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RULE 2 - PERMITS
<br />Potentially Affected Surface Water Drainages and Drainage Characteristics
<br />• Over the life of the mine, potentially affected surface water drainages include the Yampa River, as
<br />the primary receiving drainage; Grassy Creek, a perennial tributary of the Yampa River, and its
<br />tributaries; and western tributaries of Fish Creek, a perennial tributary to Trout Creek. The
<br />following small perennial and intermittent drainages within this area were identified from streams
<br />present in the USGS National Hydrography Dataset (NHD) within one mile of the PSCM permit
<br />area. They are listed below in sequence from west to east, and north to south. Unnamed ephemeral
<br />tributaries are not specifically identified. Unless identified otherwise, all listed streams are
<br />intermittent.
<br />• Grassy Creek (perennial below Little Grassy Creek confluence at site SSG2, intermittent
<br />The principal proposed surface disturbance for mine portals, facilities, stockpiles, and roads occurs
<br />in the Little Grassy Creek drainage. For the permit term, in which no subsidence is anticipated, the
<br />proposed underground mining lies under both Grassy Creek and Little Grassy Creek, portions of
<br />their respective drainages, and a portion of the drainage of the unnamed tributary to Scotchman's
<br />Gulch. While a portion of its watershed will be undermined, the unnamed Scotchman's Gulch
<br />tributary stream reach itself is not proposed to be undermined in the permit term.
<br />Given the areal extent of the proposed mining - related surface disturbance and undermining, it is
<br />proposed that adjacent area for surface water hydrology for the permit term include the watershed of
<br />Grassy Creek (a perennial stream draining to the Yampa River) and its tributaries, upstream of a
<br />point just below its confluence with Scotchman's Gulch, an intermittent tributary. The definition of
<br />the adjacent area corresponds to monitoring station YSG5, located on Grassy Creek downstream of
<br />the mouth of Scotchman's Gulch, and encompasses all mining activities, both surface and
<br />underground, for the permit term. With the inclusion of inflows from the Scotchman's Gulch
<br />tributary, it is likely to encompass the effects of mining beyond the permit term, depending on
<br />• actual coal production rates. Streamflow for individual monitoring points within this area is
<br />discussed below.
<br />PSCM Permit App. 2.04 -63 6/15/09
<br />above at site SSG1 )
<br />•
<br />Unnamed tributary #1 to Grassy Creek, joining the main stream in T6N:R87W, Section 21
<br />•
<br />Scotchman's Gulch
<br />•
<br />Annand Draw
<br />•
<br />Unnamed tributary #2 to Grassy Creek, joining the main stream in T5N:R87W, Section 21
<br />•
<br />Unnamed tributary to Scotchman's Gulch, west of Grassy Creek and joining Scotchman's
<br />Gulch main stream in T6N:R87W, Section 28
<br />•
<br />Little Grassy Creek (perennial below Pond 002)
<br />•
<br />Unnamed tributary #1 to Little Grassy Creek, joining the main stream in T6N:R87W,
<br />Section 34
<br />•
<br />Unnamed tributary #2 to Little Grassy Creek, joining the main stream in T5N:R87W,
<br />Section 3
<br />• •
<br />Unnamed tributary #3 to Little Grassy Creek, joining the main stream in T5N:R87W,
<br />Section 3
<br />•
<br />Unnamed tributary #1 to Fish Creek, joining the main stream in T5N:R87W, Section 24
<br />•
<br />Unnamed tributary #2 to Fish Creek, joining the main stream in T5N:R86W, Section 19
<br />•
<br />Cow Camp Creek
<br />The principal proposed surface disturbance for mine portals, facilities, stockpiles, and roads occurs
<br />in the Little Grassy Creek drainage. For the permit term, in which no subsidence is anticipated, the
<br />proposed underground mining lies under both Grassy Creek and Little Grassy Creek, portions of
<br />their respective drainages, and a portion of the drainage of the unnamed tributary to Scotchman's
<br />Gulch. While a portion of its watershed will be undermined, the unnamed Scotchman's Gulch
<br />tributary stream reach itself is not proposed to be undermined in the permit term.
<br />Given the areal extent of the proposed mining - related surface disturbance and undermining, it is
<br />proposed that adjacent area for surface water hydrology for the permit term include the watershed of
<br />Grassy Creek (a perennial stream draining to the Yampa River) and its tributaries, upstream of a
<br />point just below its confluence with Scotchman's Gulch, an intermittent tributary. The definition of
<br />the adjacent area corresponds to monitoring station YSG5, located on Grassy Creek downstream of
<br />the mouth of Scotchman's Gulch, and encompasses all mining activities, both surface and
<br />underground, for the permit term. With the inclusion of inflows from the Scotchman's Gulch
<br />tributary, it is likely to encompass the effects of mining beyond the permit term, depending on
<br />• actual coal production rates. Streamflow for individual monitoring points within this area is
<br />discussed below.
<br />PSCM Permit App. 2.04 -63 6/15/09
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