REP03538

• Permit No: C1981019
• IBM Index Class Name: REPORT
• Doc Date: 4/6/2007
• Doc Name: 2006 AHR & ARR Section 7 Exhibit 7A to Section 9 Exhibit 9A
• From: Colowyo Coal Company L.P.
• To: DRMS
• Annual Report Year: 2006
• Permit Index Doc Type: Hydrology Report
• Media Type: D
• Archive: No

Table of Contents
r.
1.0 Introduction ........................................................................................................................... i
2.0 Results &Discussion .............................................................................................................. 5
2.1 Overall Summary ................................................................................................................. 5
2.2 East Pit .. ................................................................................................................... ........ 12
2.2.1 EP034 - 7a' Year -Cover, Diversity, Production, & Woody Plant Density .......... ........ 12
2.2.2 EP035 - 7"' Year -Cover, Diversity, Production, & Woody Plant Density .......... ........ 14
2.2.3 EP037 - 4"' Year -Cover, Diversity, & Woody Plant Density ........................... ........ 16
2.2.4 EP042 - 4"' Year -Cover, Diversity, & Woody Plant Density ........................... ........ 18
2.2.5 EP043 - 4a' Year -Cover, Diversity, & Woody Plant Density ........................... ........ 20
2.2.6 EP046 - la Year -Cover, Diversity, & Woody Plant Density ........................... ........ 22
Z.3 West Pit .. .................................................................................................................. ........ 24
2.3.1 WP007 - 7"' Year -Cover, Diversity, Production, & Woody Plant Density ......... ........ 24
Z.4 Section i 6 ................................................................................................................ ........ 26
2.4.1 516016 - 7"' Year -Cover, Diversity, Production, & Woody Plant Density ........ ........ 26
2.4.2 516017 - 7"' Year -Cover, Diversity, Production, & Woody Plant Density ........ ........ 28
2.5 Fire Area . .................................................................................................................. ........ 30
2.5, i FA002 - 4"' Year -Cover, Diversity, & Woody Plant Density ........................... ........ 30
2.5.2 FA003 - 4a' Year -Cover, Diversity, & Woody Plant Density ........................... ........ 32
2.6 Summary by Area ...................................................................................................... ........ 34
2.6.1 East Pit ...................................................................................................... ........ 34
2.6.2 West Pit ..................................................................................................... ........ 38
2.6.3 Section 16 .................................................................................................. ........ 41
2.6.4 Fire Area .................................................................................................... ........ 44
2.7 Summary by Year ...................................................................................................... ........ 47
2.7.1 1999 Revegetation ...................................................................................... ........ 47
2.7.2 2002 Revegetation ...................................................................................... ........ 51
2.7.3 2005 Revegetation ...................................................................................... ........ 57
2.8 Reference Areas ........................................................................................................ ........ 59
2.8.1 Mountain Shrub Reference Area ................................................................... ........ 59
2.8.2 Sagebrush Reference Area ........................................................................... ........ 59
2.9 Planted Seed Establishment ........................................................................................ ........ 65
2.10 CSU Shrub Plots ...................................................................................................... ........ 69
3.0 Conclusions & Recommendations ............................................................................... ........ 94
4.0 Literature Cited ............................................................................................................ ........ 96
In-Text Tables, Charts, Figures, and Maps
Map 1 -Vegetation Sampling Unit Locations - 2006 ...................................................................... 3
Table P -Precipitation at the Colowyo Mine, 2001 - 2006 .............................................................. 4
Chart P -Precipitation by Growing Season at the Colowyo Mine, 2001 - 2006 ................................. 4
Chart 1 -All Sampled Areas -Average Ground Cover by Lifeform - 2006 ........................................ 7
Chart 2 -All Sampled Areas -Relative Ground Cover (Composition) by Lifeform - 2006 ................... 7
Chart 3 -Perennial Cover Success Criteria Comparison by Area - 2006 ........................................... 8
Chart 4 -Perennial Cover Success Criteria Comparison by Year of Revegetation - 2006 ................... 8