FLOOD00987

• Designation Number: 186
• County: Boulder
• Community: Longmont
• Stream Name: Lefthand Creek
• Title: Floodplain Information Report - Lefthand Creek, Volume I: Mouth to Foothills Highway, Boulder County and Longmont
• Date: 12/1/1981
• Designation Date: 4/1/1982
• Floodplain - Doc Type: Floodplain Report/Masterplan

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TABLE 7 (Continued)

FLOOD FREQUENCY-ELEVATION AND DISCHARGE DATA
Lefthand Creek Boulder County, Colorado
Distance Stream!L 10-Year 50-Year 100-Year 500-Year
Reference From Bed Flood Peak 2 Flood Peak 2 Flood Peak 2 Flood Peak 2
Point Mouth Elevation Elevation Discharge-L Elevation Discharge-L Elevation Discharge-L Elevation Discharge-L
Number Ft. Identification Ft.-m.s.!. Ft.-m.s.!. c.f.s. Ft. -m. s. !. c. f. s. Ft.-m.s.!. c. f. s. Ft.-m.s.!. c. f. s.
52.5 205+ 10 5003.8 5007.7 5011. 9 5014.8 5016.7
53 206+00 Northbound Colorado 5005.0 d/s 5007.7 d/s 5011.9 d/s 5014.8 d/s 5016.7
Highway 119 u/s 5008.5 u/s 5012.2 u/s 5015.5 u/s 5018.5
54 207+40 5006.3 5008.5 5012.2 5015.5 5018.5
55 208+70 Southbound Colorado 5007.0 d/s 5008.5 d/s 5012.2 d/s 5015.5 d/s 5018.5
Highway 119 u/s 5009.8 u/s 5012.9 u/s 5017.0 u/s 5019.6
56 209+85 5007.0 5009.8 5012.9 5017.0 5019.6
56.5 213+80 5008.0 5011.3 5014.6 5017.3 5019.9
57 221+10 5010.8 5014.4 5017.3 5019.0 5021. 4
58 227+80 5013.2 5017.3 5020.7 5022.1 5024.2
59 228+10 N. 87th Street 5013.3 d/s 5017.3 d/s 5020.7 d/s 5022.1 d/s 5024.2
u/s 5017.3 u/s 5020.8 u/s 5022.1 u/s 5027.2
59.5 228+80 5013.3 5017.3 5020.8 5022.1 5027.2
60 231+75 5013.6 5018.0 5021. 8 5024.0 5028.7
61 240+70 5019.0 5022.1 5025.2 5027.3 5030.8
62 248+50 5023.5 5026.9 5029.5 5031.0 5033.3
63 254+00 5024.3 5028.5 5031.4 5033.0 5035.6
64 261+60 5028.3 5031. 5 5034.5 5036.1 5038.6
65 272+ 15 5033.0 5036.8 5039.8 5041. 4 5043.8
66 282+55 5037.3 5041. 3 5044.0 5045.4 5047.3
1/ Low water elevation as determined by aerial photogrammetric methods.
2/ Discharges are prorated between stations.

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