43Ambient environmental standards for waterways

43 Ambient environmental standards for waterways (1) The ambient environmental standards for a waterway with an environmental value mentioned in a part in schedule 4 are the standards stated for the indicators in the part. Schedule 4, part 4.5 prescribes the standards for waterways used as stock water supply, for example, the Molonglo River. Under the part, the Molonglo River should have an acidity between pH 6.5 and 9.2. If it does not, the river does not meet the ambient environmental standards. (2) Subsection (1) does not apply when the waterway’s flow conditions exceed the 10-year 5 percentile high-flow value. The Cotter River generally meets the ambient environmental standards. Hypothetically, there was excessive rain last spring, which caused the river to flood. The Cotter River rose to the highest level it had been at for 25 years. Under s (2), the ambient environmental standards would not apply during the flood.