GENERAL32312

• Permit No: C1981039
• IBM Index Class Name: General Documents
• Doc Date: 3/16/1989
• Doc Name: 1988 GRASSY GAP MINE VEGETATION DATA Memo
• From: MLRD
• To: CATHY BEGEJ
• Permit Index Doc Type: VEGETATION
• Media Type: D
• Archive: No

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~~~9,^ STATE OF COLOR/°~DO
Roy Romer, Govei
DEPARTMENT OF NATURAL RESOURCES
MINED LAND RECLAMATION DIVISION
FRED R. BANTA, Dlreetor
DATE: March 16, 1989
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FROM: Cathy
Carl Begej
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RE: 1988 Grassy Gap Mine Vegetation Data. The Rockcastle Company,
Permit C-81-039
I have reviewed the 1988 vegetation data submitted by the Rockcastle Company
(TC) as you requested. Cover data was obtained, apparently, through the use
of point intercept transects of 100 meters in length. There is no explanation
of the method used in obtaining this data although usually a 100 meter tape is
stretched along an area to be sampled and "hits" are recorded at each meter
mark. In this case, the "hits" were classified as to vegetation, rock,
litter, and bare ground. While this method is acceptable for measuring total
cover (and thus gives us some idea as to whether the vegetation, rock and
litter will lessen raindrop impact and hence soil erosion) it is not what the
RC has committed to do on page II. J-12 of their permit (Revised 12/87). The
page is attached for reference.
In the future, the RC should sample their vegetation by species. Part of the
point of sampling vegetation at all is to see whether the reclaimed area is
approaching the revegetation success criteria as stated in the permit document
(pages II. J-12 and II. J-28 - also attached for your reference) and
Rule 4.15.8. The submitted vegetation data must by necessity be obtained by
species and information of alike nature be obtained on the sagebrush/grass
reference area in order to be considered at all for bond release.
As part of the review, I have summarized the raw data that was given us and
attached the summary of cover values for your use. Minimum sample size for
vegetative cover was also checked and all pit areas were adeo,uately sampled.
As you can see from the bottom summary table, vegetation cover averaged 79.4
percent across all pit areas and ranged from 61.8 (Pit 1) to 86.6 (Pit 6)
percent. Total cover (vegetation, rock and litter) averaged 97.6 percent
across all pit areas and ranged from 93,6 percent in Pit 1 to 99.2 percent in
Pit 6. All the values indicate that cover is adequate for reducing sheetwash
erosion to an acceptable level in the areas sampled.
Enclosures
4202E/scg
215 Centennial Building, 1313 Sherman Street Denver, Colorado 80203-2273 Tel. [phone]