PROJ00221

• Contract/PO #: FS0017X
• Contractor Name: Ouray, City of
• Contract Type: Loan
• Water District: 0
• County: Ouray
• Loan Projects - Doc Type: Feasibility Study

r
1'1
I
I
-,,','1
I"
F
I
1,1
it
tl
II

I
II
II
f,','1
I
\\

','I'
',' ;
.. '

(I
I
I
I
I
I
I
I

II. STUDY OBJECTIVE

The objective of the study is to present a comprehensive report of the current problem,
associated risks, proposed design alternatives, associated costs and benefits of the project.
This data has been compiled from engineering design, reports and studies prepared for
the project over the past 10 years by private consultants and the U.S. Army Corps of
Engineers (CaE). The intent of this study is to evaluate the financial feasibility of the
alternatives and to compile this data following CWCB Guidelines to facilitate funding by
CWCB. The City of Ouray has realized the need for this project for over 10 years and
potential risk to public facilities and potential for personal injury increases each year the
project is not implemented due to lack of financing.

III SCOPE OF WORK

A. Background Information

Climatic Information:

The City of Ouray is situated at close to 8000-feet above MSL and has a moderate
summer with cold snowy winters. Much of the precipitation in this location occurs as
snowfall. The Climatology Report (Number 77-1) from the Colorado Climatology Office
shows a mean annual precipitation for Ouray of 21. I-inches, which includes snowfall.
This report appears to be a summary of recorded data from 1951 to 1970. The highest
rainfall months are shown as July and August with monthly mean rainfall of2.32-inches
and 2.45-inches respectively. Localized cloudbursts of short duration with intense
rainfall are common during mid to late summer. The greatest daily rainfall is shown at
1.95-inches occurring on October 3rd, 1969. Average monthly temperatures vary from a
low of 23.4 degrees F in January to 66.4 degrees F in July.

Debris Flows:

Debris flows occur periodically in the steep, rocky, confined drainages tributary to the
Uncompahgre River in response to summer time cloudbursts. Resultant damage caused
by flash flooding is often due to the sediment and debris carried by the floodwaters rather
than the water itself. The Floodplain Information Report for Ouray County (A & S
Consultants Inc., 1978) discusses many of these types of events and the subsequent
property damage. Skyrocket Creek is specifically mentioned in the July 1927 flood event
and the July 1929 event when total damages were estimated at $40,000 and $150,000
respectively. The City also reported damage to the City hot pools due to debris
overtopping the diversion wall in Skyrocket Creek in 1951 and 1981. Several other
drainages (including Cascade Creek and Portland Creek) that run through the City
experience similar debris flows and recent structural improvements have helped alleviate
the risk of property damage.

4