Streamgage measurements, Elwha River, Washington, 2011 to 2016

Streamgage levels on the Elwha River were measured from 2011 to 2016. These measurements show the height of the river's water surface, both in meters relative to the stream bed, as well as in meters relative to vertical geographic coordinates. Measurements were collected using a Global Water WL16 battery-operated vented water level logger in a hardened casing. The instrument was installed on October 17, 2011 on the left bank of the Elwha River at a power line crossing above the Elwha Surface Water Intake (at approximately river kilometer 5.6), which is downstream of the (now historical) Elwha Dam site. Data collection ended May 12, 2016. The data were collected as part of a study investigating responses of the Elwha River to the removal of two large dams: the Glines Canyon and Elwha dams. From July 2, 2015 to October 31, 2015 the gauge was buried under a gravel bar, and the data are not reliable. These data are flagged as "BURIED" in the spreadsheet's "FLAG" column. From April 21, 2016 through May 12, 2016 periods of noise and bad data (flagged "NOISE" and "BAD") interrupted valid data values. The gauge was beginning to fail, but comparison with USGS 12046260 stage data allowed identification of valid data. After May 12, 2016, significant deviations from expected values and increased noise appeared. This was interpreted as instrument failure and no further data were marked valid. Data are included for reference purposes but flagged as "BAD."