Glossary
Hydrograph
A hydrograph is a graph of stage or discharge over time—how fast water rose or fell through a storm or drawdown. It turns a single elevation reading into trend context.
Why it matters
A lake “down three feet” means little without knowing whether it is still falling after a two-week drawdown or rebounding after rain. Hydrographs show slope and timing—the shape operators watch when managing flood pool storage.
