FLOOD00275

• County: Adams
• Community: Westminster
• Title: Bruchez Farms Property - Big Dry Creek at Wadsworth Parkway
• Date: 1/1/1998
• Prepared For: Bruchez Farm
• Prepared By: Wright Water Engineers Inc
• Floodplain - Doc Type: Floodplain Report/Masterplan

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

22

b. The 1973 study used the routed outflow from Standley Lake as It existed at
that time. The 1986 study was based on the routed outflow from Standley
Lake through a future spillway under a current agreement between the
UD&FCD and the city of West minster.
5. Improvements to the Ketner Reservoir and spi1lway have been completed since
the 1986 report was finIshed. These Improvements reduce the peak dIscharge
rate enterIng the area upstream of the exIstIng C&S Railroad culvert.
6. The size of the watershed upstream of Standley Lake and the volume of tempor-
ary storage available above the lake's surface Is such that the peak outflow rate
from the lake Is delayed long enough so that It has no effect on the peak dis-
charge rate at the railroad culvert. ThIs peak is governed by only the tributary
drainage area between the railroad and the Standley Lake dam.
7. The existing concrete arch culvert under the C&S Railroad is inadequate to
convey the 10o-year flood event wIthout causing excessive depths of flow
upstream of the culvert. This Is the prlncipa I reason that runoff from a major
flood impacts the Bruchez property.
8. The hydraulIc efficiency of the existing railroad culvert can be Increased by
constructing an Improved Inlet at the entrance to the culvert.
9. SufficIent temporary storage exists upstream of the existing railroad culvert,
either In total or only wIthin the floodway limits, to signIfIcantly reduce the
peak dIscharge rate flowing through the culvert.
10. The effects of the Improved Inlet on a decrease In the water surface elevatIon
are not reflected upstream of Wadsworth Parkway.
II. Using the approved outflow from Standley Lake, the decreased outflow from the