Doppler Area Velocity Meter Station

Dallas, Texas

Most open channel flow measurement methods require flow to transition from subcritical to supercritical.  In some cases, the flow transition is difficult or impossible to achieve due to conflicts with existing utilities, existing interceptor hydraulics, or downstream connections.  In those cases, alternate methods of flow measurement are needed.  The Trinity River Authority of Texas recently installed an area-velocity meter to measure flow in an interceptor that was not suitable for other types of metering.  Using Doppler radar and an ultrasonic level indicator, the open water surface area and the velocity of the water can be measured.  These two values are used to calculate the flow rate in the interceptor.  This meter station started operation in 2015.

Parshall Flume Meter Stations

Dallas, Texas

Accurate flow measurement is critical for many clients.  Used for billing, flow projection, and capacity evaluation, dedicated meter stations are used at treatment plants and in collection systems.  Designed with careful consideration of the upstream and downstream hydraulic conditions, our engineers are experienced in optimizing the entrance and exit conditions of Parshall Flumes to achieve a distinct, repeatable transition from subcritical to supercritical flow.  PECI recently designed multiple meter stations for the Trinity River Authority of Texas.  One meter station was particularly challenging as it was experiencing hydraulic wave action that interfered with level measurement.  PECI evaluated the installation and determined that the upstream interceptor could not provide the flow conditions needed for accurate measurement.  PECI recommended a vortex-type flow baffle in an upstream manhole and flattening the slope of the interceptor to improve entrance conditions.  The three-foot flume and associated work is under construction and is expected to be in service by the end of 2017.

Collection System Meter Stations

Perkins Engineering Consultants has become a leader in meter station evaluation and design for wastewater collection systems.  From traditional measuring devices, such as Parshall and Palmer-Bowlus Flumes, to cutting edge technology, such as the Hach Flodar® AV sensor, our engineers have evaluated and designed multiple meter stations.  Flow regimes, hydraulic calculations and interpretation of the results all play important roles in the success and accuracy of any meter station.  Our expertise extends to evaluating upstream and downstream conditions, determining the state of flow across the entire range of flows, and setting the appropriate installation conditions for successful operation.