FLOOD00824

• County: Summit
• Community: Frisco
• Stream Name: Blue River Basin
• Title: Hydrology for Flood Insurance Study
• Date: 3/10/1992
• Prepared For: Frisco
• Prepared By: Muller Engineering Company, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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V. VALIDITY OF PREVIOUS STUDIES

General

Some common procedures and methodologies were used in the previous studies which
were app1 ied to the Frisco and Summit County Hydrology Report. When a study
reach contains stream gage data, then the statistical analysis of the individual
gage is used to determi ne the appropri ate peak fl ow rates for the recurrence
intervals as part of this FrS. Adjustments for locations downstream or upstream
from the gage station are done by making a discharge - drainage area comparison.

Regional Regression Analysis of all the stream gage data within a region of
s i mi 1 ar characteri st i cs provi des a general re 1 at i onshi p that app 1 i es to most
tributaries. For the previous studies, the regression equations were simplified
to use drainage area as the only variable. The simplification was justified
because the other variables did not provide significant improvement in
correlation. These regression equations allowed peak flow rates to be calculated
for most tributaries in the study region (the Blue River Basin). Snowmelt is
recognized as the peak flow contributor for large basins and rainfall is
responsible for peak flows of small basins (less than 30 square miles) at a
longer recurrence interval, such as a 100-year storm.

The procedures and methodo 1 ogi es descri bed above were revi ewed and are cons i dered
proper for the available data, such as stream gage flow rates and precipitation
records.

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