| A | B | 
|---|
| abiotic | a nonliving part of the environment | 
| absorb | to take in or suck or swallow up | 
| biotic | a living part of the environment | 
| brackish water | the mixture of fresh and saltwater | 
| dissolved oxygen | free O2 molecules in water; important for aquatic animal life | 
| divide | an area of high elevation that separates one watershed from another | 
| cisterns | artificial reservoirs or tanks for storing water, usually underground | 
| conservation | controlled use or systematic protection of natural resources | 
| contaminate | to make impure or unfit for use by adding something harmful or unpleasant | 
| ecosystem | all the biotic communities that live in an area together with the abiotic factors in the environment | 
| erosion | the carrying away of weathered rock sediments and soil by weather and water; a natural process where soil is lost and transported | 
| estuaries | a region of water where a freshwater source meets salt water from the ocean | 
| eutrophication | excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen. | 
| flood | a rising and overflowing of a body of water onto normally dry land | 
| flood plains | a plain built up by stream deposition | 
| forestry | the science of cultivation, maintaining, and developing forests | 
| groundwater | water contained in aquifers underground in the porous or jointed bedrock | 
| habitat | the environment in which a particular species lives | 
| hypoxia (anoxia) | oxygen deficiency in a biotic environment.  Anoxia is an extreme form of hypoxia | 
| irrigation | to supply with water by artificial means (i.e. bringing water to fields that are not near water or in an area that receives plenty of rainfall) | 
| landforms | feature of the Earth’s surface attributed to natural causes | 
| macroinvertebrate | fairly large organisms that lack a spinal column such as worms, snails, and larvae of flies, dragonflies, etc. | 
| migratory | passing through periodically from one region or climate to another for feeding or breeding | 
| neutralize | To make harmful substances harmless | 
| nonpoint source | inputs and impacts which occur over a wide area and are not easily attributed to a single source | 
| nutrients | substances needed by organisms for energy, growth, repair, or maintenance | 
| organism | all living things (plants, mammals, bacteria, fungi, fish) | 
| pH | a measure of the acidity or alkalinity of a liquid or damp substance (such as soil)  The pH scale ranges from 0 – 14:  0 is the most acidic, 14 is the most alkaline, and 7 is neutral | 
| point source | a single, identifiable source of pollution, such as a pipe or a drain. | 
| pollutants | harmful materials that enter the environment | 
| pollution | contamination of air, soil, or water by the discharge of harmful substances | 
| potable water | fit or suitable for drinking | 
| reservoirs | places where water is collected and stored such as in a natural or artificial lake for use as drinking water or to create hydroelectric power | 
| river system | a river and all of its tributaries | 
| runoff | water from rainfall and the melting of ice that runs along the ground. | 
| salinity | a measure of the dissolved salts in a sample of water | 
| sanitary sewer | an underground system meant to collect and transport waste | 
| sediments | small particles (usually rock) that settle to the bottom of a body of water | 
| surface water | the water that is above ground in streams, lakes, rivers, and ponds | 
| sustainability | avoidance of the depletion of natural resources in order to maintain an ecological balance. | 
| tidal | alternate rising and falling of the surface of the water, and the area that is affected by this water level change | 
| topography | the shape of a land surface, showing the positions and changes of elevations of the land such as mountains, valleys, and rivers | 
| toxics | poisonous substances | 
| tributary | a stream of water that feeds into a larger stream, river, bay or ocean | 
| turbidity | sediments suspended in water which cause the water to be unclear or cloudy | 
| waste management | the control and regulation of waste | 
| water quality | a measurement of water pureness | 
| water supply | surface water that provides public drinking water (such as rivers, streams, lakes, reservoirs, springs, and ground water) | 
| watershed | a region or area where water travels downhill and ultimately drains into a large body of water | 
| wetlands | an ecosystem in which the roots of the plants are submerged under water at least part of the year (i.e. marshes, bogs, swamps, etc) |