Absorb: Take in or soak up by chemical or physical action.

Adsorb: Hold molecules as a thin film on the outside surface or on internal surfaces within the material.

Accumulation of sediment: A mass or quantity of sediment that has gradually built up over time.

Agricultural land: Typically land devoted to agriculture, particularly the rearing of livestock and production of crops to produce food for humans.

Agronomic: Relating to the branch of economics dealing with the distribution, management, and productivity of land.

Algae: Single or multicellular predominantly aquatic plant organisms.

Algal bloom: A sudden growth of algae in an aquatic ecosystem. It can occur naturally in spring or early summer when primary production exceeds consumption by aquatic herbivores. Algal blooms may also be induced by nutrient enrichment of waters due to pollution.

Alluvial aquifers: An aquifer comprising unconsolidated material deposited by water, typically occurring adjacent to rivers and in buried paleochannels. Alluvial aquifers are generally composed of clay, silt, sand, gravel or similar unconsolidated material deposited by running water.

Aluminium hydroxide: Aluminium is the most abundant metal in the earth’s crust, but its availability depends on soil pH. Aluminium hydroxide is one form of aluminium in the soil.

Amino acids: Amino acids are organic compounds that combine to form proteins. Amino acids and proteins are the building blocks of life.

Ammonia (NH3): Ammonia is found in the environment, in the air, soil and water; in plants and animals. It is formed naturally in the environment by the decomposition of urine and manure. It is a source of nitrogen which is needed by plants and animals.

Ammoniacal nitrogen (NH4+/NH3(g)): Ammoniacal nitrogen is a reduced inorganic form of nitrogen. It is a measure for the amount of ammonia and ammonium in solution. At low concentrations it is a nutrient. At high concentrations it is a toxic pollutant often found in landfill leachate and in waste products, such as sewage, liquid manure and other liquid organic waste products. Ammoniacal nitrogen can directly poison humans and upset the equilibrium of water systems.

Ammonium (NH4+): The cation ammonium is present in solutions of ammonia and in salts derived from ammonia.

Animal excrement or waste: Also known as manure or dung. Solid or semisolid remains of food that could not be digested in the small intestine.

Anoxic: Conditions where no oxygen is present.

Aquatic ecosystems: Aquatic ecosystems are any water-based environment in which plants and animals interact with the chemical and physical features of the aquatic environment.

Aquatic habitats: Natural aquatic habitats include ponds, lakes, rivers, streams, springs, estuaries, bays, and various types of wetlands.

Aquatic organisms: An aquatic organism is an animal, either vertebrate or invertebrate, which lives in the water for most or all of its lifetime.

Aquifer: Aquifers are underground layers of porous rock or sand through which groundwater flows.

Artificial drainage: Artificial drainage systems employ the help of pipes, wells, and other constructed materials to achieve a successful drainage solution. It can be either subsurface, such as tile and mole drains, Novaflow, or surficial, such as open ditch drains.

Artificial eutrophication: Artificial eutrophication is when humans artificially cause an overabundance of nutrients in an ecosystem.

Assimilated: The absorption and digestion of nutrients (or food) by the body or any biological system.

Atmosphere: The atmosphere of the earth is the layer of gases, commonly known as air, that surrounds the planet earth and is retained by earth's gravity.


Baseflow: Between storms and runoff events, stream flow is maintained by groundwater discharge known as base flow.

Benthic algae: Toxic algae which generally form brown or black mats that grow on rocks in the riverbed.

Biofilter: A filter bed in which pollutants are subjected to the action of microorganisms that assist in decomposing them.

Biogeochemical cycle: A biogeochemical cycle is one of several natural cycles in which conserved matter moves through the biotic and abiotic parts of an ecosystem. The abiotic components can be subdivided into three categories: the hydrosphere (water), the atmosphere (air) and the lithosphere(rock).

Biogeochemical processes: Biogeochemical processes affect the earth's ecosystems by changing fundamental processes that control the cycling of elements. Biological, hydrological, atmospheric, and geological processes play essential roles in terrestrial biogeochemical cycles by regulating the synchrony between release and uptake of nutrients by microorganisms and plants. 

Biological conditions: Refers to conditions that may occur in nature for a particular organism or cell system, in contrast to artificial laboratory conditions.

Biological processes: Biological processes are the processes vital for a living organism to live. These processes shape the organism’s capacity for interacting with its environment.

Biologically: In a way that concerns biology or living organisms.

Biosphere: The regions of the surface and atmosphere of the earth occupied by living organisms.

Biotic integrity: Term used to identify the capacity of a land to support characteristic functional and structural communities in the context of normal variability, to resist loss of this function and structure due to a disturbance, and to recover from such disturbance.

Biotic species: Biotic species are the living things that shape an ecosystem. Examples of biotic components include animals, plants, fungi, and bacteria.

Bores: A hole drilled in the earth specially to make a well for the extraction of water from the ground.

Brackish: Brackish water has a higher salinity than fresh water, but not as high as seawater.

Buffer strip: A buffer strip is an area of land maintained in permanent vegetation that helps to control air, soil, and water quality.

Bund: An embankment used to control the flow of water.


Camber: The slightly convex or arched shape of a road or track.

Carbon dioxide: Often referred to by the formula CO2 it is present in the earth's atmosphere at a low concentration (0.04%) and acts as a greenhouse gas.

Catchment: Catchment area is a term used to describe an area which collects each drop of water (rain) that falls into that area and which eventually ends up in the same river or stream going to the sea. A catchment (also known as a drainage basin) is a basin shaped area of land bounded by natural features, such as hills or mountains, from which surface and subsurface water flows into streams, rivers, and wetlands. Water flows into, and collects in, the lowest areas in the landscape.

Chemical: A chemical substance is a form of matter having constant chemical composition and characteristic properties. Steam and liquid water are two different forms of the same chemical substance, water.

Chemical contaminants: Chemical contaminants are chemicals toxic to plants and animals in waterways. Chemical contaminants are often transported by water as it flows across the land, roads, and other impermeable surfaces.

Chemical processes: A chemical process is a method or means of changing one or more chemicals or chemical compounds. A chemical process can occur by itself or be caused by an outside force and involves a chemical reaction of some sort.

Clay minerals: Clay minerals are hydrous aluminium phyllosilicates, sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths. They are the major constituent of fine-grained sediments and rocks.

Climate: Climate means the usual condition of the temperature, humidity, atmospheric pressure, wind, rainfall, and other meteorological elements in an area.

Climatic processes: Climatic processes influence temperature, evaporation, humidity, and the amount and seasonality of rainfall.

Colloid: a homogeneous non-crystalline substance consisting of large molecules or ultramicroscopic particles of one substance dispersed through a second substance. Colloids include gels, sols, and emulsions; the particles do not settle, and cannot be separated out by ordinary filtering or centrifuging like those in a suspension.

Colony Forming Units: A colony-forming unit is a unit used to estimate the number of viable bacteria or fungal cells in a sample. Viable is defined as the ability to multiply under the controlled conditions.

Compaction of soil:  Compaction is the process in which stress applied to a soil causes densification as air is displaced from the pores between the soil grains.

Complex molecules: A complex molecule is an entity formed by loose association involving two or more component molecules (ionic or uncharged), or the corresponding chemical species.

Confined aquifer: Lies between two layers of less permeable rocks and is filled with water over a much longer time period than an unconfined aquifer. Water trickles down through cracks in the upper layer of less permeable rock, and an aquifer that is partially disconnected from the land surface directly above occurs. 

Conservation: Conservation is the protection of species from extinction, maintaining and restoring habitats, enhancing ecosystem services and protecting biological diversity.

Contaminant transport: Transport of contaminants through soil is through the mechanisms of leaching, and erosion or suspension of soil particles.

Contaminants: Any physical, chemical, biological or radiological substance in water. a polluting or poisonous substance that makes something impure.

Critical source area: Critical source areas are areas such as a gully, swale, or depression where water converges and flows during rainfall events. These areas contribute a disproportionately large amount of contaminants to the environment as contaminants are collected and concentrated as the water converges in these areas and travels through them to waterways.

Cultivation: Preparation of soil by mechanical agitation of various types, such as digging, ploughing, fertilising, and drilling.

Cycling of phosphorus: The phosphorus cycle is the way in which Phosphorus moves through rocks, water, soil and sediments and organisms. Over time, rain and weathering cause rocks to release phosphate ions and other minerals. Once in the plant or animal, the phosphate is incorporated into organic molecules such as DNA.


Decomposition: Decomposition is the process by which organic substances are broken down into simpler organic matter. The process is a part of the nutrient cycle.

Deep drainage: Deep drainage or groundwater recharge is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer.

Denitrification: Denitrification is a redox reaction that deals specifically with the transformation of nitrogen, in which oxidised nitrogen (nitrate, NO3-) accepts an electron and is reduced to nitrous oxide (NO or N2O) or nitrogen gas (N2).

Disease-causing organisms: A bacterium, virus, fungus, or other microorganism that can cause disease.

dissolved colloids: Dissolved (soluble) compounds that are readily available for use by plants and algae. Dissolved reactive phosphorus concentrations are an indication of a waterbody’s ability to support nuisance algal or plant growths (algal blooms).

Dissolved organic carbon: DOC is the fraction of total organic carbon defined as that which can pass through a filter size that typically ranges in size from 0.22 and 0.7 micrometres. DOC is abundant in marine and freshwater systems and is one of the greatest cycled reservoirs of organic matter on earth, accounting for the same amount of carbon as the atmosphere.

Dissolved Reactive Phosphorus: DRP is the amount of phosphorus dissolved in water and is most immediately and readily absorbable for plant and algae growth. It is one component of total phosphorus (TP), the other being phosphate that is stuck to sediment and is therefore unavailable for plants.

DNA: DNA, short for deoxyribonucleic acid, is the molecule that contains the genetic code of organisms. This includes animals, plants and bacteria. DNA is the building blocks for life. LandscapeDNA takes this concept to show how soils, geology, hydrology, and climatic variation produces different landscape units.

Drainage basin: A drainage basin is any area of land where rain collects and drains off into a common outlet, such as a river, stream, wetland, bay, or other body of water.

Drainage network: Drainage network for a river is the network of all the streams and water bodies that are feeding water to the river.

Drainage pattern: The pattern formed by the streams, rivers, and lakes in a particular drainage basin. They are governed by the topography of the land, whether a particular region is dominated by hard or soft rocks, and the gradient of the land.

Drainage properties: Properties found in soil which affect drainage include clay content, organic matter, soil pH, water content, structure, porosity and density. Soil drainage affects the direction and rates of water and chemical movement within a soil.

Drinking water: Drinking water, also known as potable water, is water that is safe to drink or to use for food preparation.


E. coli: Escherichia coli. E. coli is used as an indicator species for the presence of more harmful bacteria due to its comparative ease to detect and quantify.

Ecological: The relation of living organisms to one another and to their physical surroundings.

Ecosystem health: Ecosystem health is a term used to describe the condition of an ecosystem. Ecosystem condition can vary as a result of flooding, drought, fire, invasive species, climate change, mining, overexploitation in fishing, farming or forestry.

Ecosystem: A biological community of interacting organisms and their physical environment.

Effluent: Liquid waste that enters the environment from a farm, factory, commercial establishment, or household. It can refer to urine or manure from livestock, or wastewater from a sewage treatment plant.

Elevated turbidity: Turbidity is a measure of the degree to which the water loses its transparency due to the presence of suspended particulates. The more total suspended solids in the water, the murkier it seems and the higher the turbidity.

Environment: Environment is everything that is around us. It can be living (biotic) or non-living (abiotic). It includes physical, chemical and other natural forces.

Environmental contaminants: Environmental contaminants are chemicals or organisms that accidentally or deliberately enter the environment, often, but not always, as a result of human activities.

Ephemeral stream: Ephemeral streams are dry stream beds that flow as streams after periods of rainfall. They are located in the swales or depressions in the landscape.

Erosion: The process of wearing away soil and land surfaces by the actions of water, wind, or ice.

Estuary: The area of water on the coast, where freshwater and seawater mix. It often forms at the mouth of a river, with large mud flats where the tides wash in and out. It is a unique home for many organisms, including fish and plants.

Eutrophication: The enrichment of water with nutrients, such as nitrogen and phosphorus. Eutrophication can lead to growth and blooms of large masses of plant material such as phytoplankton and/or macrophytes.

Exposed soil: Soil which is exposed to the atmosphere through cultivation, grazing and erosion.


Faecal contamination: High E. coli concentrations in freshwater can be harmful to humans, this is why faecal concentration in water is monitored using Faecal Indicator Bacteria. The two most commonly measured FIBs are E. coli (in freshwater) and Enterococci (in marine waters). Common sources of E. coli bacteria are untreated human wastewater discharges, stormwater run-off and animal waste. 

Faecal presence: Water can be contaminated with particles of animal dung or human faeces which carry bacteria that can be harmful if ingested. See also E. coli.

Fertiliser: Fertiliser is any material of natural or synthetic origin that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of the plant.

Field capacity: Is the amount of soil moisture or water content held in soil after excess water has drained away and the rate of downward movement has materially decreased, which usually takes place within 2‚Äď3 days after rain or irrigation in pervious soils of uniform structure and texture.

Fish index of biotic integrity: The USA Bureau of Freshwater and Biological Monitoring began implementing a Fish Index of Biotic Integrity (IBI) sampling program in 2000. The objective is to assess stream quality using the IBI. The IBI evaluates environmental conditions based on assessments of fish populations.

Fractured rock aquifer: There are two main types of aquifers, alluvial and fractured rock. A fractured rock aquifer has limited storage capacity and transports water along planar breaks.

Functioning freshwater ecosystem: A functioning ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscapes, work together to form a bubble of life. Freshwater ecosystems, especially vegetated wetlands, play an important role in mitigation against climate variability. They do so through several ecosystem functions including flood control, water purification, shoreline stabilization and sequestration of carbon dioxide.


Gastroenteritis: The inflammation of the stomach and intestines, typically resulting from bacterial toxins (in water) or viral infection and causing vomiting and diarrhoea.

Geology: Geology is the study of the Earth's structure, surface, and origins.

Green algae: Harmless bright green algae, which often form long filaments in water bodies.

Greenhouse gas emissions: A greenhouse gas is a gas that absorbs and emits radiant energy. The primary greenhouse gases in the earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide and ozone.

Groundwater: Water that is found beneath the land surface in pores and fissures in rock and soil. Permeable underground zones where groundwater accumulates are known as aquifers.

Groundwater recharge: Is where water moves downward through the soil profile. Recharge is the primary method through which water enters an aquifer. Deep drainage and lateral drainage through the soil are key transport pathways for phosphorus and microbes.


Habitat unsuitable for fish: The environment in which biological communities naturally occur is called a habitat. It includes the physical and biotic characteristics that are relevant to a certain species e.g., fish. This environment can become contaminated to such a degree that it can no longer support the particular life form (fish).

Harvesting of food: Harvesting is the process of gathering a crop or resource for food. This not only relates to soil grown plants but can also include fish and seaweeds.

Heavy metals: Any metal or alloy with high specific gravity (a density higher than 5 grams per cubic centimetre). Usually, even at low concentrations, heavy metals are toxic to most plants and animals. Mercury, plutonium, and lead are examples of toxic metals and their accumulation over time in the bodies of animals can cause serious illness.

High sediment concentrations: High concentrations of sediment create murkiness (turbidity) in water. Turbidity is a measure of the degree to which the water loses its transparency due to the presence of suspended particulates. The more total suspended solids in the water, the murkier it seems and the higher the turbidity.

Horticultural land: Horticultural land is land used for growing crops such as fruits and berries. It also includes vegetable growing. The most notable difference from agriculture is that horticulture deals with smaller scale gardening and usually on smaller holdings, while agriculture is done on large scale with extensive crop cultivation.

Humic: Humic substances are organic compounds that are important components of humus, the major organic fraction of soil, peat, and coal.

Hydric soil: Soil that formed under conditions of saturation, flooding or ponding long enough during the growing season to develop anaerobic conditions in the upper part.

Hydrological pathway: Where water moves to drain from the land. This is either through the soil by deep drainage, laterally along slowly permeable layers in the soil or bedrock, or through soil zone bypass in natural cracks or artificial drains.

Hydrology: Hydrology is the study of the movement, distribution (quantity), and quality of water on Earth and its cycle through the environment.

Hydrosphere: All the water on the earth’s surface.


Indicator species: A species or group of species whose function, population, or status can reveal the qualitative status of the environment. For example, many small water crustaceans that are present in water bodies can be monitored for changes that may indicate a problem within their ecosystem.

Indigenous: Originating or occurring naturally in a particular place; native.

Inert atmospheric molecular form: Inert means 'chemically inactive', so an inert atmosphere is an environment in which fusion can take place without the risk of contamination from reactive gases that exist in the air, such as oxygen and carbon dioxide.

Infiltration rate: Is a measure of how fast water enters the soil.

Ingested: The process of taking food, drink, or another substance into the body by swallowing or absorbing it.

Inorganic: Not consisting of or deriving from living matter. Relating to compounds which are not organic (broadly, compounds not containing carbon).

Inorganic fertilizer: Inorganic fertilizer, also referred to as synthetic fertilizer, is manufactured artificially and contains minerals or synthetic chemicals.

Inorganic nitrogen: The major forms of inorganic nitrogen are N2 gas, nitrate, nitrite, and ammonium.

Inorganic phosphorus: Phosphate (PO43‚ąí) is a dominant form of¬†inorganic phosphorus¬†in natural waters, but concentrations are often below detection in pristine waters.¬†

Instream scouring: In stream scouring is the erosion of a riverbed by flowing water. Scouring can occur gradually or during floods. Sediment deposited in the river may result in the formation of sand and gravel bars in the channel.

Interconnecting streams: The many smaller streams that are connected to form a river network within a catchment area. 

Ionic forms: Ions are electrically charged particles formed when atoms loose or gain electrons. Metal atoms form positive ions, while non-metal atoms form negative ions.

Iron: Iron in its metallic form is rare in the earth's crust whereas iron ores by contrast, are among the most abundant metals in the earth.

Iron oxides: Iron oxides and oxyhydroxides are widespread in nature and play an important role in many geological and biological processes.


Lake: A large area of water surrounded by land.

Land activities: Describes the human activities or economic functions that occur on land.

Land use decisions: Many environmental, economic and social factors influence how we decide to use our land and these different land uses can affect the environment.

Land use pressures: Each land use places different pressures on the land and on receiving environments such as waterways. These pressures can be both positive e.g. increased productivity and negative e.g. biodiversity loss and reduced functioning of ecosystems.

Landscape: A landscape is the visible features of an area of land, its landforms, and how they integrate with natural or man-made features.

Lateral drainage: Lateral drainage removes excess water from soil below its surface. It can occur naturally or be artificial as in tile drains. Lateral flow is common in areas where there is shallow bedrock, such as in hill country.

Leachability: The extent to which soluble or other constituents can be removed by the action of a percolating liquid. For example, heavy rains can leach the soil of minerals and acids in groundwater can leach calcium out of bedrock.

Leachate: A leachate is any liquid that, in the course of passing through matter, extracts soluble or suspended solids, or any other component of the material through which it has passed.

Leaching: Leaching (agriculture), the loss of water-soluble plant nutrients from the soil.

Light penetration: Light Penetration refers to the amount of sunlight that penetrates water. Sunlight is absorbed and scattered by suspended particles, dissolved substances, and the water itself.

Lithosphere: The rigid outer surface of the earth.

Low flow conditions: Low flow conditions are naturally occurring, regular, small flow events that are a vital part of the annual water flow pattern of a catchment. They are the small but vital portion of water that needs to flow across land through watercourses to maintain natural processes and catchment health.

Low order stream: A low order stream is the smallest of the streams in a network and consists of small tributaries. These are the streams that flow into and "feed" larger streams but do not normally have any water flowing into them.

Lowland streams: Upland and lowland streams flow over portions of plain that are categorized by their elevation above the sea level. Lowlands are usually no higher than 200m.

Low slope land: As defined in the Resource Management (Stock Exclusion) Regulations 2020 are areas which have a mean slope which is less than or equal to 10 degrees. 


Mahinga kai: Literally means 'to work the food' and relates to the traditional value of food resources and their ecosystems, as well as the practices involved in producing, procuring, and protecting these resources.

Main waterway: A waterway is any navigable body of water. A main waterway is the largest water pathway in a catchment.

Malleable: Able to be pressed into shape without breaking or cracking.

Management practices: Management practices refers to the working methods and innovations that managers use to improve the effectiveness of farming practices or work systems. 

Mana Whakahono a Rohe: A Mana Whakahono-ńĀ-Rohe agreement requires both iwi and councils to develop and agree on a shared understanding of their respective expectations in the context of the Resource Management Act.

Manganese: Manganese is a chemical element with the symbol Mn. It is not found as a free element in nature; it is often found in minerals in combination with iron.

Marginal land: Marginal land is land that has little or no agricultural value. Marginal land has little potential for profit and often has poor soil or other undesirable characteristics such as excessive steepness. 

Meltwater: Meltwater is water released by the melting of snow or ice, including glacial ice, tabular icebergs and ice shelves over oceans. Meltwater is often found in the ablation zone of glaciers, where the rate of snow cover is reducing.

Methane: Methane is gas that is found in small quantities in the earth's atmosphere. It is a principal component of natural gas and is a powerful greenhouse gas.

Microbes: A microorganism, or microbe, is a microscopic organism, which may exist in its single-celled form or in a colony of cells.

Microbial contaminant: A microorganism, especially a bacterium causing disease or fermentation.

Microbial mineralisation processes: Biologically induced mineralization occurs when the metabolic activity of microbes (e.g. bacteria) produces chemical conditions favourable for mineral formation.

Microorganism: A microscopic organism, especially a bacterium, virus, or fungus.

Mineral content: The minerals found in a water sample. These can include calcium, magnesium, sodium, potassium, phosphorus.

Mineral soils: There are two general kinds of¬†soils‚ÄĒmineral¬†and organic.¬† Mineral soils¬†include sandy, loamy, and clay types.

Minimise losses: To reduce contaminant losses to the smallest possible amount.

Mitigation: The action of reducing the severity or seriousness of something.

Molecular: Refers to a molecule which is an electrically neutral group of two or more atoms held together by chemical bonds. Molecules are distinguished from ions by their lack of electrical charge.

Mycorrhizal fungi: A mycorrhiza is a mutually beneficial association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's root system.


National Policy Statement for Freshwater Management: Government regulation for freshwater management.

Native forest: Native or indigenous forest is forest which consists of plants which originated in the country where the forest is growing.

Natural chemistry: Consists of chemical compounds or substances produced by a living organism.

Natural bypass flow: Is a situation in which surface water is connected with water in the subsurface due to rapid infiltration. For example when high clay soils are dry and cracked.

Natural eutrophication: Is a natural process that occurs in an aging lake or pond as that body of water gradually builds up its concentration of nutrients.

Natural landscape: A natural landscape is the original landscape that exists before it is acted upon by human culture. 

Natural processes: Natural processes are interactions among plants, animals, and the environment. These interactions include photosynthesis, pollination and decomposition and help create and shape natural communities.

Natural slips: A downward movement of earth or rock which may cause contamination of a waterway.

Negatively charged: Clay particles generally have a negative charge, so they attract and hold positively charged nutrients and non-nutrients.

Nitrate (NO3-): Nitrate is a polyatomic ion with the molecular formula NO3-.

Nitrate risk: The sources of nitrates for humans can be drinking water, food, and air. After ingestion, nitrates are converted to nitrite by gastrointestinal microflora leading to methemoglobinemia and increase in free oxide radicals that predispose cells to irreversible damage.

Nitrate-Nitrite Nitrogen (NNN): Is found in the cells of all living things and is a major component of proteins. Inorganic nitrogen may exist in the free state as a gas N2, or as nitrate NO3-, nitrite NO2-, or ammonia NH3+. Organic nitrogen is found in proteins and is continually recycled by plants and animals.

Nitrification: Is the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate. The transformation of ammonia to nitrite is usually the rate limiting step of nitrification. Nitrification is an important step in the nitrogen cycle in soil.

Nitrite (NO2-): Nitrite is an ion with the chemical formula NO2-. Concentrations of nitrite are normally low compared to the other forms of nitrogen (nitrate and ammoniacal nitrogen).

Nitrogen: Nitrogen is a naturally occurring substance, with the chemical symbol N. In its gas form (N2), nitrogen makes up about 80% of the Earth's atmosphere. In other forms it is one of the most important fertilisers for plant growth. It is also found in amino acids that make up proteins, in nucleic acids (that make up DNA) and in many other organic and inorganic compounds.

Nitrogen cycle: The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes.

Nitrogen load: Nitrogen loading is the quantity of nitrogen entering an ecosystem in a given period of time.

Nitrogen nutrition: Nitrogen is a vital component in the nutrition of plants as it is a major component of chlorophyll, the compound by which plants use sunlight energy to produce sugars. It is also a major component of amino acids, the building blocks of proteins. Without proteins, plants die.

Nitrous oxide: Nitrous oxide is a colourless and odourless gas produced as a by-product of fuel combustion. Although relatively small amounts are released, it has a high global warming potential (310 times that of carbon dioxide). Nitrous oxide also damages the ozone layer, thus reducing the protection offered from harmful UV rays.

Nucleic acids: Nucleic acids are macromolecules that store genetic information and enable protein production. Nucleic acids include DNA and RNA.

Nutrient concentrations: Nutrient concentrations are usually reported as numbers of molecules (expressed in units of moles) in a given volume of water, or in a given mass of water.

Nutrient cycling: A nutrient cycle is the movement and exchange of organic and inorganic matter back into the production of matter.

Nutrients: Nutrients are chemicals needed by all plants and animals for growth, especially nitrogen and phosphorus. Other nutrients that are added on farm are potassium, sulphur, and minor trace elements (if deficient). We typically add nutrients to land as fertiliser to improve plant growth or they are returned to the land through animal excrement. They are also released by the breakdown of any organic material.


Organic: When used in regard to food or farming methods, organic relates to being produced or involving production without the use of chemical fertilizers, pesticides, or other artificial chemicals.

Organic compounds: Organic compounds are chemical compounds that contain carbon.

Organic matter particles: Are particles such as soil organic matter or other particulates between 0.053 mm and 2 mm in size. These particles are readily decomposable, serving many soil functions and providing terrestrial material to water bodies. They can contribute substantially to turbidity, limiting photic depth which can suppress primary productivity. They also enhance soil structure leading to increased water infiltration, aeration and resistance to erosion.

Organic nitrogen: Organic nitrogen in aquatic environments consists of truly dissolved organic nitrogen and particulate organic nitrogen.

Organic phosphate: Phosphorus that has been incorporated into plant or animal tissue e.g. seeds, leaves.

Overland flow: Is the flow of water that occurs when excess rainwater, meltwater, or water from other sources flows over the surface of the ground. This might occur because soil is saturated to full capacity, because rain falls more quickly than soil can absorb it, or because the land surface is impervious (e.g. bare rock and roads).

Oxidation-reduction reaction: Known as a redox reaction, this is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the transfer of electrons between chemical species, most often with one species undergoing oxidation (loss of electrons) while another species undergoes reduction (gain of electrons).

Oxygen: Oxygen is the chemical element with the symbol O. It is a highly reactive non-metal and an oxidising agent that readily forms oxides with most elements as well as with other compounds. For example, oxygen in contact with iron will rust. Rust is an iron oxide.


Particulate Phosphorus: Phosphorus which is attached to particles and which is not immediately available for growth.

Pastoral streams: A pastoral stream is one which passes through land used for producing livestock rather than cropping. i.e. dairy farming, sheep and beef.

Pasture: Land covered with grass and other low plants suitable for grazing animals, especially cattle or sheep.

Pathogenic bacteria: Pathogenic bacteria are bacteria that can cause disease.

Peat soils: Peat is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires and moors. In the NZ Soil Classification it is called an Organic soil.

Permeable: Permeability is a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluid (water) to pass through it.

pH: pH is a measure of the acidity or alkalinity in soil or water.

Phosphorus: Phosphorus is an element which exists in two major forms, white phosphorus and red phosphorus. Because it is highly reactive, phosphorus is never found as a free element. The phosphorus cycle refers to the biogeochemical cycle by which phosphorous moves through the biosphere, hydrosphere, and lithosphere.

Physical: The part of the environment that includes purely physical factors such as soil, climate, water supply.

Physiographic Environments: A physiographic environment is one which has a distinct type of landscape, landform and evolutionary history. If two different regions are compared, you will see that they vary based on each of their characteristic categories.

Physiographics: Physiographics is the identification, mapping, and classifying of the features of a landscape. These landscape features in combination form the basis of the physiographic approach and make it possible to accurately predict the water chemistry of groundwater and surface water. Combining Physiographics with mapping enables understanding of the relationship between sediment and water movement.

Plant nutrients: Chemical elements and compounds which are necessary for plant growth and metabolism. The macronutrients necessary for plant growth are nitrogen, phosphorus, potassium, calcium, sulphur, magnesium, carbon, oxygen, hydrogen. The necessary micronutrients or trace minerals are iron, boron, chlorine, manganese, zinc, copper, molybdenum, nickel.

Plough pan: A pan that develops in heavy agricultural land from ploughing when the soil is wet, smearing the clay soil to give a slick surface which is relatively impervious to water and plant roots.

Porosity: Soil porosity is the gap between solid particles, which contains water and air.

Precipitation: Rain, snow, sleet, or hail that falls to or condenses on the ground.

Pristine: In original condition; unspoilt.

Proteins: Proteins are composed of amino acids, which are organic compounds made of carbon, hydrogen, nitrogen, oxygen or sulphur. Plants store proteins in embryo and vegetative cells to provide carbon, nitrogen, and sulphur resources for subsequent growth and development.

Protozoa: Protozoa is an informal term for single-celled eukaryotes (a group of organisms classified as neither plants nor animals), either free-living or parasitic, which feed on organic matter such as other microorganisms or organic tissues and debris.

Pugging: This is when wet soil and pasture is churned up and pushed down by heavy livestock. Extensive pugging remoulds the surface soil and destroys large soil pores. The resulting damage to plants and soil limits subsequent growth and pasture yield.


Rate of flushing:  A sudden flow of water. The rate at which this flow occurs.

Reach: A reach is a section of a stream or river along which similar hydrologic conditions exist, such as discharge, depth, area or slope. It can also be the length of a stream or river (with varying conditions) between two stream gauges, or a length of river for which the characteristics are well described by readings at a single stream gauge.

Recharge: Recharge of groundwater or deep drainage is a hydrologic process where water moves downward from the surface through the earth. Recharge is the primary method through which water enters an aquifer. 

Recharge domain: A recharge domain is the place where water is able to seep into the ground and refill an aquifer because no confining layer is present.

Recreational use: Recreational use refers to areas where recreation can take place. In a rural setting they are areas that can be used for hunting, fishing, swimming, boating.

Redox process: Redox is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the transfer of electrons between chemical species, most often with one species undergoing oxidation (loss of electrons) while another species undergoes reduction (gain of electrons).

Reduced clarity: Water clarity is a measure of how far down light can penetrate through the water. Turbid waters are marked by high levels of suspended particles that cloud visibility by absorbing and scattering light.

Reduction potential: Redox potential, also known as oxidation/reduction potential, is a measure of the tendency of a chemical species to acquire electrons from or lose electrons to an electrode and thereby be reduced or oxidised.

Regenerative agriculture: Regenerative agriculture is a system of farming practices that aims to increase biodiversity, enrich soils, improve watersheds, and enhance ecosystem services. Regenerative Agriculture aims to capture carbon in soil and aboveground biomass reversing current global trends of atmospheric accumulation.

Regional Councils: New Zealand's¬†local government system comprises two complementary sets of local authorities ‚Ästregional councils¬†and territorial authorities which are the city and¬†district councils. Regional Councils¬†were established in NZ in November 1989 after the abolition of the 22 local government¬†regions. Regional councils¬†cover every territorial authority in New¬†Zealand¬†with the exception of the Chatham Islands Territory.¬†

Reservoirs: An enlarged natural or artificial area which stores water e.g., aquifer or dam.

Riparian vegetation or buffer: A strip of planting along the margin (banks) of a waterway which is protected from grazing or cultivation.

River network: A river network is all the paths formed by every tributary of the main river.

River: A large natural stream of water flowing in a channel to the sea, a lake, or another river.

RMA: Resource Management Act 1991: The RMA promotes the sustainable management of natural and physical resources such as land, air and water.

Runoff: Overland flow. Runoff is the flow of water that occurs when excess stormwater, meltwater, or other sources flow over the earth's surface. This can occur when the soil is saturated to full capacity, and rain falls more quickly than the soil can absorb it.

Runoff events: Runoff is generated by events such as rainstorms and its occurrence and quantity are dependent on the characteristics of the rainfall event, i.e. intensity, duration and distribution. 


Safe for drinking: Water is considered safe for drinking if there are very low concentrations of contaminants present.

Sandy catchments: A catchment area where the underlying soils are sandy. Certain soil types such as sandy soils are very free-draining, and rainfall on sandy soil is likely to be quickly absorbed.

Sediment: The loose sand, silt, clay and other organic particles that are suspended in a waterway or settled on the bottom.

Sediment load: Refers to solid particles produced by weathering and transported through a channel by stream flow. The sediment load may be divided into two components: that which is suspended within the water column and that which is moved along the bed of a channel.

Sedimentation: Sedimentation is the tendency for particles in suspension to settle out of the surrounding fluid in which they are suspended and come to rest against a barrier e.g. a river bed.

Sediment-bound nutrients: These are nutrients which are attached to sediment particles. Soil erosion is not only the loss of soil particles, but also the loss of sediment-bounded nutrients and elements.

Septic tank: A tank, typically underground, in which sewage is collected and allowed to decompose through bacterial activity before draining by means of a soakaway.

Sequestration: Carbon sequestration is the long-term storage of carbon in plants, soils, geologic formations, and the ocean.

Sewage systems: A sewage system is a system of removing contaminants from domestic, industrial or agricultural wastewater. Physical, chemical, and biological processes are used to remove contaminants and produce treated wastewater that is safe enough for release into the environment.

Slow-flowing: The rate of flow in a stream or waterway e.g. slow flow.

Slurry: A semi-liquid mixture, typically of fine particles of manure suspended in water.

Soil particle: The particles that make up soil are categorized into three groups by size: sand, silt, and clay. Sand particles are the largest and clay particles the smallest.

Soluble: Able to be dissolved, especially in water.

Solutes: A solute is a substance dissolved in another substance which is known as a solvent.

Spring: Sometimes groundwater is discharged at the land surface. Where this occurs it is known as a spring or wetland (seep).

Stormwater run-off: Stormwater runoff is rainfall that flows over the ground surface. It can carry contaminants such as sediment and can erode stream banks when it is fast moving.

Strahler Order: The branching nature of a river and its tributaries are known as the stream order or Strahler order. It is used to define the size of a stream based on the hierarchy of the tributaries flowing to a point of interest.

Stream network: A stream network is the arrangement of water paths in a catchment.

Stream order: The branching nature of a river and its tributaries is known as the stream order or Strahler order. It is used to define the size of a stream based on the hierarchy of the tributaries flowing to a point of interest.

Stream banks: A stream bank or river bank is the terrain alongside the bed of a river, creek, or stream. The bank consists of the sides of the channel, between which the flow is confined.

Stream bed: A stream bed is the channel bottom of a stream or river, the physical confine of the normal water flow. The lateral confines or channel margins are known as the stream banks or river banks, during all but flood stage.

Stream: A small narrow river.

Sub-catchments: Smaller catchment areas which contribute to the main catchment.

Subsoil: The soil lying immediately under the surface soil.

Substrate: The underlying layer of the soil.

Subsurface water: Water in the lithosphere in solid, liquid, or gaseous form. It includes all water beneath the land surface and beneath bodies of surface water.

Sulphate: A sulphate is a salt of sulphuric acid. Sulphate is one of the major dissolved components of rain. High concentrations of sulphate in the water we drink when combined with calcium and magnesium produce the two most common constituents of hardness.

Surface water: Surface water is water on the surface of the earth such as in a river, lake, or wetland. It can be contrasted with groundwater and atmospheric water

Surface water bodies: Surface water is any body of water above ground, including streams, rivers, lakes, wetlands, reservoirs, and creeks. 

Surface water catchment: An area of land over which water flows and is collected. It refers only to the water on the surface of the land.

Surficial runoff: Surficial runoff is what occurs when rain is not absorbed by the ground on which it falls and so then flows downhill. Eventually runoff water will drain into a stream or river.

Suspended particles: Suspended particles are the small solid particles which remain in suspension in water as a colloid or remain suspended due to the motion of the water.

Suspended sediment: Suspended sediment is particles in suspension in the water as opposed to being dissolved. This sediment is generally transported within and at the same velocity as the water surrounding it. Most sediment particles are not continuously suspended, but are continuously settling through the surrounding water and may eventually return to the bed of the waterway.


Tangata whenua: People of the land.

Te Mana o te Wai: Te Mana o te Wai refers to the vital importance of water, the health and well-being of water. the health needs of people, the ability of people and communities to provide for their social, economic and cultural well-being.

Tillage: Ploughing.

Topography: The arrangement of the natural physical features of an area.

Total Kjeldahl Nitrogen (TKN): The TKN value (Total Kjeldahl Nitrogen) represents a total Nitrogen concentration, which is the sum of organic Nitrogen compounds and ammonium Nitrogen (TKN = org-N + NH4-N [mg/L]). Kjeldahl-Nitrogen is generally applied as a measure of Nitrogen in wastewater.

Total Nitrogen (TN): Total Nitrogen is the sum of all organic and inorganic forms of Nitrogen that are found in a water sample (i.e., nitrate-nitrogen (NO3-N), nitrite-nitrogen (NO2-N), ammoniacal-nitrogen (NH4-N) and organic nitrogen such as amino acids or plant tissue.

Total Phosphorus: Total phosphorus is the best way to measure Phosphorus in water because it includes both ortho-phosphate and the Phosphorus in plant and animal fragments suspended in the water.  Total Phosphorus levels are more stable and an annual mean can disclose a lot about the health of the waterway and it's trophic state. 

Total Suspended Sediment: Suspended sediment is generally transported within and at the same velocity as the water surrounding it. Most sediment particles are not continuously suspended but are continuously settling through the motion of the water. Total suspended sediment (TSS) = Inorganic + Volatile Forms (both <0.2 mm in diameter).

Toxic: Poisonous.

Transport of contaminants: The most important mechanisms of transport of contaminants through soil are leaching, and erosion or suspension of soil particles. Most contaminants are introduced to the subsurface by filtration through soils. Some contaminants adsorb readily onto soil particles and slowly dissolve during precipitation events, resulting in concentrations of contaminants migrating to groundwater.

Transport pathways: The transport of pollutants in water can occur under particulate or dissolved forms, either in surface or groundwaters. The paths these particles take are known as transport pathways.

Tributaries: Small feeder streams that empty into larger streams or rivers. The catchments of tributaries are referred to as sub-catchments. Large catchments are often made up of a number of smaller sub-catchments.

Trophic connectivity: A succession of organisms in an ecological community that are linked to each other through the transfer of energy and nutrients, beginning with an autotrophic organism such as a plant and continuing with each organism being consumed by one higher in the chain.

Trophic state: The trophic state is defined as the total weight of biomass in a given water body at the time of measurement.

Turbidity: A measure of the optical properties of water that may be influenced by both dissolved and solid constituents.


Unconfined aquifer: An unconfined aquifer is covered by soil and permeable rock and can receive water from the land surface directly above. This water is young and hydrologically connected to the surface water network.

Unitary authority: A local authority which is responsible for all local government functions within its area.

Unsafe to drink: Contaminants may make water unsafe for humans or animals to drink. For example, too much E. coli means that the water is unsafe to drink or swim in and can cause gastroenteritis, or infections of ears, eyes etc. Nitrate is one of the most common groundwater contaminants in rural areas and high concentrations can also make water unsafe to drink.

Upstream: In the opposite direction from which a stream or river flows. Nearer to the source of the stream.

Urbanisation: Urbanisation refers to the population shift from rural to urban areas.

Useful indicator: A substance that indicates the presence or concentration of a certain constituent. For example, E. coli is used as an indicator species for the presence of more harmful bacteria due to its comparative ease to detect and quantify.


Vegetated buffer: Buffers and filter strips are areas of permanent vegetation located within and between agricultural fields and the water courses to which they drain. These buffers are intended to intercept and slow runoff thereby providing water quality benefits.

Vegetation clearance: The disturbance, cutting, burning, clearing, damaging or removal of vegetation which may cause contaminants to enter a waterway.

Virus: An infective agent that typically consists of a nucleic acid molecule in a protein coat. It is too small to be seen by light microscopy and is able to multiply only within the living cells of a host causing illness.

Visual clarity: The state or quality of being clear to the eye. E.g. the clarity of water.

Volatile Suspended Sediment: Volatile suspended solids (VSS)¬†is a¬†water quality¬†measure obtained from the¬†loss on ignition¬†of the mass of measured¬†total suspended solids.¬†This ignition generally takes place in an oven at a temperature of 550¬†¬įC¬†to 600¬†¬įC. It represents the amount of¬†volatile¬†matter present in the solid fraction of the measured solution.


Wai tapu: Sacred water.

Wastewater: Wastewater is any water that has been affected by human use. Wastewater is used water from any combination of domestic, industrial, commercial or agricultural activities and any sewer inflow or sewer infiltration.

Wastewater discharge: Wastewater - treated or untreated - that flows out of a treatment plant, sewer, or industrial outfall. Generally refers to wastes discharged into surface waters. Effluent only refers to liquid discharge.

Water clarity: Water clarity refers to the ability of light to travel through water and has two important aspects, light penetration and visual clarity.

Water quality: Water quality refers to the chemical, physical, biological, and radiological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species or to any human need.

Water quality guidelines: These are guidelines set by local councils or central government to provide land use managers with tools and guidance to assess, manage and monitor their water quality.

Water sample: A water sample is a portion of water taken for analysis or other testing, e.g. drinking water to check that it complies with relevant water quality standards, or river water to check for pollutants.

Water table: The top of the water level in an aquifer is called the water table. A water table describes the boundary between water-saturated ground and unsaturated ground. Below the water table, rocks and soil are full of water.

Water-bearing rock: Rock containing water-filled pore spaces, which, when the spaces are connected, the water is able to flow through the matrix of the rock.

Water-saturated ground: Ground where easily drained spaces between soil particles are temporarily or permanently filled with water.

Waterway: A river, stream, channel or other route for water to travel

Weathered rock: Rock which is breaking down as a result of contact with the earth's atmosphere, water, and biological organisms.

Weathering: Weathering is the breaking down of rocks, soil, and minerals through contact with the earth's atmosphere, water, and biological organisms.

Well drained soils: Well-drained soil refers to soil which allows water to drain through it reasonably quickly and not pool on the surface.

Wells: A well is a hole in the ground, held open by a pipe or casing that extends to an aquifer.

Wetland: A wetland is a distinct ecosystem that is flooded by water, either permanently or seasonally, where oxygen-free processes prevail. Wetlands play a number of functions, including water purification, water storage, processing of carbon and other nutrients, stabilization of shorelines, and support of plants and animals. Wetlands are also considered the most biologically diverse of all ecosystems, hosting a wide range of plant and animal life. Common names for wetlands include marshes, estuaries, mangroves, mudflats, mires, ponds, fens, swamps, deltas, billabongs, lagoons, bogs, lakes, and floodplains.