Gungoandra Creek rock weir

Published 05 Sep 2014 
about  Scottsdale Reserve  
Individually placed rocks<br/> Individually placed rocks
The eroding head cut<br/> The eroding head cut
one by slow one<br/> one by slow one
Wall taking shape<br/> Wall taking shape
Now they are big rocks<br/> Now they are big rocks
Soil consulatant and volunteer Peter Fogarty checking in<br/> Soil consulatant and volunteer Peter Fogarty checking in
Slowly growing<br/> Slowly growing
Delayed by rain and small flood<br/> Delayed by rain and small flood
Brad patiently explaining the mess to even more visitors<br/> Brad patiently explaining the mess to even more visitors
Main wall in place with stream diverted over it<br/> Main wall in place with stream diverted over it
Fishway starts<br/> Fishway starts
Growing fishway<br/> Growing fishway
The first cut<br/> The first cut
Completed fishway<br/> Completed fishway
Seeding banks over working fishway<br/> Seeding banks over working fishway
Fishway<br/> Fishway
Clean up and weed removal<br/> Clean up and weed removal
The proud builders<br/> The proud builders
A work of art<br/> A work of art
The drill rig moves in<br/> The drill rig moves in
Diversion pipes<br/> Diversion pipes
First steel in<br/> First steel in
You need faith this mess will get better<br/> You need faith this mess will get better
Modern art<br/> Modern art
Oh the mud<br/> Oh the mud

There's a very exciting project that was finished at Scottsdale this week! Nearly four years in the planning, design and funding the Gungoandra Creek rock weir and fish way has been successfully constructed over the last three weeks.

It's the most significant component of the erosion control plan that volunteer soil consultant Peter Fogarty has helped Scottsdale with.  

Funded by Actions for Clean Water (ACWA) through the Local Land Services with the help of Matt de Jongh, construction was ably undertaken by Brad Davies of NSW Soil Conservation Service and Jeff Kent of excavator prowess extraordinaire.

Its purpose is to halt the migration of an active head cut up through the creek into several kilometres of creek wetland. Controlling this head reduces the current high release rates of sediment from the creek into the Murrumbidgee River, significantly improves water quality and protects the valuable habitat of a wide range of frogs, mountain galaxia and many, many water bugs!

The construction of the weir entailed the installation of a large rock wall, cut into both banks and held in place by vertical steel columns that have been drilled into the bedrock.

Geofabric, some impregnated with bentonite, has been used to help contain the surrounding soil and to some degree to waterproof the main structure.

A fish way or ladder, carefully constructed on the original stream course, is a series of steps where the water drops 10cm for every 80cm of horizontal flow, this allows resting pools for the galaxia between their ‘bursts’ to climb the 10cm. In times of flood the main flow will overflow the wall itself.

 Positively beautiful!

The eroding head cut<br/> The eroding head cut
one by slow one<br/> one by slow one
Wall taking shape<br/> Wall taking shape
Now they are big rocks<br/> Now they are big rocks
Soil consulatant and volunteer Peter Fogarty checking in<br/> Soil consulatant and volunteer Peter Fogarty checking in
Slowly growing<br/> Slowly growing
Delayed by rain and small flood<br/> Delayed by rain and small flood
Brad patiently explaining the mess to even more visitors<br/> Brad patiently explaining the mess to even more visitors
Main wall in place with stream diverted over it<br/> Main wall in place with stream diverted over it
Fishway starts<br/> Fishway starts
Growing fishway<br/> Growing fishway
The first cut<br/> The first cut
Completed fishway<br/> Completed fishway
Seeding banks over working fishway<br/> Seeding banks over working fishway
Fishway<br/> Fishway
Clean up and weed removal<br/> Clean up and weed removal
The proud builders<br/> The proud builders
A work of art<br/> A work of art
The drill rig moves in<br/> The drill rig moves in
Diversion pipes<br/> Diversion pipes
First steel in<br/> First steel in
You need faith this mess will get better<br/> You need faith this mess will get better
Modern art<br/> Modern art
Oh the mud<br/> Oh the mud