Where the water came from and where it went, in acre-feet per day at current rates. Dam releases and withdrawals have no complete public feed, so the residual is what the conservation-of-mass equation requires — it is an inference, not a measurement.
USGS gauges, at current rates
Climatological estimate over ~22,330 acres
Level trend since midnight, scaled to 24 h
What conservation of mass requires to balance the books
The residual is equivalent to roughly 64 cfs flowing out of the lake — mostly dam releases and withdrawals, plus whatever the gauges upstream didn’t see.
The river leg is measured at a USGS gauge downstream of the dam — a proxy for releases. The balance leg is whatever the mass-balance residual can’t attribute: municipal intake, ungauged runoff, and estimation error. Legs can overlap conceptually; treat proportions as honest approximation, not gospel.
Inflow converts current streamflow at the USGS gauges to acre-feet per day (1 cfs ≈ 1.9835 af/day). Evaporation uses long-term monthly averages for the region over an estimated current surface area — it will switch to TWDB’s daily lake-evaporation model once an API key is configured. Storage change scales today’s level change (vs. midnight, LCRA) to a 24-hour rate using an elevation–area approximation. The residual closes the balance and bundles dam releases, withdrawals, and ungauged runoff — inseparable without data the operator does not publish.
Early in the day (before ~3 a.m.) the storage trend is withheld to avoid wild extrapolation. All inputs are provisional; treat this page as an honest estimate, not an official accounting.