Table 2. Performance Number values of stilling basin models S.No Name of model L dm (cm) ds (cm) PN Remarks 1 SQA-1 12.9d 8.8 19.2 0.15 USBR BASE MODEL 2 SQA-2 12.9d 5.6 14.3 0.22 3 SQA-3 12.9d 3.4 13.9 0.44 4 SQA-4 12.9d 7.5 20.5 0.20 5 SQA-5 12.9d 4.9 15.7 0.29 BEST USBR MODEL IN 12.9d 6 SQA-6 12.9d 3.0 14.7 0.56 7 SQA-7 12.9d 5.7 17.3 0.25 8 SQA-8 12.9d 4.6 27.4 0.56 9 SQA-9 12.9d 2.7 19.3 0.87 BEST MODEL IN 12.9d 10 SQA-10 10.9d 5.0 24.5 0.44 11 SQA-11 10.9d 3.3 12.5 0.42 12 SQA-12 10.9d 3.2 14.1 0.59 13 SQA-13 10.9d 4.1 17.1 0.41 14 SQA-14 10.9d 3.8 11.6 0.31 15 SQA-15 10.9d 3.1 19.4 0.71 BEST MODEL IN 10.9d (Rounded end sill) 16 SQA-16 10.9d 4.3 13.4 0.30 17 SQA-17 10.9d 4.3 13.5 0.30 18 SQA-18 10.9d 4.2 15.6 0.36 19 SQA-19 10.9d 6.5 17.6 0.21 20 SQA-20 10.9d 6.7 17.8 0.20 21 SQA-21 10.9d 2.6 10.8 0.51 BEST MODEL IN 10.9d (Sloping end sill)