David Stephenson and Martin Walch, Lake King William, 28/06/2011, four-channel HD video, curation 13:30. © Martin Walch, 2011

The Derwent Project

The morning-after complaint of a Currawong pierces the pre-dawn silence as we drift soundlessly through a thick fog blanketing the glassy waters of Lake King William. Our own voices have been silenced since the video take began; slow measured breaths merge in puffs of steam with the icy fog, congealing in a crystalline icing on every surface of the boat and our recording equipment. The blinking red recording lights of the four video cameras are the only chromatic punctuation in the dim monochrome ether we float through. Slowly, the soft darkness grows brighter from a magenta glimmer to the east, gradually suffusing a warm tint through the grey soup of our world. The ruined skeletons of the drowned forests of the Derwent gradually emerge from the mist as the pink light grows in intensity and the fog transforms into a brilliant white cloud around us.

Our idyll is shattered by the intensifying bass tyre-rumble of a log truck approaching on the Lyell Highway a few kilometres away, its air brakes resonating loudly as it slows down for one of the highway’s many tight bends. A few minutes later, the recording ends and we are finally able to break our self-imposed silence to move aching backs and wiggle frozen fingers and toes. It is September 2011 on a sub-zero morning in the Tasmanian highlands, and we are one year into the Derwent Project, exploring the many layers of interaction between human and non-human forces in this complex environment.

From its headwaters in the Tasmanian Wilderness World Heritage Area, the Derwent River is rich in natural and cultural history, flowing through ten hydroelectric energy developments before entering the urban estuary at Hobart. The Derwent Project is developing new aesthetic approaches for representing such a multi‑layered ecosystem, to convey its environmental changes and energy exchanges with clarity and impact. A mobile system of 360° video and sound capture and display has been developed that virtually immerses the viewer in the environment, conveying an embodied experience of the river. To complement this mobile platform, twelve fixed cameras are arrayed across the system in characteristic environments, each recording a photograph every five minutes. This data is reconstructed in a variety of ways, from multi-channel video to still photographic matrices to visualise environmental phenomena and histories across the 180-kilometre expanse of the Derwent watershed.

Our multi-screen panoramic video works integrate highly portable image and sound capture devices into multiple arrays that can be used in remote environments. To create an embedded viewpoint and allow the energy flows in the environment to be an active agency in the creations of these representations, the 360° footage is recorded at water level. To do this, we shoot with multiple cameras from small watercraft drifting on the river—this has technical challenges but produces smooth, slow-tracking shots, and a sense of immersion in the river’s flow. By working in close proximity to the water surface, we are able to simultaneously obtain and integrate imagery of the underwater environment. Our video capture is partially generative through the energy of the river system itself—the drift of the capture platform is driven by localised air and water flows on the river’s passage from source to sea, via the paths, currents and eddies of the “lie of the land”.[1]

David Stephenson on Lake King William, Tasmania, 28/6/2011, © Martin Walch, 2011

In 2014 we started using fixed camera positions to record environmental changes in the watershed. Sophisticated commercial time-lapse camera installations start at around $4,000 each. We designed a simple and affordable system using a basic DSLR with a simple timer remote to allow the programming of regular exposure intervals. Waterproof moulded polypropylene equipment cases are adapted to provide weatherproof enclosures for the cameras, which are powered by 12-volt deep-charge batteries to allow them to run for several months between services. The Derwent Time-Lapse Array (DTLA) now has twelve camera stations providing a method of continuous visual sampling of the environment through a range of connected sites and ecosystems. These still photographs taken every five minutes provide the raw data—3,456 images per day and 1,258,000 images per year. Choosing how that data is selected, filtered and displayed affects our perceptions of time, environmental change and energy flow.

Our initial display concept for the DTLA was a row of twelve synchronised time-lapse videos that presented one year of capture. An early video exhibition test from one camera station was presented at MARS Gallery in May 2015 as part of Climarte 2015 in Melbourne. Moving into drought: equinox to solstice to equinox (Lake King William, Tasmania, 21/09/2014 – 21/03/2015), juxtaposes two three-month blocks of time-lapse video. Each day passes in just under one minute; at any viewing moment, the same time of day is depicted on both sides of the video diptych, but three months apart. As the watershed moves into the drought period of an El Niño climate cycle during the six months at Lake King William that the 87-minute video represents, the water level of the impoundment drops by six metres, causing the lake to recede into the far distance.

Exhibited at the Gold Coast City Gallery in Queensland in March 2015. The longest day of the year: Tasmania’s Derwent River watershed from its headwaters to the sea, 21/12/2014 shows photographs taken every hour by each of the twelve cameras and arranged in a grid. This still photographic matrix traces the course of the river from its source to the sea, and the course of the day on the southern summer solstice, mapping space across the horizontal axis, and time down the vertical axis.

Derwent Project, Longest day, digital compilation
David Stephenson and Martin Walch, Derwent River and surrounds lookings north from Evans Street, Hobart, Tasmania, 13-17 May 2016, pigment ink print. © David Stephenson and Martin Walch, 2016

A related visualisation of still files from the DTLA was exhibited in April 2015 at Bath Spa University in England, using their 30-screen MediaWall to represent each day of November 2014 at Lake King William. On each screen, photographs taken at five-minute intervals were displayed for five-second intervals, cycling through the 24-hour day in 24 minutes. As the month progressed from upper left to lower right of the MediaWall, Lake King William recedes with the approach of summer drought. At any moment of viewing the work, the same time of day was seen simultaneously for all 30 days of the month. Time was mapped spatially (in the 30 days displayed over the 30-screen grid) and temporally (in the 24-minute display of each 24-hour day on each screen).

This spatial mapping of time was further developed in our 2016 TimeSlice works, one of which was recently exhibited in the 2016 Fleurieu Art Prize in Adelaide. The slicing and recombination of sequential frames allows the passage of time to be represented spatially across a single coherent image. These pictures—each made up of vertical slices five minutes apart in time—can be animated in time-lapse videos or presented as high-resolution still photographs. Considering the photographs, video and sound we are capturing as raw data sets has allowed us to reconsider the ways in which we might represent this data, and the changes and energy flows thus revealed. The Derwent Time Lapse Array records: the motion of the earth through its daily rotation and affect on the sun, the moon, and the stars; the yearly orbit around the sun, cycling between winter and summer; the motion of the moon, and its affect on tides and night illumination; wind and weather flows, and how they change over time; the effects of weather and power production on the levels of rivers, lakes, and hydroelectric impoundments. These changes are recorded along two vectors: time (every five minutes for up to two years) and space (through twelve nodes across the Derwent watershed).

The Derwent Project_Time Slice
David Stephenson and Martin Walch, Derwent River and surrounds looking north from Evans Street, Hobart, Tasmania, 13–17 May, 2016, pigment ink print. © David Stephenson and Martin Walch, 2016

The longest day maps both vectors on the two dimensions of a still photograph, but only for one day. Our Bath MediaWall work mapped the time vector for one month, in two modes: spatially, (across the 30 days and screens) and narratively (in time-lapse imagery for 24 hours of each day of the month). The six-month video diptych of Lake King William maps six months of time in a comparative fashion (at any moment in the video, the same time of day is seen simultaneously, but three months apart). A twelve-channel synchronised DTLA will map both space and time vectors in time-lapse video, with the 180-kilometre expanse of the watershed seen across twelve screens, and one year of footage displayed in hours. The TimeSlice still images and videos provide almost infinite choice in the selection and spatialisation of temporal moments, intervals and duration, allowing us to reveal subtle patterns of change in the environment not easily visible to the human eye and time scale.

Ultimately the sun is the engine that drives most global energy flows, including those represented in the Derwent Project. Solar energy drives the precipitation falling on the Derwent watershed, which flows through the Derwent Power Scheme to generate electricity. This energy is converted to the artificial lights in our nocturnal urban imagery, and is used to recharge our camera batteries and power our computers and video screens. It creates the wind and water movement recorded by our mobile camera platforms drifting on lake and river surfaces, and the swaying of our tree-mounted fixed cameras as they are pounded by recurrent south-westerly weather fronts. It is in the sunlight and moonlight that generate the photographs themselves. More subtle solar energy forces appear as well: in the atomic particle stream of the solar wind that helps generates the Aurora Australis visible at times in our south-facing camera installations; in the bloom of yellow flowers that spread across the dry bed of Lake King William; the flights of swallows in our videos and the movement of spiders across the lenses of our fixed cameras—creatures feeding on aquatic insects, whose population explosions respond directly to solar energy captured by aquatic flora in the lengthening summer days.

David Stephenson and Martin Walch, Lake King William, 26/11/2011, four-channel HD video, duration 12:00. © David Stephenson and Martin Walch, 2011

Variations in the hydroelectric lake levels that appear in our imagery are the result of the flux between energy input (precipitation) and energy output (evaporation and power generation). As the Derwent Power Scheme is part of a National Electricity Grid, power generation decisions—and their effect on lake levels—are the result of complex hourly decisions made by Hydro Tasmania to maximise profit. These decisions are educated gambles, tempered by fluctuations in daily wholesale energy pricing, predictions of long-term weather forecasting, and political decisions such as the presence or absence of renewable energy credits.

The hydroelectric dams have a significant impact on the many energy flows in a watershed like the Derwent. An unregulated river such as that seen in the first camera station of the DTLA responds immediately to weather events such as floods, which bring about massive variations in water flow and curtail the ability for riparian plants to colonise riverbeds. When a river such as the middle Derwent is heavily hydro-industrialised, the dams and resulting impoundments have a throttling effect on flood events. Plants like tea tree begin to colonise the now mainly dry riverbeds, completely changing the ecology of the watershed. Then only the very biggest storm events force the dams to spill and temporarily enable a more natural flux in water levels.

Dams create barriers to other types of energy flows characteristic of unregulated rivers, particularly the ability for species to migrate freely through the system. In the Derwent, this has resulted in the inability of native catadromous eels to make their annual spawning run to the Coral Sea. Eels resident in the watershed above Meadowbank Dam, the lowest impoundment on the Derwent, have been denied their natural life cycle for 48 years. Elvers can still be seen every year obeying their genetic imperative, and trying to climb the Meadowbank Dam to return to their ancestral waters.

We are also creatures who live in the Derwent watershed. Its water flows past our homes and from our household taps. We bath in it and drink it—some 60% our bodies are composed of Derwent water. Our challenge is to represent some of the deeper histories and hidden energy flows of our home watershed.


  1. ^ In reference to Paul Carter, The Lie Of The Land, London & Boston: Faber and Faber, 1996.

The Derwent Project is supported by the University of Tasmania and Hydro Tasmania, and funded by an Australian Research Council Discovery Grant, 2014—16, and will be exhibited at the Tasmanian Museum and Art Gallery in 2017 | www.derwent-project.org