FLOOD10114

• County: Saguache
• Stream Name: Saguache Creek
• Basin: Rio Grande
• Title: Radar Rainfall Reconstruction of Saguache Creek Flash Flood
• Date: 7/25/1999
• Prepared For: CWCB
• Prepared By: HDR Engineering, Inc.
• Floodplain - Doc Type: Flood Documentation Report

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Figure 7 shows the HMS radar-estimated storm rainfall from 1428 MDT
until 1642 MDT across the basin based on the technique described above. The
basin average rainfall during this period was 3,50 inches of rain with a peak 0.65
square mile rainfall of 5,20 inches, The peak square mile rainfall was 4,99
inches. Note that the storm has formed a rather symmetric pattern with lobes of
heavy rainfall extending to the northeast and southeast. The radar pattern
indicated that two storm complexes moves within the pattern with first one
moving from southwest to northeast and the second one moving from northwest
to southeast, This change in cell direction suggests that a disturbance moved
across the area affecting the movement of the cells,

0.10 0.10 0.25 0.20 0.30 0.15 0.20 0.20 0.10 0.10 0.10 0.31 0.47 0.42 0.26 0.16 0.75 0.92 1.20 !.I4 0.'lI'
0.10 0.10 0.20 0.20 0.25 0.20 0.20 0.15 0.05 0.25 0.31 0.58 0.78 0.85 0.79 0.86 !.I9 1.31 1.37 1.26 0.97
0.00 0.00 0.15 0.20 0.20 0.20 0.15 0.15 0.30 0.35 0.30 0.66 0.88 0.95 !.I3 1.07 !.I4 1.09 1.37 1.21 1.01'
0.00 0.00 0.00 0.00 0.05 0.10 0.20 0.25 0.35 0.35 0.77 0.93 1.20 1.54 1.40 1.40 !.I9 1.57 1.91 1.90 1.6C
0.00 0.00 0.00 0.00 0.05 0.10 0.20 0.20 0.72 0.94 0.83 1.31 !.IS 2.0' 1.67 1.78 1.41 1.92 b"19''2-I8' f2~1~
0.00 0.00 0.00 0.00 0.00 0.05 0.2~ 0.40 1.39 1.46 2.18 2.62 2.20 2.32 2.1 2. 2.35 2".91 ;J.,'16Z!~ ,2,,(1
0.00 0.00 0.00 0.00 0.00 0.05 0.2~ 0.73 0.08 2.48 2.se 2.78 2.49 2.48 '2!9' ,2.5Q
0.00 0.00 0.16 0.00 0.00 0.05 0.68 1.20 2.82 2. 2.68 2.78 2\98
. ,
0.00 0.00 0.16 0.00 0.16 0.21 1.23 1.81 4.21 4.12 4.30 [2.92
0.00 0.00 0.16 0.00 0.48 0.85 4.18 4.61 4.40 4.15 4.03 4.13 4.30 4.46 4.22 2.952.
0.00 0.00 0.16 0.16 0.80 1.29 4.194.91 4.97 4.27 4.62 4.15 4.13 '2.
0.00 0.00 0.00 0.00 0.16 1.02 1.83 2.74 4.43 4.96 4.90 4.31 4.33 4.40 2.8''''2.8
0.00 0.00 0.00 0.16 0.16 1.02 1. 4.89 4.91 4.74 4.76 4.57 4.60 4.38 4.32
0.00 0.16 0.00 0.16 0.32 1.02 2.1 4.57 4.72 4.71 4.3' 4.33 4.87 4.61 4.26 4.21
0.38 0.38 0.16 0.16 0.16 0.86 2.0 2.93 4.40 4.09 4.1 4.23 4.64 4.38 Vi! 2:t
0.38 0.38 0.16 0.16 0.32 0.80 0' 2.88 4.00 2.
0.54 0.54 0.32 0.22 0.54 0.96 1.90 2.<43 2.66 2.92 2.99 2. 2.65 ,v.81
0.54 0.54 0.54 0.60 0.70 0.60 0.86 1.78 '.17. 2.58 .,.Q, 2.7~ 2. 2.54 2.60 ,.,j 1.9
0.16 0.48 0.54 0.38 0.70 0.76 0.92 1.46 1.67 2.0~ 1.86 1.92 1.92 ',41 ,2.~~ .23' 251! 2.27 2.0j 1.92 1.86
0.16 0.54 0.54 0.54 0.86 0.60 0.76 1.08 !.I4 1.58 1.79 1.42 1.37 1.57 1.63 1.42 1.60 1.88 1.31 1.36 1.31
0.16 0.54 0.54 0.54 0.64 0.60 0.76 0.44 0.60 0.92 1.20 1.36 1.09 1.40 1.02 1.22 1.50 1.48 1.38 1.32 0.9'

Figure 7
Shows Total Rainfall for Each Grid Square

The estimated volume of the rainfall was approximately 13,242 acre-feet of
water and it fell over a roughly 8 mile by 8-mile volume covered by the storm's
1-inch or greater coverage area, It is little wonder that flooding occurred given
the volume of rain.