FLOOD06449

• County: Delta
• County: Montrose
• Community: Collbran, Cedaredge, Paonia
• Stream Name: Buzzard, Plateau, Grove Creeks
• Basin: Gunnison
• Title: Hydrology Report Unincorporated Areas of Delta and Montrose Counties
• Date: 4/1/1979
• Prepared For: FIA
• Prepared By: Meuer Serafini & Meuer, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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HYDROLOGY: MONTROSE, DELTA AND MESA COUNTIES, COLORADO

1. Introduction - The purpose of this report is to document the
methods and procedures used to determine flood discharges for
streams in Montrose, Delta and Mesa Counties. This hydrologic
study is a technical addendum for the Flood Insurance Studies for
Montrose and Delta Counties, as well as for the Towns of Collbran,
Cedaredge, Orchard City, Paonia and Naturita, Colorado. It is
prepared for review by the Federal Insurance Administration and the
Colorado Water Conservation Board.

The streams in the unincorporated areas of Delta and Montrose
Counties and in the communities of Collbran, Orchard City,
Cedaredge, Paonia and Naturita are included in this report (see
Figures 2-7). Not included are streams in the City of Montrose and
some of the unincorporated area around it whose hydrology is being
studied by Hydro-Triad Engineering of Lakewood, Colorado. Also
excluded is the hydrology for the Uncompahgre River (Montrose and
Delta Counties) and the North Fork Gunnison River (Delta County)
which is being prepared by the U.S. Army Corps of Engineers.

The 10-, 50-, 100- and 500-year frequency discharges were obtained
for streams to be studied by detailed methods and only 100-year
frequency flows were obtained for streams to be studied by approxi-
mate methods. These flows were compared to flows calculated by
other methodologies to determine reasonableness.

2. Ph~sical Features - For purposes of study, the streams
include were divIded between two separate areas called Region I
and Region II, each region having fairly consistent topography and
climate. The areas were selected for regional hydrologic analysis
because data on the individual study streams is very limited.
Region II was outlined by Camp, Dresser and McKee, Inc. of Denver
for use in the San Miguel County Flood Insurance Study. Because two
of the Meurer, Serafini and Meurer, Inc. study reaches on the San
Miguel River are in Region II (Naturi ta and Uravan in Montrose
County), the hydrologic area and data used in the San Miguel County
Flood Insurance Study were used in this report.

The area for Region I was selected to encompass the watersheds of
Surface Creek (Orchard City, Cedaredge and Delta County), Minnesota
Creek (Paonia) and Collbran streams of Grove Creek, Buzzard Creek
and Plateau Creek. The Grand Mesa divides Region I roughly one-
third of the way from the north edge of the region. The area north
of this divide (also the Delta-Mesa County boundary) is in the
Plateau Creek Basin and the streams drain northwest toward the
Colorado River. The streams south of this divide are in the
Gunnison River Basin and drain southwest toward the North Fork

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