FLOOD05175

• County: Summit
• Community: Breckenridge
• Stream Name: Blue River
• Basin: Colorado Mainstem
• Title: Technical Addendum Floodplain Information Blue River
• Date: 12/1/1974
• Prepared For: Summit County
• Prepared By: Leonard Rice Consulting Water Engineers, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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Using the design flows in Table 4 discharge-frequency curves
were prepared for each design point. These are shown in Figures
3 through 9.

EFFECTS OF DEVELOPMENT ON RUNOFF

Development, unless properly engineered, can increase runoff
significantly. This is particularly true in the eastern plains
of Colorado where estimates of increased runoff range from three
to tenfold over historic runoff. However, the effects from a
mountain type development would not be as great as the effects
from a development in the eastern plains. Most developments in
the mountains retain a natural setting including most of the
vegetative cover. Runoff from this environment would not be in-
creased significantly. Another important factor is that the
maximum Blue River flood producing storms for the town of Brecken-
ridge were found to occur above the town. Continued development
within Breckenridge and adjacent to the town will increase runoff
if a storm is centered over that particular area. However, if
a storm is located close to Breckenridge, then flows in the Blue
River through the town will be less than if the same event were
located above the town. Increased runoff from the development
will have very little affect on the design floods of the Blue
River through the town of Breckenridge. Runoff from developments
is more of an internal drainage problem, although increased runoff
can be expected.

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Leonard Rice Consulting Waler Engineers. Inc.