FLOOD08485

• County: Jefferson
• Community: Golden
• Stream Name: Tucker Gulch, Kenneys Run
• Basin: South Platte
• Title: Flood Hazard Area Delineation
• Date: 1/1/1983
• Prepared For: Jefferson County / Arapahoe County
• Prepared By: UDFCD
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

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which wallowed in the muddy waters pushing fill into the rapidly
disappearing banks. The bridge was saved, though a portion of a
city tile sewer line adjacent to the bank was carried away in the
flood."

- HYDROLOGY AND HYDRAULIC DETERMINATIONS -

Hydrologic Analysis

Hydrologic analysis of the Tucker Gulch and Kenneys Run drainage basins were
performed to determine peak discharges and flood hydrographs at selected
critical points along the studied streams. Flood discharges were determined
for the 10-, 50- and 100-year rainfall events assuming future developed basin
conditions. Table I shows the peak flow rates selected for hydraulic model-
ling.

"Another famil i ar source of fl oodi ng in Gol den was Kinney Run. a
gulch which drains part of Lookout Mountain and comes through Golden
into Clear Creek. The relentless rain was too much for the most
often dry gulch, and its waters spilled over onto Golden Road at a
point next to the Lookout Mountain School for Boys. The water
there joined with another torrent from south Table Mountain and
closed down Ford and Jackson Streets for part of the day.

Many homes in the area, particularly around Ford and Jackson at
21st, were badly hit by the rising waters, their basements filling
up like bathtubs."

Tucker Gulch: The hydrologic analysis for the Tucker Gulch drainage basin
involved dividing the basin into five sub-basins and utilizing the Colorado
Urban Hydrograph Procedure (CUHP) to determine runoff hydrographs from each
sub-basin. The hydrographs were combined and routed down stream channels
using the Convex Routing Method. The resulting flood hydrographs were used
to select the peak discharges for hydraulic modelling. Figure 1 shows the
basin and sub-basin boundaries; Figure 2 shows the discharge probability
profiles. and Figure 3 shows typical 100-year flood hydrographs.

The preceding are examples of some of the most damaging floods experienced in
Golden. It should be noted that many other floods have also inflicted damage.
Although only one newspaper article was found regarding flooding on Kenneys
Run, local sources noted that the storm sewers commonly became plugged,
forcing floodwaters down Jackson and Ford Streets.

The basin and unit hydrograph parameters are tabulated in Table II. The
procedure used to determine the CUHP parameters is outlined in the Urban Drainage
and Flood Control District's Urban Storm Drainage Criteria Manual. Recent
modifications were applied to the procedure as recommended by the Urban Drainage
and Flood Control District. The modified CUHP equations are listed following
Table II. Detailed documentation of the hydrologic analysis is available at
the office of the Urban Drainage and Flood Control District.

One-hour point rainfall depths were determined from the Precipitation-Frequency
Atlas of the Western United States, NOAA Atlas 2, Vol. III, Colorado, 1973,
for the 2-, 5-, 10-, 50- and 100-hear return periods. These values were used
to develop the two-hour design storms based upon a time distribution of rainfall
recommended by Urban Drai nage and Fl ood Control Di strict. Areal reducti ons of

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