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How to read this
Every page is built the same way, so once you read one you can read all of them.
The chart
The solid line is the current value: reservoir storage in acre-feet, or streamflow in cubic feet per second. The shaded band behind it, when shown, is the historical envelope for the same time of year. Inside the band is normal. Below it is dry. Above it is wet. The dot marks the latest reading.
The "vs normal" number
Our yardstick for normal is the median of the same calendar week over the prior five years. When a page says something is 34% below normal, that is a computed figure: today's value against that five-year median, not a feel for the season. The colored tag at the top of each page bins it: well below normal, below normal, or at or above normal.
The table
Under or beside the chart is the same data as numbers: the latest value and how it moved week over week, month over month, year over year, and against the five-year median. The chart is for the glance; the table is for the decision.
The note
One short paragraph in plain English, leading with the number that matters. It only uses figures already on the page. It never forecasts.
What we do not say
We do not predict storage, runoff, or allocations. We report allocations as the agencies announce them. We are not investment, legal, or water-rights advice. Where a figure comes from a public agency, the page names it: the US Bureau of Reclamation, the USGS, the US Drought Monitor.
How often it updates
The underlying data is pulled daily, and a brief that reads the week's movements goes out once a week. Every page carries a visible "Last updated" date so you always know how fresh the reading is.
New to the vocabulary? The glossary defines every term the brief uses.