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<br />Volumetric calibrations were also performed to compare to the orifice meter readings. A known <br />volume in the head box of the model was filled and timed to obtain a discharge. This calibration <br />was within 1 percent of the orifice meter. These calibrations were necessary since the t10ws being <br />modeled were very small - as low as 50 ft'ls (0.036 ft'ls model). Care was taken during model <br />construction to prevent leakage through the Union Avenue dam and at the downstream rock dam. <br />Checks after the model was built confirmed that very little leakage occurred. <br /> <br />Calibration of dam, radial gate, and intake. - The Union Avenue dam was calibrated for t10w vs. <br />water surface elevation by taking point gauge readings of the water surface approximately 30 feet <br />upstream of the boatchute. A discharge rating curve of the Union Avenue dam and boatchute is <br />presented on figures 9A and 9B. Two regression equations are presented on figure 9A, depending <br />on the elevation of the water surface. The breaks in the curve correspond to the configuration of <br />the boatchute in relation to the water surface elevation. Figure 9B shows an enlargement of the <br />lower portion of the discharge rating curve. <br /> <br />The Englewood sluice radial gate was also calibrated for flow vs. water surface. Water surface <br />readings were made at the boatchute centerline about 30 feet upstream of the Union Avenue dam <br />for different gate openings between 1/2 foot and 3 feel. The t10w over the dam (figs. 9A and 9B) <br />was subtracted from the total inflow to obtain the radial gate flow. Figure 10 shows discharge <br />rating curves for different gate openings. <br /> <br />The Englewood water intake model t10w was also calibrated. Flow through the Englewood intake <br />was measured volumetrically. The number of turns on a valve controlling the model now through <br />the intake was related to the water surface elevation (fig. ] I). The model was normally operated <br />with the valve open two turns representing 30 ft'/s. This operation was necessary to ensure the <br />correct distribution of now between the Englewood intake, the sluice, and the now over the <br />boatchute and dam. Table 1 presents a typical distribution of nows that Englewood takes <br />throughout the year. During the boating season (May-September), Englewood's withdrawal is <br />typically 25 to 30 ft'/s. <br /> <br />Study of Boating Conditions <br /> <br />WWE provided Reclamation with drawings to construct the original boatchute configuration in the <br />physical model (figs. ]2 and 13). Boatchute] was 32 feet wide and the invert elevation was <br />5288 feel. Boatchute 2 downstream was also 32 feet wide and the invert elevation was 5284.5 feel. <br />The effect of the third boatchute on the upstream pool elevations was simulated by incorporating <br />a weir in the downstream end of the model with the proper shape and elevations to simulate <br />boatchute 3. Boatchute I curved toward the left to attempt to make the boats approach <br />boatchute 2. Tests were conducted for boating t10ws ranging between 100 and 3,000 ft'/s. The <br />results of the tests showed that the original boatchute configuration was not satisfactory for boating <br />nows. Rafts and kayaks impinged on the right side of the boatchute. Boatchute 2 handled boats <br />better, but some design changes were also necessary to further improve the now. <br /> <br />In January ]989, a revised boatchute design was constructed and tested in the physical model. The <br />Union Avenue dam boatchute was 32 feet wide and boatchute 2 was ()4 feet wide. Both chutes <br />employed a center trough to concentrate flow for smaller boating nows. An open bar barricade was <br />placed along the Englewood intake (fig. ]4) to prevent boaters from entering the sluiceway. The <br />left side of the boatchute was lowered (causing a superelevated chute) to try to force now to the <br /> <br />6 <br />