| #D001 | | Acre-foot (acre-ft) | a common measure in agricultural irrigation which represents the volume of water required to cover 1 acre of land (43,560 square feet) to a depth of 1 foot. Equal to 325,851 gallons or 1,233 cubic metres. | high |
| #D002 | | Adaptive Management | A systematic process for continually improving management policies and practices by learning from the outcomes of previously employed policies and practices. In active adaptive management, management is treated as a deliberate experiment for the purpose of learning. Management is flexible but within the context of a governance framework and vision within which it operates and to which decisions are cross-referenced. Management informs governance and vice versa over time. | high |
| #D003 | | Adjudication | conflict resolution via a litigation process drawing on the court system to provide a binding ruling based on the interpretation of law. | high |
| #D004 | | Alluvium | deposits of clay, silt, sand, gravel, or other particulate material that has been deposited by a stream or other body of running water in a streambed, on a flood plain, on a delta, or at the base of a mountain. | high |
| #D005 | | Approach | a way of dealing with, for the purposes of this study, managing water resources management including policy, program and science aspects. For the purposes of a water quantity assessment, an approach means specifically a strategy or framework for the application of a water resources assessment that includes, but not limited to, defining objectives, data collection, analyses, tools and models, implementation, monitoring and adaptation. | high |
| #D006 | | Aquifer | A geological formation or structure that stores and/or transmits water, such as to wells and springs. Use of the term is usually restricted to those water-bearing formations ly for people's uses. Or in Ontario 'Aquifer means a water-bearing formation that is capable of transmitting water in sufficient quantities to serve as a source of water supply' (R.R.O. 1990, Reg. 903: WELLS under Ontario Water Resources Act, R.S.O. 1990, c. O.40). | high |
| #D007 | | Aquifer (confined) | soil or rock below the land surface that is saturated with water. There are layers of impermeable material both above and below the aquifer. It is under pressure so that when the aquifer is penetrated by a well, the water will rise above the top of the aquifer. | high |
| #D008 | | Aquifer (unconfined) | an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall. | high |
| #D009 | | Arbitration | a form of conflict resolution where a neutral party or panel meeting with parties in a dispute to hear presentations and makes an award based on predefined rules and procedures | high |
| #D010 | | Artesian water | groundwater that is under pressure and is able to rise above the level at which it is first encountered when tapped by a well. It may or may not flow out at ground level. The pressure in such an aquifer commonly is called artesian pressure, and the formation containing artesian water is an artesian aquifer or confined aquifer. See Flowing well . | high |
| #D011 | | Artificial recharge | a process where water is put back into groundwater storage from surfacewater supplies such as irrigation, or induced infiltration from streams or wells. | high |
| #D012 | | Average Annual Flow Map | the map entitled 'Water Use - Average Annual Flow Conditions', dated November, 2004 and on file in the offices of the Ministry of the Environment and Climate Change at Toronto and available on the Government of Ontario website. | high |
| #D013 | | Base flow | sustained flow of a stream in the absence of direct runoff. It includes natural and human-induced stream flows. Natural base flow is sustained largely by groundwater discharge. | high |
| #D014 | | Bedrock | the solid rock beneath the soil and superficial rock. A general term for solid rock that lies beneath soil, loose sediments, or other unconsolidated material. | high |
| #D015 | | Best Available Science | information available on a topic that has been determined to be the best to be used to make informed science-based decisions or recommendations. | high |
| #D016 | | Best Science | for the purposes of this study, best available science includes the best approaches and tools available to do water quantity management science in the literature and Ontario / Jurisdictional practice under a variety of conditions. | high |
| #D017 | | Best Practices | are the practices and approaches being used for water management science in Ontario and other jurisdictions under a variety of conditions that are effective and efficient and produce reasonable results. | high |
| #D018 | | Bottled water | potable water that is intended for human consumption and that is packaged in bottles or other portable containers. | high |
| #D019 | | Capillary action | the means by which liquid moves through the porous spaces in a solid, such as soil, plant roots, and the capillary blood vessels in our bodies due to the forces of adhesion, cohesion, and surface tension. Capillary action is essential in carrying substances and nutrients from one place to another in plants and animals. | high |
| #D020 | | Co-management | a process of management in which government shares authority with resource users, with each given specific rights and responsibilities relating to information and decision-making. | high |
| #D021 | | Condensation | the process of water vapor in the air turning into liquid water. Water drops on the outside of a cold glass of water are condensed water. Condensation is the opposite process of evaporation. | high |
| #D022 | | Considerations / Conditions | for the purpose of this study means the range of Ontario conditions that need to be considered in reviewing and making recommendations on Ontario's water quantity management framework including policy, program and science. | high |
| #D023 | | Conflict Resolution | the management of disputes. | high |
| #D024 | | Consumptive use | that part of water withdrawn that is evaporated, transpired by plants, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. Also referred to as water consumed. | high |
| #D025 | | Conveyance loss | water that is lost in transit from a pipe, canal, or ditch by leakage or evaporation. Generally, the water is not available for further use; however, leakage from an irrigation ditch, for example, may percolate to a groundwater source and be available for further use. | high |
| #D026 | | Cumulative Effects/Impacts | changes to surface water or groundwater resources that are caused or altered by an action in combination with other human or natural actions or conditions. In the context of the Assessment of Water Resources to Support a Review of Ontario's Water Quantity Management Framework (2018), Cumulative Effects include not only consideration of the changes to surface water and groundwater caused by multiple takings of surface or groundwater, but also considers the effects of climate change, population growth and related land use changes. In comparison, Cumulative Impacts only considers changes to surface water or groundwater resources that are caused or altered by multiple takings of surface or groundwater and their impact on other human or natural features. | high |
| #D027 | | Desalination | the removal of salts from saline water to provide freshwater. This method is becoming a more popular way of providing freshwater to populations. | high |
| #D028 | | Discharge | the volume of water that passes a given location within a given period of time. Usually expressed as volume over time (m 3 /s). | high |
| #D029 | | Drainage basin | land area where precipitation runs off into streams, rivers, lakes, and reservoirs. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Large drainage basins, like the area that drains into the Grand River contain smaller drainage basins or sub-watersheds. See Watershed . | high |
| #D030 | | Drawdown | a lowering of the groundwater surface caused by pumping. | high |
| #D031 | | Drip irrigation | an irrigation method where pipes or tubes filled with water slowly drip onto crops. Drip irrigation is a low-pressure method of irrigation and less water is lost to evaporation than high-pressure spray irrigation. | high |
| #D032 | | Drought | a period of below-average precipitation in a given region, resulting in prolonged shortages in the water supply, whether atmospheric, surface water or ground water. What officially constitutes drought differs from jurisdiction to jurisdiction. | high |
| #D033 | | Ecosystem-based management | an integrated management approach that recognizes the full array of interactions within an ecosystem, including humans, rather than considering single issues, species, or ecosystem services in isolation. | high |
| #D034 | | Environmental Setting | the milieu or aggregate of the surroundings including climate, diversity, geographic variability, watershed characteristics, geological and hydrogeological variability and aquifer types. | high |
| #D035 | | Evaporation | the process of liquid water becoming water vapor, including vaporization from water surfaces, land surfaces, and snow fields, but not from leaf surfaces. See Transpiration . | high |
| #D036 | | Evapotranspiration | the sum of evaporation and transpiration. | high |
| #D037 | | Evidence-based decision making means | using the best available research, analytics, information and data supported by clear standards to guide decisions on policy and program development, delivery and evaluation process. | high |
| #D038 | | Environmental Flow Needs | the flows (quantity and timing) and water levels required in a water body to sustain freshwater ecosystems and the ecological function of the flora and fauna present within that water body and its margins. | high |
| #D039 | | Flood | an overflow of water onto lands that are used or usable by man and not normally covered by water. Floods have two essential characteristics: The inundation of land is temporary; and the land is adjacent to and inundated by overflow from a river, stream, lake, or ocean. | high |
| #D040 | | Flood, 100-year | a 100-year flood does not refer to a flood that occurs once every 100 years, but to a flood level with a 1 percent chance of being equaled or exceeded in any given year. | high |
| #D041 | | Flood plain | a strip of relatively flat and normally dry land alongside a stream, river, or lake that is covered by water during a flood. In Ontario, Under the Conservation Act, each Conservation Authority (CA) prescribes how it is determined. The Regulations for each CA use the Regulatory Flood Event Standard and the 100-year flood level plus wave uprush. The Regulatory Flood Event is a historic event of maximum flooding such as Hurricane Hazel for the Toronto area. Different CAs have different Regulatory Flood Events. | high |
| #D042 | | Flood stage | the elevation at which overflow of the natural banks of a stream or body of water begins in the reach or area in which the elevation is measured. | high |
| #D043 | | Floodway | the channel of a river or stream and the parts of the floodplain adjoining the channel that are reasonably required to efficiently carry and discharge the flood water or flood flow of a river or stream. | high |
| #D044 | | Flowing well/spring | a well or spring that taps groundwater under pressure so that water rises above ground surface without pumping. See Artesian water. | high |
| #D045 | | Freshwater | water that contains less than 1,000 milligrams per liter (mg/L) of dissolved solids; generally, more than 500 mg/L of dissolved solids is undesirable for drinking and many industrial uses. | high |
| #D046 | | Gauge height | the height of the water surface above the gage datum (zero point). Gage height is often used interchangeably with the more general term, stage, although gage height is more appropriate when used with a gage reading. | high |
| #D047 | | Gauging station | a site on a stream, lake, reservoir or other body of water where observations and hydrologic data are obtained. | high |
| #D048 | | Groundwater | (1) water that flows or seeps downward and saturates soil or rock, supplying springs and wells. The upper surface of the saturated zone at atmospheric pressure is called the water table. (2) Water stored underground in rock crevices and in the pores of geologic materials that make up the Earth's crust. | high |
| #D049 | | Groundwater, confined | groundwater under pressure significantly greater than atmospheric, with its upper limit corresponding to the bottom of a bed with hydraulic conductivity distinctly lower than that of the material in which the confined water occurs. | high |
| #D050 | | Groundwater recharge | inflow of water to a groundwater reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural recharge. Also used to define the volume of water added by this process. Alternatively, 'groundwater recharge' means the replenishment of subsurface water, (a) resulting from natural processes, such as the infiltration of rainfall and snowmelt and the seepage of surface water from lakes, streams and wetlands, and (b) resulting from human intervention, such as the use of stormwater management systems (O. Reg. 140/02: OAK RIDGES MORAINE CONSERVATION PLAN under Oak Ridges Moraine Conservation Act, 2001, S.O. 2001, c. 31) | high |
| #D051 | | Groundwater, unconfined | water in an aquifer that has a water table that is exposed to the atmosphere. | high |
| #D052 | | Headwater(s) | (1) the source and upper reaches of a stream; also the upper reaches of a reservoir. (2) the water upstream from a structure or point on a stream. (3) the small streams that come together to form a river. Also may be thought of as any and all parts of a river basin except the mainstream river and main tributaries. | high |
| #D053 | | High Use Watershed | the areas shown on the Average Annual Flow Map or the Summer Low Flow Map in Ontario Regulation 387/04 (Water Taking and Transfer). | high |
| #D054 | | Hydrologic cycle | the cyclic transfer of water vapor from the Earth's surface via evapotranspiration into the atmosphere, from the atmosphere via precipitation back to the Earth's surface where it either enters the subsurface through infiltration, evaporates into the atmosphere or becomes runoff that flows into streams, rivers, and lakes, and ultimately into the oceans. See Water Cycle . | high |
| #D055 | | Impermeable layer | a layer of solid material, such as rock or clay, which does not allow water to pass through. | high |
| #D056 | | Infiltration | flow of water from the land surface into the subsurface. | high |
| #D057 | | Injection well | refers to a well-constructed for the purpose of injecting treated water directly into the ground. Water is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. | high |
| #D058 | | Instream flow | the amount of water needed in a stream to adequately provide for downstream uses occurring within the stream channel. Instream uses may include some or all of the following: aquatic habitat, recreation, wetlands maintenance, navigation, hydropower, riparian vegetation, and water quality. | high |
| #D059 | | Integrated water resources management (IWRM) | a systematic process for the sustainable development, allocation and monitoring of water resource use in the context of social, economic and environmental objectives. IWRM is based on the understanding that all the different uses of finite water resources are interdependent. | high |
| #D060 | | Irrigation | the controlled application of water for agricultural purposes through manmade systems to supply water requirements not satisfied by rainfall. | high |
| #D061 | | Irrigation water use | water application on lands to assist in the growing of crops and pastures or to maintain vegetative growth in recreational lands, such as parks and golf courses. | high |
| #D062 | | Lotic waters | flowing waters, as in streams and rivers. | high |
| #D063 | | Mediation | a form of conflict resolution that uses a use of a neutral mediator who oversees negotiation between two parties. | high |
| #D064 | | Method(s) | a procedure, technique or routine. | high |
| #D065 | | Negotiation | a form of conflict resolution that involves the presentation of interests and working toward solutions within an acceptable settlement range among involved parties. | high |
| #D066 | | Ontario Water Managers or 'Water Managers | any person responsible for the regulation, planning, development and distribution and use of water resources. | high |
| #D067 | | Peak flow | the maximum instantaneous discharge of a stream or river at a given location. It usually occurs at or near the time of maximum stage. | high |
| #D068 | | Percolation | (1) The movement of water through the openings in rock or soil. (2) the entrance of a portion of the streamflow into the channel materials to contribute to groundwater replenishment. | high |
| #D069 | | Permeability | the ability of a material to allow the passage of a liquid, such as water through rocks. Permeable materials, such as gravel and sand, allow water to move quickly through them, whereas impermeable materials, such as clay, do not allow water to flow freely. | high |
| #D070 | | Porosity | a measure of the water-bearing capacity of subsurface rock or unconsolidated overburden materials. With respect to water movement, it is not just the total magnitude of porosity that is important, but the size of the voids and the extent to which they are interconnected (effective porosity), as the pores in a formation may be open, or interconnected, or closed and isolated. For example, clay may have a very high porosity with respect to potential water content, but it constitutes a poor medium as an aquifer because the pores are usually so small. | high |
| #D071 | | Potable water | water of a quality suitable for drinking that at a minimum meets the requirements of the prescribed drinking water quality standards; or in Ontario, 'Despite any other Act, a requirement that water be 'potable' in any Act, regulation, order or other document issued under the authority of any Act or in a municipal by-law shall be deemed to be a requirement to meet, at a minimum, the requirements of the prescribed drinking water quality standards' (Safe Drinking Water Act, 2002, c. 32, s. 10.' | high |
| #D072 | | Potentiometric surface/piezometric surface | the imaginary line where a given reservoir of fluid under pressure would rise if allowed to flow, for example if penetrated by wells; a potentiometric surface is based on hydraulic principles. | high |
| #D073 | | Precipitation | rain, snow, hail, sleet, dew, and frost. | high |
| #D074 | | Prior appropriation doctrine | the system for allocating water to private individuals used in most Western states. The prior appropriation system evolved in the western United States so that people could divert water for use on land that does not abut a water course. The doctrine was in common use throughout the arid west as early settlers and miners began to develop the land. The prior appropriation doctrine is based on the concept of "First in Time, First in Right." The first person to take a quantity of water and put it to Beneficial Use has a higher priority of right than a subsequent user. Under drought conditions, higher priority users are satisfied before junior users receive water. Appropriative rights can be lost through non-use; they can also be sold or transferred apart from the land. Appropriation rights are considered to be property rights and continue to exist as long as water continues to be used for beneficial purposes. Contrasts with Riparian Water Rights . | high |
| #D075 | | Prior Allocation | A prior allocation system is a government-controlled system where water rights are issued to individual users for specific volumes and purposes. Western Canadian provinces generally employ prior allocation systems where priority among users is also based on first in time, first in right, with seniority based on the date of application. | high |
| #D076 | | Priority of water use | a hierarchy of water users and the resulting prioritization of use. | high |
| #D077 | | PTTW | a permit-to-take-water under the Ontario Water Resources Act . | high |
| #D078 | | Rating curve | a drawn curve showing the relation between gauge height and discharge of a stream at a given gaging station. | high |
| #D079 | | Recharge | water added to an aquifer. For instance, rainfall that seeps into the ground. | high |
| #D080 | | Reclaimed wastewater | wastewater-treatment plant effluent that has been diverted for beneficial uses such as irrigation, industry, or thermoelectric cooling instead of being released to a natural waterway or aquifer. | high |
| #D081 | | Recycled water | water that is used more than one time before it passes back into the natural hydrologic system. | high |
| #D082 | | Reservoir | a pond, lake, or basin, either natural or artificial, for the storage, regulation, and control of water. | high |
| #D083 | | Return flow | (1) That part of a diverted flow that is not consumptively used and returned to its original source or another body of water. (2) (Irrigation) Drainage water from irrigated farmlands that re-enters the water system to be used further downstream. | high |
| #D084 | | Return flow (irrigation) | irrigation water that is applied to an area and which is not consumed in evaporation or transpiration and returns to a surface stream or aquifer. | high |
| #D085 | | Riparian water rights | the rights of an owner whose land abuts water. A riparian owner or occupier is a person whose land abuts the shore of a natural water course or water body and, under common law, they can take water for domestic and other purposes as long as their water use does not impair the rights of other riparian owners. Riparian rights differ between jurisdictions within Canada and in the United States from state to state and often depend on whether the water is a river, lake, or ocean. Riparian systems are typically employed in the eastern part of North America and are used in Ontario, Tennessee and North Carolina. Specifically, persons who own land adjacent to a stream have the right to make reasonable use of the stream. Shortages are expected to be shared among all users. Riparian users of a stream share the streamflow among themselves, and the concept of priority of use (Prior Appropriation Doctrine) is not applicable. Riparian rights cannot be sold or transferred for use on nonriparian land. | high |
| #D086 | | River | a natural stream of water of considerable volume, larger than a brook or creek. | high |
| #D087 | | Runoff | (1) That part of the precipitation, snow melt, or irrigation water that appears in uncontrolled surface streams, rivers, drains or sewers. Runoff may be classified according to speed of appearance after rainfall or melting snow as direct runoff or base runoff, and according to source as surface runoff, storm interflow, or groundwater runoff. (2) The total discharge described in (1), above, during a specified period of time. (3) Also defined as the depth to which a drainage area would be covered if all of the runoff for a given period of time were uniformly distributed over it. | high |
| #D088 | | Science | the body of knowledge, methodologies and tools used to understand, communicate, manage and support regulation of Water Resources, including work characterization, monitoring, data management, mapping, assessment and tools to manage these. | high |
| #D089 | | Setting | the physical, chemical and biological environment ((such as climate, geology, soil, and plants and animals living in or on the water) in which a resource is situated and which determine its characteristics and behaviour. | high |
| #D090 | | Source Water Protection Authority | A conservation authority or other person or body that is required to exercise and perform the powers and duties of a drinking water source protection authority under the Ontario Clean Water Act. | high |
| #D091 | | Spring | a water body formed when the side of a hill, a valley bottom or other excavation intersects a flowing body of groundwater at or below the local water table, below which the subsurface material is saturated with water. | high |
| #D092 | | Stakeholders | people who have a share or an interest in water. | high |
| #D093 | | Stream | a general term for a body of flowing water; natural water course containing water at least part of the year. In hydrology, it is generally applied to the water flowing in a natural channel as distinct from a canal. | high |
| #D094 | | Streamflow | the water discharge that occurs in a natural channel. A more general term than runoff, streamflow may be applied to discharge whether or not it is affected by diversion or regulation. | high |
| #D095 | | Summer Low Flow Map | the map entitled 'Water Use - Summer Low Flow Conditions', dated November, 2004 and on file in the offices of the Ministry of the Environment and Climate Change at Toronto and available on the Government of Ontario website; | high |
| #D096 | | Surface water | water that is on the Earth's surface, such as in a stream, river, lake, or reservoir. | high |
| #D097 | | Sustainability | development that meets the needs of the present, without compromising the ability of future generations to meet their own needs. There are three spheres of sustainability: the economy, society and the environment. They have a dynamic relationship, which means that any change to one affects the others. It is the reason why we cannot consider our economy or quality of life separately from the well- being of our natural environment. | high |
| #D098 | | Tool | a process, method or computer program / routine used in the implementation of an 'approach' as defined for the purposes of this project. For the purposes of this study a tool does not include a physical device or physical implement. | high |
| #D099 | | Transmissivity (T) | the rate at which groundwater is transmitted through a unit width of an aquifer under a unit hydraulic gradient. It is often expressed as the product of hydraulic conductivity and the full saturated thickness of the aquifer and has units of the form m 3 /day/m. | high |
| #D100 | | Transpiration | process by which water that is absorbed by plants, usually through the roots, is evaporated into the atmosphere from the plant surface, such as leaf pores. See Evapotranspiration . | high |
| #D101 | | Tributary | a smaller river or stream that flows into a larger river or stream. Usually, a number of smaller tributaries merge to form a river. | high |
| #D102 | | Water bottling facility | any facility that requires a permit for taking ground water for the purpose of producing bottled water. | high |
| #D103 | | Water Bottling Study Area and WBSA | each of the 11 areas that are being assessed as part of the Assessment of Water Resources to Support a Review of Ontario's Water Quantity Management Framework (2018). | high |
| #D104 | | Water Cycle | the circuit of water movement from the oceans to the atmosphere and to the Earth and return to the atmosphere through various stages or processes such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transportation. See Hydrologic Cycle . | high |
| #D105 | | Water Quantity Assessment | the determination of the sources, extent, dependability and quality of water resources for their utilization and control. Water resources in turn can be defined as the water available, or capable of being made available, for use in sufficient quantity and quality at a location and over a period of time appropriate for an identifiable demand. | high |
| #D106 | | Water Quantity Management Framework | policies, programs and science, information including data collection and assessment tools, used in the management of water use. | high |
| #D107 | | Water Quantity Protection External Working Group | an external working group established by the Ministry to provide an open and collaborative forum to share expertise and provide input to strengthen groundwater and surface water quantity protection as part of Ontario's strategy to better protect water in the province. | high |
| #D108 | | Water Quantity Study Area and WQSA | an area being assessed as part of the Assessment of Water Resources to Support a Review of Ontario's Water Quantity Management Framework (2018). | high |
| #D109 | | Water Resources | any groundwater and surface water source that supplies water to the natural environment and that are useful or potentially useful to study. In the context of the Assessment of Water Resources to Support a Review of Ontario's Water Quantity Management Framework (2018), the Great Lakes are not included in the Water Resources being addressed and the focus is on water resources quantity. | high |
| #D110 | | Water Security | the capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for sustaining livelihoods, human well-being, and socioeconomic development, for ensuring protection against water- borne pollution and waterrelated disasters, and for preserving ecosystems in a climate of peace and political stability. (UN-Water, 2013) | high |
| #D111 | | Water table | the top of the water surface in the saturated part of an aquifer that is at atmospheric pressure, also referenced as an unconfined aquifer. | high |
| #D112 | | Water year | continuous 12-month period selected to present data relative to hydrologic or meteorological phenomena during which a complete annual hydrologic cycle normally occurs. The water year used by the U.S. Geological Survey runs from October 1 through September 30, and is designated by the year in which it ends. | high |
| #D113 | | Watershed | land area where precipitation runs off into streams, rivers, lakes, and reservoirs. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Large drainage basins, like the area that drains into the Grand River, contain smaller drainage basins or sub-watersheds. See Drainage basin . | high |
| #D114 | | MECP | Ministry of the Environment, Conservation and Parks | high |
| #D115 | | Evidence-based decision making | using the best available research, analytics, information and data supported by clear standards to guide decisions on policy and program development, delivery and evaluation process. | high |
| #D116 | | Ontario Water Managers or 'Water Managers' | any person responsible for the regulation, planning, development and distribution and use of water resources. | high |