A commonly used measure of water for the purposes of reservoirs and large-scale water use. One acre-foot is equal to one acre of water at a depth of one foot. In other words, one acre-foot equals 325,851 gallons of water, roughly half the size of an Olympic swimming pool.
Geologic formation that contains sufficient saturated permeable material to yield significant quantities of groundwater to wells and springs. The formation could be sand, gravel, limestone, sandstone or fractured igneous rocks.
Aquifer Storage and Recovery:
Aquifer storage and recovery (ASR) is the storage of water in a suitable aquifer through a well during times when water is available, and the recovery of water from the same aquifer during times when it is needed.
Maximum amount of raw water that could be produced by a source during a repeat of the Drought of Record, regardless of whether the supply is physically connected to or legally accessible by Water User Groups.
Best Management Practice (BMP):
Best Management Practices are a menu of options for which entities within a water use sector can choose to implement in order to achieve benchmarks and goals through water conservation. Best management practices are voluntary efficiency measures that are intended to save a quantifiable amount of water, either directly or indirectly, and can be implemented within a specified timeframe.
The process of removing salt from seawater or brackish water.
Desired Future Condition (DFC):
Criteria which is used to define the amount of available groundwater from an aquifer.
Drought of Record:
The period of time when historical records indicate that natural hydrological conditions would have provided the least amount of water supply.In the case of Texas, the generally accepted drought of record is the drought of 1950 to 1957.
Liquid waste or sewage discharged into a river or sea.
Existing Water Supply:
Maximum amount of water that is physically and legally accessible from existing sources for immediate use by a Water User Group under a repeat of Drought of Record conditions.
Maximum water volume a reservoir can provide each year under a repeat of the Drought of Record using anticipated sedimentation rates and assuming that all senior water rights will be totally utilized and all applicable permit conditions met.
Gallons Per Capita Per Day:
For Regional Water Planning purposes, Gallons Per Capita Per Day is the annual volume of water pumped, diverted, or purchased minus the volume exported (sold) to other water systems or large industrial facilities divided by 365 and divided by the permanent resident population of the Municipal Water User Group in the regional water planning process. Coastal saline and reused/recycled water is not included in this volume.
Water located beneath the ground’s surface in soil pore spaces and in the fractures of rock formations, including water found in underground aquifers.
Groundwater Availability Model (GAM):
Numerical groundwater flow model. GAMs are used to determine the aquifer response to pumping scenarios. These are the preferred models to assess groundwater availability.
Groundwater Conservation District (GCD):
Generic term for all or individual state recognized Districts that oversee the groundwater resources within a specified political boundary.
Groundwater Management Area (GMA):
Sixteen GMAs in Texas. Tasked by the Legislature to define the desired future conditions for major and minor aquifers within the GMA.
Initially Prepared Plan (IPP):
Draft Regional Water Plan that is presented at a public hearing in accordance with §357.21(h) of this title (relating to Notice and Public Participation) and submitted for Board review and comment.
Water flow and water quality regime adequate to maintain an ecologically sound environment in streams and rivers.
Interbasin Transfer of Surface Water:
Defined and governed in Texas Water Code §11.085 (relating to Interbasin Transfers) as the diverting of any state water from a river basin and transfer of that water to any other river basin.
An interregional conflict exists when:
- (A) more than one Regional Water Plan includes the same source of water supply for identified and quantified recommended Water Management Strategies and there is insufficient water available to implement such Water Management Strategies; or
- (B) in the instance of a recommended Water Management Strategy proposed to be supplied from a different Regional Water Planning Area, the Regional Water Planning Group with the location of the strategy has studied the impacts of the recommended Water Management Strategy on its economic, agricultural, and natural resources, and demonstrates to the Board that there is a potential for a substantial adverse effect on the region as a result of those impacts.
A conflict between two or more identified, quantified, and recommended Water Management Strategies in the same Initially Prepared Plan that rely upon the same water source, so that there is not sufficient water available to fully implement all Water Management Strategies and thereby creating an over-allocation of that source.
Major Water Provider:
A Water User Group or Wholesale Water Provider of particular significance to the region’s water supply as determined by the Regional Water Planning Group. This may include public or private entities that provide water for any water use category.
Modeled Available Groundwater (MAG):
The MAG is the amount of groundwater that can be permitted by a GCD on an annual basis. It is determined by the TWDB based on the DFC approved by the GMA. Once the MAG is established, this value must be used as the available groundwater in regional water planning.
Modeled Available Groundwater (MAG) Peak Factor:
A percentage (e.g., greater than 100 percent) that is applied to a modeled available groundwater value reflecting the annual groundwater availability that, for planning purposes, shall be considered temporarily available for pumping consistent with desired future conditions. The approval of a MAG Peak Factor is not intended as a limit to permits or as guaranteed approval or pre-approval of any future permit application.
Palmer Drought Severity Index:
A measure of dryness based on precipitation, temperature, soil moisture and other factors.
Regional Water Planning Group (RWPG):
The generic term for the planning groups that oversee the regional water plan development in each respective region in the State of Texas.
Reuse (direct and indirect):
- Direct Reuse: A process by which wastewater is cycled back into the water treatment process and made safe for use by introduction into a treatment facility directly.
- Indirect Reuse: A process by which wastewater discharged into a groundwater or surface body of water, and taken back into the water treatment process and made safe for use.
Senate Bill 1:
Legislation passed by the 75th Texas Legislature that is the basis for the current regional water planning process.
a body of water that is found above surface level, such as a lake or pond.
Documentation of the RWPG’s preliminary analysis of Water Demand projections, water Availability, Existing Water Supplies, and Water Needs and declaration of the RWPG’s intent of whether or not to pursue simplified planning.
Texas Commission on Environmental Quality (TCEQ):
Agency charged with oversight of Texas surface water rights and WAM program.
Texas Water Development Board (TWDB):
Texas Agency charged with oversight of regional water plan development and oversight of GCDs.
Total Dissolved Solids (TDS):
A measure of the combined total organic and inorganic substances contained in the water.
Total Maximum Daily Load (TMDL):
A Total Maximum Daily Load is a regulatory term in the U.S. Clean Water Act, describing a plan for restoring impaired waters that identifies the maximum amount of a pollutant that a body of water can receive while still meeting water quality standards.
Unmet Water Need:
The portion of an identified Water Need that is not met by recommended Water Management Strategies.
Water Availability Model (WAM):
Computer model of a river watershed that evaluates surface water availability based on Texas water rights.
Water Conservation Measures:
Practices, techniques, programs, and technologies that will protect water resources, reduce the consumption of water, reduce the loss or waste of water, or improve the efficiency in the use of water that may be presented as Water Management Strategies, so that a water supply is made available for future or alternative uses. For planning purposes, Water Conservation Measures do not include reservoirs, aquifer storage and recovery, or other types of projects that develop new water supplies.
Volume of water required to carry out the anticipated domestic, public, and/or economic activities of a Water User Group during drought conditions.
Water Management Strategy (WMS):
A plan to meet a need for additional water by a discrete Water User Group, which can mean increasing the total water supply or maximizing an existing supply, including through reducing demands. A Water Management Strategy may or may not require associated Water Management Strategy Projects to be implemented.
Water Management Strategy Project (WMSP):
Water project that has a non-zero capital costs and that when implemented, would develop, deliver, or treat additional water supply volumes, or conserve water for Water User Groups or Wholesale Water Providers. One WMSP may be associated with multiple WMSs.
A potential water supply shortage based on the difference between projected Water Demands and Existing Water Supplies.
Water User Group (WUG):
Identified user or group of users for which Water Demands and Existing Water Supplies have been identified and analyzed and plans developed to meet Water Needs. These include:
- (A) Privately-owned utilities that provide an average of more than 100 acre-feet per year for municipal use for all owned water systems;
- (B) Water systems serving institutions or facilities owned by the state or federal government that provide more than 100 acre-feet per year for municipal use;
- (C) All other Retail Public Utilities not covered in subparagraphs (A) and (B) of this paragraph that provide more than 100 acre-feet per year for municipal use;
- (D) Collective Reporting Units, or groups of Retail Public Utilities that have a common association and are requested for inclusion by the RWPG;
- (E) Municipal and domestic water use, referred to as County-Other, not included in subparagraphs (A) – (D) of this paragraph; and
- (F) Non-municipal water use including manufacturing, irrigation, steam electric power generation, mining, and livestock for each county or portion of a county in an RWPA.
Wholesale Water Provider (WWP):
Any person or entity, including river authorities and irrigation districts, that delivers or sells water wholesale (treated or raw) to WUGs or other WWPs or that the RWPG expects or recommends to deliver or sell water wholesale to WUGs or other WWPs during the period covered by the plan. The RWPGs shall identify the WWPs within each region to be evaluated for plan development.