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~ ~ t On June 28, 2001, discharge measurements were made at main canal and diversion locations from CH09 to CEND, a 3.7-mile subreach of Chilili Canal beginning about 1.2 miles downstream from the headgate (fig. 8 and table A3). No leak- age was observed at the diversion gates. The loss from CH09 to CEND was computed to be 1.4 ft3/S, or 28 percent of the subreach inflow (fig. 9 and table 6). On June 19,2003, discharge measurements were made at main canal and diversion locations from CHHG to CEND, a distance of about 4.9 miles (fig. 8 and table A3). Minor leak- age of about 0.002 ft3/S was estimated at each of two diver- sion gates (table A3). The loss from CHHG to CEND was computed to be 2.8 ft3/s, or 34 percent of the headgate inflow (fig. 9 and table 6). Losses in Chilili Canal ranged from about 2 percent of the head gate inflow to about 34 percent of the head gate inflow (table 6). The variability in losses may be somewhat related to length of time the canal was flowing before the measure- ment. For example, the canal had been flowing continuously for about 97 days before the loss and gain measurements on August 1,2000. A loss of about 0.2 ft3/S, or 2 percent of the headgate inflow, was measured on August 1, 2000. This is compared with a loss of 2.8 ft3/s, or 34 percent of the head- gate inflow measured on June 19,2003, when the canal had been flowing for about 38 days before the measurements were made. \ \ 'I I Enlarged Southside Canal Enlarged Southside Canal diverts water from the right bank of the Purgatoire River downstream from the Picketwire and Chilili canal diversions. Enlarged Southside Canal flows along the southeast side (right bank) of the Purgatoire River (fig. 10). A lO-ft Parshall flume with a free-flow capacity of about 300 ft3/S is used to measure irrigation diversions at the Enlarged Southside Canal headgate. Loss and gain measurements were made along Enlarged Southside Canal on August 9-11, 2000, May 22-23, 2001, June 27,2001, and June 8-9, 2D04, Information for individual measurements is summarized in table A4 in the Appendix. The computed losses and gains for seven main canal subreaches, including main Enlarged Southside Canal from the headgate (SSHG) to the Palaski Extension (SSSl), Pa1aski Extension (SSSl to SP1D), main Enlarged Southside Canal to the Sandova1/Wagner split (SSS 1 to SSS2), Sandoval Extension (SSS2 to SS08), Enlarged Southside Canal from SSS2 to SSS3 (fig. 10), South Wagner Extension (SSS3 to SW05), and the North Wagner Extension (SSS3 to SW12) are listed in table 7. Measurement site locations are shown in figure 10. Figure 11 shows losses and gains in relation to distance downstream from the Enlarged Southside Canal headgate. On August 9-11, 2000, discharge measurements were made at main channel and diversion locations along Enlarged Southside Canal (fig. 10). Leakage was reported at one closed diversion gate. The leakage was determined to be about Canal Losses and Gains 23 0.1 ft3/s. Before the measurements were made, the canal had been continuously flowing for about 92 days. Losses and gains only were computed between SSS2 and SS07 along the Sandoval Extension, because a main-channel measurement was not made at SS08 during 2000. A gain of about 3.4 ft3/s (19 percent of the subreach inflow) was detennined between SSS 1 and SPlO (Palaski Extension), and losses of 3.5 ft3/S (10 percent of the subreach inflow) and 1.2 ft3/S (13 percent of the subreach inflow) were determined between SSS2 and SS07 (Sandoval Extension) and SSS3 and SW05 (South Wagner Extension), respectively (table 7 and figs. 10 and 11). All other losses and gains were within the measurement uncertainty, Discharge measurements were made from SSHG to SSSl, SSSl to SP10, SSSl to SSS2, SSS2 to SS08, and SSS2 to SSS3 on May 22-23, 2001 (fig. 10). One diversion gate (SP05) was closed with some leakage reported; however, no estimate of leakage was made. Before the measurements, the canal had been continuously flowing for only about 10 days. Computed losses and gains in the subreaches were all within the measurement error of 8 percent except along the Sandoval Extension between sites SSS2 to SS08. This subreach had a computed loss of 2.9 ft3/s, or about 11 percent of the subreach inflow (fig. 11 and table 7). Discharge measurements were made from SSS 1 to SSS2, SSS2 to SSS3, SSS3 to SW05, and SSS3 to SWl2 on June 27, 2001 (fig. 10). One diversion gate was closed with no leakage observed (table A4). Before the measurements were made, the canal had been continuously flowing for about 45 days. Computed losses and gains in the subreaches were all within the measurement error of 8 percent except along the main Enlarged Southside Canal between sites SSS2 and SSS3. This subreach had a computed loss of 5.0 fe/s, or about 14 percent of the subreach inflow (fig. 11 and table 7). On June 8-9, 2004, discharge measurements were made at main channel and diversion locations along Enlarged Southside Canal (fig. 10). Two diversion gates were closed. Some leakage was reported at one of the closed gates (SP05); however, no estimate of leakage was made (table A4). Before the measurements were made, the canal had been continuously flowing for about 32 days. Computed losses and gains in the subreaches were all within the measurement error of 8 percent except along the North Wagner Extension between sites SSS3 and SWI2. This subreach had a computed loss of 1.5 ft3/s, or about 9 percent of the subreach inflow (table 7 and fig. 11). Model Inlet and Outlet Canals Model Canal diverts water from the left bank of Purgatoire River downstream from the Picketwire, Chilili, and Enlarged Southside canal diversions (fig. 1). Water diverted into Model Canal is used to supply Model and John Flood Canals with water for irrigation. A 10-ft Parshall flume with a free-flow capacity of about 300 ft3/s is used to measure irrigation diversions at the Model Canal headgate. Model Inlet Canal (Model Canal upstream from the Model Reservoir)