20080868 Ver 2_Section I C Drainage Basins 2020 PCS Creeks Report_20210701

C. Cumulative and 2020 Mining, Mine -related Activities, and Drainage Basins
Overall mine progress through 2020 is visible in a February 2021 aerial photograph with
the approximate historic drainage basins and Alt E and Mod Alt L permit boundaries shown for
north of NC Highway 33 (Figure I-C1). A summary of drainage basin alterations of monitored
creeks is depicted on a LiDAR base map (Figure I-C2) and in a table that also shows current
land use in the basins (Table I-C1). Drainage basin acreages and reductions have been
estimated using these data.
Percent basin reductions are presented for several periods of reference (i.e., pre -Alt E,
post -Alt E or pre -Mod Alt L, and post -Mod Alt L); however, the focus of the Corps 404 permit
and the State 401 certification is associated with Mod Alt L impacts.
While mine activities continued across the Bonnerton Tract in 2020 as evident from the
2021 aerial base of Figure I-C1, among the creeks in the study, no drainage basins were
affected by mine progress within the Mod Alt L boundary in 2020; therefore, the acreages and
percent reduction have not changed from the 2018 report. The Huddles Cut drainage basin was
last reduced by Mod Alt L in 2011; Tooley Creek drainage basin was last reduced by Mod Alt L
in 2013; Drinkwater Creek drainage basin was last reduced by Mod Alt L in 2014; Jacobs Creek
and Jacks Creek drainage basins were last reduced by Mod Alt L in 2015; Porter Creek was last
reduced by Mod Alt L in 2017, and all impacts to DCUT11 basin occurred in 2018. No
additional Mod Alt L reductions will occur to study creeks in the NCPC or Bonnerton tracts.
Durham Creek is not one of the creeks identified in the study plan for multiple parameter
data collection (permitted basin reduction will be less than 10 percent); however, salinity and
water depth are collected at one location approximately 2,500 feet downstream from the mouth
of DCUT11 (Figure I-B15). Basin reductions in 2020 occurred in the Bonnerton Tract south of
the Porter Creek drainage basin; resulting in impacts to approximately 291 acres (261 in
Durham Creek and 20 in Bailey Creek). Additional impacts to Durham Creek drainage basin will
occur when the mine progresses to the southern end of the Bonnerton Tract (Figure I-C2).
Table I-C1 shows the estimated historic and current basins for all creeks included in the study
(impact and controls).
Note: the 2017 report accurately showed the Durham Creek drainage basin reduction on
Figure I-C2 but Figure I-C3 (impact to Porter Creek) of that report showed only reductions to the
Porter Creek drainage basin.
I-C-1

AERIALS PROVIDED BY: PCS PHOSPHATE COMPANY. INC.
1530 NC HIGHWAY 306 SOUTH, AURORA, NORTH
CAROLINA 27806, 252-322-5121, DATE: FEBRUARY 04. 2021
Figure I-Cl. Mine continuation through 2020.
I-C-2

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I-C-3

Table I-C-1. Estimated historic and current drainage basin of each control and impact creek in the
study as described in CZR 2011 (PA2, Little Creek, Long Creek, Duck Creek, and DCUT19), in CZR
2017 (SCUT1 and Broomfield Swamp Creek), and in previous annual creeks reports (Jacks, Jacobs,
Drinkwater, Tooley, and Porter creeks, Huddles Cut, and DCUT11). Permitted impacts to all NCPC
creeks north of Highway 306 have been completed; after permitted impacts are completed in the
Bonnerton Tract, the mine will move into the South 33 Tract and Broomfield Swamp Creek will have
permitted basin reductions. (Estimate sources: USGS topoquads, LiDAR, USGS stream stats
https://streamstatus. usgs.gov/ss/)
Control creek
Drainage basin
Basin land use
Historic (ac)
Current (ac)
Reduction (%)
SCUT1
-
1,965
0
Agriculture
Little Creek
1,822
1,722
5
Agriculture
Long Creek
630
223
65
Natural vegetation
PA2
-
22
0
Natural vegetation
Duck Creek
3,118
3,118
0
Silviculture; agriculture
DCUT19
121
121
0
Agriculture
Impact creek
Broomfield Swamp Creek
-
1,946
0
Agriculture
Jacks Creek
645
150
77
Natural vegetation
Jacobs Creek
751
202
73
Natural vegetation
Drinkwater Creek
605
153
75
Natural vegetation
Tooley Creek
563
257
54
Natural vegetation
Huddles Cut
1,014
289
71
Natural vegetation
Porter Creek
3,745
840
78
Natural vegetation
DCUT11
166
81
51
Natural vegetation
Note: Due to heavy agricultural use and flat topography, SCUT1 and Broomfield Swamp Creek
historic basins have not been estimated and are presumed to not be significantly different than what
the USGS stream stats web tool calculated; CZR biologists verified flow direction in all contributory
ditches in both basins in 2017. PA2 was excavated from uplands between Jacobs and Drinkwater
creeks and therefore had no historic basin. Muddy Creek (control) is monitored only for fish/benthos
and sediment/water column metals; its basin is amongst the largest of the creeks in the study and
land use is predominantly silviculture and agriculture. Durham Creek (control) is monitored only for
depth and salinity at one location, has the largest basin, and land use is mixed between natural
vegetation, silviculture, agriculture, and other human development.
I-C-4