2012-07-12_REVISION - C1981012

• Permit No: C1981012
• IBM Index Class Name: REVISION
• Doc Date: 7/12/2012
• Doc Name: 2nd Adequacy for Ditches and Containment Structure ‎(Memo)‎
• From: Rob Zuber
• To: Zack Trujillo
• Type & Sequence: TR64
• Email Name: ZTT
• Email Name: RDZ
• Email Name: DIH
• Media Type: D
• Archive: No

To:
From:
Subject:
Date:
Zach —
Interoffice Memorandum
Zach Trujillo
Rob Zuber
Elk (C1981012), TR -64 Review: Second adequacy for ditches and containment structure
7/12/2012
Regarding the NECC TR -64 responses to our first adequacy review (letter from Jim Stover dated 7/9/12), I have reviewed
their responses to my initial comments and have the following new comments.
If you have any questions or would like me to look at any additional items regarding TR -64, please let me know.
Thanks,
Rob
5. It appears that ditch D26 flows into ditch D58. Please provide an explanation on how this is accounted for in the
design, including the size of the drainage area.
The NECC response is sufficient.
6. A drainage reaches the valley floor approximately 80 feet west of the proposed Bates Shaft in close proximity to the
point where ditches D59 and D60 both begin (the up gradient ends). Please provide an explanation on how the flow
down this drainage will be directed to D60 rather than D56. (Based on areas in the SEDCAD model, it is apparent
that D60 receives these flows.)
The NECC response is sufficient.
7. Please send a revised Table 20, Ditch Data. Some of the values for ditch D59 appear to be incorrect including the
peak discharge and the ditch slope; they do not match the values in the SEDCAD printouts. Also, the page number
for this table may be incorrect. Should it be 2.05 -11b?
The NECC response is sufficient.
8. In Table 21, culverts C79 and C80 are listed as having a minimum diameter of 36 inches. A field inspection from early
May 2012 reveals that C79 will need to be replaced to meet this requirement. If this project is constructed, please
make sure this replacement is performed.
The NECC response is sufficient.
9. It appears that a mistake may have been detected on page EXH 19(21) -2. The units for the three year sediment
volume should be acre -feet, not cubic feet. Please provide an updated page EXH 19(21) -2.
The NECC response is sufficient.