FLOOD10941

• County: Jefferson
• County: Douglas
• Stream Name: Chatfield Reservoir
• Basin: South Platte
• Title: Chatfield State Park Recreational Mitigation Study Roadway Feasibility Analysis Correspondence
• Date: 1/6/2004
• Floodplain - Doc Type: Correspondence

CTL THOMPSON

I N C O R P O R A T E D
January 6, 2004

Sear-Brown
209 South Meldrum
Fort Collins, Colorado 80521

Attention: Mr. Bret A. Cummock, PE Associate

Subject: Geotechnical Engineering Consultation Chatfield Reservoir
Reallocation Study-
“Roadway Analysis Study”
Denver, Colorado
Job No. FC-2998

Sear-Brown:

The Colorado Water Conservation Board (CWCB) is doing a study for
reallocation of the water in Chatfield Reservoir. We understand CWCB is considering
a 12-foot raise of the normal water elevation to 5446 in Chatfield Reservoir. This
raise in the reservoir level will inundate parts of the existing roadway in the recreation
area around the reservoir. Sear-Brown is reviewing the feasibility of moving stretches
of the roadway and raising other stretches (the “Roadway Analysis Study”). We have
been retained to provide our opinions regarding the feasibility of moving or raising the
roadway, from the geotechnical engineering viewpoint. The undersigned made a
reconnaissance of the project with Mr. Joe Busto and Mr. Larry Lang of the Colorado
Water Conservation Board, Mr. Tom Keith of EDAW and your Mr. Cummock on
December 19, 2003.

The roadway in question serves the recreation sites around Chatfield
Reservoir. The roadway begins near the north or left abutment (looking downstream)
of Chatfield Dam. The roadway alignment is west past Eagle Cove, across a bridge
over Deer Creek, along the north side of the reservoir, then around the west
(upstream) end of the reservoir and finally across a bridge over the South Platte
River to the south side of the reservoir.

The approximate stretches of the existing roadway that will be inundated by
the raise of the normal water elevation are: a) the approximately 1.5 miles on the east
end on the north side of the reservoir where the alignment drops down onto the Deer
Creek flood plain and is aligned west to the Fox Run Group Picnic Area; b) the
approximately 0.4 mile stretch of the alignment on the north side of the reservoir
about to upstream end of the reservoir; and c) the stretch of the alignment around the
upstream end of the reservoir. The existing bridges across Deer Creek and the South
Platte River will be nearly inundated by the raise in the normal water surface
elevation of the reservoir.

I
375 E. Horsetooth Road The Shores Office Park Building 3, Suite 100 I Ft. Collins, Colorado 80525

Telephone: [phone] Fax: [phone]
1
SEAR-BROWN
CHATFIELD RESERVOIR REALLOCATION STUDY
“ROADWAY ANALYSIS STUDY”

CTL I T JOB NO. FC.2998