Aquifer—An area where large amounts of water are stored underground in natural formations of sand, gravel or rock.

Base flow—The water that is in the river during dry periods. The source of base flow is usually groundwater.

Basin—A depression in the earth's surface. A body of water such as a lake or river is often located in the bottom of the basin.

Buffer strip—An undisturbed natural area near a stream. Buffer strips help prevent excessive runoff.

Capital Improvement Project (CIP)—A project funded through a governmental entity that is designed to improve a community’s infrastructure, such as flood control structures, stormwater drainage, highways, streets, parks and public buildings.

Contributing zone—The portion of a watershed upstream of an aquifer recharge zone that supplies runoff for potential recharge.

Conveyance—The process of channeling water in a particular direction or controlling the amount of water flow for the purpose of flood management.

Dam—A barrier built across a watercourse for the purpose of impounding water.

Detention Facilities—Structures such as dams, levees, reservoirs and floodways that are designed to detain water or retard water flow.

Drainage path—The direction that water flows in a watershed.

Erosion—The wearing away of the earth's surface by any natural process, most commonly caused by flowing water.

Floodplain—The area along the edges of a stream or river where floodwaters deposit sediments and that is subject to flooding.

Impervious cover—Any type of material on the ground that prevents water from infiltrating. Examples are asphalt, concrete, brick or metal.

Low Water Crossing—A low-lying roadway that is subject to flooding during rain events.

Mitigation—The process of reducing water flow for the purpose of flood management, which includes structural and non-structural methods.

Non-point source pollution—Pollution that can't be traced to a single source. Non-point source pollution usually enters the water as overland flow, rather than from a single pipe. (see point source pollution)

One-hundred year flood—This is a flood that has a 1 percent chance of happening in any given year.

Outfall—The end point of a drainage system where water is discharged into a waterway or detention facility.

Point source pollution—Pollution that can be traced to a single source such as a factory. The pollution generally flows from a single pipe.

Property Buyouts—The purchase of property within an identified flood hazard zone by government agencies for the purpose of protecting lives and property.

Recharge—The water that infiltrates into the soil and replenishes the groundwater supply of an aquifer.

Recharge zone—The area of land where water infiltrates into the soil and replenishes the groundwater supply of an aquifer.

Regional Project—An area above a creek or stream measuring 960 acres or more (1.5 square miles) where a flood mitigation project is implemented. Work of the BRWM targets areas that meet this definition.

Reservoir—A place where a liquid, especially water, is stored.

Return flow—Treated effluent released from wastewater treatment plants into a river or stream.

Riparian—Of, on or relating to the banks of a natural course of water; the vegetated corridor along streams and rivers.

Runoff—Water that flows over the surface of the land when rainfall is not able to infiltrate into the soil, either because the soil is already saturated with water or because the land surface is impermeable.

Stream segment—A section of a stream that has the same types of conditions along its entire length.

Watershed—All of the land area that drains water into a common point, usually a stream, river or lake.