About
About The Waterline
Public water data, read the way an operator reads it, with no forecast attached.
What this is
The Waterline is a weekly brief plus a set of always-current data pages on western US water: reservoir storage, river-basin rollups, drought class, and CVP and SWP water-supply allocations. It is built for the people who have to act on the numbers: irrigators, district staff, ag lenders, and consultants. It is not written for water lawyers, and it does not try to settle a water-rights question.
Who writes it
The Waterline is published by Alex Willen. The data pages are generated from the public record on a fixed schedule; the weekly brief reads what moved and writes it up in plain English. Every hard number on every page traces back to the agency that published it.
Where the numbers come from
Reservoir storage comes from the US Bureau of Reclamation, pulled through its RISE API. Streamflow comes from the USGS Water Data OGC API. Drought class comes from the US Drought Monitor. CVP and SWP allocation percentages come from California DWR and Bureau of Reclamation announcements, read directly off the agencies' own releases. Nothing here is estimated, interpolated, or sourced from a private data vendor.
How often it updates
The underlying data is pulled from the public record daily. One brief goes out a week, reading the movements that mattered. Every data page carries a visible "Last updated" date so you know exactly how fresh the reading is before you use it.
What we will and will not do
We report public data and attribute every hard number to its agency source. We do not forecast storage, runoff, drought, or allocations. We are not investment, legal, or water-rights advice; decisions are yours to make with your own counsel and the primary agency data.
New here? Start with how to read this, or see the exact math behind every comparison on the methodology page.