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WORWEST <br /> COR PORAT ION <br /> conditions. A flow meter will be used for high flow conditions, a flume used for lower <br /> flow conditions, and the float test used when the channel bottom and/or banks are too <br /> unstable to enter the stream. Professional judgment and safety concerns will be used to <br /> determine the best method to measure flow during each site visit; however, the flow <br /> meter will be used whenever possible. When possible, flow will be measured in a <br /> straight reach of the stream containing laminar flow, avoiding disturbances such as <br /> boulders, dead vegetative debris and aquatic vegetation. <br /> 2.3.2.1 Flow Meter <br /> A Marsh-McBirney Flo-Mate 2000 flow meter, Figure 2-1, or a similar flow meter will <br /> be used with a top-setting wading rod to measure flow when the depth of the channel is <br /> approximately 0.20 feet or greater (Marsh-McBirney, 2000). To stabilize the velocity <br /> readings, the instrument will be programed to display the average of velocities over a <br /> period of 20 seconds using the Fixed Point Averaging feature. <br /> M2 <br /> FIGURE 2-1 <br /> MARSH-MCBIRNEY FLO-MATE 2000 <br /> Once the location for the cross-section is established, a measuring tape will be stretched <br /> between the end-points of the cross-section perpendicular to flow and secured to both <br /> banks. The distance from left water's edge to right water's edge will be divided into <br /> equal sections ranging from 0.2 feet to 0.5 feet, depending on the width of the channel, to <br /> form the subsections. The depth within each subsection will be recorded and the meter <br /> sensor will be positioned on the top-setting wading rod to 60% of the depth by lining up <br /> the foot scale on the sliding rod with the tenth scale on the top of the depth gauge rod. <br /> Velocity will be measured within the subsections of the stream's cross-section by the flow <br /> meter calculating the voltage that is produced as water passes through the magnetic field <br /> TRANSIT MIX CONCRETE CO. <br /> SURFACE WATER AND GROUNDWATER MONITORING PLAN <br /> 2-4 <br />