Hydrology is the scientific study of the waters of the earth, with a particular focus on how rainfall and evaporation affect the flow of water in streams and storm drains. Hydraulics is the engineering analysis of the flow of water in channels, pipelines, and other hydraulic structures.

Hydrology and hydraulics are a key part of the District’s work, serving as the scientific foundation for all of the District’s planning, design, and construction projects.

We collect hydrologic data in the form of precipitation and stream flow measurements. District staff and its consultants use sophisticated software tools to model the hydrology and hydraulics of the District’s flood control system. We have also developed a hydrology and hydraulics manual that outlines the requirements for new developments and modifications to existing flood control systems.