HYDRO20379

• Permit No: C1981071
• IBM Index Class Name: Hydrology
• Doc Date: 2/21/1989
• Doc Name: CHANNEL CERTIFICATIONS-AREAS 7 31 41 51 AND 51W-ECKMAN PARK C-81-071
• From: MLRD
• To: JIM PENDLETON
• Permit Index Doc Type: PROF POND CERTIFICATIONS
• Media Type: D
• Archive: No

• , iii iuiiiiiiiiiiiii
STATE OF COLORADO

Roy Romer, Gove
DEPARTMENT OF NATURAL RESOURCES
MINED LAND RECLAMATION DIVISION
FRED R. BANTA, Dlreetor
DATE: February 21, 1989
TD: Jim Pendleton
FROM: David Berry
RE: Channel Certifications -Areas 7, 31, 41, 51 and 51W - Eckman Park
C-81-071
Colorado Yampa Coal Company (CYCC) recently submitted certification
information pertaining to the above-referenced channel improvement projects.
The information includes:
1. A letter from Conrad Parrish (ACZ, Inc.) to Rick Ptills (CYCC),
dated IJovember 1, 1988, which states that all channels have
been constructed in accordance with the design criteria, but
which contains no supporting information;
2. Ten inspection reports, generated during various ACZ, Inc.
field visits, which discuss the construction progress, and
which indicate several unresolved problems; and,
3. Seven reports from Ground Engineering Consultants, Inc. (GEC)
which contain information specifically pertaining to riprap
gradation and durability.
Copies of these documents are attached for your reference. I am requesting
your advice regarding variations noted between design and as-built riprap
specifications (GEC reports).
As we previously discussed, I will request that CYCC submit additional
information which verifies that the pending problems discussed in the various
ACZ, Inc. field reports have been resolved. I will also note that the GEC
reports indicate that rounded to subrounded riprap has been used, which may
lead to stability problems in the future.
The discrepancies noted between the as-huilt riprap gradations and the design
riprap criteria are summarized in Tables 1 through 5. I am concerned that
some of the areas contain riprap which may be significantly out of
specification. Please review the tables and let me know if you believe that
the variations are indeed significant, and perhaps you can recommend a
reasonable course of action based on your experience.
cc: Mike Savage
215 Centennial Building, 1313 Sherman Street Denver, Colorado 802032273 Tel. [phone]