Bushwalk Australia

Took a sunny stroll this morning behind Macquarie Uni, the area connected by Christie Rd. The original intent was to walk down and cross to the northern bank of Lane Cove River and an easy stroll along that section of the Great North Walk track. Unfortunately, the crossing was largely flooded and I was kept on the southern bank. What was interesting was the amount of plastic hanging on tree branches, suggesting that the water level can rise by 10m or more in that valley.

Given this is inner city and easily accessed, has anyone seen this area in a flood? Can Lane Cove River's water level really get this high?

I think the big recent flood was after those storms in June. I walk down that valley quite regularly and noticed all the debris in the trees and a lot of the banks smashed. But have never been along the river in really high water. Its rare that you have to wade across. I think this river goes up and down quite quickly. One tricky crossing is on the GNW - the normally small creek not far downstream from De Burgh's bridge - which can be hard to cross when it has been raining - you need to jump across on boulders.

Dave

Thanks. I'll need to remind myself to visit that section come the next storm to convince myself and record it photographically. This is much easier to organise than going down the Royal after a storm.

GPSGuided wrote:Can Lane Cove River's water level really get this high?

Tim Flannery didn't think so

Proof will be in the photograph!

Some of the side creeks have very large flows, so might produce high flood levels. Shrimptons, near where I live is taking even more water as everything is built on. They need storage ponds but it is a bit late now.

Yes, I've been to some of the creeks upstream in the past and have seen evidence of the high flow. Given it's in inner Sydney, still find it hard to believe.

In an urban setting surfaces tend to be hardened increasing and speeding runoff and minimising infiltration and the area is sandstone with quite shallow soils so not much ability to detain rainfall. This causes rivers like Lane Cove River to become very peaky - very high flood levels but they drop off more quickly. I grew up nearby and have seen it in flood several times - quite spectacular.

that is interesting information

Mark F wrote:I grew up nearby and

anywhere in the Lindfield/Roseville area Mark ?
I did, and in the 60s as kids, we misspent our youth down at Lane Cove National Park, around the weir area and a bit upstream past the boat hire, swinging off the old rope and plunging in lol

great days...........

Rob Gosford wrote:that is interesting information
did, and in the 60s as kids, we misspent our youth down at Lane Cove National Park, around the weir area and a bit upstream past the boat hire, swinging off the old rope and plunging in lol

great days...........

Doesn't seem as idyllic these days. Runoff from a lot of suburbs and from the transfer station.

Given the population density and accessibility, I'm surprised not more have seen these storm run-offs.

Rob Gosford wrote:... Lane Cove National Park, around the weir area and a bit upstream past the boat hire, swinging off the old rope and plunging in lol

I remember that too. As a child in the 1960s, the rope swings upstream from the boat hire were the best thing. But the disappointment when I visited the park and the rope swings had been cut down

ribuck wrote:

Rob Gosford wrote:... Lane Cove National Park, around the weir area and a bit upstream past the boat hire, swinging off the old rope and plunging in lol

I remember that too. As a child in the 1960s, the rope swings upstream from the boat hire were the best thing. But the disappointment when I visited the park and the rope swings had been cut down

There was a case where one of the park systems was sued because they knew about a rope swing and didn't cut it down, and someone was seriously injured, so after that they cut them all down.