FLOOD10331

• County: Weld
• Community: Wattenberg
• Stream Name: South Platte River
• Title: Flood Hazard Mitigation Plan, Wattenberg, Weld County, Colorado
• Date: 8/1/1996
• Prepared For: Wattenberg
• Prepared By: Kistner and Associates
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

WATTENBERG, COLORADO FLOOD HAZARD MlTIGA TlON PLAN

AUGUST 1996

as the floodplain concept provides a national
standard for the National Flood Insurance
Program (NFIP).

FLOOD RECURRENCE INTERVALS

10- Year Flood Recurrence interval of
about 10 years but a"} 0%
chance of occurring in any
year.

50- Year Flood Recurrence interval of
about 50 years but a 2 %
chance of occurring in any
year.

1 00- Year Flood Recurrence interVal of
about 100 years but al %
chance of occurring in any
year.

500- Year Flood Recurrence interval of
about 500 years but a .2%
chance of occurring in any
year.

Figure 5

The 100-year floodplain located within the
Community of Wattenberg has been mapped
and is printed in the 1979 Flood Insurance
Study conducted by the Federal Emergency
Management Agency (FEMA) (See Figure
6). It is critical, however, for the floodplain
residents to remember that floods greater
than the standard 100-year flood event may
occur at any time.

Types of Floods

Floods occur on nvenne systems.
Commonly, a nver basin is fed by a
hierarchical order of stream channels that
convey the normal flow of water from

smaller watersheds contained within the
basins. Flooding results when the flow of
water becomes greater than the carrying
capacity of the individual stream channel.
Rate of rise, peak discharge (magnitude),
duration, and frequency of floods, are all a
function of physical features and weather
conditions which contribute to the volume of
water in the river system. The following
describes sources of riverine floods which
can effect Wattenberg:

Snow-Melt Floods - Snow-melt flooding
typically occurs May through June.
Generally, this occurs when warm spring
temperatures create a fast snow-melt and/or
a combination of spring runoff and rainfall
over the affected watershed. Serious
flooding can result when heavy spring rain
accompanies a snow-melt in May and June.

Flash Floods - These floods result from
intense summer thunderstorms. This flood
event is characterized by an intense
cloudburst, a sudden rise in stream level,
short duration, and almost no warning.
Typically, the flash flood season in Colorado
stretches from May through September.

General Rain Floods - These floods are
caused by general rainfall events that occur
over a wide geographic area for several days,
completely saturating the shallow soils.
These floods are characterized by a slow,
steady rise in the stream level and a peak
discharge of long duration. The slow rise
rate of the stream provides time for warning.

Flood History of Wattenberg and
Weld County

As discussed previously, flooding presents a
potential problem in Wattenberg and

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