FLOOD03385

• Designation Number: 312
• County: Arapahoe
• Community: Littleton
• Stream Name: Lower Dad Clark Gulch, and DFA 0068
• Basin: South Platte
• Title: Flood Hazard Area Delineation - Lower Dad Clark Gulch, and DFA 0068
• Date: 11/1/1990
• Designation Date: 3/1/1991
• Floodplain - Doc Type: Floodplain Report/Masterplan

I
I
I
I
I
I
I
I

4.5

~

-

I
I
I
I
I
I
I
I
I
I

Jackass Gulch.

. Flood waters will pond at the intersection of Santa Fe Drive and Mineral
Avenue causing traffic problems. During a 1 DO-year event, pending will
be Dver 7 feet deep.

Lower Dad Clark Gulch.

. Flood waters will only affect one house which is built near the channel
banks.

Floodolain and Floodwav Data

The limits of future flooding are outlined on the FIDOd Hazard Area Delineation
drawings and are tabulated in Table B-1. The drawings graphically represent the
100-year water surface profile, channel thalweg profile, channel thalweg
reference line, and floodplain limits. The table lists the 1 DO-year flood discharge,
flood elevations, flooding widths, and channel thalweg elevations at each cross-
section of the drainage reaches studied.

Floodways were also computed for each drainageway. A floodway represents
that portion of the floodplain which is required to pass the 1 DO-year flood event
without raising the water surface more than an acceptable amount and which
represents hazards to personal safety and welfare. In this study, the maximum
amount of rise was 0.5 foot. Floodway widths, which represent the maximum
limits of encroachment into the floodplain, are tabulated in Table B-1 along with
the floodplain data. The locations of encroachments and expected water surface
elevations after encroachment are also tabulated. In some locations, the 100-
year water surface is contained entirely within a well-defined channel.

6