Flow Stage and Pore Pressure
Stage is measured by both radar and laser distance meters suspended over the channel. Both devices measures the distance from the sensor to the surface below. When no runoff is present, the measurement surface is the surface of the channel bed. Distance measurements are converted into a stage above a datum, which is 0.5 m below the pressure transducer in the channel bed.
The radar sensor is better suited for measuring clear-water flows. The laser, which can be sampled at a much higher rate, is better suited for resolving the rapid stage changes associated with fast-moving debris flows. The laser is only operated during rain events to conserve power.
A pressure transducer vented to the atmosphere is used to measure fluid pressures in the pores of the bed directly beneath the stage gage. The pressure transducer is mounted in the bedrock. Pressure is displayed as an equivalent stage of water in meters.
Stage, pore pressure, and rainfall for last hour
Stage, pore pressure, and rainfall for last 3 days
