FLOOD04286

• Designation Number: 23
• County: Adams
• Community: Westminster
• Stream Name: Big Dry Creek
• Basin: South Platte
• Title: Major Drainageway Planning - Master Plan - Big Dry Creek - Westminster - Volume I
• Date: 3/1/1973
• Designation Date: 7/1/1973
• Floodplain - Doc Type: Floodplain Report/Masterplan

RONALD C. McLAUGHLIN
KENNETH R. WRIGHT
HALFORD E. ERICKSON
~OUGLAS T. SOVERN
KENNETH ASH. M....N.GER
^iJPEN OP"F"ICII
P.O. 80): 2.810
A."PI!:N, COl.O. !!llell

WRIGHT.MCL"UGHl.I~1 E"'GINEEIIS
ENGINEERII"'lG CONSUL.TANTS

19 March 1973

';OMPL.I,nt ENI)INRIUIING IlI[RVICf!:S
!N THF. .PItCI"',I-T'f P"lltl.O. OP"
W.TER lJ.UPPLY AND DI.TRlrlUTIOI'l
WATER AHO III:WA./i1l TIlfE^T""ENT
..WAQIt COI.LECTIOH ....NO FlI!IJ!III!:
INDUSTRIAL "..A.TI(.
II-rORN DR^INAGlI:
"L.oao CONTROl.. AND
C"'I~IUIl WATIIA.OIllII:NTI:D r"O.IRe"n

2420 ....LCOTT j;TREET
DENVF.R, COLORI,DO aO~:ll
(303) 4!1/J-S201

Mr. L. Scott Tucker, Executive DIrector
Urban Drainage and Flood Control District
600 Lucas Building
181 East 56th Avenue
Denver, Colorado 80216

Gentlemen:

Re: Big Dry Creek Prel iminary Design

The report entItled "Big Dry Creek Preliminary Design" In two volumes
is attached. The ass Ignment was undertaken h ac:;ordance with the agree-
ment dated April 25, 1972. The preliminary desig., was done for a drainage
basin covering 86.3 square miles and a channel reach of 110,600 feet.

In addition to this report, we have previousiy prepared and submItted to
your office a Phase A report entitled "Urban Storm Drainage. Major Drainage
Planning, Big Dry Creek," dated October 15, 1972. In many "espects the Phase A
report I s a compan Ion to th I s report as it was a <ey step in the thought
process by which the prel imlnary des ign approach I',as determined. Some of the
Information presented In the Phase .A reqort has been lifted and amplified in
the attached report for Phase B.

In Phase B the detailed hydrologIc studies, "Iood plain determination and
the various alternatives were re-examined to insure that the numbers and the
concepts used during the alternate selection process were appropriate and valid.
The legal analysis, done under the direction of Mr. Ronald Strahle of Fort
Collins, Is capsulized in the report, and the complete legal opInion is con-
tained in the Appendix,

Nineteen plan and profl Ie sheets at a sCille ()f I" ~ 20Cl' have been pre-
pared and reduced to half size fo,. reproduction In Volume 2. In addition,
there is a drawing showing the draInage basin and sub-basins and two drawings
which have been reduced from a scale of I" .=. 200' that show the extens ive
flood plain area in the vicinity of the Union Pac:fic RaIlroad and the County
LIne Road.

After the structures, channels, drops, checks, and other appurtenances had
been "rough-s ized", the backwater prog1"ilm developed during Phase fJ. was again
utilized to determine the flood water elevation as shown on the drawings.
The full-sized drawings will, of co~rse, be placed on file v.'ith the 1)lstrict.,

Big Dry Creek Is a unique study for the Denver Metropolitan RegIon In
that It Is preventative rather than con'ectlve In nature, which .aIIOl"s for use
of the flood plain from County LIne Road to Standley Lake as a broad green-
belt with Its attendant recreation "nd "esthetic benefits. Flood pldln