Abiotic. Non-living; as applied to the physical and chemical components of the ecosystem.
Adaptive Management. An approach to natural resources management that acknowledges the risk and uncertainty of ecosystem restoration and allows for modification of restoration measures to optimize performance. The process of implementing policy decisions as scientifically driven management experiments that test predictions and assumptions in management plans, and using the resulting information to improve the plans. A mechanism for integrating scientific knowledge and experience for the purpose of understanding and managing natural systems.
Anthropogenic. Caused by humans.
Area of potential effect. The geographic area within which an undertaking or activity may directly or indirectly cause change.
Avoid and minimize. Measures developed to avoid and minimize impacts to the river environment.
Avoidance zone. Voluntary avoidance areas established by the USFWS to protect native plants and animals.
Backwater. A small, generally shallow body of water attached to the main channel, with little or no current of its own; shallow, slow-moving water associated with a river but outside the river's main channel.
Bed load. Material that remains in contact with the bottom of a stream when moved by flowing water.
Benchmark. A point of reference by which something can be measured.
Benthic. Refers to the bottom layer of any body of water and the organisms therein.
Biodiversity. The variety of living organisms considered at all levels of organization, from genetics through species, to higher taxonomic levels, and including the variety of habitats and ecosystems, as well as the process occurring therein. Biodiversity occurs at four levels; genetic diversity, species richness, ecosystem diversity, and landscape diversity.
Biotic. Living; as applied to the components of an ecosystem.
Catchment. Watershed; the area drained by a stream, lake or other body of water. Frequently used to refer to areas that feed into dams; may also refer to areas served by a sewerage or stormwater system.
Channel Training Structure. A man-made flow obstruction (e.g., wing dam, closing dam or revetment) used to divert river flow to a desired location, usually toward the center of the main channel to increase flow and limit sedimentation or to protect the river bank from eroding.
Cofferdam. A temporary dam built to keep the riverbed dry to allow construction of a permanent dam or infrastructure.
Community. A grouping of populations of different species found living together in a particular environment.
Comprehensive Conservation Plan. A document that describes the desired future conditions of a USFWS refuge and provides long-range guidance and management direction for the refuge manager to accomplish the purposes of the refuge, contribute to the mission of the system, and to meet other relevant mandates.
Conceptual model. A conceptual model in problem formulation is a written description and visual representation of predicted relationships between ecological entities and the stressors to which they may be exposed.
Conservation. Active management to ensure the survival of the maximum diversity of species, and the maintenance of genetic diversity within species; implies the maintenance of ecosystem functions; embraces the concept of long-term sustainability. A careful preservation and protection of something; esp. planned management of a natural resource to prevent exploitation, destruction, or neglect.
Corridor. A relatively narrow strip of habitat that crosses an area of non-habitat land and serves to connect larger areas of habitat.
Cumulative effects. Effects on the environment that result from the incremental impact of any action when added to other past, present or future actions, regardless of which agency or person undertakes such actions.
Demand elasticity. In reference to the Navigation Study, a measure of the price responsiveness to waterway demand.
Desired future conditions. A description of management goals for an area to achieve optimal conditions; the descriptions should be constructed with the input of all interested parties in the region and should include clear goals for species, communities, and ecosystem composition, structure, and functions across the landscape. For this system study, the desired future condition was based on coordination with resource managers and became the system objectives.
Disturbance regime. The spatial and temporal characteristics of disturbances affecting a particular landscape over a particular time (e.g., fire, flood, drought). Any relatively discrete event in time that disrupts the ecosystem, community or population structure and changes resources or the physical environment.
Draft. Depth below the waterline that the vessel is submerged.
Drawdown. Lowering the level of the water in a selected portion of an aquatic system; conducted for habitat management purposes with dams or pumps.
Dredged material. The excavated material from dredging operations.
Dredging. The removal of underwater material (e.g., sediment) from the bottom of a harbor or waterway.
Ecological (or Biological) integrity. The ability of an ecosystem to retain its complexity and capacity for sustainability (i.e., its health).
Ecological processes. The dynamic biological, geological, and chemical interactions that occur among and between biotic and abiotic components in an ecosystem.
Ecological stressor. A substance or action that has the potential to cause an adverse effect on an ecosystem.
Ecosystem. Dynamic and interrelating complex of plant and animal communities and their associated nonliving environment; a biological community together with the physical and chemical environment with which it interacts.
Ecosystem (or environmental) restoration. Management actions that attempt to accomplish a return of natural areas or ecosystems to a close approximation of their conditions prior to human disturbance, or to less degraded, more natural conditions.
Ecosystem function. Processes that drive the ecosystem; any performance attribute or rate function at some level of biological organization (e.g., energy flow, sedimentation, detritus processing, nutrient spiraling).
Ecosystem health. A condition when a system's inherent potential is realized, its capacity for self-repair, when disturbed, is preserved, and minimal external support for management is needed.
Ecosystem management. Protecting, conserving, or restoring the function, structure, and species composition of an ecosystem, recognizing that all components are interrelated.
Ecosystem processes. The aggregate of all interactions among the various biotic components of an ecosystem (e.g., migration, pollination, predation), between the abiotic and biotic components of an ecosystem (e.g., nutrient uptake, erosion, respiration) and natural events and cycles (e.g., fire regimes, hydrologic cycles).
Ecosystem services. All of the goods and services provided to humanity by natural ecosystems; examples include wood products, fertile soils, genetic variation, clean water, and clean air.
Ecotype. Populations adapted to a particular set of environmental conditions; a collection of plants that evolved in response to the specific local environment of an area; a population adapted to a restricted habitat as a result of natural selection within a local environment.
Enhancement. In the context of restoration ecology, any improvement of a structural or functional attribute.
Environmental assessment. A document required to determine if there are significant impacts from the effects for proposed activities on the environment, in compliance with the National Environmental Policy Act (NEPA) of 1969. An EA should address unresolved environmental conflicts and have sufficient analysis to determine significant impacts.
Environmental impact statement. A detailed written statement following the format and procedures outlined in the National Environmental Policy Act (NEPA) of 1969. This document is prepared to determine and provide a detailed explanation of the significant environmental consequences of the proposed action. The EIS addresses public input.
Environmental sustainability. The ability of aquatic, wetland, and terrestrial complexes to maintain themselves as self-regulating, functioning systems.
Fish entrainment. Process by which fish are wounded or killed after being swept in and through a boat's propellers.
Fleeting area. A permanent facility within defined boundaries used to provide barge mooring service and ancillary harbor towing under the care of the fleeting operator.
Floodplain. Lowlands bordering a river that are subject to flooding. Floodplains are composed of sediments carried by rivers and deposited on land during flooding.
Funerary object. Of, relating to, or for a funeral or burial; an object discovered in close proximity to human remains and interred with the remains.
General Plan Land. Lands that the USACE outgrants to the USFWS through a Cooperative Agreement for fish and wildlife management purposes.
Genetically Modified Organism. An organism that has been modified by gene technology.
Geographic Information Systems (GIS). A set of computer hardware and software for analyzing and displaying spatially referenced features, such as points, lines or polygons, with non-geographic attributes, such as species, age, etc. utilized for mapping and analysis.
Geomorphology. The science that deals with land and submarine relief features (landforms) of the earths surface; the physical structure of the river floodplain environment.
Guard wall. An extension or new construction of a wall to prevent tows or loose barges from colliding with a dam during entry or exit from a lock chamber. Guard walls are various lengths depending on lock and dam configuration.
Guidewall. The extension of the inner lockwall on the upper and lower side of the lock chamber to assist navigators in guiding vessels or tows into the lock chamber. It is usually 600 feet in length, although some are now 1,200 feet long.
Habitat. The living place of an organism or community, characterized by its physical or biotic properties; habitats can be described on many scales from microhabitat to ecosystems to biomes.
Habitat fragmentation. The process whereby a larger, continuous area is both reduced in area and divided into two or more pieces. The disruption of extensive habitats into isolated and small patches. Fragmentation has three negative components: loss of total habitat area and smaller, more isolated remaining habitat patches, increased potential for edge effects.
Harbinger. A forerunner of something; a person, event, or situation that announces or signals the approach of something else.
Historic property. Any prehistoric or historic district, site, building, structure, or object included in, or eligible for inclusion in, the National Resister of Historic Places; includes artifacts, records, and remains that are related to and located within such properties.
Hydrologic. (1) Rise and fall of river crest; (2) Pertaining to the water cycle; through precipitation, runoff, storage and evaporation, and transevaporation and quantitatively as to distribution concentration, and quality.
Hydrology. A science dealing with the properties, distribution, and circulation of water on the surface of the land, in the soil and underlying rocks, and in the atmosphere.
Hypoxia. The condition in which dissolved oxygen concentrations are less than 2 parts per million of water.
Impoundment. In reference to rivers, the area of water that is captured and held back by a dam.
Index of Biotic Integrity (IBI). Index of Biotic Integrity utilizes numerous metrics or measures (often between 10 and 15) to assess aquatic biological integrity using fish community or macroinvertebrate community sampling. There are three broad categories under which the metrics fall: species composition; trophic composition; and fish abundance, condition, and tolerance to stressors.
Indicator. A measurable surrogate for environmental end points, such as biodiversity, that is; sensitive to changes in the environment and can warn that environmental changes are taking place.
Invasive species. Any species that has the tendency to invade or enter a new location or niche; an introduced species that out competes native species for space and resources; whose introduction does or is likely to cause economic or environmental harm or harm to human health.
Keystone species. A species whose presence is crucial in maintaining organization and diversity in their communities and who are much more important than the abundance of the species would suggest.
Landscape. A heterogeneous land area composed of interacting ecosystems that are repeated in similar form throughout; landscapes are variable in size; usually overlaps governmental jurisdictions, thus requiring collaboration from a broad range of participants.
Landscape ecology. The study of the structure, function, and change in a heterogeneous land area composed on interacting ecosystems.
Large-scale measure. A new 1200 foot lock or extending the existing lock to 1200 feet.
Lateral connectivity. The connection of a river and its floodplain, allowing access across aquatic and terrestrial habitats by organisms as well as flood waters.
Lentic. Of, or relating to, or living in still water, such as a pond or lake.
Levee. An embankment constructed to prevent flooding.
Levee district. Cooperative quasi-governmental organizations that protect areas from flood waters and serve as wildlife refuges.
Levee setback. The process of moving levees back a sufficient distance from the Ordinary High Water Mark to allow an escape valve for flood water, to replenish the floodplain and to allow restoration of the riparian corridor.
Life history. An organisms patterns of growth, reproduction, and longevity that are related to specific demands for survival.
Limiting factor. The ecologic influence that limits or controls the abundance and/or distribution of a species.
Litter. An accumulation of dead plant materials on the soil surface.
Littoral. Area of a stream, river, wetland, lake or pond that can support rooted aquatic plant growth.
Longitudinal connectivity. Allows for the upstream and downstream movement and/or migration of aquatic organisms; increases opportunities for aquatic organisms to utilize and move between exiting stream environments, colonize new habitats, or recolonize aquatic habitats following local extinctions.
Lotic. Of, or relating to, or living in flowing water, such as a river or stream.
Macroinvertebrates. Small, but visible with the naked eye, animals without backbones (insects, worms, larvae, etc.). The species composition, species diversity and abundance in a given water body can provide valuable information on the relative health and water quality of a waterway.
Management action. Measures used to modify or adjust the condition of the river system.
Mitigation. Actions taken to avoid, reduce or compensate for the effects of environmental damage. Among the broad spectrum of possible actions are those that restore, enhance, create, or replace damaged ecosystems.
Moist soil unit. Areas where water levels are controlled to provide a desired mix of moist soil vegetation.
Monoculture. A simplified biotic community dominated by one species.
Mooring buoy. A buoy attached to the river bottom by permanent moorings with means for securing a vessel by use of its mooring lines.
Mooring cell. A riverfront structure generally comprised of steel piling or a cluster of wooden piles used for securing barges along the bank at loading facilities.
N-up/N-down. A lock operating policy in which up to N upbound vessels are serviced, followed by up to N downbound vessels, where N is positive integers.
Naturalization. Establishing a sustainable, varied, yet stable natural area or system that is capable of supporting a healthy, biologically diverse ecosystem within the context of the developed landscape. When abiotic and biotic barriers to survival are surmounted and when various barriers to reproduction are overcome.
Navigation improvement. Structural and nonstructural measures that can increase the efficiency or capacity of the navigation system.
Non-indigenous species. Species of plants and animals that are not native to an area.
Non-point source pollution. Water pollution produced by diffuse land-use activities.
Open river condition. The condition when all dam gates are out of the water and the pool water level is no longer controlled by the dam.
Operation and Maintenance. Activities and costs associated with operating and maintaining the navigation system including funding for lock and dam personnel, maintenance crews, dredging, utilities, and minor repairs.
Patch. A nonlinear surface area that differs in appearance from its surroundings; the term used for distinct areas, such as ecosystems, on a landscape.
Performance measures. Metrics or indicators that are related to an ecosystem process or function and which are measurable in a natural ecosystem that can be used to judge the performance of restoration actions.
Piping. Removal of fine particles from the soil structure, usually near the toe of an embankment. Piping occurs when the forces produced by water moving through the soil exceed the resistance of the soil particles to movement.
Planform. The shape or form of an object, as seen from above, as in a plan view.
Point source pollution. Pollution into bodies of water from specific discharge points such as sewer outfalls or industrial-waste pipes.
Pool. The area of water that is impounded and maintained at a higher level behind a navigation dam; generally refers to the entire length of river between sequential dams.
Pool Plans. Maps and descriptions of desired future conditions of the Mississippi River.
Pool aging. A term used to broadly describe degradation in the quantity and quality of non-channel aquatic habitats since impoundment.
Pool reach. A portion of a pool between navigation dams.
Population. A group of individuals of the same species occupying an area small enough to permit interbreeding among all members of the group.
Pre-settlement. A condition or state prior to human intervention.
Preservation. To keep safe from injury, harm, or destruction.
Project Management Plan. A plan that outlines the scope, cost, and schedule for executing a study.
Project Management Plan. A plan that outlines the scope, cost, and schedule for executing a study. Chapter 14 contains the Project Management Plan for this study.
Reach. A continuous stretch or expanse. In reference to rivers, it can be used to define portions of rivers at different scales (i.e., floodplain reach, pool reach, and reach between two river bends).
Reference condition. The range of factors (e.g., hydrology, sediment movement, vegetation, and channel geometry) that are representative of a rivers recent historical values prior to significant alteration of its environment.
Region. A large geographical area that is distinguished by certain characteristics (e.g., biological, ecological, social, political, economic).
Rehabilitation. Used primarily to indicate improvements to a natural resource; putting back into good condition or working order.
Resilience. The ability of a system to maintain its structure and patterns of disturbance in the face of disturbance.
Restoration. The objective of ecosystem restoration is to restore degraded ecosystem structure, function, and dynamic processes to a less degraded, more natural condition (ER 1105-2-100). As defined under Section 519, in its broadest usage, restoration encompasses the following concepts: conservation, enhancement, naturalization, preservation, protection, rehabilitation, restoration, and stabilization.
Riparian. Areas that are contiguous to and affected by surface and subsurface hydrologic features of perennial or intermittent water bodies (e.g., rivers, streams, lakes, or drainage ways).
Riparian corridor. A corridor of habitat that is directly related to or situated along the banks of rivers or streams; a riparian corridor is in contact with the stream during annual floods.
River stage. The elevation of the water surface, usually above an arbitrary datum.
Secondary (side) channel. Aquatic channel connected to the main channel and separated from the main channel by an island; usually has flowing water.
Sediment resuspension. The movement of sediment from the river bed into the water column due to a disturbance (e.g., wave action).
Sediment transport. The movement of sediment (usually by water).
Sedimentation. The process of sediment being deposited in a given location.
Small-scale measures. Any navigation improvement less costly than extending or constructing a new 1200' lock.
Spatial. Relating to the nature of space.
Species. One or more populations of individuals that can interbreed, but cannot successfully breed with other organisms.
Species diversity. The richness, abundance, and variability of plant and animal species and communities.
Species evenness. A measure of diversity that quantifies unequal species representation in a community against a hypothetical community in which all species are equally common; the degree of heterogeneity in the spatial distribution of species in a community or ecosystem.
Species richness. A simple count of the number of species in an area.
Stability. The propensity of a system to attain or retain an equilibrium condition of steady state or stable oscillation; having a resistance to departure from that equilibrium condition, and if perturbed, returning rapidly to that equilibrium condition.
Stabilization. Protect from further degradation; restore the original condition when disturbed from a condition of equilibrium or steady motion.
Stakeholder. Those organizations and/or individuals having a vested interest in the outcome of a decision making process.
Structure. The horizontal and vertical spatial arrangement, or configuration, of a habitat, community or ecosystem; includes biotic and abiotic diversity.
Subwatershed (sub-basin). A subdivision of a watershed, based on hydrology, generally corresponding to the area drained by a small tributary or stream, as opposed to a major river. Nineteen major sub-basins have been delineated in the Illinois River Basin: Chicago, Des Plaines, Spoon, Upper Sangamon, South Fork Sangamon, Lower Sangamon, Salt Creek, LaMoine, Lower Illinois, Lower Illinois - Lake Chautauqua, Lower Illinois -Lake Senachwine, Macoupin, Upper Fox, Lower Fox, Upper Illinois, Kankakee, Iroquois, Vermilion and Mackinaw.
Succession. Sequential change in the vegetation at a particular location over time.
Sustainable/sustainability. A level and method of resource use that does not destroy the health and integrity of the systems that provide the resource; thus the long-term resource availability does not ever diminish due to such use.
Tainter Gate. The Tainter gate was invented in the 19th century by American structural engineer and Wisconsin native Jeremiah Burnham Tainter. The Tainter gate is a type of radial arm floodgate used in locks and dams to control water flow. The curved gate is attached to one or more truss-like, triangular framework pieces. The wide end of the triangle framework is attached to the curved gate, and the apex point of the truss rotates to move the gate. A side view of a Tainter gate resembles a slice of pie with the curved part of the piece facing the source or upper pool of water and the tip pointing toward the destination or lower pool. The water pressure actually helps move the gate up and down.
Temporal. Of, relating to, or limited by time.
Thalweg. The line defining the lowest points along the length of a riverbed or valley.
Threat assessment. The identification, evaluation, and ranking of stresses and sources of stress to populations, species, ecological communities or ecosystems at a site or within a landscape.
Threatened and endangered species. Those species that are listed as threatened or endangered under the Federal Endangered Species Act (ESA) of 1973, and those species that are candidates or proposed as candidates for listing under the ESA; listing can occur at the Federal or state level or both.
Threshold. The level (duration or intensity) of a stimulus required to produce an effect.
Total Maximum Daily Load. A calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources.
Tractive Force Scour. Removal of bank materials by the shear forces produced by flowing water moving past the bank.
Tributary. A stream or river whose water flows into a larger stream or river.
Tributary, major. The larger rivers or streams flowing directly into a larger river. There are 10 major tributaries of the Illinois River Basin. They are the: Chicago, Des Plaines, Spoon, Sangamon, LaMoine, Fox, Kankakee, Vermilion, and Mackinaw Rivers and Macoupin Creek.
Trust Species. USFWS trust species include migratory birds, anadromous and interjurisdictional fish, and endangered species, certain marine mammals, and National Wildlife Refuge and Wilderness Areas.
Turbidity. Measure of the "black of clearness" of water. Degree to which light is blocked because water is muddy or cloudy.
Turnback lockage. A lockage in which no vessels are served; a reversal of the water level in a lock chamber with no vessels in the chamber. A turnback includes closing one set of gates, filling or emptying the chamber, and opening the other set of gates. Also called a "swingaround" or an "empty lockage".
Upper Mississippi River - Illinois Waterway (UMR-IWW). The narrow (300-500m) 1,200 miles of 9-foot navigation channel, 37 locks and dam sites (43 locks), and thousands of channel training structures of the Upper Mississippi River and Illinois Waterway.
Upper Mississippi River System (UMRS). The entire floodplain area and associated physical, chemical, and biological components of the Upper Mississippi and Illinois Rivers.
Volitional. Voluntary or directed movements under direct control of the organism (swimming, running) as opposed to movements regulated unconsciously (breathing).
Watershed. The geographic area that naturally drains into a given watercourse such as a stream or river.
Wicket gate. A rectangular heavily constructed slab of wood and steel hinged in a counterbalanced way so as to be lying flat on the river bed when down, and when raised will be held upright by the pressure of the water. Wicket gates are placed in a parallel line across the river and when all are in raised position they form a wall or dam, thus backing up the water and raising it to the pool level.