Water Resources Engineering Glossary

A subsurface geological formation capable of storing and transmitting groundwater in quantities sufficient for extraction.

The portion of streamflow contributed by groundwater discharge, sustaining flow during dry periods between storms.

A fundamental equation relating pressure, velocity, and elevation in fluid flow, expressing the conservation of energy along a streamline.

A closed conduit that conveys water under a road, railroad, or embankment, designed to pass a specific design flow without overtopping.

A barrier constructed across a waterway to impound water for storage, flood control, hydropower, or other purposes.

The volume of water flowing past a given point per unit time, typically measured in cubic feet per second (cfs) or cubic meters per second (cms).

The combined process of evaporation from surfaces and transpiration from vegetation, representing a major water loss in the hydrologic cycle.

The relatively flat area adjacent to a river channel that is periodically inundated during high-flow events.

The vertical distance between the design water surface elevation and the top of a channel, levee, or dam, providing a safety margin against overtopping.

Water stored in the saturated zone beneath the Earth's surface, filling the pore spaces of soil and rock formations.

The rate of change of hydraulic head with distance, which drives groundwater flow from areas of high head to low head.

A graph showing the variation of streamflow discharge over time at a specific location, used to analyze watershed response to precipitation.

The process by which surface water enters the soil through pores and fractures, recharging soil moisture and groundwater.

A line on a map connecting points of equal rainfall depth, used in spatial rainfall analysis over a watershed.

An embankment built along a waterway to prevent flooding of adjacent lands by containing floodwaters within the channel.

Paving materials designed to allow stormwater to infiltrate through the surface into a stone reservoir beneath, reducing runoff volume.

Water falling from the atmosphere in the form of rain, snow, sleet, or hail, serving as the primary input to the hydrologic cycle.

A natural or artificial lake used for the storage and regulation of water for supply, flood control, irrigation, or hydropower.

The portion of precipitation that flows over the land surface to streams, rivers, and other water bodies rather than infiltrating into the ground.

A structure designed to safely pass excess water from a reservoir downstream, preventing the dam from being overtopped.

Runoff generated by precipitation events, which can carry pollutants from urban and agricultural surfaces into receiving water bodies.

The rate at which groundwater flows through a unit width of aquifer under a unit hydraulic gradient, equal to hydraulic conductivity times aquifer thickness.

The upper surface of the saturated zone in an unconfined aquifer, where water pressure equals atmospheric pressure.

A topographically defined area of land where all precipitation and surface water drains to a common outlet point.

A low dam or barrier across a channel used to measure or control the flow of water, with a known relationship between water depth and discharge.