The Croppers Creek Hydrology Project

A Personal History
Leon Bren (bio)

The project is located 22 km s-w of Myrtleford and about 6km from the Lake Buffalo Dam wall. Monitoring of three small catchments – Clem, Ella, and Betsy Creeks started in 1975. This involved measurement of streamflow and rainfall. The catchments all carried native eucalypt forest. In December 1979 Clem Creek slopes were cleared. The debris was burnt in April 1980 and the slopes planted with radiata pine. This grew steadily if not spectacularly and the trees were becoming of harvestable size about 2005. An on-site meeting in November of that year discussed this with plans to be formulated in the coming months. However, in January 2006 the area was burnt by the “second megafire” and this destroyed all equipment and the plantation. The equipment was replaced by the University of Melbourne insurance policy, the burnt pines were harvested, and the slopes replanted. Measurement of outflows is continuing. The work was mainly concerned with water and nutrient balances but many other aspects of forest hydrology have been considered. Now read on….


The Unvarnished History

Well the correct name is probably the “Cropper Creek Paired Catchment Hydrology Project” and I think that title might be on a collection of files somewhere in the Government Archives. The project was and is a “classic” paired catchment (aka “watershed”) project in which three small streams were gauged in north eastern Victoria. After some years of this, the slopes of one of the catchments was converted from native eucalypt forest to radiata pine, and the changes in water and nutrient flow emanating from the catchment measured. It is still continuing, albeit in a rather reduced form. The project has, I believe, been productive in terms of books, papers, and training.

Anyway, the saga really began about 1972. I had been recruited as a young researcher in hydrology– they probably decided I had “potential.” God knows how because I knew nothing about hydrology (there were no courses in it then). However, I was keen and read up about it as much as I could, and did a lot of maths studying too. The Forests Commission Victoria, in its wisdom, had decided that water issues were important and they needed to get some “in-house knowledge” Then the boss – the late Dr Fred Craig (“Chief Forest Research Officer”)– called me over to his office and, amidst clouds of cigarette smoke (did I say it was a different age then?), said that we needed a paired catchment project to look at the water impacts of radiata pine, and it was my job to get one in.

By this time I did know a bit about the subject. The FCV had been involved with the Experimental Catchments Committee – a multi-department group really run by the Soil Conservation Authority but also involving the State Rivers Department that had gone down this pathway before. They had a number of such projects – the Stewarts Creek Project, Long Corner Creek Project, and the Reefton Project to name three, but none had every really produced much knowledge. They always seem to flounder in data processing issues. Looking back, I think The ECC aims were as much about stopping the Forests Commission doing anything or “getting ahead” as getting knowledge. Anyway, this caused the FCV in general and Freddy in particular a lot of distress – hence this project.

So Fred’s view was that we needed a project outside this Committee, and I was the tool that would be used to produce it. “You have chosen a very blunt tool” was my assessment of this view. But he’s the boss so that’s it; let’s get down to the nitty-gritty.

During the planning phase I became painfully aware of my manifold inadequacies, and that some of my scientific training was lacking as well. Anyway, I thought I’d go and introduce myself to the “hydrologic gurus” and see what they thought of this yet-to-be project. Most were helpful, and some very helpful, but I did discover that they liked models and modelling, and that long field-measurement campaigns were beyond their experience. The most common advice was that we could do it all by “modelling” (which, in hindsight, would have been a waste of time without good field data). Anyway it was all helpful, but suddenly the time for planning was over and it was time to get the shebang on the road.

Lots of poring over maps of plantation areas and it seemed that the north-east offered the best prospects. The FCV was being hammered with complaints over “peak flows” from its Warrenbayne plantation development (mind you, an inspection of the so-called affected land showed that the farming practices were nothing to boast about). So “investigation of peak flows associated with plantation formation on steep country” was the rationale. And then into one of the Forests Commission Victoria fleet to go and look at such sites.

Koetong Plantation seemed to offer the best chances. Lots of native forest, lots of plantation development, and lots of steeper country. But it was a long way away. Anyway, I spent a fair amount of time looking at the unpropitiously-named “Dry Creek” area. There had been a lot of tin-mining there a century or so before. We got as far as defining a notional project, but the distance from Melbourne worried me, as did the name. And I marked out a notional road to get in there but noted it crossed over an old surveyed road on the Parish Plan. I checked this with the Survey Branch who almost had a stroke – some long-dead surveyor had pegged out a road and township that was never built. But the survey and gazetting of this tin-mining megalopolis-to-be had been well done and effectively it would have been a big (and costly) survey amendment process if I was not to have a paper town in the midst of my Paired Catchment Project. So it was off to look elsewhere!

That “Elsewhere” was Myrtleford, Veteran researcher George Minko discussed the project, pulled out a map showing the Croppers Creek Basin, and said “that was likely to be a good spot”. What I found out years later was that Forester Bert Semmens in the 1950’s had thought that we should do some “hydrologic monitoring” and that he and Bert had concluded that this basin was the ideal one, but the project in itself never got off the ground. But some decades later, here was a person looking for the same sort of stuff. Well done, George and Bertie. Anyway. there was a flurry of letter writing and we got a sort of grudging permission to proceed. The project was in the catchment of the current Buffalo Dam, and there was a vague plan to build “Big Buffalo” which would have impinged on the project, so we did have some communication on that. Half a century later and there is still a vague plan to build “Big Buffalo” emerging from time to time..

The road in was by a wandering track through abandoned paddocks (“Fletchers”) that took you into the bush. After that you hopped out of the car and walked for about an hour up the side creek. There was a small track that went up a spur well to the south of us, but apart from the first 100m, that wasn’t much use to us. I did a lot of wandering by myself in there, trying to visualise the project and then finding weir sites. It always seemed to be raining and the streams were always flowing in 1973 (it was, indeed a wet year). Pleasantly I always did find my way back to the car but such sole excursions wouldn’t meet current occupational health rules. Because navigation was always by map-reading or dead-reckoning, I was pleased to find (years later) that where I thought we were actually coincided with the maps. Anyway, we marked out construction areas and an access-roads., and we were set to go. Also pleasantly the area had been well-mapped for possible future plantation work, and those maps then and now have been so valuable.

All of this sounds logical and rational, but there was always a concern that, notwithstanding our best efforts, it wouldn’t happen. We had a realisation that much of the cost of the project would ultimately be in the pine conversion, and it was hard to get any agreement from anyone as to where that was going. Best we could do was to try to keep people informed and put up with the yawns of boredom. We knew, sooner or later, that there would be a heated discussion on all of this.


Construction really started in October 1974. First about 6km of roads were built using whatever bulldozers we could scrounge. In hindsight this went smoothly enough but there lots of breakdowns and frustration. The three weirs were built using day-labour purloined from the Myrtleford Gang – the work was led by the late Kevin Rothenberger who had cut his teeth on the Kiewa Hydro-electric scheme. From my point of view it was strange and difficult – I had little or no training in building or concrete works and here I was both as construction overseer and designer. However we muddled through with lots of “learning experiences” and some real help from the workers. Originally it was an ambitious plan to have four weirs but excavation of one site showed that, although it was a large gully, there was no real stream course. The net result was three weirs substantially complete structurally but had a lot of other work to be done by May 1974. However, 1974 seemed to be continuously wet summer and the work was brought to a halt by State-wide flooding (including our weirs) in May 1974. We were surprised (for the first of many times) by how much sediment these little streams would move when they put their mind to it. Just-married colleague Dave Williams was living in the old converted Ovens office at the time and recalled being flooded to a depth of 1m by this storm.

Sometime after this, the “Management Branch” somehow realised we weren’t kidding and that they were going to end up with a plantation block a fair way south from existing plantations. I got summoned to an on-site meeting with management officer Peter Sheehan, where we had a “long and frank” discussion about planning, communication, and the like. It was in front of Ella Creek Weir which was carrying a high flow and I was really pleased at how well the weir was functioning (and impressed at the noise representing dissipation of hydraulic energy). Peter was less impressed, arguing that all we’d done was to build a management problem. As it happened, in the next five years the plantation development moved towards us and perhaps the management people shrugged their shoulders. I think that the paper trail-that we had left did make our position relatively defendable (“What – you didn’t read our memo of February 1973….!”).

After a really wet winter and spring we finally got back to the site about October 1974 and finished the weirs. It was a great day (well, actually a week) when we installed the recorders and started logging streamflow and rainfall – real data at last. The learning experiences then started flowing in thick and fast.

In hindsight, doing all the construction ourselves was probably inefficient in some ways but it did greatly reduce the apparent cost and kept the net cash outflow within tolerable limits. If the work had been done by contract, everyone would have fainted at the contract cost and that would have been the end of the project.

With data coming in our priorities changed and it was back to research. First, we discovered that each of the streams was quite distinctive. Secondly their summer-time behaviour was particularly different and distinctive. Thus the largest stream (Ella Ck) would cease flowing in early January and resume flowing about May. Betsy Creek would only really flow in late winter and spring, while Clem Creek never ceased flowing. At the time of site-selection it had been so wet that everything was flowing all the time. We also seized every opportunity we could to purloin passing bulldozers and had lots of project development. This included extensions to our road network, cutting of steps, corduroying of some sections of road to make them more passable in winter, cutting “turnarounds” and putting fire tracks in the spurs. We discovered it was like having a small kingdom and rather fun. The “corduroying” of 100m of really wet road worked amazingly well. “It has a forty-year life – that’s that” I opined in 1975 and then found myself worrying about it in 2015.

Data-wise we went through a solid period of learning how to get reproduceable data and to have “quality control”. It was pretty social because we invited lots of people coming to see what we were doing – so much so that we purloined a Stanley hut from the Ovens Depot (“The Croppers Creek Hilton”), a picnic table, and a barbeque and a stove and had so many pleasant times out there. It was and is a lovely spot with warm sunny winter days and lots of wildlife (“Wombat City”). We also did get on with writing our work up and produced a Bulletin with lots and lots of basic information in it (“The hydrology of small forested catchments in North-eastern Victoria 1: Establishment of the Croppers Creek Project”,) – easy because it still sits on my desk. We purloined specialists to write bits about the catchments, measured areas, geology, etc. and, over the next 40 years it became a useful reference document. It had a bit on the future development of the project and, reading through it now, we actually did the things we said we would (and more).

The next five years went like a flash. Lots of work on the basic hydrology, nutrients, and rainfall, Data processing was always time-consuming and sometimes difficult. Lots of programming, lots of talking to people, I did a doctorate on the groundwater hydrology of the slopes (and am still working on some aspects of it now). We discovered that we were, in general, well-ahead of the game and that existing “hydrology theory” really didn’t apply to catchments at this level. Similar findings were being made by young forest hydrologists in other states – I guess, looking back, you would say it as a creative and stimulating time for all of us. We were greatly helped by the interactions of the “Forest Hydrology Working Group” which allowed us to exchange experiences and techniques nationally, too.

In undertaking this work there were always a number of fears – the main one was that the powers-that-be would suddenly decide that the treatment was too expensive, or that clearing steep native eucalypt forest for pine was not within their policy and that this would leave the project high-and-dry. We had observed this in other projects, so we tried our best to ensure communications about our plans so that we couldn’t be accused of “presenting a surprise”. This also guided our hospitality somewhat – we were keen to be not only “doing it” but to be seen to be doing it. Anyway, these fears were quite tangible until that point of time where we laid them to rest by “treating” one catchment.

We were also under some pressure to come up with results, but colleagues talked about how we needed a 30-year calibration period (“What – I’d be around 60 before we even did a treatment”). Anyway, we settled on a five-year calibration (which proved to be fine, and four decades later showed to be about optimal) and scheduled treatment of the first catchment (Clem Creek) in late 1979. In that time, we had a professional hydrologic scientist (Colin Leitch) stationed at Myrtleford and he did a lot of good work in all sorts of fields. We also extended the track network and put useful things like turn-around points and unloading banks to facilitate work.

By 1979 we reckoned it was time to clear a catchment and see what happened. The Forests Commission was a bit nervous – firstly they had to pay the cost of the treatment on steeper land than they would like. Secondly, although the catchment by then wasn’t far outside existing plantation boundaries, it was a bit isolated. Thirdly, the steepness meant that heaping wasn’t really feasible so it was going to be broadcast burning and planting in the debris, which was viewed as a bit primitive by then. I forgotten how we organised it but since I had a formal organisational streak, I guess there was a flurry of memoranda. We were never very sure just how much the “high-ups” knew about it all (Fred Craig was adept at hiding the cost of it all from them) but everyone ultimately seemed happy. I suspect now that they knew a lot about it but preferred “not to know” officially. So it was out there with the spray cans and ribbons, a 30m buffer was marked out in Clem Creek, and the “treatment” was ready to go.

Lo and behold, in December 1979 two D8’s and a Komatsu D84 (if I remember rightly) were suddenly snorting and rumbling there and the clearing began. This was by a chain pulled by two tractors knocking down the eucalypt forest, with a third tractor giving stubborn trees a push. It wouldn’t meet environmental muster these days but it was marginally acceptable then (and indeed, other projects had failed because they had baulked at this step). As it happened a group of scientists from CSIRO were in the area and heard about it and asked to see it. Anyway, they couldn’t get enough of it – when they weren’t babbling about “rape of the earth” they were trying to get ahead of the tractors to get the perfect photograph of it (were they voyeurs or moralists?).

The clearing done, we left the pushed-over vegetation to cure. The District had the job of burning it, which they did with some apprehension because of its high position in the landscape. The burn wasn’t as vigorous as I would have liked (I was after something more akin to a huge pyro-cumulus/nuclear holocaust event) but it did the job satisfactorily in April 1980. I’ve forgotten why but I couldn’t be there (perhaps fortunately). The area was then planted and we settled down to await results of the flow and nutrient measurement.

Well the project is still running, albeit in a reduced form. Over that time it has produced a lot of papers on catchment hydrology and we also produced a book substantially based on it. It is hard to believe that it is some 45 years since we started “mucking about there”. At the time it was viewed as “long-term” but I guess that was viewed as something over five years; then (as now) it would be hard to visualise that far into the future.

And indeed:

  • The Forests Commission Victoria (God bless its soul) has long ceased to exist.
  • I left the Forests Commission about 1981 and after a couple of years in a Consulting firm joined the University of Melbourne. Although I loved the work I felt I needed new challenges and was somewhat weary of field work. I also had the horrid sensation that I was going to be bound to Croppers Creek for my working life (which has sort of happened anyway and isn’t such a bad fate).
  • The Research Branch of the organisation vanished with it, and the project languished under various “owners” until the project was “shut-down” as having achieved its aims in 1987. In 1997 the impact of drought and a burgeoning interest in plantation hydrology led to the newly formed Victorian Plantations Company asking the University of Melbourne to reopen the project. This was supported by the Forests and Wood Products Corporation, and it was back into the long drive up to Myrtleford.
  • At the time of installation, the Forests Commission looked after both plantation and native forest. The plantations were then “privatised” to the Victorian Plantation Company with later became HVP plantations. Thus the “ownership” of the land of the plantations was divided with the two eucalypt catchments being run by the successors of the Forests Commission Victoria and the treated pine plantation by HVP Plantations.
  • The University of Melbourne and HVP Plantations ended up being the driving forces. The successors-in-law of the Forests Commission seemed to have little interest overall in the project, although they were most helpful when any problems within their purview were encountered.
  • The 2006 fires thoroughly burnt over the catchments and destroyed all recording data. God bless The University of Melbourne insurance because they paid for all of this to be rebuilt and we got some great data from it. We had been talking about how we would log the Clem Creek plantation a few months beforehand and it suddenly became a reality.

I don’t think that any of these things could have been envisaged in 1973. Partly because of all of this activity the site is much less “remote” than it was in the mid-1970’s.


Was It Worth It?

The project has produced (and is still producing) an excellent collection of papers which were published in the top journals and achieved international recognition for the results it produced. “Overview work” concluded that paired catchment experimentation has probably been the most consistently successful approach in forest hydrology, although it has many downsides and large “errors” inherent. The project has had its share of international recognition. I did an overview of forest hydrology research for an international reference book two years ago and concluded that these experiments were the “great leap forward” and occupied an intermediate place in the ranks of formal scientific approaches. I have been pleasantly surprised how well the project is known overseas.

At the researcher level, the project did have a very large “overhead” involved to get it running. This was particularly exacerbated since we were not engineers or builders and had to learn from scratch. But learn we did and build we did, and the results have lasted pretty well. It would, probably, have been more efficient to go to an organisation like the State Rivers who did this stuff regularly and get them to build the weirs, but the shackles imposed by such groups were exactly those we were trying to cast off. I think that if we had “paid” someone to do it we would have been up around the $2-3 million in today’s currency and that it would not have happened. At various stages we had a lot to do with the then MMBW developments in hydrology (Coranderrk, etc.) and I used to envy the logistic clout they could easily bring to bear. However we also noted that, as researchers, we had far more flexibility to follow our ideas than our opposite numbers did, so I guess it’s a matter or pro’s and cons.

On the pro side, it was a real learning experience in so many ways, and it put us in squarely in the world of forest hydrology. As well as papers there are a number of books in which the project features squarely. Although there were subsequent water-conflicts about plantations they were relatively minor. I got the impression that when the plantation bodies had excellent data and knew more than opponents did, you were rarely attacked.

In hindsight, there were many other directions we could have taken in the project, and some of these (unfortunately) remain unexplored to the present day. However, that’s a facile criticism since we effectively worked as hard as we could at any time – perhaps in an ideal world we’d have got far more grant money and employed a battery of scientists, but we got the impression that granting agencies would hear the word “forestry” and turn-off. Interestingly we’ve been almost the last-man-standing in the sense that other hydrology projects all seem to disappear in the late 1990’s.

So, yes, it was worth it and the project should be recognised for what it was – a relatively early venture into forest hydrology. If we had our time over, perhaps we’d do it a bit differently, but we’d certainly have many elements of the Croppers Creek approach in our solution.

I’m writing this in September 2018 and I’ve just been to a Conference espousing the sophisticated package Mathematica, I’ve been using this to redo some of my doctoral work (attacking the partial differential equations of groundwater flow), and have been contemplating where the Croppers Creek project sits in the world of science. Basically, it is an unreplicated experiment or, if you like, a case-study following hydrologic change over time. It does have a “control” (good) but because the differences between catchments can be so great, it is not a perfect control. The net consequences are the error levels are larger than one might desire. The concept of replication is not really there either because of the treatment cost and the spatial difficulties of finding more but similar catchments. A driver in the work was the theory that it was all “deterministic” and that if we were good enough at the fundamental scientific level (soil physics, etc.) then it would all tumble out in a cascade of equations, etc. This, indeed, was the view of many scientists in the 1970’s when it was put in. Having spent almost half a century playing along such lines I think that the theory is nowhere near approaching such an ideal – it is good enough to tempt you along those lines but never good enough to deliver a useful answer. Thus, projects like Croppers Creek were and are necessary, notwithstanding their imperfections. The glitzy computer packages like Mathematica add a lot to the work, but the real producer of the information was those three small catchments and their ancillary weirs, roads, and other stuff – and we research staff. And, not only that, it was a hell of a lot of fun to do. So full credit to the Forests Commission for allowing it to be (or driving us on to make it happen). I really can’t see the modern variants of the organisations taking the same approach now,

Thanks to...

Thanks to....

The list is so very long – so many people ultimately contributed by discussing problems, lending equipment, going out on a limb for me. In some cases I didn’t really appreciate it all until years later. But I guess one might single out for that first decade:

John Jack, Head of Research. He led us and (probably unbeknown to us) protected us from the high-ups who wondered just what researchers actually did.
The late Dr Fred Craig, whose idea and support led to it. I don’t think that Fred ever got the credit he deserved for this and many other things.
Next boss down, Dave Flinn, who was always enthusiastic about the project.
Dr Peter Hopmans who did such great work in nutrient balance.
Myrtleford District Staff Herb Caldwell and Don Thomson who provided the workers and put up with me.
Previous district Forester Bert Semmens did much of the site thinking for me.
Divisional Forester Russ Ritchie who became enthusiastic about the project.
Peter Sheehan who embedded the project in Divisional planning.
Colin Leitch who was a field officer on the project in the late 1970’s
Technical staff Leon Stephens and Bob Beasley who kept it running.
Bill Incoll who would graciously take aerial photographs (no drones in those days).
The many forestry workers who helped me out in building, falling, blasting, digging, and filling.

It’s a very inadequate list because so many other people helped in so many different ways. These included things like vehicle recovery, towing compressors to the construction sites, lending of pumps, sorting out the management implications, taking aerial photographs, advising us on this and that,…. The list goes on and on.

See also:
FCV Bulletin 27