Dave's ACT: THE THARWA SANDWASH

Thursday, October 18, 2012

THE THARWA SANDWASH

A trip today just past Tharwa to the Tharwa Sandwash. Beautiful weather, no traffic, just a leisurely ride in the warm sun. Not that I did but it's a great spot for a swim on a hot day. Depending on the river flow it can be as pictured or showing sandbars when the river is lower. It's been raining somewhere... I learned something today about the effects of historical land clearing in the region. The ACT Governments information board is interesting. It paints a picture of a much different place in the past.. From the signage…

Alan Cunningham 1791 - 1839

Clues to the past.

“This area looks very different to how botanist-explorer Alan Cunningham saw it in 1824. The Ribbon Gums – tall white eucalypts with peeling bark – provide an ecological clue. They are all that remains of the original lush sheltered forest, where lyrebirds scratched for food in fallen leaves among tree-ferns and giant daisies.

With settlement came tree clearing. The water loving shrubs lost their protection and dried out. Tougher grasses moved in, and the riverbanks, like the surrounding hills, became home to dry forests of Scribbly Gum and Red Stringybark.

Fortunately, all is not lost. Protecting the remnants is important. Wet forests still exist along the creek banks in Namadgi National Park and the Brindabellas, and the Murrumbidgee is flanked by nature reserves along most of its ACT route.”

Re-creating habitats.

“The Murrumbidgee used to contain deep pools, where native fish would thrive. But human activities, floods and droughts changed the river’s flow. Sandwashes along the river’s Tharwa stretch left it just 30 to 40cm deep in places.

As the deep pools silted up, local species became rare.

Captive breeding is helping – 100,000 young Trout Cod have been released near here to re-establish a wild population, but they need good habitat for long-term survival.”

Tree plantings along the riverbank...