HYDRO29714

• Permit No: C1981071
• IBM Index Class Name: Hydrology
• Doc Date: 9/20/1993
• Doc Name: AS BUILT CERTIFICATIONS LIVESTOCK WATER TANKS
• From: CYPRUS YAMPA VALLEY
• To: DMG
• Permit Index Doc Type: PROF POND CERTIFICATIONS
• Media Type: D
• Archive: No

September 8, 1993
~- To: Rick Mills
From: Pat Sollars
Re: CYCC's Livestock Ponds
On August 13 Peter Epp, of Epp and Associates, and myself
travelled to each of CYCC's stock ponds that require certification.
The purpose of this inspection was to examine the ponds for any
structural problems and become familiar with their locations. Peter
then performed as-built surveys for each pond using the mine's
survey grid to insure accurate locations. The as-built maps for
each pond are being submitted with this memo. Copies of these maps
were given to ACZ to determine tributary areas and perform a SEDCAD
analysis on each pond in order to calculate the spillway
requirements. The results of ACZ's analysis are shown in Attachment
D of this document. Please note that for the SEDCAD analysis
performed, ACZ was informed to use a minimum width of 8 feet for
the spillway since the contractor who will most likely perform
repairs will use a D-4 dozer with an 8 foot blade width. If the
equipment employed for the repairs can produce a smaller width
please let me know so that additional spillway calculations can be
performed. You should also note that there were three ponds for
which ACZ used a 10 foot wide spillway. This was done prior to our
decision to use an 8 foot minimum width. If you would like these
three ponds checked at 8 feet please let me know.
Using the same as-built surveys given to ACZ, the ponds were
checked to insure the as-built conditions of the ponds are adequate
to meet CYCC's permit requirements. The permit states that the
ponds will meet the livestock water tank requirements of the Soil
Conservation Service and the Division of Water Resources, Office of
State Engineer. Attachment A provides the as-built measurements and
data for each pond for the requirements of the State Engineer.
Attachment B provides the as-built measurements and data for each
pond as required by the SCS. Attachment C then summarizes this data
in terms of which items for each pond must be repaired.
During the evaluation of the ponds, there were several
requirements from these two agencies that were very difficult to
interpolate or determine. The first involved the State Engineer's
requirement that the spillway must extend at least 20 feet below
the toe of the dam. Since a large number of CYCC's ponds are
excavated ponds, I am uncertain as to where to define the toe of
the dam. Another issue that is difficult to determine involves the
State Engineer's requirement that in order to not require a fee and
the State Engineer Approval, the vertical height from the bottom of
the channel to the bottom of the spillway shall not exceed 5 feet
and the pond must not impound more than 2 acre feet of water. When
I discussed this with Sally Lewis at the Division of Water
Resources in Steamboat Springs she informed me that the bottom of
the channel is meant to be the bottom of the channel prior to
,~ construction. This data cannot be obtained for the ponds being
considered because the bottom of the channel was surveyed as a