Figure Measuring Sacramento River Diversions with ADFM Technology in the Glenn-Colusa Irrigation District

The ADFM Velocity Profiler (ADFM) is a variation of the well-known Acoustic Doppler Current Profiler (ADCP). Although the ADFM relies on the same BroadBand signal processing found in the RD Instruments ADCP, there is a fundamental difference between the two systems. An ADCP is designed to provide the user with profiles of the three vector components of water motion — the x, y and z components of a water current flow velocity vector. By comparison, the ADFM measures multiple x-velocity component profiles in order to derive a distribution of x-velocity components throughout the water column. This distribution is used to calculate the total downstream volumetric flow. In other words, an ADCP measures all velocity components to determine the three-dimensional velocity structure in a column of water. The ADFM measures a specific velocity component in order to calculate the total volumetric rate of flow of the column of water. In April of this year, three (3) ADFMs were installed in the Stony Creek Siphon in the Glenn-Colusa Irrigation District (GCID). The purpose of the ADFM installations is to provide continuous monitoring of the volume of water diverted from the Sacramento River by the GCID. The installations were performed while the channel was "live" — there was no diversion or reduction in flow rate during the installation. The paper presents the methods of installation and initial flow data results from the ADFMs.