Area Area Catchment Soil Class Contributing Area Coefficient Base Time(hrs)

Catchment
No.
A(Ha) A(Sq. Km) Slope C/S I CS CW CL CA A S TS

1 56.42 0.56 7.0 4 0.37 1.0 1.5 0.56 0.56 4 1

2 62.61 0.63 7.0 4 0.37 1.0 1.5 0.56 0.63 4 1
3 38.13 0.38 8.8 4 0.37 1.0 1.5 0.56 0.38 4 1
4 59.78 0.60 8.3 4 0.37 1.0 1.5 0.56 0.60 4 1
5 38.73 0.39 4.6 4 0.37 1.0 1.5 0.56 0.39 4 1
6 50.90 0.51 3.5 4 0.29 1.0 1.5 0.44 0.51 3 1
7 49.96 0.50 3.8 4 0.29 1.0 1.5 0.44 0.50 3 1
8 1.60 0.02 0.4 4 0.21 1.0 1.5 0.32 0.02 2 1
9 0.15 0.00 0.5 4 0.21 1.0 1.5 0.32 0.00 2 1
10 97.15 0.97 5.2 4 0.37 1.0 1.5 0.56 0.97 4 2
11 88.99 0.89 4.1 4 0.37 1.0 1.5 0.56 0.89 4 3
12 32.46 0.32 3.8 4 0.29 1.0 1.5 0.44 0.32 3 4
13 69.08 0.69 6.3 4 0.37 1.0 1.5 0.56 0.69 4 5
14 35.24 0.35 4.2 4 0.37 1.0 1.5 0.56 0.35 4 6
15 31.24 0.31 2.2 4 0.29 1.0 1.5 0.44 0.31 3 7
16 48.80 0.49 2.0 4 0.29 1.0 1.5 0.44 0.49 3 8
17 34.93 0.35 2.3 4 0.29 1.0 1.5 0.44 0.35 3 9
18 27.25 0.27 3.0 4 0.29 1.0 1.5 0.44 0.27 3 10
19 103.45 1.03 4.5 4 0.37 1.0 1 0.37 1.03 4 11
20 39.05 0.39 3.0 4 0.29 1.0 1 0.29 0.39 3 12
21 21.60 0.22 0.7 4 0.21 1.0 1 0.21 0.22 2 13
22 9.82 0.10 2.3 4 0.29 1.0 1 0.29 0.10 3 14
23 0.35 0.00 4.3 4 0.37 1.0 1 0.37 0.00 4 15
24 1.98 0.02 1.6 4 0.29 1.0 1 0.29 0.02 3 16
25 120.74 1.21 2.32 4 0.29 1.0 1 0.29 1.21 3 17
26 28.93 0.29 2.25 4 0.29 1.0 1 0.29 0.29 3 18
 Area Area Catchment Soil Class Contributing Area Coefficient Base Time(hrs)
Catchment
No.
A(Ha) A(Sq. Km) Slope C/S I CS CW CL CA A S TS

27 43.81 0.44 4.55 4 0.37 1.0 1 0.37 0.44 4 19

28 43.07 0.43 4.13 4 0.37 1.0 1 0.37 0.43 4 20
29 40.79 0.41 3.64 4 0.29 1.0 1 0.29 0.41 3 21
30 6.34 0.06 0.26 4 0.21 1.0 1 0.21 0.06 2 22
31 88.68 0.89 2.27 4 0.29 1.0 1 0.29 0.89 3 23
32 28.40 0.28 3.52 4 0.29 1.0 1 0.29 0.28 3 24
33 77.13 0.77 3.10 4 0.29 1.0 1 0.29 0.77 3 25
34 170.24 1.70 4.06 4 0.37 1.0 1 0.37 1.70 4 26
35 12.51 0.13 0.63 4 0.21 1.0 1 0.21 0.13 2 27
36 34.64 0.35 3.16 4 0.29 1.0 1 0.29 0.35 3 28
37 37.17 0.37 4.19 4 0.37 1.0 1 0.37 0.37 4 29
38 2.17 0.02 1.56 4 0.29 1.0 1 0.29 0.02 3 30
39 3.05 0.03 1.81 5 0.17 1.0 0.33 0.06 0.03 3 31
40 37.14 0.37 2.28 5 0.17 1.0 0.33 0.06 0.37 3 32
41 100.75 1.01 1.97 5 0.17 1.0 0.33 0.06 1.01 3 33
42 74.36 0.74 2.22 5 0.17 1.0 0.33 0.06 0.74 3 34
43 48.77 0.49 3.92 5 0.17 1.0 0.33 0.06 0.49 3 35
44 80.58 0.81 3.36 5 0.17 1.0 0.33 0.06 0.81 3 36
45 109.69 1.10 6.76 5 0.25 1.0 0.33 0.08 1.10 4 37
46 42.45 0.42 2.13 5 0.17 1.0 0.33 0.06 0.42 3 38
47 49.09 0.49 3.03 5 0.17 1.0 0.33 0.06 0.49 3 39
48 97.24 0.97 2.94 5 0.17 1.0 0.33 0.06 0.97 3 40
49 37.31 0.37 3.89 5 0.17 1.0 0.33 0.06 0.37 3 41
 Rainfall
Ratios Rainfall Ratio Area Reduction factor
Catchment Storm(mm)
No.
TB 2yr:24hr 2:10yr 25:10yr 50:10yr b n TB RR TB A ARF

1 2.41 70 1.49 1.74 2.05 0.3 0.96 2.4 0.82 2.4 0.56 0.98
2 2.48 70 1.49 1.74 2.05 0.3 0.96 2.5 0.83 2.5 0.63 0.98
3 2.16 70 1.49 1.74 2.05 0.3 0.96 2.2 0.81 2.2 0.38 0.98
4 2.45 70 1.49 1.74 2.05 0.3 0.96 2.4 0.83 2.4 0.60 0.98
5 2.17 70 1.49 1.74 2.05 0.3 0.96 2.2 0.81 2.2 0.39 0.98
6 3.38 70 1.49 1.74 2.05 0.3 0.96 3.4 0.86 3.4 0.51 0.98
7 3.36 70 1.49 1.74 2.05 0.3 0.96 3.4 0.86 3.4 0.50 0.98
8 1.95 70 1.49 1.74 2.05 0.3 0.96 1.9 0.80 1.9 0.02 1.00
9 1.29 70 1.49 1.74 2.05 0.3 0.96 1.3 0.74 1.3 0.00 1.00
10 3.85 70 1.49 1.74 2.05 0.3 0.96 3.8 0.88 3.8 0.97 0.97
11 4.77 70 1.49 1.74 2.05 0.3 0.96 4.8 0.89 4.8 0.89 0.98
12 5.90 70 1.49 1.74 2.05 0.3 0.96 5.9 0.91 5.9 0.32 0.99
13 6.56 70 1.49 1.74 2.05 0.3 0.96 6.6 0.92 6.6 0.69 0.98
14 7.11 70 1.49 1.74 2.05 0.3 0.96 7.1 0.93 7.1 0.35 0.99
15 8.86 70 1.49 1.74 2.05 0.3 0.96 8.9 0.94 8.9 0.31 0.99
16 10.33 70 1.49 1.74 2.05 0.3 0.96 10.3 0.95 10.3 0.49 0.99
17 10.97 70 1.49 1.74 2.05 0.3 0.96 11.0 0.96 11.0 0.35 0.99
18 11.74 70 1.49 1.74 2.05 0.3 0.96 11.7 0.96 11.7 0.27 0.99
19 12.91 70 1.49 1.74 2.05 0.3 0.96 12.9 0.97 12.9 1.03 0.98
20 14.08 70 1.49 1.74 2.05 0.3 0.96 14.1 0.97 14.1 0.39 0.99
21 16.49 70 1.49 1.74 2.05 0.3 0.96 16.5 0.98 16.5 0.22 0.99
22 15.04 70 1.49 1.74 2.05 0.3 0.96 15.0 0.97 15.0 0.10 0.99
23 15.11 70 1.49 1.74 2.05 0.3 0.96 15.1 0.97 15.1 0.00 1.00
24 16.47 70 1.49 1.74 2.05 0.3 0.96 16.5 0.98 16.5 0.02 1.00
25 20.66 70 1.49 1.74 2.05 0.3 0.96 20.7 0.99 20.7 1.21 0.98
26 19.79 70 1.49 1.74 2.05 0.3 0.96 19.8 0.99 19.8 0.29 0.99
 Rainfall
Ratios Rainfall Ratio Area Reduction factor
Catchment Storm(mm)
No.
TB 2yr:24hr 2:10yr 25:10yr 50:10yr b n TB RR TB A ARF

27 20.24 70 1.49 1.74 2.05 0.3 0.96 20.2 0.99 20.2 0.44 0.99
28 21.23 70 1.49 1.74 2.05 0.3 0.96 21.2 0.99 21.2 0.43 0.99
29 23.13 70 1.49 1.74 2.05 0.3 0.96 23.1 1.00 23.1 0.41 0.99
30 23.89 70 1.49 1.74 2.05 0.3 0.96 23.9 1.00 23.9 0.06 1.00
31 26.14 70 1.49 1.74 2.05 0.3 0.96 26.1 1.00 26.1 0.89 0.99
32 25.78 70 1.49 1.74 2.05 0.3 0.96 25.8 1.00 25.8 0.28 0.99
33 27.93 70 1.49 1.74 2.05 0.3 0.96 27.9 1.01 27.9 0.77 0.99
34 28.45 70 1.49 1.74 2.05 0.3 0.96 28.4 1.01 28.4 1.70 0.98
35 29.65 70 1.49 1.74 2.05 0.3 0.96 29.7 1.01 29.7 0.13 1.00
36 29.96 70 1.49 1.74 2.05 0.3 0.96 30.0 1.01 30.0 0.35 0.99
37 30.14 70 1.49 1.74 2.05 0.3 0.96 30.1 1.01 30.1 0.37 0.99
38 30.49 70 1.49 1.74 2.05 0.3 0.96 30.5 1.01 30.5 0.02 1.00
39 31.58 70 1.49 1.74 2.05 0.3 0.96 31.6 1.01 31.6 0.03 1.00
40 34.03 70 1.49 1.74 2.05 0.3 0.96 34.0 1.02 34.0 0.37 0.99
41 36.35 70 1.49 1.74 2.05 0.3 0.96 36.3 1.02 36.3 1.01 0.99
42 36.87 70 1.49 1.74 2.05 0.3 0.96 36.9 1.02 36.9 0.74 0.99
43 37.33 70 1.49 1.74 2.05 0.3 0.96 37.3 1.02 37.3 0.49 0.99
44 38.99 70 1.49 1.74 2.05 0.3 0.96 39.0 1.02 39.0 0.81 0.99
45 38.96 70 1.49 1.74 2.05 0.3 0.96 39.0 1.02 39.0 1.10 0.99
46 40.17 70 1.49 1.74 2.05 0.3 0.96 40.2 1.03 40.2 0.42 0.99
47 41.34 70 1.49 1.74 2.05 0.3 0.96 41.3 1.03 41.3 0.49 0.99
48 43.29 70 1.49 1.74 2.05 0.3 0.96 43.3 1.03 43.3 0.97 0.99
49 43.04 70 1.49 1.74 2.05 0.3 0.96 43.0 1.03 43.0 0.37 0.99
 Peak flow
Design Rainfall storm P (mm) Average flow(m3/s) Peak Flow(m3/s)
Catchment factor
No. (Design (Design (Check
P10yr P25yr P50yr Qv10yr Qv25yr Qv50yr PFF
Flow)Qp10yr Flow)Qp25yr Flood)Qp50yr
1 86.02 100.4 118.3 3.1 3.63 4.27 1.7 5.28 6.17 7.27
2 86.40 100.9 118.9 3.4 3.92 4.62 1.7 5.71 6.67 7.85
3 84.59 98.8 116.4 2.3 2.69 3.17 1.7 3.92 4.58 5.39
4 86.23 100.7 118.6 3.2 3.79 4.46 1.7 5.51 6.44 7.59
5 84.65 98.9 116.5 2.3 2.72 3.21 1.7 3.97 4.63 5.46
6 89.93 105.0 123.7 1.6 1.91 2.25 1.7 2.78 3.25 3.83
7 89.87 104.9 123.6 1.6 1.89 2.22 1.7 2.75 3.21 3.78
8 83.20 97.2 114.5 0.1 0.07 0.08 1.7 0.10 0.12 0.14
9 76.88 89.8 105.8 0.0 0.01 0.01 1.7 0.01 0.02 0.02
10 91.28 106.6 125.6 3.6 4.15 4.89 1.7 6.04 7.05 8.31
11 93.32 109.0 128.4 2.7 3.14 3.69 1.7 4.56 5.33 6.28
12 95.15 111.1 130.9 0.6 0.74 0.87 1.7 1.08 1.26 1.48
13 96.00 112.1 132.1 1.6 1.82 2.14 1.7 2.65 3.09 3.65
14 96.63 112.8 132.9 0.7 0.86 1.02 1.7 1.25 1.47 1.73
15 98.24 114.7 135.2 0.4 0.49 0.58 1.7 0.71 0.83 0.98
16 99.28 115.9 136.6 0.6 0.66 0.78 1.7 0.96 1.13 1.33
17 99.68 116.4 137.1 0.4 0.45 0.53 1.7 0.65 0.76 0.90
18 100.12 116.9 137.7 0.3 0.33 0.39 1.7 0.48 0.56 0.66
19 100.72 117.6 138.6 0.8 0.97 1.14 1.7 1.41 1.65 1.94
20 101.25 118.2 139.3 0.2 0.26 0.31 1.7 0.38 0.45 0.53
21 102.19 119.3 140.6 0.1 0.09 0.11 1.7 0.13 0.16 0.18
22 101.65 118.7 139.9 0.1 0.06 0.07 1.7 0.09 0.11 0.13
23 101.68 118.7 139.9 0.0 0.00 0.00 1.7 0.00 0.00 0.01
24 102.19 119.3 140.6 0.0 0.01 0.01 1.7 0.02 0.02 0.02
25 103.48 120.8 142.4 0.5 0.57 0.67 1.7 0.83 0.97 1.14
26 103.24 120.6 142.0 0.1 0.14 0.17 1.7 0.21 0.24 0.28
 Peak flow
Design Rainfall storm P (mm) Average flow(m3/s) Peak Flow(m3/s)
Catchment factor
No. (Design (Design (Check
P10yr P25yr P50yr Qv10yr Qv25yr Qv50yr PFF
Flow)Qp10yr Flow)Qp25yr Flood)Qp50yr
27 103.36 120.7 142.2 0.2 0.27 0.32 1.7 0.39 0.46 0.54
28 103.63 121.0 142.6 0.2 0.25 0.30 2.5 0.54 0.63 0.74
29 104.10 121.6 143.2 0.1 0.17 0.20 2.5 0.37 0.43 0.51
30 104.27 121.8 143.5 0.0 0.02 0.02 2.5 0.04 0.05 0.06
31 104.76 122.3 144.1 0.3 0.33 0.39 2.5 0.72 0.84 0.98
32 104.68 122.2 144.0 0.1 0.11 0.13 2.5 0.23 0.27 0.32
33 105.11 122.7 144.6 0.2 0.27 0.32 2.5 0.58 0.68 0.80
34 105.21 122.9 144.7 0.6 0.76 0.89 2.5 1.62 1.89 2.23
35 105.42 123.1 145.0 0.0 0.03 0.04 2.5 0.06 0.08 0.09
36 105.48 123.2 145.1 0.1 0.11 0.14 2.5 0.25 0.29 0.34
37 105.51 123.2 145.2 0.1 0.16 0.18 2.5 0.33 0.39 0.46
38 105.57 123.3 145.2 0.0 0.01 0.01 2.5 0.02 0.02 0.02
39 105.75 123.5 145.5 0.0 0.00 0.00 2.5 0.00 0.00 0.01
40 106.14 123.9 146.0 0.0 0.02 0.02 2.5 0.05 0.05 0.06
41 106.47 124.3 146.5 0.0 0.05 0.06 2.5 0.11 0.13 0.16
42 106.55 124.4 146.6 0.0 0.04 0.05 2.5 0.08 0.10 0.12
43 106.61 124.5 146.7 0.0 0.03 0.03 2.5 0.05 0.06 0.07
44 106.83 124.8 147.0 0.0 0.04 0.05 2.5 0.09 0.10 0.12
45 106.83 124.8 147.0 0.1 0.08 0.09 2.5 0.17 0.20 0.24
46 106.98 124.9 147.2 0.0 0.02 0.02 2.5 0.04 0.05 0.06
47 107.13 125.1 147.4 0.0 0.02 0.03 2.5 0.05 0.06 0.07
48 107.36 125.4 147.7 0.0 0.04 0.05 2.5 0.09 0.11 0.13
49 107.33 125.3 147.7 0.0 0.02 0.02 2.5 0.04 0.04 0.05
TOTAL DISCHARGE 57.43 67.07 79.02