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<br />I <br /> <br />I <br /> <br />I <br /> <br />I <br />I <br /> <br />I <br /> <br />I <br /> <br />I <br />I <br /> <br />I <br /> <br />I <br />I <br /> <br />I <br />I <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />I <br /> <br />PLAN OF DEVELOPMENT <br /> <br />Existing Condition: <br /> <br />The Highland Lateral and Farmers Irrigation Ditch is plagued with many problems. <br /> <br /> <br />These include excessive scour erosion and structural problems involving the check <br /> <br />structures and turnouts. These problems have occurred from improper hydraulic <br /> <br />design at the time the ditch was originally built. Three (3) items associated <br /> <br /> <br />with irrigation ditch design are measuring devices, check structures and the canal <br /> <br /> <br />itself. These items will be briefly described in the following pages, with respect <br /> <br /> <br />to their relationship to the existing ditch and future proposed improvements. <br /> <br />Measuring Devices: <br /> <br />Irrigation water from this ditch is supplied to the stockholders through metering <br /> <br />gates which gauge the flow of the water by measuring the difference in head at <br /> <br /> <br />the inlet and outlet sides of the gate. A diagram of these metering gates is <br /> <br />shown on Exhibit 2. <br /> <br />To measure flow, all one must do is measure E1 and E2. Using Bernoulli's Equation, <br /> <br />the velocity can then be obtained. When the area of the pipe is known, the Con- <br /> <br />tinuity Equation is used to establish the flow. All the metering gates used along <br /> <br />the ditch are premanufactured and have been approved by the Ditch Companies. Manu- <br /> <br />facturers* of these gates publish a booklet which lets one directly find the flow <br /> <br />through the pipe merely by calculating the difference in the E's. <br /> <br />This makes the gates very easy to use. The ditch rider can adjust the amount of <br /> <br /> <br />flow each stockholder needs simply by adjusting the level of E1, using the check <br /> <br />structures which are just downstream of each set of measuring gates. He can also <br /> <br />adjust the flow by partially opening the supply gate. <br /> <br />Currently, there are sixty-one (61) meter gates along the length of the ditch <br /> <br />which distribute water to the shareholders. It is known that, in general, the <br /> <br /> <br />gates are working well; but there are some which have been damaged over the years <br /> <br />and are not operating properly. One of the more noticeable problems is the buildup <br /> <br />of silt and trash in the measuring ports. This is a maintenance problem, which <br /> <br />*Example: <br /> <br />Model CM-I0 Cahal Gate by Waterman Industries, Inc. Exeter Calif. <br /> <br />14 <br />