Simple, rootless plants that grow in bodies of water in relative proportion to the amounts of nutrients available. Blue-green algae are primitive algae, typically found in water high in phosphorus that form scum blooms that congregate at the water’s surface. Diatoms are algae that have silica in their cell walls.


Agricultural Research Service


Single celled organisms having no cellular nucleus. Pathogenic bacteria are capable of causing disease. Coliform bacteria are prolific in the intestines of warm blooded animals and are used as an indicator of fecal waste pollution.


Bottom terrain (generally submerged under water) of a surface water body, from shoreline to greatest depths.

Best Management Practices (BMPs)

Methods, measures or practices to prevent or reduce surface runoff and/or water pollution, including but not limited to, structural non-structural controls, operation and maintenance procedures, other requirements and scheduling and distribution of activities.


Best management practice


Biological oxygen demand


An area maintained in permanent vegetation and managed to reduce the impacts of adjacent land use.


Cedar Creek Wildlife Project


Cooperative Extension Service


Cubic feet per second


The practice of straightening a waterway to remove meanders in order to increase the column and/or rate of discharge. Sometimes concrete is used to line the sides and bottom of the channel.


The flowing together of two or more streams. A point of juncture.


A protozoan of the genus cryptosporidium that is an intestinal parasite in humans and other vertebrates and some times causes diarrhea that is especially severe in immuno-compromised (weakened immune system) individuals.


Combined Sewer Overflow

Detention/Retention Basin

Impoundment constructed to detain/retain stormwater for extended periods of time and allow for the retention of pollutants in the pond through deposition of sediments and attached pollutants.


1. Release of water at a given point into a water body. 2. The rate and volume of flow of water such as in a stream, generally expressed as cubic feet per second.

Dissolved Oxygen (DO)

Amount of oxygen gas dissolved in a given quantity of water at a given temperature and atmospheric pressure. It is usually expressed as a concentration in parts per million or as a percentage of saturation.


Department of Natural Resources


Dissolved oxygen


Process of the stream channel bottom being rapidly and excessively eroded creating a deeply incised stream channel.

Drinking Water Standards

In the U.S. National Primary Drinking Water Regulations ((NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards protect health by limiting the levels of contaminants in drinking water.


The system formed by the interaction of a community of organisms with their environment.

Ecosystem Management

The careful and skillful use of ecological, economic, social, and managerial principles in managing ecosystems to produce, restore, or sustain ecosystem integrity and desired uses, products, and services over the long term.


Environmental Protection Agency


The wearing away of land surface by water or wind which occurs naturally from weather or runoff, but is often intensified by human activities.




Habitats, particularly soils and water, that are rich in nutrients and plant growth. Eutrophic waters generally have high sedimentation at their bottoms. The lower levels of eutrophic waters have very low levels of dissolved oxygen.


The aging process by which lakes, estuaries, or water bodies are fertilized with nutrients. Natural eutrophication changes the character of a lake or water body, very gradually. Cultural eutrophication is the accelerated aging of a lake or water body resulting from human activities. The process by which nutrients increase in the water body, increasing algal growth. Then as algal blooms die off and fall to the bottom, their decay depletes the water body of dissolved oxygen, which in turn reduces the ability of the water body to support fish and other aquatic life.


The total loss of water to the atmosphere by evaporation from land and water surface and by transpiration from plants.

Exotic (or invasive) Species

An organism that is out of its naturally occurring range and environment, and occupying the habitat of native species.

Filter Strip

A linear strip of land maintained to slow the velocity of runoff and filter sediment.


The mechanical process which removes particulate matter by separating water from solid material, usually by passing it through sand. .


Occurs when the total volume of surface water runoff and baseflow entering a stream channel exceeds the capacity of the channel resulting in out-of-bank flow.


That portion of a stream valley adjacent to the channel that is created by erosion and sediment deposited from the stream and covered with water when the stream overflows its banks at flood stage. Also, the nearly level land situated on either side of a channel that is subject to overflow flooding.


Geographic information system


Great Lakes Commission

Grassed Waterway

Grass established in a shaped drainageway to prevent gullies from forming.

Ground Water

Water that occurs in the subsurface and fills or saturates the porous openings, factures and fissures of under-ground soils and rock units.


A place where the physical and biological elements of ecosystems provide a suitable environment and the food, cover, and space resources needed for plant and animal livelihood.


The uppermost tributaries of a stream or river; often refers to first order streams.


Hydrologic unit code


The study of the properties, distribution, circulation, and effects of water on the Earth’s surface, soil, and atmosphere.


Indiana Department of Environmental Management


Indiana Department of Natural Resources

Impaired Stream

A stream or other surface water body determined by field assessment to no longer meet the state water quality standards for its designated protected use.

Impervious Surface

Ground cover that does not allow, or minimally allows, for infiltration of water (e.g., roofs, paved parking lots, and roads) and which increases the volume and speed of runoff after a rainfall.


Movement of surface water into the soil, where it is absorbed by plant roots, evaporated into the atmosphere, or percolates downward to recharge ground water.

Intermittent Stream

A defined channel in which surface water is absent during a portion of the year, as ground water levels drop below the channel bottom.


Indiana University – Purdue University


The total amount (generally measured in pounds or kilograms per acre per year) of material (sediment, nutrients, oxygen-demanding material, or other chemicals or compounds) brought into a lake, stream or water body by inflowing streams, runoff, direct discharge through pipes, ground water, the air (aerial or atmosphere deposition) and other sources over a specific period of time (often annually).


Invertebrate animal (without back bones) large enough to be observed without the aid of a microscope or other magnification.

Maximum Contaminant Level (MCL)

The designation given by the U.S. Environmental Protection Agency (EPA) to water-quality standards promulgated under the Safe Drinking Water Act. The MCL is the greatest amount of a contaminant that can be present in drinking water without causing a risk to human health.


A circuitous winding or bend in the river.


Maumee River Basin Commission

Native Species

A naturally occurring plant or other organism that is within its range and normal environment.


A salt of nitric acid; a common water pollutant.

Nonpoint Source

Nutrient and pollution sources not discharged from a single point, e.g. runoff from agricultural fields, feedlots, residential lawns, septic leach fields, or urban streets, etc.


Nonpoint source


USDA Natural Resources Conservation Service


National Soil Erosion Research Laboratory (West Lafayette, Indiana)


Elements or compounds essential to growth and development of living things (e.g., nitrogen, potassium, phosphorus).

Parts Per Million (PPM)

A common basis of reporting water analysis. One part per million (PPM) equals one pound per million pounds of water. One part per billion (PPB) equals one pound per billion pounds of water.


Microorganism which can cause disease. .


1. The slow seepage of water into and through the ground. 2. The slow seepage of water through a filter medium 3. The movement, under hydrostatic pressure, of water through the interstices of a rock or soil.


A measure of the relative acidity or alkalinity of water. Water with a pH of 7 is neutral; lower pH levels indicate increasing acidity, while pH levels higher than 7 indicate increasingly basic solutions.


Salt of phosphoric acid, often found in fertilizers.

Point Source Pollution

Water pollution coming from a single point, such as a sewage-outflow pipe.


The process of contaminating air, water and land with impurities to a level that is undesirable and results in a decrease in usefulness of the environment for beneficial purposes.


Parts per billion


Parts per million


Quality Assurance Project Plan


The replenishment of ground water through the infiltration of rainfall, other surface waters, or land application of water or treated wastewater.


The prevention of direct discharge of stormwater runoff into receiving waters by temporary containment in a pond or depression; examples include systems which discharge by percolation to ground water, exfiltration, and/or evaporation process and which generally have residence times of less than three days.

Retention Time

The length of time that water, nutrients, or other chemical substances remain in a lake, impoundment or standing pool. .


Shallow section of a stream or river with rapid current and a surface broken by gravel, rubble, or boulders.


Pertaining to anything connected with or immediately adjacent to the banks of a stream or other body of water.

Riparian Forest Buffer

An area of trees, usually accompanied by shrubs and other vegetation, adjacent to a body of water and managed to maintain the integrity of stream channels and shorelines to 1) reduce the impact of upland sources of pollution by trapping, filtering, and converting sediments, nutrients, and other chemicals, and 2) supply food, cover, and thermal protection to fish and other wildlife.


Stones of varying size used to dissipate energy or stabilize a soil surface.


Surface water (usually rainfall) that is not evaporated, transpired, used, or infiltrated into the ground water system, and thus flows over land to a surface water body.


The relative proportion of salt in a solution, typically measured in g/l, or parts per thousand (ppt). Seawater is typically around 335 ppt.


Local removal of soil, sediment, or other channel material from a streambed by flowing water. .


Fragmented material that originated from weathering rocks and decomposing organic material that is transported by, suspended in, and eventually deposited in the streambed.


Occurs when sediment particles that have been suspended within flowing water are deposited on the stream bottom or floodplain.


A flow process associated with broad, shallow water movement on sloping ground surfaces that is not channelized or concentrated.


St. Joseph River Watershed Initiative


Semisolid material such as the type precipitated by sewage treatment. Mud, mire, or ooze covering the ground or forming a deposit, as on a riverbed.

Source Water

The point at which water springs into being or from which it derives or is obtained. The point of origin, such as a spring, of a stream or river.


A point where ground water emerges (or seeps out) onto the surface of the ground, often forming the beginning of a stream.


Runoff water that results from a storm (usually rainfall) event.


Includes all rivers, creeks, brooks, tributaries and other flowing surface waters within a natural channel. More specifically, a perennial, intermittent, or ephemeral watercourse having a defined channel (excluding man-made ditches) which contains flow from surface and/or ground water sources during at least a portion of an average rainfall year. .

Stream Discharge

Quantity of stream flow per unit of time, generally expressed as cubic feet per second (CFS).

Stream Order

A numerical system (ranking from headwaters to river terminus) used to designate the relative position of a stream or stream segment in a drainage basin.


The portion of the channel cross-section that restricts lateral movement of water at normal water levels.

Surface Water

Water that is on Earth’s surface, such as in a stream, river, lake, or reservoir. A natural or artificial pond or lake used for the storage and regulation of water. .


The state in which the particles of a substance are mixed with a liquid but are not dissolved.


A depression or wide shallow ditch used to temporarily store, route, infiltrate, filter, or convey runoff.


Soil & Water Assessment Tool


Soil and Water Conservation District


Source Water Protection Initiative


Total dissolved solids


Total maximum daily load

Total Maximum Daily Load (TMDL)

A regulatory process that determines the volume or quantity of a given pollutant, calculated by watershed computer modeling, that can be assimilated by a receiving stream or water body on an average daily basis while maintaining the state designated water quality standard and designated use of the water body. Where existing pollutant loads to the receiving water body are in excess of the calculated TMDL, the responsibility for reducing the excess pollutant loads is allocated among existing sources of the pollutant to achieve the reductions necessary to re-attain the designated use of the water body.


Total suspended solids


Murkiness or cloudiness of water, indicating the presence of suspended sediments, dissolved solids, natural or man-made chemicals, algae, etc.


U.S. Department of Agriculture


U.S. Environmental Protection Agency


U.S. Geological Survey

Water Budget

An accounting of the movement of water through the components of the hydrologic cycle in a watershed, including precipitation, evapo-transpiration, surface runoff, ground water recharge, and ground water discharge to stream baseflow.

Water Quality

A state of water represented by a combination of productivity, chemistry, cleanliness and recreational potential. .

Water Table

The upper-most level of saturation of pore space or fractures by subsurface water in an aquifer.

Water Treatment

Systematic purification of water for human consumption.


The land area that drains water into a particular stream, river or lake. 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 watersheds, like the Mississippi River basin, contain thousands of smaller watersheds.

Watershed Management

Coordinated assessment and characterization of watershed conditions, and planning and implementation of strategies, approaches, tools, and techniques to protect and enhance the quality and quantity of water resources while achieving desired land and water uses.


Low-lying areas inundated or saturated by water at a frequency and duration sufficient to support wetland vegetation (e.g. wetlands include such areas as swamps, marshes and wet meadows). Wetlands remove pollutants through a series of chemical, physical and biological mechanisms.


The practice of dividing land into regions or parcels pertaining to its use or activities within it.