FLOOD07967

• Designation Number: 181
• County: Larimer
• Community: Loveland
• Stream Name: Big Thompson River
• Basin: South Platte
• Title: Floodplain Information Report - Big Thompson River, Loveland
• Date: 10/1/1981
• Designation Date: 12/1/1981
• Floodplain - Doc Type: Floodplain Report/Masterplan

Purpose and Scope

This report was prepared to guide local officials in planning the use
and regulation of the floodplain areas such that flood hazards and future
flood damagea are minimized. It includes information on historical floods,
existing factors which influence the flood hazard, and the nature and
extent of probable future flOOds. The report has attempted to revise and
update the previous studies of the Corps of Engineers (Ref. 1) and Federal
Insurance Administration (FlA) (Ref. 7).

lhe report data includes flooded area maps delineating the 100-year
flood boundary, flood profiles and flood-plain crOss sections showing the
high water elevations for the 100- and 500-year floods at selected refer-
ence points. A supplement to this report in the form of a Technical
Addendum includes the supporting engineering and hydraulic data which may
also be used in the location and deaignof roads, bridges, andcha nnel
modifications.

Acknowled~ements

The assistance and cooperation of the below listed agencies snd
indiViduals, inadditioll to nurnCro"s private citizens, in supplying infoma-
tion nlld data are appreciated and gratefully acknowledged.

Colorado Water Conservation Board--Larry Lang, Chief,
Flood Control and Flood-Plain Management Section

Larimer County Planning ~epartment--Rex Burns, FlOOd-Plain
Administrator

City of Loveland, Colorado--E. G. Wilkinson, City Engineer

Aerial photo~r8phy and contour mapping were provided by Larimer County
and prepared by Kucera .. A~"ociat..~, Tn~_., rof ))>ollv,,1', r..-,lrorJldo.

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RE:\OURCE: CON\ULT~NT\ INC

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Maps and Surveys

Aerial photography and topographic maps for this study ~ere provided
by Larimer County in cooperation with the Colorado Water Conservation
Board. Mapping at the scale of 1"-200' with 2-foot contour intervals was
prepared by Kucera & Associates, Inc., from a ground control survey per-
formed by Delgado & Associates.

The ground control survey was performed to 3rd order accuracy standards
or better as defined by the U. S. Department of Commerce, Federal Geodetic
Control Committee. Mapping in this study complies with the United States
National Map Accuracy Standards with field checks.

There were thirteen permanent control marks set within the atudy area
for uSe in determining site elevations by field survey methods. These
permanent control markers are described in Table 1 and are intended for use
only in conjunction with this report.

Table 1. IIi~ Thompson River Mappin>; Control

Station Fieldbook
Larimer County Coordinates reference
Bench ",,' Elevation North East number
LCR."l'36 5005.575 389845.0 2103807.4 36
LCBM'37 5000.651 388893.9 2105118.4 35
LCBM 138 4988.793 388974.0 2107243.6 "
LCBM'39 4994.806 388065.7 2108520.0 31
LCBM 140 4980.994 388151.9 2109792.6 29
LCBM #41 4961.416 386160.4 2112860.0 27
LCBM #42 4953.896 386124.6 2114696.2 "
COM '" 4939.556 384302.1 2117118.5 "
COM '" 4932,632 382826.9 2119045.2 7
"'1M '45 4915.727 381538.1 2121662.0 9
LCBI'! '46 4909.967 381004.1 2124175.5 11
LeBM '" 4898.272 382948.2 2l24914.7 "
LeBM '" 4882.436 384038.1 2129574.0 15

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RE:\OURCE: CON\ULT~NT\ INC