57 Figure 3.6.Stiff diagrams for Rapid City’s municipal water production from Stiff diagrams with similar shapes indicate similar water quality and are likely from a common source. Water quality data from the Rapid City Water Division (based on data from Mr. Ron Barber, written comm., 2005). (Surface Water) (Rapid Creek Alluvial Aquifer) (Minnelusa Aquifer) (Madison Aquifer)

Figure 3.12.Map of the Rapid Creek area showing location of major springs ( ) and other important landmarks ( ). Rapid Creek loses about 8 to 10 ft 3 /sec across the Madison (Pahasapa) outcrop (Table 3.7). This map is centered on Section 13, T. 1 N., R. 6 E., and Section 18, T. 1 N., R. 7 E., and is within the Rapid City West 7.5 minute topographic map. Figure 3.13.Map of the Spring Creek area showing location of major springs ( ), loss zones ( ), and other important landmarks ( ). This map is centered on Sections 5 and 6, T. 1 S., R. 7 E., and Sections 31 and 32, T. 1 N., R. 7 E., in the Rapid City West and Rockerville 7.5 minute topographic maps. Figure 3.11.Map of the Boxelder Creek area showing location of major springs ( ), loss zones ( ), and other important landmarks ( ). This map is centered on Sections and 21-24, T. 2 N., R. 6 E., and consists of the corners common to the Rapid City West, Blackhawk, Piedmont, and Pactola Dam 7.5 minute topographic maps. 72

Figure 4.4Topographic map of part of Rapid Creek canyon showing stratigraphic section location (black line) and locations where joints were measured using the 1 m x 1 m inventory method (numbers in circles). The circled numbers correspond with the Madison (Pahasapa) units as defined in this study. Unit 4 is not present within Rapid Creek canyon. This map is centered on Section 13, T. 1 N., R. 6 E., and is within the Rapid City West quadrangle. Figure 4.3Topographic map of part of Boxelder Creek canyon showing stratigraphic section location (two black lines connected with dashed arrow) and sites where joints were measured using the 1 m x 1 m inventory method (numbers in circles). The circled numbers correspond with the Madison (Pahasapa) units as defined in this study. This map is centered on Section 16, T. 2 N., R. 6 E., and consists of parts of the Pactola Dam and Piedmont quadrangles. Figure 4.5Topographic map of part of Spring Creek canyon showing stratigraphic section location (black line) and locations where joints were measured using the 1 m x 1 m inventory method (numbers in circles). The circled numbers correspond with the Madison (Pahasapa) units as defined in this study. This map is centered on Section 6, T. 1 S., R. 7 E., and is within the Rockerville quadrangle. 84

101 Figure 5.2. Rose diagrams showing fracture trace, joint, and cave passageway orientations at 10° segments. n=3725 Fracture Trace Orientations Aerial Photograph (1:40,000) Scale Entire Study Area n=585 n=127 n=272 n=186 Spring Creek Rapid Creek Boxelder Creek Joint Orientations 1m x 1m Inventory Method Madison (Pahasapa) Limestone Fracture Trace Orientations Aerial Photograph (1:40,000) Scale Madison (Pahasapa) Limestone Joint Orientations Outcrop Scale Madison (Pahasapa) Limestone Entire Study Area n=295 n=219 n=238 n=209 n=129 n=202 Crystal Cave n=34 Black Hills Cavern n=198 Sitting Bull Crystal Cavern n=32 Commercial Caves Joint and Cave Passage Orientations Madison (Pahasapa) Limestone a.b. f.i. g. l. j. m. c. d. e.k. n. h. N65°E N55°E N25°E N50°E N75°W N55°E N40°W N5°W N15°E N75°W N70°E N15°W N45°E N85°E N50°E N15°W N60°E N75°E N45°EN40°W N65°E N20°E N35°W N55°W N75°E N40°E N40°W N65°E N40°W N75°W N75°E N35°E N40°W N75°W N75°E N45°E N35°W N65°W

Figure 6.3. Conceptual model showing structural controls on ground-water flow paths in the Rapid City area, SD. Ground-water flow paths are shown in light green, large springs are illustrated by the upward pointing light blue arrows, faults are red, fold axes along anticlines are solid black, fold axes along synclines are dashed black lines, and fault surfaces are shown in blue. Note the graben-like structural depression bounded by the Victoria Creek fault and the City Springs monocline and fault. Also, note that ground-water flow paths from Boxelder, Rapid, and Spring creeks converge toward the structural depression along Rapid Creek and then flow is generally to the east. 121 Madison (Pahasapa) Limestone