News May 10: Port River breaks bank and Mutton Cove flooded yesterday

The high tide and cold pressure system of yesterday (May 9th, 2016) finally did what Cheryl Karnaitis has been concerned about for a number of years; the levee bank at Mutton Cove has been breached and the tide filled the reserve. The tide was predicted to be 2.73m around 5.39pm though, like elsewhere in SA, its effect was greater.

Jean Turner and Dave Potter were on hand as the River was peaking and took these photos.

Port River testing the levee bank at high tide

Port River testing the levee bank at high tide

Port River cascading over levee bank

Port River cascading over levee bank

Cheryl returned to Mutton Cove at 7am today (May 10th) with Catherine McMahon and Kym Murphy to see the impact and for Kym to photograph it.

While tides have filled great areas of the reserve before, this time dune vegetation, that has been planted in the south, has been flooded, a channel has been created through the east-west walking trail and the water, after high tide (1.83m) around 6am this morning, was rushing through the breach.

Receding tide through levee bank breach 8am 10.5.16

Receding tide through levee bank breach 8am 10.5.16

Walking trail cut at Mutton Cove by Port River flooding

Walking trail from west to east now cut by tidal channel

View south across flooded Mutton Cove, from western boundary

View south across flooded Mutton Cove, from western boundary

Panoramic view of Mutton Cove from western boundary

Panoramic view of Mutton Cove from western boundary

Along the southern boundary, next to ASC, River water poured over the levee bank (rocks) around the shelter area and up the dirt road.

River water came close to shelter

River water came close to shelter

Along the riverbank while there is the breach above, there are other places also where the levee bank is coming close to breaking through.

Another breach emerging.

Another breach emerging.

Residents of the reserve including lizards, snakes, skinks won’t have fared well and the habitat of the area will begin to change in months, with a lot of the samphire lost, if the levee bank is not repaired.

Trial of a ‘Living Shoreline’ has been proposed for about a year and DEWNR had agreed in April 2016 to develop the design, for patching the levee bank, so that the community could marshall the resources to implement the trial.

Outline for a 'Living Shoreline' trial at Mutton Cove

Outline for a ‘Living Shoreline’ trial at Mutton Cove

The community wants to protect Mutton Cove conservation reserve because of its samphire and sand dune habitat and its importance to migratory shore birds and our enjoyment of them; because buried waste material at the southern end could otherwise leach into the River; because the neighboring industrial landholders to the north, west and south do not have seawall protection; because Mutton Cove is a lovely place to walk and is used regularly, including by ASC workers.

DEWNR, until it recently agreed to the Living Shoreline trial, had advised its Minister not to repair or replace the levee, based on the cost of repairs and that a shift from a samphire dominated to mangrove dominated environment system was acceptable.

What provision will be made for rising sea levels and more adverse weather events as a consequence of climate change? Will the levee bank be repaired with the trial of a Living Shoreline to enhance the resilience of the shoreline?¬† Will the levee bank be progressively lost, meaning the loss of Mutton Cove reserve and creating an early example of ‘retreat’ along the LeFevre Peninsula? What forms of adaptation will we have?

The local community will not want the area abandoned and environmental and community benefits should be sought. What kind of management plan will now be prepared and how will the community be engaged?