Queensland Hydro's Borumba Pump Hydro Project: Site for the Top Dam on Cedar Creek, Walkers Top.
The Borumba Pump Hydro Electricity Scheme of Queensland Hydro will require an enlarged Lake Borumba as the lower regulating storage, and an upper 'industrial' pondage providing a hydraulic head of 400m. This top storage will be impounded by a rock-filled concrete-faced wall across this gorge (pictured).
The immediate foreground is forested by a regrowth dry sclerophyll forest which has regrown since a severe devastating fire. The areas east (to the right) of the gorge are more heavily timbered because the gorge has inhibited the advance of the fire front resulting in a less severe fire on those slopes leaving some old-growth forest that has had understorey fires pass through, as they gradually re-intensify.
Cleared areas on the valley floor in the background indicate the area has been used primarily for grazing, the cattle grazing on the forested plateau as well as on the valley floor. Traditionally graziers lit free ranging fires which were extinguished by storms or were fought by firefighters when the fires advanced as far as the State Forest reserve on the next plateau and ranges to the east.
This plateau has a cliffed escarpment in part on its eastern side, which often stopped the advance of the fires, but where the escarpment was absent, the grazier in the next tributary valley (Borumba Creek) would back burn the slopes to prevent wildfires descending upon his estate, stock and buildings. The free or wild fires were partially controlled by relief, resulting in some remnant forest patches which contain the original species including native softwoods (Araucaria spp) and red cedar. The small creek that flows through this gorge and descends to its confluence with Yabba Creek was called Cedar Creek by the 19th century timbergetters and subsequently by the 20th century graziers.
The slopes in the midground are patchily forested with significant bare green areas which have resulted from repeated severe wildfires this century (e.g. 2015, 2021).
To finish this account, it has to be admitted that 20% of the proposed pondage area (out of photo to the south) has no forest at all, and even the grasses are overgrazed and the soils impoverished of carbon. And this is due to the frequency of fire (match-box management) lit by graziers combined with granitic geology.
Once the pondage is created for the pump hydro project, the forests in the impounded area will have been cleared, but the resulting lake 5 kms long transverse to the direction of fire advance will provide a significant fire barrier and thus protect the forests in Conondale National Park and Imbil State Forest to the east. And furthermore, should a fire whether lit by dry lightning strike, arsonist or grazier eventuate, the pondage will provide the fire-fighting helicopters with an immediate source of water.
So the history of fire in this area is not "pretty" sadly, and now a significant area of existing regrowth forest and some remnant natural stands in the gorge depths will be sacrificed. Then my protesting spirit is sobered when I admit that one thermal power station requires opencut coal pits that extend over areas 8 times (as in the case of Callide thermal power station) the area to be cleared and inundated for this Borumba scheme.
Queensland Hydro's Borumba Pump Hydro Project: Site for the Top Dam on Cedar Creek, Walkers Top.
The Borumba Pump Hydro Electricity Scheme of Queensland Hydro will require an enlarged Lake Borumba as the lower regulating storage, and an upper 'industrial' pondage providing a hydraulic head of 400m. This top storage will be impounded by a rock-filled concrete-faced wall across this gorge (pictured).
The immediate foreground is forested by a regrowth dry sclerophyll forest which has regrown since a severe devastating fire. The areas east (to the right) of the gorge are more heavily timbered because the gorge has inhibited the advance of the fire front resulting in a less severe fire on those slopes leaving some old-growth forest that has had understorey fires pass through, as they gradually re-intensify.
Cleared areas on the valley floor in the background indicate the area has been used primarily for grazing, the cattle grazing on the forested plateau as well as on the valley floor. Traditionally graziers lit free ranging fires which were extinguished by storms or were fought by firefighters when the fires advanced as far as the State Forest reserve on the next plateau and ranges to the east.
This plateau has a cliffed escarpment in part on its eastern side, which often stopped the advance of the fires, but where the escarpment was absent, the grazier in the next tributary valley (Borumba Creek) would back burn the slopes to prevent wildfires descending upon his estate, stock and buildings. The free or wild fires were partially controlled by relief, resulting in some remnant forest patches which contain the original species including native softwoods (Araucaria spp) and red cedar. The small creek that flows through this gorge and descends to its confluence with Yabba Creek was called Cedar Creek by the 19th century timbergetters and subsequently by the 20th century graziers.
The slopes in the midground are patchily forested with significant bare green areas which have resulted from repeated severe wildfires this century (e.g. 2015, 2021).
To finish this account, it has to be admitted that 20% of the proposed pondage area (out of photo to the south) has no forest at all, and even the grasses are overgrazed and the soils impoverished of carbon. And this is due to the frequency of fire (match-box management) lit by graziers combined with granitic geology.
Once the pondage is created for the pump hydro project, the forests in the impounded area will have been cleared, but the resulting lake 5 kms long transverse to the direction of fire advance will provide a significant fire barrier and thus protect the forests in Conondale National Park and Imbil State Forest to the east. And furthermore, should a fire whether lit by dry lightning strike, arsonist or grazier eventuate, the pondage will provide the fire-fighting helicopters with an immediate source of water.
So the history of fire in this area is not "pretty" sadly, and now a significant area of existing regrowth forest and some remnant natural stands in the gorge depths will be sacrificed. Then my protesting spirit is sobered when I admit that one thermal power station requires opencut coal pits that extend over areas 8 times (as in the case of Callide thermal power station) the area to be cleared and inundated for this Borumba scheme.