Great Lakes Surface Water (GLSW) - the Great Lakes, their connecting channels (the St. Clair River, the Detroit River, the Niagara River and the St. Mary's River), and the St. Lawrence River 

Other Surface Water (OSW) - tributary streams, lakes, ponds, and reservoirs within the Great Lakes Basin 

Groundwater (GW) - all subsurface water distinct from surface water 

Withdrawal Amount - The amount of water removed or taken from surface or groundwater. 

Intrabasin Diversion - The amount of water transferred from the watershed of one of the Great Lakes into that of another. 

Interbasin Diversion - The amount of water transferred from the Great Lakes Basin into another watershed. 

Consumptive Use - That portion of water withdrawn or withheld from the Great Lakes Basin and assumed to be lost or otherwise not returned to the Great Lakes Basin due to evapotranspiration, incorporation into products, or other processes. 

Principal Facilities - Facilities withdrawing (or consuming) in excess of the Great Lakes Charter uniform trigger level of 100,000 U.S. gallons/day (380,000 liters/day) average over a 30-day period. A principal facility is determined by the total withdrawal (or consumption) of all sources combined (Great Lakes surface water, other surface water, and groundwater) rather than a single source. The combined withdrawals (or consumption) of separate wells or operations undertaken by the same facility or company will be evaluated separately for the purpose of determining principal facility status unless those operations are covered under the same registration (or permit) or are physically contiguous. Principal facilities are a subset of all facilities in the Database. Therefore, when viewing the reports generated by the Database, the withdrawal amount for principal facilities must always be equal to or less than the amount for all facilities for any summary report. This is true except for diversions. Here, principal facility amounts may be greater than all facilities due to the fact that the Database sums outgoing and incoming diversion amounts. If the number and amount of incoming diversions (shown as a negative number) is greater for all facilities than for principal facilities, the summary table may show a greater amount for the principal facilities. 

Water Use Categories 

Public Water Supply - Water withdrawn for all uses by public and private water suppliers and delivered to users that do not supply their own water. (Water suppliers provide water for a variety of uses such as residential, commercial, industrial, and public water use.) 

Self-Supply - Domestic: (residential, commercial, institutional): Water used for normal household purposes. Also referred to as residential water use, this category includes water used for drinking, food preparation, bathing, washing clothes and dishes, flushing toilets, and watering lawns. Commercial uses include water used by motels, hotels, restaurants, office buildings and institutions, both civilian and military. This category also includes water for mobile homes, hospitals, schools, fire fighting, air conditioning and other similar uses not covered under a public supply. In addition, this category includes amusement and recreational water uses such as snowmaking and water slides. The coefficient for domestic per capita water use is 75 gallons a day (U.S.) unless otherwise indicated by the reporting state or province. 

Self-Supply - Irrigation: Water artificially applied on lands to assist in the growing of crops and pastures or in the maintenance of recreational lands, such as parks and golf courses. 

Self-Supply - Livestock: Water used by horses, cattle, sheep, goats, hogs, poultry, and other commercially important animals. Water used in fish hatchery operations are also included under this category. 

Self-Supply - Industrial (manufacturing and mining): Industrial water includes water used in the manufacture of metals, chemicals, paper, and allied products. Mining water use includes water used in the extraction or washing of minerals; for example solids, such as coal and ores, and liquids such as crude petroleum and natural gas. Water used in quarrying and milling is also included in the industrial category. Brine extraction from oil and gas operations is not included. Withdrawals and consumptive uses for industrial and mining purposes (including dewatering operations) recorded under another category (e.g., public supply) will not be recorded here. Water uses in a closed cycle (recirculation) will not be reported as a withdrawal. Other situations should be evaluated on a case-by-case basis. 

Self-Supply - Thermoelectric Power (fossil fuel plants): Water used by plants fueled by fossil fuels such as coal, oil or natural gas. Withdrawals and consumptive uses already recorded under another category (e.g., public supply) will not be reported here. 

Self-Supply - Thermoelectric Power (nuclear plants): Water used by plants fueled by nuclear generation. Withdrawals and consumptive uses already recorded under another category (e.g., public supply) will not be reported here. 

Self-Supply - Hydroelectric Power: Water used to drive turbines that generate electric power. This category includes both "instream use" where water is used on a once-through basis and "offstream use" where water is recycled through pumped-storage systems. Neither use is considered a consumptive use. 

Other - Water used for purposes not reported in categories one through nine. Examples include, but are not limited to, withdrawals for fish/wildlife, environmental, recreation, navigation, and water quality purposes. Specifically, water used to maintain levels for navigation, for recreation, for fish and wildlife habitat creation and enhancement (excluding fish hatchery operations included under Category 5), for flow augmentation (or diversion), for sanitation, pollution confinement, and other water quality purposes and agricultural activities (services) other than those directly related to irrigation such as field drainage are included. Water used in temporary or immediate emergency situations (e.g., fighting forest or peat fires) is also reported here. 

Data Accuracy 

Partially Measured - Data reflects partially (great than 50 %) measured withdrawal amount. 

Calculated/Estimated - Data reflects calculated or estimated withdrawal amount. 

Measured - Data reflects measured withdrawal amount.