16 Nov 10: A weir-d day in the Brindabellas

16 November 2010 A weir-d day in the Brindabellas

Maps: Cotter Dam and Tidbinbilla 1:25000

Getting There

This walk was organised and led by me as an irregular CBC Tuesday walk:

Tuesday 16 November - A weir-d day in the Brindabellas - L/M,ptX. A modest day below Piccadilly Circus ground-truthing weirs for KHA. At least it's a change from border markers. Via Old Mill Road and 300m down a ridge to Warks Road, visit Piccadilly weir, Lees Creek sawmill, Ferny weir, Bulls Head wier, Pago weir and Warks weir. If time and enthusiasm allow, a further poke around Bulls Head. Around 15km and 700m climb. Maps: Cotter Dam and Tidbinbilla. Leader: John Evans - jevans@pcug.org.au, (h) 6288 7235. Transport: ~$8 per person.

6 of us met at my place and drove via the Cotter (with a little dam viewing extension) and Brindabella Road to park at Reids Pinch at the Namadgi National Park sign.

Further Information

KHA contacts have been kind enough to provide me with an extract of their Namadgi database ... provided I wander about and ground-truth sites. At least it's a change from border markers.

Photographs

Access all photographs here. All thumbnails in the walk report are active - click for a larger picture.

Walk


Track overview	Track 1	Track 2

It sure was a weird day, with some unknown force having an effect on the navigation. The first occurrence was when I drove past the right hand turn into Brindabella Road at the Cotter and headed out Paddys River Road. But we turned around and got a great view of the new dam construction.

We parked at Reids Pinch, at the NNP sign, just at the top of Blundells Creek Road. All going well, we'd appear up here later in the day. The plan was to walk the 1.8km up the Brindabella Road to the start of Old Mill Road first, rather than park up there and have the road bash at the end of the day. All went according to plan, until we overshot and had to come back.

At last we were away and heading to our first objective. Hitting the corner of the road, we began searching down the creek line. No joy at first, so a couple of the lads went back up the road to begin searching upstream. Success on two counts, as the downstreamers found Piccadilly weir and the upstreamers found Lees Creek sawmill site. As I've found with most KHA locations, they're out a bit. Piccadilly weir is at UTM 55H 664890-6085551 (MGA94), whilst KHA currently have it as #702 at 664812-6085583. The downstreamers wandered back up to the sawmill site and also across to the KHA location. Lees Creek Sawmill site is at UTM 55H 664772-6085597 (MGA94), whilst KHA currently have it as #740 at 664762-6085533.

On along Old Mill Road the third weird thing happened. A check of the GPS revealed that our next objective was behind us and, as I'd been talking and taking little notice of our progress, we about turned for a little while. Feeling weird, a little map check showed the huge U-bends in the road, so we about turned again and continued on to the area containing Ferny weir.

The KHA location plots up along a ridge so, following down the creek in the area, we made several forays into the dense vegetation of the creek line. It was impossible to follow the creek in the water, with huge trees fallen across it and very thick vegetation. No joy, so we sat in the middle of the road and had morning tea (including Gemma's yummy brownies) at 10.30am. Back at it, we continued to walk Old Mills Road towards our next weir, but the lads gave a shout of discovery and we found Ferny weir (well away from the current KHA location). Like border marker hunting, weir hunting has its own technique - listen for the increased sound from the creek, bash down to it and you'll find either a noisy cascade or a weir. Ferny weir is at UTM 55H 665089-6084582 (MGA94), whilst KHA currently have it as #703 at 664812-6084483.

It was easy to spot the next one. Approaching the bend in the road, Bulls Head weir rears high above the road through the trees. We bashed up the side of the creek to it - a couple of us returned via the benched vehicle track on one side. This weir is a substantial structure. Bulls Head weir is at UTM 55H 665068-6083627 (MGA94), whilst KHA currently have it as #707 at 665012-6083683.

I'd always thought that the next weir would be hard to find. It was and we didn't. The current KHA location positions it well up on a ridge away from Old Mill Road and, from the preparatory map work, I'd made a best guess as to where it could be. We bashed our way to the best guess location - in one place through a blanket bush forest - to find nothing. Even the drainage line was dry, so this is obviously the wrong creek. We'll have to go back and work on the creek line running East of the KHA location. So Pago weir remains undiscovered by us.

Our next leg took us generally NE down a spur towards the next weir. Garry did a marvellous job of making the going for the first half, but when I took over the weirdness of the day kicked in again and I slipped of the crest (this actually often happens). At last gaining the creek, the noisy water led us to a lovely cascade and we clambered up above it for lunch at 10 to 2. This bush bashing leg of 1.7km took 1hr 40mins.

Thinking that we were still 150m from the weir, we were pleasantly surprised when we very soon came to Warks weir. A great structure, complete with concrete gauging cylinder and a locked metal box. Warks weir is at UTM 55H 666415-6084472 (MGA94), whilst KHA currently have it as #704 at 666512-6084483.

Down onto Warks Road, it was nearly all over bar the shouting. We popped down to visit the map-marked weir on Blundells Creek, which I'd seen before. Passed through a magestic stand of unburnt mountain ash. (Just discovered that KHA call this) Lees Central weir is at UTM 55H 667289-6085673 (MGA94), whilst KHA have it very close as #705 at 667312-6085683.

We wandered back to the intersection with Blundells Creek Road and up it to the cars.

Not a bad day, with a bit of interest. Will have to return to search for Pago weir and to pick up the more southerly Bushranger weir.

Many thanks for your company Tony B, Margaret C, Gemma D, Garry M and Phillip S. A fun day for a weir-d mob.

Distance: 18.1km Climb: 550m. Time: 8.20am - 4.00pm (7hrs 40mins), with 45mins of stops.
Grading: L/E&R,ptX,ptX; M(11)

KMZ file for Google Earth/Maps: A weir-d day in the Brindabellas

Post-Walk Research

Thanks to Matthew Higgins who comments:

The large, long pieces of iron in some of your shots are fire-box bars from the steam engine that stood on the site in the 1930s. This site is, I believe, on the ACT interim heritage register.

Re the weirs, while stream-gauging was no doubt part of the story around here, a number of the weirs in this area were built as part of bushfire research (strangely enough!). The principle was that fires would be lit and then the impact of the burn on the catchment and run-off would be gauged via examination of the weirs.

Thanks to Tony Beasley who provides:

I have done some investigation about the gauge that we found, it is called a Staff gauge, the company Leupold and Stevens is still going but under the name of Stevens now, they still make the same type A Staff Gauge (see here), the measurements appear to be in feet, so far I have not been able to remember how calculate water flow from it but will do some more work soon.

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This page last updated 23Aug22