FLOOD01135

• Designation Number: 223
• County: Boulder
• Community: Unincorporated Boulder County
• Stream Name: Upper Lefthand Creek
• Title: Floodplain Information Report - Upper Lefthand Creek, Volume II, Boulder County, Colorado
• Date: 8/1/1983
• Designation Date: 11/1/1983
• Floodplain - Doc Type: Floodplain Report/Masterplan

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necessary, were also furnished by Boulder County and the Colorado Water

Conservation Board. Survey control monuments (Table 7) exist in the

field for use in relating information contained in the report to actual

STUDY AREA DESCRIPTION

ground conditions.

Drainage Basin Characteristics
Lefthand Creek is located in Boulder County approximately 30 miles
northwest of Denver. Its headwaters originate on the eastern slope of
the Continental Divide at elevations over 13,000 feet. The creek then
flows in an easterly direction, draining into St. Vrain Creek at
Longmont, Colorado.
James Creek is a major tributary of Lefthand Creek. James Creek
originates north of the Town of Ward, Colorado at an elevation over 9,400
feet. James Creek is joined by Little James Creek in the Town of
Jamestown and joins Lefthand Creek about a mile southwest of the com-

munity of Springdale.
Approximate drainage areas are given in Table 1.

Table 1

Drainage Areas

Area (sq.mi.)

Location

Lefthand Creek at downstream
study limit (Foothills Highway)

56.0
1.4

Lefthand Creek at upstream
study limit (Peak to Peak Highway)

James Creek at confluence with
Lefthand Creek

18.7

Little James Creek at confluence
with James Creek

2.9

3