Long Swamp Restoration Trial – Phase 3 structure is complete!

Long Swamp Restoration Trial – Phase 3 structure is complete!

After an inspired effort from our crew on Monday, it is great to be able report that on Day 9 of works we completed the job!

Isn’t the phase 3 structure – with a total of¬†about 6,600 sandbags in place –¬†quite a sight?

This image form the end of Day 8 shows where we left things on Friday the 24th April 2015

After a massive Day 9 (Monday 27th April 2015), plus a bit of tidying up on Tuesday – and the job is complete!

From the downstream side (above images) it is a pretty imposing looking structure – but a view from the upstream side helps to bring things into perspective…

Some very happy sandbaggers enjoying the view from the structure after completing the job on Monday the 27th April 2015.

As predicted, lifting the weir above the standing water level in the swamp on the last day (Day 9) of sandbagging, to our target height, has been met with a slower response in water levels upstream.

End of Day 8 – 24th April 2015
Upstream Water Level – 144 cm. Swamp Level – 36 cm.

End of Day 9 (and end of sandbagging) – 27th April 2015
Upstream Water Level – 151 cm. Swamp Level – 43 cm.

End of Day 10 (tidy up day) – 28th April 2015
Upstream Water Level – 153 cm. Swamp Level – 45 cm.

As we have now inundated the Phase 2 structure, every incremental rise in water elevation is having to cover an increasing area of wetland habitat within the swamp upstream – so the rapid height increases we saw a couple of weeks ago (when the channel was first filling) are now a distant memory.

The appearance of the Phase 2 structure on the 12th of April 2015, before the Phase 3 structure had taken full effect.

The now redundant Phase 2 structure, as it appeared on the 28th April 2015, being inundated as a result of the successful completion of the Phase 3 structure.

And now, for the final, and most important view; of habitat in Long Swamp itself. Despite the imposing sight of the Phase 3 structure, it is this view that (along with our ecological monitoring program) will tell us about the success of the trial over the months and years ahead. Monitoring water levels and habitat change at this location and further into the adjacent portion of Long Swamp are going to be very revealing!

The deepest corner of Long Swamp proper, situated near the beginning of the Nobles Rocks channel – as it appeared at the end of Day 8 – 36 cm deep.

A subtle but significant change, and a sign of things to come when the winter rains arrive… By the 28th of April, swamp levels have risen to 45 cm deep.

Mark Bachmann
Mark Bachmann
mark.bachmann@natureglenelg.org.au