Every lake on this site, on one pair of charts: how far down it is from full, and how fast it is moving. Pick a season from the dropdown — this one, last one, or the median across all the years each lake has data for.

The lakes are different sizes and shapes, so "feet down" is not really an apples-to-apples measure of how much water each one holds. It is a fair measure of what you would see standing on the shore.

Speed is the 28 day moving average, not the day-to-day change — several lakes of raw daily change on one chart is unreadable.

These are three managed reservoirs — water managers decide how to draw each one down through the year as part of one system. This chart compares how they manage the three differently: when do they start a drawdown, how fast do they drain it, and how deep do they draw it?

It is really just a re-scaled, re-timed version of the same "feet down" data, changed in three ways so the three lakes can be compared on one chart:

Scaled to each lake's own capacity. The three lakes have very different drawdown capacities — the deepest each has ever been drawn below full is about 64 ft for Kachess, 90 ft for Keechelus, and 129 ft for Cle Elum. Dividing each day's feet-down by that lake's own all-time maximum drawdown normalizes them onto one scale: 0% is full, 100% is the deepest that lake has ever gone.

0% is at the top, so the line drops as the lake empties — full at the top, deepest drawdown at the bottom, matching what the water actually does. A lower line means further drawn down relative to that lake's own capacity.

The year starts May 1, not January, because that is when the reservoirs sit near full, just before the summer draw. Read left to right you see the whole arc: full in spring, drawn down through summer and fall, refilling over winter.

Pick a season from the same dropdown above — this year, last year, or the median across all the years each lake has data for.