Laserfiche WebLink
WORWEST <br /> COR PORAT ION <br /> of the meter sensor. Each subsection's velocity will be multiplied by the depth and width <br /> of that subsection to get a flow volume. The individual subsection velocities will be <br /> summed to get a total flow volume. <br /> 2.3.2.2 Flume <br /> A one-inch (1") Parshall Flume, illustrated in Figure 2-2, will be used to measure low <br /> flows where the channel depth is less than 0.2 feet deep. Three-foot (3') wooden wing <br /> walls will be used to divert the stream into the upstream convergent section of the flume. <br /> The staff gauge, located on the upstream end of the flume, will be read and matched <br /> against the Parshall Flume Flow Table, Attachment C. <br /> y <br /> �? <br /> FIGURE 2-2 <br /> PARSHALL FLUME <br /> The flume will be set in a narrow part of the stream at a location where the wing walls <br /> can be positioned to divert the water into the flume. A bubble level will be used to <br /> balance the flume and the wing walls will be set to capture the flow, with dirt used to seal <br /> leaking around the wing walls. Once all water appears to be routed through the flume, <br /> the water depth measurement on the upstream end of the flume will be recorded and a <br /> flow value retrieved from the corresponding flow table. <br /> 2.3.2.3 Float Test <br /> The float test will only be used when channel conditions do not allow a person to safely <br /> enter the stream. A straight section of the stream, uniform in width and depth, will be <br /> measured and marked with flagging. The mean width and depth will be estimated or <br /> measured and recorded in the field book. A piece of cork will be tossed into the middle <br /> of the stream above the upstream marker. A stopwatch will be started when the cork <br /> passes the upstream marker and stopped when it passes the downstream marker. The <br /> time of travel in seconds will be recorded in the field book and the float test will be <br /> TRANSIT MIX CONCRETE CO. <br /> SURFACE WATER AND GROUNDWATER MONITORING PLAN <br /> 2-5 <br />