Final snow survey

Final snow survey of the season today shows continuing melt through March. The snow melts twice as fast in the larch stand compared to the mature cedar stand due to the lack of shading and higher net radiation under the deciduous canopy without leaves.

Snow survey summary, snow water equivalent
Larch: 35 cm (down from 51 cm to 35 cm over 16 days = 1.0 cm/day)
Mature cedar: 28 cm (down from 36 cm to 28 cm over 16 days = 0.5 cm/day)

A discharge measurement was also taken under rainy and very cold conditions to confirm the stage-rating curve after the winter and before the main snowmelt season.

Stage = 57.25 cm, Q = 3.14 m3/s

Log jam removal

Today's main task was to remove the log jam below the gauging station, in addition to downloading the Hobo water level recorder and resetting it under the water by the staff gauge. This was cold work in a stream swollen with snowmelt water. After removing the log jam, the water level immediately dropped by about 55 mm at the gauging station, confirming a backwater effect which had been influencing stage measurement.

March snow survey

Snow survey results showed that the snow water equivalent (SWE) was less than in February, with about 51 cm SWE in the larch stand and about 35 cm SWE in the cedar stand (see photo above).

The snowmelt season has already begun with two runoff events early March, and the winter season also shows several significant runoff events during January and February (see hydrograph below).

The photo above shows a small log jam below the gauging station that was likely having an impact on the gauged water level and the stage-rating curve. The log jam was removed two days later on March 8th, when water levels immediately dropped by about 55 mm at the gauging station.