Glossary
Acre (ac)
A measure of land area measuring 43,560 square ft
Acre-feet (af)
The amount of water it takes to cover one acre to a depth of one foot, 43,560 cubic ft or 1,233.5 cubic meters
Active Storage
The volume of water in a reservoir between its minimum operating elevation and its maximum normal operating elevation
Adit
An almost vertical pipe or short horizontal passage entering a tunnel, either to add water from a conduit, sluice or other water source or as a maintenance access tunnel (also referred to as a portal if located at the beginning or end of the tunnel)
Afterbay
A reservoir located immediately downstream from a powerhouse, sometimes used to re-regulate flows to the river or stream
Alluvium
Material such as sand, silt or clay, deposited on land by water such as on floodplains
Anadromous fish
Fish that live in saltwater habitats most of their lives, but periodically migrate into freshwater to spawn and develop to the juvenile stage (e.g., striped bass)
Automatic/Semi-automatic/Manual Powerhouses
An automatic powerhouse can be started, stopped, and have its load and voltage changed from a remote or master station, via supervisory control. A semiautomatic powerhouse with SCADA may allow a remote station to change load and/or voltage, and may allow a remote shutdown, but must be started manually. A semi-automatic powerhouse without SCADA will send alarms to a remote or master station. A manual powerhouse must have all its functions performed at the powerhouse.
Aquatic Life
Any plants or animals which live at least part of their life cycle in water
APE
Area of Potential Effect as pertaining to Section 106 of the National Historic Preservation Act
Baseline
A set of existing environmental conditions upon which comparisons are made during the NEPA process
Base Load
A power plant that is planned to run continually except for maintenance and scheduled or unscheduled outages. Also refers to the nearly steady level of demand on a utility system.
Benthic
Associated with lake or river bottom or substrate
Black Start Capability
The ability of a unit to start up without the use of an external transmission or distribution voltage power source
Benthic Macroinvertebrates
Animals without backbones, which are visible to the eye and which live on, under, and around rocks and sediment on the bottoms of lakes, rivers, and streams
°C
Degrees Celsius
Capacity
The load for which an electric generating unit, or other electrical equipment or power line is rated
Catadromous fish
Fish that live in freshwater most of their lives and when mature migrate to the sea to spawn (e.g., American eel)
Critical Energy Infrastructure Information (CEII)
Project-related documents that are restricted from public viewing in accordance with FERC regulations (18 CFR 388.113) related to the design and safety of dams and appurtenant facilities, and that is necessary to protect national security and public safety
Cubic Feet (cf)
The volume of a cube with edges one foot in length
Clean Water Act (CWA)
The Federal Water Pollution Control Act of 1972 and subsequent amendments in 1977, 1981, and 1987 (commonly referred to as the Clean Water Act). The Act established a regulatory system for navigable waters in the United States, whether on public or private land. The Act set national policy to eliminate discharge of water pollutants into navigable waters, to regulate discharge of toxic pollutants, and to prohibit discharge of pollutants from point source without permits. Most importantly it authorized EPA to set water quality criteria for states to use to establish water quality standards.
Colluvium
Soil material and/or rock fragments moved by gravity such as during creep, slide, or localized wash-outs, which is deposited at the base of steep slopes
Combustion turbine
A fuel-fired turbine engine used to drive an electric generator
Commission
Federal Energy Regulatory Commission also referenced as FERC
Conduit
A tunnel or pipe, used for diverting or moving water from one point to another, usually used when there is no existing streambed or waterway
Conservation
A process or program designed to increase the efficiency of energy and water use, production, or distribution
Creel Census
Counting and interviewing anglers to determine fishing effort and catch. Usually conducted by a census clerk on systematic regularly scheduled visits to significant fishing areas.
Cubic feet per Second (cfs)
A measurement of water flow representing one cubic foot of water moving past a given point in one second. One cfs is equal to 0.0283 cubic meters per second and 0.646 mgd.
Cultural Resources
Includes items, structures, etc. of historical, archaeological, or architectural significance
Cumulative Impact
The effect on the environment that results from the incremental impact of the action when added to other past, present, and reasonably foreseen future actions. Can result from individually minor but collectively significant actions taking place over a period of time.
Dam
A structure constructed across a water body typically used to increase the hydraulic head at hydroelectric generating units. A dam typically reduces the velocity of water in a particular river segment and increases the depth of water by forming an impoundment behind the dam. It also generally serves as a water control structure.
Demand
The rate at which electric energy is delivered to or by a system at a given instant or averaged over a designated period, usually expressed in kilowatts or megawatts
Dependable Capacity
The maximum dependable MW output of a generator or group of generators during the critical hydrologic period coincident with peak electrical system load
Development
One of several hydroelectric plants collectively licensed by the Federal Energy Regulatory Commission as a Project (e.g., The Coosa River Project consists of five developments: Weiss, Henry, Logan Martin, Lay, and Bouldin)
Dike
A raised bank, typically earthen, constructed along a waterway to impound the water and to prevent flooding
Dissolved Oxygen (DO)
A commonly employed measure of water quality that describes the amount of oxygen dissolved in water. Low DO levels adversely affect aquatic life.
Distribution Lines
Power lines, like those in neighborhoods, used to carry moderate voltage electricity which is "stepped down" to household levels by transformers on power poles
Distribution System
The substations, transformers and lines that convey electricity from high-voltage transmission lines to the consumer
Drawdown
The distance the water surface of a reservoir is lowered from a given elevation as the result of releasing water
Emergent aquatic vegetation
Plants rooted in substrate covered by shallow water (of up to 6.6 ft depth), with most of the parts out of the water
Energy
Average power production over a stated interval of time, expressed in kilowatt-hours, megawatt-hours, average kilowatts and average megawatts
Environmental Impact Statement (EIS)
An environmental review document prepared under NEPA to determine the environmental impact of a specific action. A Draft Environmental Impact Statement (DEIS) is prepared and circulated for public comment. After incorporation of public comments, a Final Environmental Impact Statement (FEIS) is published.
Eutrophic
Waters with a high concentration of nutrients and a high level of primary production
Evapotranspiration
The evaporation from all water, soil, snow, ice, vegetation, and other surfaces, plus transpiration
°F
Degrees Fahrenheit
Federal Energy Regulatory Commission (FERC)
The governing federal agency responsible for overseeing the licensing/relicensing and operation of hydroelectric projects in the United States
Federal Power Act (FPA)
Federal statute enacted in 1920 that established the Federal Power Commission (now FERC) and the statutes for licensing hydroelectric projects
Federal Power Commission (FPC)
Predecessor of FERC
Federal Register
A publication of the Federal Government that includes official transactions of the U.S. Congress, as well as all federal agencies such as FERC. Copies of the Federal Register are usually available at large public and university libraries.
Flow
The volume of water passing a given point per unit time
Flow Duration Curve
A graphical representation of the percentage of time in the historical record that a flow of any given magnitude has been equaled or exceeded
Forebay
A reservoir upstream from a powerhouse, from which water is drawn into a tunnel or penstock for delivery to the powerhouse
Francis turbine
A radial-inflow reaction turbine, where flow through the runner is perpendicular to the turbine shaft
Generation
The process of producing electricity from other forms of energy, such as steam, heat, or water. Refers to the amount of electric energy produced, expressed in kilowatt hours
Generator
A machine that converts mechanical energy into electricity often powered by a turbine
Grizzly trash rack
A metal grating across the entry to a water conduit
Gross Storage
The sum of the dead storage and the live storage volumes of a reservoir, the total amount of water contained in a reservoir at its maximum normal operating elevation
H-Frame Structure
A wood pole transmission structure that consists of two wood poles with a horizontal cross arm above the conductor
Habitat
The locality or external environment in which a plant or animal normally lives and grows
Head
The distance that water falls in passing through a hydraulic structure or device such as a hydroelectric plant. Gross head is the difference between the headwater and tailwater levels; net head is the gross head minus hydraulic losses such as friction incurred as water passes through the structure; and rated head is the head at which the full-gate discharge of a turbine will produce the rated capacity of the connected generator.
Headwater
The waters immediately upstream of a dam. For power dams, also referred to as the water in the impoundment which supplies the turbines (see also forebay).
Horsepower (hp)
A measure of power equal to about 746 watts
Hydraulic
Relating to water in motion
Hydroelectric Plant
A facility at which the turbine generators are driven by falling water
Hydroelectric Power
Capturing flowing water to produce electrical energy
Hydrologic Unit Code (HUC)
Developed by the Water Resources Council corresponding to hierarchal classification of hydrologic drainage basins in the United States. Each hydrologic unit is identified by a unique hydrologic unit code (HUC).
Hypolimnetic
The deeper cooler portions of a reservoir or lake that result from stratification
Hz
hertz (cycles per second)
Impoundment
The body of water created by a dam
Induced Surcharge Curve
A set of lake level elevations used to manage flows during periods of high inflow to ensure protection of downstream lands from flooding
Installed Capacity
The nameplate MW rating of a generator or group of generators
Integrated Licensing Process (ILP)
The ILP is the default process by which a hydropower project obtains a new license to operate
Interested parties
Individuals who have expressed and interest in the relicensing proceeding
Kilovolts (kV)
A unit of pressure, or push, of an electric current equal to 1,000 volts
Kilowatt (kW)
A unit of electrical power equal to 1,000 watts or 1.341 horsepower
Kilowatt-hour (kWh)
Basic unit of electric energy equal to an average of one kilowatt of power applied over one hour
Lacustrine
Pertaining to or living in lakes or ponds
Lake Rule Curve
A set of target lake level elevations that vary seasonally. The lake level is normally maintained at or below the elevations specified by the rule curve, except when storing floodwater. Rule curves are often set by federal agencies responsible for operating storage reservoirs, such as the Army Corp of Engineers.
Lentic
Standing or still water including lakes, ponds and swamps
License Application
Application for a new license; submitted to FERC no less than two years in advance of expiration of an existing license
License
FERC authorization to construct a new project or continue operating and existing project. The license contains the operating conditions for a term of 30 to 50 years.
Licensee
This is another term that refers to the Alabama Power Company (APC)
Littoral
Associated with shallow (shoreline area) water (e.g., the littoral zone of an impoundment)
Load
The total consumer demand of electric service at any given time
Lotic
Flowing or actively moving water including rivers and streams
Mainstream
The main channel of a river a opposed to the streams and smaller rivers that feed into it
Martin Datum (MD)
Local datum of the Lake Martin project; equivalent to 491 ft mean sea level
Maximum drawdown elevation
The lowest surface elevation to which a reservoir can be lowered and still maintain generation capability. This is usually somewhat lower than the minimum operating elevation.
Maximum normal operating elevation
The maximum surface elevation to which the reservoir can be raised without surcharging or exceeding the license provisions
Megawatt (MW)
A unit of electrical power equal to one million watts or 1,000 kW
Megawatt-hour (MWh)
A unit of electrical energy equal to 1 MW of power used for one hour
Minimum normal operating elevation
The lowest elevation to which a reservoir is normally lowered during power generation operations. Below this point power output and generation efficiency is significantly impacted.
Nameplate Capacity
A measurement indicating the approximate generating capability of a project or unit, as designated by the manufacturer. In many cases, the unit is capable of generating substantially more than the nameplate capacity since most generators installed in newer hydroelectric plants have a continuous overload capacity of 115 percent of the nameplate capacity. Also called Installed Capacity.
National Environmental Policy Act (NEPA)
A law passed by the U.S. Congress in 1969 to establish methods and standards for review of development projects requiring Federal action such as permitting or licensing
Non-Governmental Organization (NGO)
Local, regional and national organizations such as conservation, sportsman’s or commerce groups
Normal Operating Capacity
The maximum MW output or a generator or group of generators under normal maximum head and flow conditions
Normal Operating Elevation
The reservoir elevation approximating an average surface elevation at which a reservoir is kept
Normal Operating Elevation Range
The elevation difference between the normal maximum and normal minimum operating elevations
Off Peak
A period of relatively low demand for electrical energy, such as the middle of the night
On Peak
A period of relatively high demand for electrical energy
Outage
The period during which a generating unit, transmission line, or other facility is out of service
Palustrine Emergent Wetland
Contains rooted herbaceous vegetation that extend above the water surface (i.e., cattails, sedges)
Palustrine Forested Wetland
Dominated by woody vegetation less than 20 ft tall (i.e., willows, dogwood)
Palustrine Scrub/Shrub Wetland
Comprised of woody vegetation that is 20 ft tall or greater (i.e., American elm, swamp white oak)
Peaking Operations
A powerplant that is scheduled to operate during peak energy demand. Operation of generating facilities to meet maximum instantaneous electrical demands
Periphyton
Macroscopic (visible without a microscope) and microscopic (visible only with a microscope) algae (single- and multi-celled plants) that grow on or attach to rocks, logs, and aquatic plants. Periphyton, phytoplankton, and aquatic plants are the primary producers that convert nutrients into plant material by the process of photosynthesis.
Phytoplankton
Microscopic single-celled and colonial forms of algae floating in the water column
Ponding Operations
The process of storing and releasing water based on electric demand or flood control
Peak Demand
A one hour period in a year representing the highest point of customer consumption of electricity
Piezometer
A device that measures water pressure
Pool
Refers to the reservoir or an impounded body of water
Powerhouse
The building that typically houses electric generating equipment
Power Factor
The ratio of actual power to apparent power. Power factor is the cosine of the phase angle difference between the current and voltage of a given phase. Unity power factor exists when the voltage and current are in phase.
Power Pool
A regional organization of electric companies interconnected for the sharing of reserve generating capacity.
Pre-Application Document (PAD)
A document, required by FERC when relicensing a project, that brings together all existing, relevant, and reasonably available information about the project and its effects on resources; and includes a well-defined process plan that sets the schedule for developing the license application and a list of preliminary studies and issues.
Probable Maximum Flood (PMF)
A statistical formula used to calculate a hypothetical flood event that could occur on a particular river basin over a particular duration. This is derived from the probable maximum precipitation over time.
Project
This refers to Alabama Power Company’s Martin Hydroelectric Project, FERC Project No. 349
Project Area
The geographic area defined in the license issued by FERC for the Project as needed for Project operations and maintenance
Project Boundary
The boundary defined in the license issued by FERC for the Project outlining the geographic area needed for Project operations and maintenance
Project Drainage Basins
The area of land that contributes surface water to the Tallapoosa River system
Project Region
The area around the Project on the order of a County or National Forest in size
Project Roads
Roads within Project Boundary and constructed for Project purposes and necessary for Project operation and maintenance
Project Vicinity
The area extending to about five miles from the Project Boundary
Project Viewshed
The area from which Project features are visible. The land base from which the Project may be seen.
Project Works
All of the infrastructure associated with the operations of the Project
Protection
All of the relays and other equipment which are used to open the necessary circuit breakers to separate pieces of equipment from each other when trouble develops
Protective Relay
A device whose function is to detect defective lines or apparatus, or other power system conditions of an abnormal or dangerous nature, and to initiate appropriate control circuit action
Public Reference File
A listing of important materials pertaining to the relicensing
Public Utility
A business enterprise rendering a service considered essential to the public and, as such, subject to regulation
Ramp Rate
The rate of change in output from a power plant. A maximum ramp rate is sometimes established to prevent undesirable effects due to rapid changes in loading or, in the case of hydroelectric plants, discharge.
Ramping
The act of increasing or decreasing stream flows from a powerhouse, dam or division structure
Regulated Hydrology
The hydrology of Project-affected streams subsequent to construction of the Project
Relicensing
The administrative proceeding in which FERC, in consultation with other federal and state agencies, decide whether and on what terms to issue a new license for an existing hydroelectric project at the expiration of the original license
Relicensing Participants
Individuals who actively participate in the relicensing proceedings
Reserve Capacity
Extra generating capacity available to meet unanticipated demand for power or to generate power in the event of loss of generation
Reservoir
An artificial lake into which water flows and is stored for future use
Reservoir Useable Capacity
A volume measurement of the amount of water that can be stored for generation, down to a minimum level
Resident Fish
Fish that spend their entire life cycle in freshwater, such as sunfish and bass
Resource Agency
A federal, state, or interstate agency with responsibilities in the areas of flood control, navigation, irrigation, recreation, fish or wildlife, water resource management, or cultural or other relevant resources of the state in which a project is or will be located.
Rhizome
Underground stem
Riparian Area
A specialized form of wetland with characteristic vegetation restricted to areas along, adjacent to or contiguous with rivers and streams. Also, periodically flooded lake and reservoir shore areas, as well as lakes with stable water.
River Miles (RM)
Miles from the mouth of a river; for upstream tributaries, from the confluence with the main river
Run-of-River
A term used to describe the operation of a hydroelectric project in which the quantity of water discharged from the project essentially equals the flow in the river
Runner
The rotating part of a turbine
Scoping Document 1 (SD1)
A document prepared by FERC as part of NEPA environmental review that initially identifies issues pertinent to FERC's review of a project. FERC circulates the SD1 and holds a public meeting to obtain the public's comment.
Scoping Document 2 (SD2)
A revision to SD1 which takes into account public comment on that document
Scoping process
The process of identifying issues, potential impacts, and reasonable alternatives associated with the operation of a hydroelectric project. "Scoping" is a process required by any federal agency taking an action that might affect the quality of the human environment, pursuant to the National Environmental Policy Act (NEPA) of 1969. In the case of hydro projects, FERC's issuance of an operating license qualifies as a federal action.
Secchi depth
Average depth at which a standard size black and white disk disappears and reappears when viewed from the lake surface as it is lowered. An indicator of water clarity.
Seepage
The amount of water that leaks through a structure, such as a dam
Spawn
The act of fish releasing and fertilizing eggs
Spawning Run
A general term referring to migration of anadromous or catadromous fish over a particular time and area
Spillway
A passage for releasing surplus water from a reservoir or canal
Stakeholder
Any individual or organization (government or non-governmental) with an interest in a hydroelectric project
State
State of Alabama
Stock
The introduction of a particular species of fish into an aquatic system as part of a resource management plan or goal.
STORET
The USEPA’s computerized water quality data storage system
Stratification
A physical and chemical process that results in the formation of distinct layers of water within a lake or reservoir (i.e., epilimnion, metalimnion, and hypolimnion)
Streamflow
The rate at which water passes a given point in a stream, usually expressed in cubic ft per second (cfs)
Study Description
A detailed description of an individual study
Study Plan
The aggregate of all study descriptions
Submerged Aquatic Vegetation
Plants with rigid stems and/or leaves rooted in substrate and generally covered by deep water (greater than 6.6 ft depth), with all of the plant parts covered by water
Tailrace
The channel located between a hydroelectric powerhouse and the river into which the water is discharged after passing through the turbines
Tailwater
The waters immediately downstream of a dam. For power dams, also referred to as the water discharged from the draft tubes.
Tainter Gate
A gate with a curved skin or face plate connected with steel arms to an axle. It is usually lifted or lowered by a cable connected to a hook at the top of the gate rotating on the axle as it is moved.
Taxon
A means of referring to a set of animals or plants of related classification, such as all of the species (i.e., brook trout, lake trout) in a genus (trout); or all of the genera (all trout and salmon) in a family of fishes (salmonidae). Plural form of taxon is taxa.
Transformer
Equipment vital to the transmission and distribution of electricity designed to increase or decrease voltage
Transmission
The act or process of transporting electric energy in bulk from one point to another in the power system, rather than to individual customers
Transmission Lines
Power lines normally used to carry high voltage electricity to substations which then is "stepped down" for distribution to individual customers
Transpiration
The process by which water absorbed by plants is converted to vapor and discharged to the atmosphere
Trash Rack
A series of vertical steel bars found on a dam or intake structure, which clears the water of debris before the water passes through the structure
Turbidity
A measure of the extent to which light passing through water is reduced due to suspended materials
Turbine
A machine for generating rotary mechanical power from the energy in a stream of fluid (such as water, steam, or hot gas). Turbines covert the energy of fluids to mechanical energy through the principles of impulse and reaction, or a mixture of the two.
Vantage Point
The location from which a viewer sees the landscape
Volt (V)
The unit of electromotive force or electric pressure, akin to water pressure in pounds per square inch
Warmwater Fish
Fish species typical of southeastern warm water environments (e.g., bass, sunfish, pickerel, sucker)
Watershed
An entire drainage basin including all living and nonliving components of the system
Wetlands
Lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water. Wetlands must have the following three attributes: 1) at least periodically, the land supports predominantly hydrophytes; 2) the substrate is predominantly undrained hydric soil; 3) the substrate is on soil and is saturated with water or covered by shallow water at some time during the growing season of each year.
Zooplankton
Microscopic and macroscopic animals that swim in the water column. These invertebrates include chiefly three groups: rotifers, cladocerans, and copepods.
