The bushfires have caused significant damage to water storage sites around the ACT. These sites include Bendora, Corin and Cotter reservoirs. After the firestorm swept through the catchment areas in January, the ground covers were severely burnt with much of the catchment vegetation burnt away. The soils surrounding the reservoirs became unstable by being exposed to intense heat and the loss of plant roots which left the catchments vulnerable to erosion and sediment accumulation. A storm in March 2003 made water from these reservoirs unusable, by washing soil, ash and charcoal and other debris left by the firestorm, into the streams of the burnt catchments. The sediments made the water turbid, added nutrients and salts and reduced the dissolved oxygen in the water. Consequently, water from these reservoirs had to be suspended. (Canberra times)
The cotter river catchment is part of a national park and is heavily protected from outside activities, which may affect water quality. The water from this catchment is usually of high standard and normally does not require full treatment. …
