FLOOD05827

• County: Boulder
• Community: Boulder
• Stream Name: Boulder Creek
• Basin: South Platte
• Title: Boulder Creek Phase B
• Date: 12/1/1979
• Prepared For: Boulder
• Prepared By: UDFCD
• Floodplain - Doc Type: Floodplain Report/Masterplan

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SECTION II

BASIN DESCRIPTION AND DATA

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BASIN DESCRIPTION

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Boulder Creek and its tributaries drain a 440-square mile area on the

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eastern slope of the Rocky Mountains in north-central Colorado as pre-

sented in Figure 11-1. Slightly more than half of the basin I ies in the

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mountains; the remainder is in the plains. The headwaters of Boulder

Creek originate at the Continental Divide at elevations of as much as

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13,500 feet m.s. 1. The stream flows eastward through steep narrow

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mountain canyons about 22 miles before reaching Boulder at about 5440

feet m.s. l. Boulder is located on the physiographic boundary between

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the rugged, forested mountains on the west and the gentle slopes and

plains on the east. After leaving the mountains, the stream flows

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eastward through the heart of the city for three miles as presented in

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Figure 11-2. From Boulder, the creek turns northeastward to join St.

Vrain Creek about 18 miles downstream near Longmont, Colorado. St.

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Vrain Creek is tributary to the South Platte River.

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Major streams of the Boulder Creek basin upstream from Boulder include

North Boulder Creek, Middle Boulder Creek, and Fourmile Creek. The

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drainage area upstream from the west edge of Boulder is 130 square

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miles. South Boulder Creek, the largest tributary of Boulder Creek,

flows to the south and east of Boulder and becomes tributary a short

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distance downstream.

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