Page 306 - VEWH Seasonal Watering Plan 2020-21
P. 306

 6.2 Glossary
6.2 Glossary
Acid sulphate soils – Naturally occurring soils containing high quantities of iron sulphates. When these soils remain underwater they are stable, but if they are exposed to
air, sulphuric acid is generated and can result in severe environmental impacts.
Adaptive management – An iterative decision-making process based on continuous learning that aims to reduce uncertainty over time.
Allocation (of water) – The specific volume of water allocated to water entitlements in a given water year or allocated as specified in a water resource plan.
Australian Height Datum (AHD) – Height above sea level.
Azolla – A native aquatic fern which grows in waterways in dense patches. Its presence usually indicates high levels of nutrients.
Bank erosion – The wearing-away of the banks of a stream or river (as distinct from erosion of the bed) that can occur in extensively dry conditions.
Bank slumping – A form of mass wasting in a river or stream that occurs when a coherent mass of loosely consolidated materials or rock layers moves a short distance down a slope.
Bankfull flows – Flows of sufficient size to reach the top of the riverbank, with little flow spilling onto the floodplain.
Baseflows – A relatively stable, sustained and low flow in a river, generally being its minimum natural level.
Biodiversity – The variety or abundance of plant and animal species in a particular habitat or environment.
Biofilms – Slimy films of bacteria, other microbes and organic materials that cover underwater surfaces including rocks and snags.
Biota – The animal or plant life of a particular area, habitat or geological period.
Blackwater – A natural occurrence caused by the breakdown of plant matter causing the water to discolour. The water turns black and can have very low dissolved- oxygen levels, which can stress or kill fish and other animals that breathe underwater.
Brackish water – Water that is moderately salty but not as salty as sea water. It may result from the mixing of seawater with freshwater, as in estuaries.
Carryover – Unused water of which entitlement holders are allowed to retain ownership into the following season, according to specified rules.
Catchment management authority – A statutory authority established to manage river health and regional and catchment planning and to manage waterways, floodplains, salinity and water quality.
Cease-to-flow – The period in which there is no discernible flow in a river and partial or total drying of the river channel.
Cold water pollution – A phenomena caused by cold water being released into rivers, primarily from large dams, in warmer months.
Commonwealth Environmental Water Office – An office that manages water entitlements recovered by
the Australian Government through a combination of investments in water-saving infrastructure, water purchases and other water recovery programs. The entitlements are held by the CEWH.
Confluence – The point where a tributary joins a larger river (called the main stem) or where two streams meet to become the source of a river of a new name.
Consumptive water – Water owned by water corporations or private entitlement holders held in storages and actively released to meet domestic, stock, town and irrigation needs.
Diadromous fish – Fish that migrate between freshwater and saltwater.
Drawdown – Water released from a body of water (such as a reservoir) at the end of the irrigation season for dam operation and maintenance purposes.
    304 | Victorian Environmental Water Holder | Seasonal Watering Plan 2020–21

   304   305   306   307   308