HEC-HMS is a hydrological modeling software developed by the U.S. Army Corps of Engineers to simulate the precipitation, runoff, and streamflow of watersheds. It allows water resource managers, engineers and other professionals to forecast river flows, calculate dam and levee capacities and design reservoirs. HEC-HMS uses precipitation data, soil characteristics, land use and vegetation cover, and other parameters to simulate the hydrological cycle and hydraulic processes in a watershed. The software is used to support water management and planning decisions by providing data and information to stakeholders.

HEC-RAS (Hydrologic Engineering Centers-River Analysis System) is a software application used for modeling water flow in rivers, channels, and other waterways. It is mainly used by engineers and hydrologists for hydraulic analysis, floodplain mapping, and bridge and culvert design. The application uses hydraulic and hydrologic principles to calculate water depths, velocities, and flow rates in order to predict how a river or waterway will behave under specific conditions. It also helps in predicting the impact of changes in flow on the environment and infrastructure.

Hydraulic structure pertains to the design, construction, and maintenance of structures that manage water resources such as dams, channels, culverts, and water treatment plants. This field requires expertise in engineering, hydrology, and geology to create sustainable structures that ensure the efficient and safe management of water for human consumption, irrigation, and flood control. As a specialized skill, professionals in hydraulic structure work closely with environmental experts, government officials, and communities to ensure water security and safety.

Hydrologic Analysis refers to the study and evaluation of the distribution, movement, and properties of water in the environment. This skill encompasses the use of mathematical models and data collection techniques to assess water flow, precipitation patterns, and watershed characteristics. Knowledge of Hydrologic Analysis is applied in various fields such as water resource management, flood risk assessment, and environmental protection to inform decision-making and develop effective management strategies.

SewerCAD refers to the use of software for planning, analyzing, and designing sanitary sewer systems. It is used to build hydraulic models, evaluate system capacity, and support the sizing of pipes, manholes, and related components. The skill is applied in engineering and infrastructure work to assess flow conditions, compare design options, and document sewer network performance.