PERMFILE40711

• Permit No: M2005045
• IBM Index Class Name: Permit File
• Doc Date: 3/3/2006
• Doc Name: Proposed Detention Pond
• From: Gravel LLC
• To: DRMS
• Media Type: D
• Archive: No

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February 27, 2006
Attn: Allen Sorenson
State of Colorado
Division of Minerals and Geology
Office of Mined Land Reclamation
1313 Sherman Street, Rm. 215
Denver Colorado 80203
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MAR 0 3 2006 ~/
DMewn of Minerels and Geology
RE: Rock Dog #i Pit, File # M-2005-045, Proposed Detention Pond v
Dear Mr. Sorenson:
The following with attachments is in response to your request for additional information
concerning the proposed detention pond and stormwater analysis for the proposed Rock
Dog # l Pit. Kate Pickford of the Durango Field Office suggested that I send this directly
to you for review.
The responses to follow are in the numerical order to your memorandum of January 25,
2006:
1. The surface water hydrology report is presented in attached Tables 1 and 2.
2. A review was completed of the available FIRM documentation. The FIRM
Community Panel No. 080097 represents an area several miles upstream of
the subject property. It provided little information relative to this project. 1'he
high flood water mark recorded from the Spring 2005 emergency release from
Lemon Dam was surveyed and is shown on Figure 1 a.
3. 3.1 Plans and cross sections are shown on the attached figures and drawings.
3.2 The required earthwork specifications involve the removal and storage of
approximately 12 inches of topsoil from the footprint of the detention pond
perimeter. This soil will be placed in adjacent berms as shown on the mining
plan map C-2. Borrow material from excavation of stormwater drainage
swales/ditches and previously disturbed overburden material will comprise the
material for construction of the detention pond floor and embankments.
Adequate compaction based on soil assessment proctors will be maintained in
the construction of the pond embankments, ramps and spillway.
3.3 The spillway plan is shown on drawing (DWG) I.