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.l. Ft.-m.s.l. c.f.s. Ft. -m. s. 1. c. f.s. Ft.-m.s.l. c.f.s. Ft.-m.s.l. c.f.s.
28 106+70 4959.2 4964.6 4969.1 4970.9 4973.1
29 107+25 Footbridge 4959.4 dls 4964.6 dls 4969.1 dls 4970.9 dls 4973.1
u/s 4965.0 u/s 4969.3 u/s 4971. 9 u/s 4974.4
29.5 107+55 4959.9 4965.0 4969.3 4971. 9 4974.4
30 109+30 4961. 0 4966.0 4970.3 4973.6 4977 .2
32 110+00 Pike Road 4962.0 dls 4966.0 dls 4970.3 dls 4973.6 dls 4977 .2
u/s 4974.5 u/s 4977 . 1 u/s 4978.7 u/s 4979.4
32.5 110+50 4962.5 4974.5 4977.1 4978.7 4979.4
33 114+55 4964.9 4974.5 4977.1 4978.7 4979.5
34 122+20 4967.0 4974.5 4977.3 4978.8 4979.8
35 125+10 4967.2 4974.6 4977 . 5 4979.0 4980.1
35.1 130+ 35 4969.2 4975.1 4978.3 4979.8 4981.2
36 130+75 Farm Bridge 4969.3 dls 4975.1 dls 4978.3 dls 4979.8 dls 4981. 2
u/s 4975.1 u/s 4978.6 u/s 4980.0 u/s 4981. 5
37 130+95 4969.3 4975.1 4978.6 4980.0 4981.5
38 132+75 4970.0 4975.8 4978.9 4980.2 4981.8
39 137+85 4971.2 4977.0 4980.6 4981. 8 4983.2
40 143+05 4973.0 4978.4 4982.4 4983.8 4985.4
41 147+70 4973.4 4979.5 4983.5 4985.3 4987.5
42 152+40 4975.0 4980.5 4984.7 4986.6 4988.9
lL Low water elevation as determined by aerial photogrammetric methods.
21 Discharges are prorated between stations.

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