relieve pressure on Swan Hill and its surrounds. This indicated how important the lake was during past floods, and remains so today in local flood management.

I suggest Lake Tutchewop should resume its natural role as the terminal lake for the Avoca River, and henceforth be used only for flood relief.

______*3. Restore collapsed bridge at outlet of Lake Tutchewop on the Benjeroop-Tresco Road for future flood water escape to Murray River.

The outlet bridge collapse at Lake Tutchewop was caused by mismanagement of flood water at a time of high excitement. It needs reinstating to allow water escape from the lake. If Tutchewop reverts to Avoca floodwater relief (which seems likely), the lake will need an outlet to lower its water level for flood relief in succeeding floods. Recently the collapsed bridge was removed and the road cavity filled in with earth. In future, when an urgent need arises to exhaust the lake, a major road will be closed again unless the bridge is replaced. Far greater benefit for future flood management will result if the lake can be filled and exhausted easily via a restored bridge.

This is an important structure which needs immediate replacement. ______

4. Open existing (covered up) siphon beneath 6/7 contour channel to allow Avoca Outfall flows to enter Lake Tutchewop. Place control gate at siphon.

An old siphon already in exists to allow Avoca flows to enter Tutchewop. It has been there since the 1930’s and was closed off in 1968. It only needs re-opening and a control gate added, to avoid the need to breach the 6/7 channel, as was done recently. Careful management using this 5 foot diameter siphon should be adequate for Avoca floodwater entry into Lake Tutchewop. If a regulator gate is placed across the siphon, it will make the need for future channel breaching unnecessary and give easier overall flood management in this area. ______

*5. The Lake Kangaroo channel outlet structure on the Little Murray River needs increased capacity to restore original full flows from lake to river.

This channel (6/7) has carried 1600ml in past floods, but is now confined to 600ml because of a restriction at its discharge point at the Little Murray River. Floodwater flow management is restricted because of this problem. Loddon water was released into Lake Tutchewop during the latest flood, mostly because of a restricted channel flow to the Little Murray River. During recent floods, as 600ml went to the Little Murray, 800ml entered Tutchewop due to this problem. Had full 1400 – 1600ml capacity been available, another 1000ml would have reached the river. If Tutchewop had received Avoca water only, it would have eased problems at Lake Boga and Benjeroop, with full use of Loddon floodwater from Kangaroo Lake. The present small outlet structure was erected since the last major flood in 1973-74, replacing a full channel-width structure. The problem became apparent during this latest flood. This main channel (6/7) outlet into the Little Murray River from Kangaroo Lake needs restoration to original capacity. It will allow better flood control and early Kangaroo Lake reduction before floods arrive through the lakes system from the Loddon River. It is ridiculous for existing channel capacity to be so badly restricted because of a bottleneck at its discharge point into the Little Murray River.

A larger outlet structure is needed immediately. ______

6. Clear all undergrowth and trees from Avoca Outfall, particularly at the M.V. highway end.

Heavy natural undergrowth has occurred at the Murray Valley Highway end of the Avoca Outfall channel since the last floods passed through in 1995. Floodwater escape was restricted because the outfall channel lacked a clear passageway. Lack of any maintenance to the Avoca Outfall channel has caused a situation which needs rectifying.

Maintenance and clearing of the Outfall channel is needed immediately. ______

7. Enlarge and raise banks 45 cm of Avoca Outfall, from Marsh to highway, also increase bridge capacity at Mystic Park/ Kangaroo Lake tarred road.

The Avoca outfall channel needs greater capacity to allow speedier escape of Marsh floodwater and further protect Mystic Park and surrounding areas. The present height of banks does not offer sufficient security. A permanent regulating structure needs to be placed in the outfall western bank to regulate flow into the Mystic Park forest.

Work is required on the Avoca Outfall to protect Mystic Park and improve management. ______

8. A levee bank is needed on the north-western side of the Mystic Park forest, off Bailey Road, to contain forest floodwater.

A water supply channel (2/5/7) recently levelled during re-arrangement by Goulburn- Murray Water, formerly acted as a levee bank to contain water within the Mystic Park forest at its north-western side. Since the channel was removed, there is no control over floodwater. Water flowed westward beside Bailey Road and reached the railway line during the recent flood, because there is no levee bank to contain it.

A levee bank is needed along the north-western forest boundary; from the Bailey Road-Mystic Park forest road intersection to the railway line. ______9. Increase Murray Valley Highway culvert capacity & bank maintenance on the Mystic Park forest by-pass channel at Bailey Road.

The culvert at the Murray Valley Highway on the by-pass channel from the Mystic Park forest needs increased capacity to allow easier flow from the forest. The channel banks require raising and maintenance work. ______

10. Place permanent levee bank around Mystic Park cemetery.

The Mystic Park cemetery needs levee protection because the cemetery was close to becoming flooded as the latest flood passed through the Mystic Park forest. A bank erected in the forest during the 1973 flood protecting the forest road, was breached by ignorant authorities and the small western portion of the forest flooded, threatening the cemetery. This levee bank presently needs restoring. (See item 13.) ______

11. Close off abandoned Mineral Reserve channel at point where construction ceased, to guard against future water entry.

The abandoned Mineral Reserve channel needs closing off where construction finished at the north side of the Mystic Park forest to safeguard property, despite a bank belatedly placed half way along it after a home was unnecessarily flooded. ______

12. Raise southern bank of a water channel on north side of Mystic Park forest another 45 cm.

The south bank of an existing water channel (5/7) running parallel with the abandoned Mineral Reserve channel needs increased height because it came close to being overtopped during the recent flood. This channel may soon become unused, and consequently filled in, but the southern bank needs to remain as a levee bank and be improved to keep the forest floodwater contained. ______

13. A levee bank within the Mystic Park forest was breached and needs closing off.

A levee bank on the eastern side of the Mystic Park-Tresco (forest) road, made by the water commission during the 1973 flood, was breached to allow floodwater to escape into the smaller western side of the forest. This breach requires immediate closure. The breach caused dire consequences for a home on the Murray Valley Highway, near Bailey Road, when water escaped east along the abandoned Mineral Reserves channel. Water flooded the property and home as it continued back to Lake Tutchewop, then through the abandoned pumphouse into the lake. Floodwater also escaped westward and reached the railway line. These flooding occurrences were the consequence of mishandling by authorities during the recent flood, and reflected their ignorance of the situation. No one ever came to ask any local for information or advice gained from previous flood experience. This corner of the forest needs attention to ensure forest floodwater is contained. (See item 8) ______

14. Future flood control needs to have more local input from experienced locals, with local headquarters; not in Bendigo or .

There were too many idle people present during the recent flood without any useful control. Top heavy administration caused mistakes in flood direction, e.g. – happenings at Benjeroop, and unnecessary breach in Marsh levee. There is too much bureaucratic interference with local affairs and dismissal of local knowledge as a source of value. People in offices poring over survey maps; or flying over floods in helicopters; are no substitute for practical local knowledge. ______

With the likelihood of a series of wet years again occurring and more frequent floods happening, the foregoing works are needed now.

If the above suggestions are carried out, management of Avoca floodwater in this area will be enhanced. There will be less likelihood of property being flooded.

It is to be noted that the Avoca River from Lake Bael Bael to, and including, Lake Tutchewop is within the Gannawarra Shire. Lake Tutchewop outlet to the Little Murray River is within the Swan Hill Rural City. The dividing line between the two shires is the Benjeroop-Tresco Road, with Gannawarra Shire controlling that section of the road. The collapsed bridge over the Tutchewop outlet is within the Gannawarra Shire. ______

Avoca River flood control in this area.

Instances of poor control and poor deployment of volunteers can be found in many places in this 2010-2011 flood stricken region. The attitude of authorities during the recent flood to “spread” Avoca floodwater anywhere, and not try to contain it, was totally wrong. Is not the whole purpose of dealing with floods an aim to control them?

A breach made in the Marsh levee bank to “spread” water westward failed, because of ignorance by authorities. At the time, it caused great apprehension for Tresco horticulturists and Tresco township residents when floodwaters seemed destined to flow along the western side of the railway line. This action caused the Swan Hill Rural City Council to erect a 2½ km levee bank along Jeffer Road in case water flowed along the western side of the railway line toward Tresco. The exercise clearly showed ignorance on the part of authorities, and their lack of consultation with experienced locals, as to flow characteristics within the local area. As it happened, the Avoca Outfall system successfully carried the extraordinary flow of floodwater from the Yassam Plain and the Mystic Park Marshes, despite failed interference.

All previous floods were handled by local inhabitants, with a lifetime of local flood experience. They patrolled and guarded levee banks and made decisions based upon their experience. Flood flow management beyond the Marsh outlet was handled by water commission personnel.

Since the 1973-74 floods, bureaucratic departments have increased in number, resulting in confusion in the control of these natural disasters. Government department staff movement during periods between major floods causes flood experience to be lost for use in future major floods. It seems each succeeding generation of bureaucrats approach major floods armed with little more than academic study, and think they can manage floods without local consultation. There are instances where local flood wardens were totally ignored during the latest flood.

Management of the latest flood indicated the need for great improvement in using local farmers’ experience and knowledge.

It is hoped future floods are handled by authorities in a superior way to the latest flood.