Communities caring for catchments
Module 1 - background
Waterwatch Australia Steering Committee
Environment Australia, June 2003
ISBN 0 6425 4856 0
These appendixes consist of key terms you will need to understand as well as a list of land uses and their impacts on the environment. Both appendixes are arranged in alphabetical order.
Accuracy - measure of how close repeated measurements are to the accepted or true value. Accuracy can be measured as a standard deviation.
Acid - a substance that releases hydrogen (H+) ions in solution. Acid solutions have a pH value less than 7 units.
Aerobic - living or occurring in the presence of oxygen; organisms and processes that require free oxygen.
Algae - unicellular, multicellular, or colonial aquatic photosynthetic plants which do not have true roots, stems, or leaves.
Algal bloom - extensive growth of algae in or on a body of water; blooms may occur from excess nutrients in waterbodies, or from particular climatic conditions.
Ammonia (NH3) - colourless gas consisting of nitrogen and hydrogen atoms which is very soluble in water. Ammonium (NH4+) is the ionic form of ammonia.
Anaerobic - living or occurring without oxygen.
Anoxic - conditions where oxygen is absent.
Aquatic - living in or on water.
Aquatic vegetation - includes emergent, submergent and floating plants. Emergent plants include those species with true stems, roots and leaves, and most of their vegetative parts above the water. Submergent plants include similar species to emergent plants except that they are completely immersed in the water. Floating plants are those species which are not fixed in place but are carried by the water.
Aquifer - any rock or soil layer capable of storing water and which allows water to pass through.
Arable - land suitable for the economic production of crops, usually involving regular cultivation.
Autoclave - an apparatus used to sterilise objects by means of steam under pressure.
Autotroph - any organism able to use inorganic substances, e.g. carbon dioxide, to make their own chemical compounds using either sunlight (photosynthesis) or chemical energy (chemosynthesis).
Bacteria - single-celled microscopic organisms which break down organic material.
Bank - sloping ground bordering a river, stream or lake.
Baseflow - water that has sunk deep into the soil and met the groundwater which seeps into a creek.
Basin - area of land drained by a river and its tributaries.
Bedload - the sediment that moves by sliding or rolling along the bed of a channel due to the action of the water.
Benthic - plants or animals living in or on the bottom of a water body.
Best Management Practices (BMPs) - any engineered structure or management activity or combination that eliminates or reduces the adverse effects of pollutants.
Biochemical Oxygen Demand (BOD) - the amount of dissolved oxygen required for aerobic organisms to break down organic matter in a volume of water. BOD is an estimate of organic loads in water samples.
Biodegradable - compounds and materials capable of being decomposed by micro-organisms.
Biomass - the amount of living material existing at a given instant of time in a specified area or unit volume.
Bore - a deep hole that reaches an underground water source and through which water rises due to hydrostatic pressure.
Brackish - water that contains dissolved salts in the range 800 to 50 000µS/cm (500 to 30 000mg/L), which is less than sea water (58 000µS/cm or 35 000mg/L).
Buffer zone - an area of vegetation surrounding a water body which protects it from the effects of human activity by minimising runoff and erosion.
Buffering capacity - the ability of a solution to resist a change in pH when an acidic solution is added.
Calibration blank - deionised water processed as a sample. It is the first sample analysed and used to set the meter to zero.
Calibration standard - solutions of known concentration used to calibrate a meter before running a test.
Carnivore - an animal that feeds on other animals.
Carrying capacity - the maximum number of animals that can be supported by an ecosystem without the ecosystem suffering deterioration.
Catchment - an area or basin of land bounded by natural features of hills or mountains from which all run-off water drains to a river, stream, lake, wetland or estuary. Also known as a watershed (American).
Channelisation - process of altering the channel of a watercourse by deepening, straightening, or lining the bed with cement or other materials to direct the flow of water or prevent flooding.
Chlorination - the addition of chlorine to wastewater or drinking water to disinfect the water.
Chlorophyll - the green pigment in plants that enables them to use the energy of the sun for photosynthesis.
Coarse particulate organic matter (CPOM) - food particles e.g. leaf fragments greater than 1mm in size.
Coliform bacteria - bacteria found in the intestines of warm blooded animals that help digestion. They are used to indicate faecal contamination in water quality analysis.
Combined Sewer Overflow (CSO) - sewer systems in which sanitary waste and stormwater are combined in heavy rains; common in older cities. Discharge from CSO is usually untreated and flows directly to streams.
Community - the assemblage of plant and animal populations inhabiting a given area.
Completeness - a measure of the amount of valid data actually obtained compared to the amount expected to be obtained; usually expressed as a percentage.
Confluence - place where a tributary joins a river.
Contour bank - a constructed earth bank which follows the contour of the land and is used to direct water flow over the land to prevent erosion and drainage problems.
Culvert - a covered channel or large pipe that diverts the natural flow of water.
Decomposition - breakdown of organic materials by micro-organisms.
Deionized water - water that has had all the ions (atoms and molecules) other than hydrogen and oxygen, removed. Sometimes called distilled water.
Designated uses - a formal list of desirable uses that a waterbody should support such as fishing, swimming and aquatic life.
Detection limit - the lowest concentration of a parameter that a given method or piece of equipment can reliably determine and report as greater than zero.
Detritus - small pieces of dead and decomposing plant and animal material.
Diffuse-source pollution - contaminants that have originated from a widespread area or from various dispersed locations, such as roads, shopping centres and agricultural activity. Also known as non-point source pollution.
Discharge - release of liquid into a water body such as treated waste water from industrial plants, power plants and wastewater treatment plants; also refers to volume of run-off which enters water bodies.
Discharge zone - an area where the groundwater moves upward and escapes through natural springs, evaporation, transpiration and surface drainage.
Dissolved Oxygen (DO) - oxygen gas (O2) dissolved in water.
Distilled water - water that has most of its impurities removed. Also known as deionised water.
Drift - the down-stream, free-floating movement of, normally benthic, animals in a flowing river or stream.
E. coli (Escherichia coli) - a species of bacteria belonging to the faecal coliform group which is found in the intestines of warm blooded animals in large numbers. The presence of E. coli in water is considered to be evidence of fresh faecal contamination.
Ecosystem - a community of living organisms and their non-living (abiotic) environment functioning as one system e.g. a pond ecosystem.
Edge water - is an area near the bank with slow or little current compared with the main flow. Vegetation may be overhanging and surface-dwelling insects can be present in well sheltered edge waters.
Effluent - waste material, such as sewage, discharged into the environment.
Electrode - an electric conductor through which current flows.
Emergent plants - plants rooted underwater but with their tops extending above the water.
Endemic - plants or animals peculiar to a particular geographical area.
Ephemeral stream - one that only flows for a short time, e.g. after rain.
Erosion - the wearing away of the earth's surface by running water, wind, ice or other geologic agent or process, including weathering, dissolution, abrasion and corrosion.
Estuary - a body of water adjacent to the sea, typically at the mouth of a river, in which the tide ebbs and flows. At its mouth it meets the ocean but its upstream limit is marked by the extent of tides.
Eutrophication - enrichment of a waterbody by nutrients (mostly nitrates and phosphates) from erosion and run-off from the surrounding land. This process is natural but can be accelerated by human activities, e.g. sewage disposal and fertiliser run-off.
Evaporation - the process by which water changes its physical state from a liquid to a gas.
Evapo-transpiration - the process of living plants transforming water into vapour that is released into the atmosphere.
Exotic species - an introduced non native species, e.g. weeds, feral animals.
Faecal - relating to animal or human excrement.
Fauna - animal life.
Fertilizer - any substance, natural or manufactured, added to the soil to supply nutrients for plant growth.
Field blank - deionised water treated as a sample; also known as a trip blank.
Field replicates sample - a duplicate sample that is collected at the same time and place. It is used to measure precision of sampling and analysis.
Filamentous - plant body of some types of algae, made up of thread-like rows of similar cells.
Filter feeder - animal that filters microscopic organisms from water.
Fine Particulate Organic Matter (FPOM) - consists of fine food particles less than 1mm in diameter.
First flush - initial flow of storm water run-off that often contains high concentrations of contaminants that have built up during the previous dry period.
Fish kill - the sudden death of fish; usually due to the introduction of pollutants and/or the reduction of dissolved oxygen concentrations in a water body.
Flagellum/flagella - a whip-like structure present in motile algae, which serves as an organ of propulsion.
Flocculant (floc) - mass of particles that form into clumps as a result of a chemical reaction.
Flood plain - a relatively level part of the valley that is covered by water during a major flood. It is formed from deposits laid down from previous flooding.
Flora - plant life.
Fluvial - belonging to or produced by a river.
Food chain - a 'chain' of organisms, through which energy is transferred. Each organism in the chain feeds on and obtains energy from the one preceding it, and in turn is eaten by and provides energy for the one following it, e.g. plant to herbivore to carnivore.
Genera (genus) - group of closely related organisms. Only the species group contain more similar organisms.
Glide/pool - section of the stream with low velocity and with little or no turbulence on the surface of the water.
Grazer/scraper - animals that consume algae and associated material attached to the surface of submerged plants or rocks.
Groundwater - water that infiltrates into the earth and is stored in the rock and soil below the earth's surface.
Habitat - preferred place or home for each species of plant and animal to live and reproduce.
Headwaters - upper tributaries of a stream.
Heavy metals - a metal whose specific gravity is approximately 5.0 or higher e.g. copper, cadmium, zinc, nickel, mercury and chromium. They are present in industrial, municipal and urban run-off.
Herbicide - a chemical substance used for killing plants, usually weeds.
Herbivore - an animal that feeds solely on plants.
Hydrograph - a graph showing the seasonal variation in the level, velocity or discharge of a body of water.
Hydrology - applied science concerned with the water cycle which includes precipitation, run-off or infiltration, storage and evaporation.
Impact site - a site located immediately downstream of a pollution source where the pollutant is completely mixed with the water.
Impervious surface - a surface that resists the penetration of water, e.g. asphalt roads.
Impoundment - body of water contained by a barrier such as a dam.
Infiltration - the movement of water through the pores of soil or other porous medium.
In-stream cover - the amount of living space or hard substrate available for aquatic life. In-stream cover includes aquatic plants, snags, logs, rocks, branches and islands. Many insects begin their life underwater and need to attach themselves to a firm surface. Fish and other aquatic organisms require in-stream cover where they can feed, and shelter from predators and the current. These sites also help them establish territories, reproduce and provide markers that help in navigation. Aquatic plants provide food and oxygen for fish and other creatures in the stream. Islands and protruding snags provide roosting and preening sites for birds; concrete lined channels or drainage lines provide almost no in-stream cover that is necessary for the survival of aquatic life.
Integrated catchment management (total catchment management) - management of land, water and other biophysical resources and activities on a catchment basis.
Invertebrates - organisms without a backbone.
Ions - electrically charged molecules formed by the loss or gain of an electron.
Land use - purpose for which land is used; activities that take place on land such as construction, farming or tree clearing.
Larva (plural: larvae) - developmental stage of an insect in which it proceeds from an egg to larva to pupa to adult.
Leachate - water carrying impurities which has percolated through contaminated soil, e.g. from a rubbish tip or mine site.
Leaching - the process in which water percolating through the earth dissolves many substances and then carries them away in solution or suspension.
Limiting factor - a factor such as temperature, light, water or a chemical that limits the existence, growth, abundance, distribution or presence of an organism.
Load - volume or mass of a substance transported by a river, which is derived from multiplying the concentration by the flow rate over a specific period of time.
Macro-invertebrate - animal lacking a backbone and visible to the unaided eye, e.g. crayfish.
Macrophytes - large aquatic plants that can be seen with the unaided eye.
Mangroves - a swamp forest in tidal, saline or brackish water which grows along the shore of estuaries.
Meanders - bends in the course of a river which continually curve from side to side in wide loops.
Metabolic rate - the rate at which an organism uses energy to sustain essential life processes such as respiration, growth and reproduction.
Metamorphosis - period of transformation from a larva to adult.
Micro-organisms - single celled microbes (plants, fungi, animals, viruses) that are invisible to the unaided eye.
mL - millilitre: one thousandth of a litre.
ML - megalitre - one million litres (approximately the quantity contained in one Olympic-sized swimming pool).
Motile - capable of motion, particularly locomotion in some algae through the beating of flagella.
Mystery (unknown) samples - solutions made up by a quality control lab. The concentrations of particular indicators are unknown to samplers.
Nitrate (NO3) - main source of nitrogen for plants; fertiliser consisting of sodium nitrate or potassium nitrate is an agricultural and urban pollutant.
Nitrogen (N) - one of the major nutrients required for the growth of plants, it is usually present as organic nitrogen, ammonia, nitrate and forms of nitrite. Excess nitrogen can cause accelerated eutrophication in water bodies.
Non-point source pollution (NPS) - a source of pollution that cannot be pinpointed as it comes from many individual places. Also called diffuse-source pollution.
Nutrient - an element or compound such as nitrogen, phosphorus or potassium that is necessary for plant growth.
Nymph - young, sexually immature stage of certain insects which is usually similar to the adult in form and where partial metamorphosis is undertaken, i.e. egg-nymph-adult.
Oligotrophic - water which is relatively low in nutrients.
Omnivore - an animal that eats both animals and plants.
Organic compounds - molecules that typically contain atoms of carbon and hydrogen. Oxygen and nitrogen may also be present.
Organism - any living individual plant or animal.
Outfall - pipe through which industrial facilities and wastewater treatment plants discharge their effluent (wastewater) into a water body.
Overclearing - the removal of trees and shrubs, particularly from steep areas which results in accelerated erosion by wind and water and can lead to salinity problems.
Overgrazing - continued grazing of pasture or rangeland at a level that permanently and adversely affects vegetation and leads to land degradation.
Overstorey - woody plants greater than 5m tall, usually with a single stem, e.g. eucalypt trees.
Parameter - a component of the environment or water that is being measured, e.g. temperature or nitrogen.
Parasitic - living off another organism (host).
Parts per million (ppm) - the number of parts by weight of a substance per million parts of liquid.
Pathogen - disease-causing organism such as bacteria, virus or fungi.
Pathogenic - capable of causing disease.
Peak flow - maximum flow of a waterway.
Percolation - downward movement through the subsurface soil layers to groundwater.
Periphyton - plants and animals that are attached to submerged objects such as rocks, macrophytes and tree debris; often microscopic.
Permeability - ease with which water flows through soil or rock.
Pesticide - any chemical or biological agent that kills plant or animal pests. Herbicides, insecticides, fungicides and rodenticides are all types of pesticides.
pH - a measure of the concentration of hydrogen ions in a solution. The pH scale ranges from 0 to 14.
Phosphorus (P) - a non-metallic element that is an important nutrient for all organisms. A deficiency is considered a major 'growth-limiting factor'. It is a common ingredient in fertilisers and cleaning agents. The Australian environment is adapted to very low levels of P in soils and water.
Photosynthesis - process that occurs in the cells of green plants where solar energy is used to combine water and carbon dioxide to produce a simple sugar such as glucose. As a result of the process, plants release oxygen.
Phytoplankton - small animals and plants which float or drift in a water body.
Pipette - eye dropper-like instrument that can measure very small amounts of liquid.
Point source pollution - pollution that can be traced to a single point such as a pipe or culvert which discharges industrial or wastewater treatment plant effluent.
Pollutant - any substance which causes pollution.
Pollution - any harmful or undesirable change in the physical, chemical or biological quality of air, water or soil as a result of the release of chemicals, radioactivity, heat or large amounts of organic matter.
Pools - distinct habitats within a stream where velocity is low and depth greater. The bottom sediments are usually soft. Pools are important habitats for fish.
Potable - suitable for drinking.
Precision - the degree of agreement among repeated measurements of the same characteristic on the same sample, or separate samples, collected as close as possible in time and space. It tells you how consistent and reproducible your field and lab methods are to each other.
Predator - an animal that kills and eats other animals.
Pristine - an environment which remains untouched and undeveloped.
Productivity - production of organic material.
Protocol - defined procedure.
Pupae - developmental stage of an insect between larva and adult.
Quality assurance (QA) - a broad plan for maintaining quality in all aspects of the program, e.g. training, keeping written records, quality control and reporting.
Quality control (QC) - those activities you do to ensure accuracy and precision of your monitoring/surveys. A QC program aims to ensure that the data are good enough for their intended use.
Reagent - substance or chemical for use in a chemical reaction.
Recharge zone - area of land where surface water from rain, irrigation or streams moves downward and infiltrates an aquifer.
Recovery site - a site located well downstream of a suspected pollution source which is monitored to see how far the pollution impact extends.
Reference collection - a standard set of plants or animals that is used to verify identification, e.g. macro-invertebrates.
Reference site - a site located immediately upstream of the potential pollution source and is unaffected by the pollution source.
Regulated river - a river in which structures have been built to control or divert the flow of water.
Relative percent difference - compares how close the result from a water sample is to the true result. Expressed as either a positive difference (the sample result is higher than the true value) or a negative difference (the sample result is lower than the true value).
Relative standard deviation - standard deviation expressed as a percentage.
Representativeness - the extent to which collected data actually represent the conditions you are monitoring. It is most affected by site location.
Respiration - a process in which animals and plants absorb and use oxygen from the surroundings and give off carbon dioxide.
Riffles - occur where rocks and debris in the stream create shallow areas over which the water rushes quickly to form a rapid. Because of the variety of rock sizes in the stream bed, riffles provide many different habitats for macro-invertebrates (water bugs) as well as richly oxygenated water.
Riparian zone - transition habitat between water and land. The riparian zone occurs between a normal river level and the edge of the flood plain and can vary from 5m to 100m or so wide and forms a transition between the watercourse and the land.
Riparian vegetation - vegetation found on the banks of a river or stream that is directly influenced by the presence of water. A healthy stream system generally has a healthy riparian zone. Damage occurs when riparian vegetation is cleared for roads, parking areas, buildings, fields, lawns, agriculture, timber harvesting, quarries, etc. Many streams in urban settings have almost no riparian vegetation.
Riprap - rock used on an embankment to protect the bank against erosion.
Run (glide) - a fast flowing area of a stream where shallow to deeper water flows gently and smoothly over boulders, rocks and gravel where the water's surface is not broken, that is, there is little or no turbulence at the surface.
Run-off - portion of rainfall, melted snow or irrigation water, that flows across the land's surface instead of soaking into the ground. Run-off may pick up and carry a variety of pollutants.
Salinisation - a process in which the concentration of salts in the root zone of the soil increases. This is often caused by the capillary rise of saline moisture from a shallow water table.
Salinity - concentration of salts, measured in milligrams per litre (mg/L) or microsiemens per centimetre µS/cm).
Salts - compounds that dissociate in water to yield a positively charged ion and a negatively charged acid radical ion.
Saturation - a point at which a solution contains enough of a dissolved solid, liquid or gas so that no more will dissolve into the solution at a given temperature and pressure.
Scavenger - animal that feeds on dead organic material.
Sediment - insoluble material suspended in the water that consists mainly of particles derived from rocks, soil and organic materials. It is a major non-point source pollutant to which other pollutants may attach.
Sedimentation - the transport and deposition of sediment particles by flowing water or wind.
Seepage - the process by which water percolates downwards and/or laterally through the soil, often emerging at ground level lower down a slope.
Sensitivity - related to detection limits, it refers to the capability of a method or instrument to discriminate between two samples that have very similar concentrations.
Sewage - domestic or commercial wastewater that contains human waste.
Sewerage system - a complete and contained pipe system that facilitates the collection, transportation, treatment and discharge of wastewater (sewage).
Shock-loading - the sudden introduction of pollution to a water body that severely impacts on aquatic life.
Silt - fine particles of mud or clay in a water body.
Siltation - the deposition of silt carried by flowing water.
Soil degradation - decline in soil quality, commonly caused through its improper use by humans. Examples are loss of organic matter, decline in soil fertility, decline in structural condition, erosion, adverse changes in salinity, acidity or alkalinity and the effects of toxic chemicals, pollutants or excessive flooding.
Soil salinity - characteristic of soils relating to their content of water-soluble salts; such salts predominantly involve sodium chloride, but sulphates, carbonates and magnesium salts may occur. High salinity adversely affects the growth of plants and therefore increases erosion hazard.
Soluble - dissolves in a solution, usually water.
Split sample - one sample that is divided equally into two sub-samples. Split samples are used to measure precision.
Standard deviation - a statistical measure used to compare how closely three or more results are clustered around the average value. It is expressed as a ± from the average value.
Storm flow - that portion of rain that leaves a drainage area in a comparatively short time; also called excess rainfall or surface run-off.
Stratification - formation of layers where different conditions such as temperature, light, nutrients, prevail in a body of water, e.g. thermal stratification.
Stream reach - a length of stream that has relatively similar features, e.g. numerous riffles.
Streambank - zone forming the margin of a stream channel which results from erosion and deposition of the stream; streambanks are identified right bank or left bank looking downstream.
Submergent plants - plants that live and grow fully submerged underwater.
Substrate - material forming the bottom of waterways. It includes:
Surface run-off - water originating from rain or snow that flows across land surfaces instead of soaking in.
Suspended sediment - the sediment that is being transported by water or air while held in suspension.
Taxon (taxa) - any named group of organisms; level of classification within a scientific system that categorises living organisms based on their physical characteristics.
Taxonomic key - reference guide used to identify organisms.
Through flow - flow of water through the ground. Water which has been absorbed into the top soil then moves downhill to a water body.
Titration - addition of small, precise quantities of a reagent to a sample until the sample reaches a certain endpoint, which is usually indicated by a colour change.
Tolerance - the degree to which an organism is able to endure normally unfavourable environmental conditions.
Topographic map - a map that shows the surface features of a region.
Topography - the representation of surface features of a region on maps or charts.
Total dissolved salts - dissolved salts in water.
Toxic - being harmful, destructive or deadly to humans, animals or plants.
Toxic chemicals - any chemical that causes death or harm to humans, animals or plants.
Trace metals - naturally occurring metals found in minute quantities in the environment.
Transpiration - the process by which water taken up by plants from the soil, is evaporated from tiny pores on the leaf surfaces to the atmosphere.
Tributary - a smaller stream that flows into a larger one.
Turbidity - the cloudy or muddy appearance of a naturally clear liquid caused by the suspension of particulate matter.
Understorey - the zone consisting of shrubs, herbs and grasses growing underneath trees. Understorey shrubs are woody plants less than 5m tall, frequently with many stems near the base.
Unknown (mystery) samples - solutions made up by a quality control lab. The concentrations of particular indicators are unknown to samplers.
Verge - the area commencing at the top of the bank and extending from the bank to the next major vegetation or land use change.
Water cycle - movement of water from the atmosphere to the earth and back to the atmosphere through precipitation, run-off, infiltration, percolation, storage, evaporation and transpiration.
Water logged - the condition of a soil saturated with water and lacking most or all of the soil air. The condition may be caused by excessive rainfall, poor soil drainage or excessive irrigation.
Water pollution - any human-caused contamination of water that reduces its usefulness to humans and other organisms in nature.
Water quality criteria - maximum concentrations of pollutants that are acceptable if waters are to meet water quality standards.
Water table - upper surface of the zone of groundwater saturation.
Watercourse - channel, having a defined bed and banks which surface water flows on a permanent or intermittent basis under natural conditions, e.g. creeks, springs, streams and rivers.
Watershed - a dividing ridge between two catchments. Also a North American term for catchment.
Wetland - areas featuring permanent or temporary shallow open water. Land which is regularly or occasionally covered with water that is still or flowing, fresh, brackish, or salt, including areas of marine water which does not exceed a depth of 6m at low tide. Includes billabongs, marshes, swamps, lakes, mud flats and mangrove forests.
Woody debris - stems, branches or roots of dead or living trees that have fallen into the stream. It helps to form important fish habitats, such as pools, and provides hiding places.
Zone of saturation - the underground area above an impermeable layer where water fills all open spaces between rock, sand and soil particles.