U.S. Department of the Interior Prepared in Cooperation with the Mojave Water Agency, Water-Resources Investigations Report 95-4209 Trayler, C.R., and Koczot, K.M., 1995, Regional Water Table (1994) and Water-Level U.S. Geological Survey and the U.S. Marine Corps, Department of the Navy Changes in the , San Bernardino County, California

INTRODUCTION R2W R1W R1E R2E R3E R4E R5E R6E R7E R8E R9E Table 1. Summary of well data, Morongo Basin

The Morongo Basin is in the region of southern California, about 100 mi east of Los Angeles. Ground water SAN BERNARDINO MERIDIAN [State well No.: See "Well-Numbering System" section; some numbers subject to change upon is virtually the sole source of water in the Morongo Basin. Increased pumping to meet the needs of an increasing resident population 5J1 verification. USGS identification No. consists of latitude, longitude, and sequence number. 3,105 Altitude of land surface and altitude of water level in feet (rounded) above sea level. Casing has resulted in ground-water overdraft in parts of the ground-water basin. Most of the water resources of the basin are managed by 3,100 depth, perforations, and obstruction in feet below land surface. Measurement method: S, steel the Mojave Water Agency (MWA) and the U.S. Marine Corps Air/Ground Combat Center at Twentynine Palms (USMCAGCC). tape; R, reported by other agencies; V, calibrated electric tape. Well notes: M, USGS multiple- To help manage the ground-water resources, the MWA and the U.S. Marine Corps, Department of the Navy, requested the U.S. Ord Mountains U.S. Marine Corps depth piezometer; O, obstruction at specified depth; P, public-supply well; PW, perched water; Geological Survey (USGS) to construct a regional water-table map of the Morongo ground-water basin. 3,000 Air/Ground Combat Center EXPLANATION Z, destroyed well; *, data not plotted on map because of overcrowding of similar information] USGS Date of Altitude Water level Meas- Perforations State well identification measure- of land urement Casing No. depth Well notes The purposes of this study were to construct a regional water-table map and determine areas of water-level change in the T6N 2,825 2,825 T6N No. ment surface Depth Altitude method Top Bottom Note: Closely spaced data appear as Fault - Dashed where approximately located, 1N/5E-10B2 341139116263801 07-27-94 3,590 158.77 3,431 S 355 310 350 O at 192 Morongo Basin. Existing data were evaluated and water levels were measured in selected wells throughout the Morongo 2,800 solid lines on all graphs; dashed 2,800 dotted where concealed 1N/5E-28N1 340815116281301 05-06-94 3,635 107.45 3,528 S 155 -- -- lines represent periods of 1N/5E-33J1 340729116272901 05-06-94 3,371 255.97 3,115 S 310 245 310 O at 280 Basin. Water-level measurements were used to construct a regional water-table map for 1994 conditions (fig. 1), and available 1N/5E-34K1 340729116264701 01-05-94 3,380 415.20 2,965 R 640 340 640 P 2,775 sporadic data 2,775 historical water levels were used to construct hydrographs (shown in fig. 1) and determine water-level change at selected wells. 22P1 Approximate boundary of ground-water basin and 1N/5E-34N1 340725116272401 01-04-94 3,340 385 2,955 R 548 200 545 P 2,900 1N/5E-34P4 340727116270801 01-06-94 3,360 428.5 2,932 R 1,020 398 1,010 P 2,909 2,750 Granite Mountains 27B1 2,750 subbasins (see fig. 2) 1N/5E-34Q1 340724116264801 01-04-94 3,360 423.7 2,936 R 757 370 571 P Results of this study will aid the USGS in evaluating its current ground-water monitoring network in the Morongo Basin. 2,898 Bullion Mountains 1N/5E-34Q2 340727116263801 01-05-94 3,360 409.6 2,950 R 990 360 900 P 2,725 Well 5N/1W-25G1 2,725 Well 5N/1E-17D1 1N/5E-35K1 340729116253701 01-06-94 3,260 354 2,906 R 860 300 850 P Water-table contour - Shows altitude of water table. 1N/5E-35P1 340722116260301 01-05-94 3,280 335.2 2,945 R 504 194 494 P In addition, information gained through this study will contribute to ongoing projects in the area, such as the Regional 27R1 2,200 ? 2,700 2,700 1N/5E-36G1 340746116244201 01-05-94 3,225 346.51 2,878 V 570 550 570 */M ALTITUDE, IN FEET ABOVE SEA LEVEL ALTITUDE, 2,855 IN FEET ABOVE SEA LEVEL ALTITUDE, 2,220 ? Contour interval, in feet, is variable. Dashed where 1N/5E-36G2 340746116244202 01-05-94 3,225 348.04 2,877 S 400 380 400 M Aquifer-System Analysis (RASA) of Southern California. 1940 5045 6055 7065 8075 85 90 95 1940 5045 6055 7065 8075 85 90 95 2,325 YEAR YEAR Intermediate Contour approximately located, queried where doubtful. 1N/5E-36H2 340751116241901 01-05-94 3,210 322.3 2,888 R 1,000 400 1,000 P 2,800 ? ? Note: Closely spaced data appear as solid lines on all 1N/5E-36K2 340736116244601 01-05-94 3,230 423.20 2,807 R ------P Acknowledgments 2,780 36J1 ? 2,300 graphs; dashed lines represent periods of sporadic data Hachures indicate depression. Datum is sea level 1N/5E-36K3 340738116244301 01-04-94 3,230 374 2,856 R 1,115 550 1,115 P 2,750 1N/5E-36L1 340734116245401 01-04-94 3,230 413.1 2,817 R 735 275 725 P 2,760 2,275 1N/5E-36M1 340737116250801 01-02-94 3,250 429.90 2,820 V 570 550 570 M ? ? 2,850 2,600 1N/5E-36M4 340731116251001 01-04-94 3,245 430.4 2,815 R 800 400 800 P Several local water agencies contributed water-level data used in this report. Those agencies include the Bighorn-Desert Generalized direction of ground-water movement - 1N/5E-36M5 340732116251701 01-04-94 3,245 485.1 2,760 R 1,450 920 1,450 P ? 2,250 1N/5E-36M6 340732116251601 01-04-94 3,245 414.7 2,830 R 800 450 800 P 2,825 2,575 ? View Water Agency in Landers, the Hi-Desert Water District in Yucca Valley, the Joshua Basin Water District in Joshua Tree, 12H2 Queried where doubtful 1N/6E-13R1 340953116175801 05-03-94 2,650 440.52 2,209 V 715 455 710 and the Twentynine Palms Water District in Twentynine Palms. In addition, the results of studies at the USMCAGCC by Jacobs 2,740 2,721 10H3 2,225 Well 4N/6E-27M1 1N/6E-17A1 341036116221301 06-09-94 3,309 297.57 3,011 R ------P 2,790 2,800 2,550 1N/6E-25K2 340822116182601 03-30-94 2,705 422.00 2,283 R 740 -- -- P Engineering were very helpful to this study. 2,200 02J1 1N/6E-25M2 340817116185801 03-30-94 2,723 444.62 2,278 R 500 452 -- */P Gateway Lake IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 2,775 2,525 Well and data - Top number is well number; bottom 1N/6E-25M3 340821116185801 03-30-94 2,720 438.00 2,282 R 704 452 -- P (Dry) YEAR 2,251 1N/6E-28L2 340821116215001 05-05-94 3,065 163.36 2,902 S 300 -- -- 17D1 Well 4N/3E-23G1 Well 4N/4E-36B1 1N/6E-28N1 340809116215201 05-05-94 3,107 392.31 2,715 S 500 -- -- 2,750 Mojave Water Agency number is altitude of water table in feet above sea level Description of Study Area 2,723 2,500 1N/6E-29J3 340821116220901 07-29-94 3,095 180 2,915 R 803 350 773 Lucerne 1N/6E-29R3 340816116220901 07-29-94 3,105 186 2,919 R 680 360 660 T5N 2,725 2,475 2,325 T5N 1N/6E-31C1 340750116234401 01-05-94 3,199 230.9 2,968 R ------P ALTITUDE, IN FEET ABOVE SEA LEVEL ALTITUDE, 247 IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 Lake 1940 5045 6055 7065 8075 85 90 95 1N/6E-31E1 340744116240601 07-29-94 3,200 378 2,822 R ------As defined for this study, the 1,000-square-mile Morongo ground-water basin consists of several alluvium-filled valleys USMCAGCC 18L1 (Dry) YEAR YEAR 2,300 1N/6E-31G1 340740116233401 07-29-94 3,250 315 2,935 R ------and basins that are surrounded by the on the west, the Ord and Granite Mountains on the north, the 2,253 Destroyed well and data - Top number is well number; 1N/7E-10N1 341044116144301 02-02-94 2,385 208.24 2,177 V 267 -- -- 1N/7E-22D1 340947116144101 02-28-94 2,405 233.94 2,171 V 506 464 506 2,720 2,275 Bullion Mountains on the east, and the Pinto and Little San Bernardino Mountains on the south. (Generally, the lightest and 20Q1 bottom number is former altitude of water table in feet 1N/7E-22L2 340923116142501 02-02-94 2,408 232.82 2,175 V 393 241 387 darkest gray areas of the shaded-relief map represent higher topography.) Previous investigators divided the Morongo Basin 2,716 above sea level 1N/7E-23A1 340945116125001 05-02-94 2,376 205.15 2,171 S 370 360 370 2,250 1N/7E-23P1 340901116132301 02-03-94 2,382 203.93 2,178 V 429 -- -- area into 17 or more separate ground-water basins or subbasins, including the Lucerne, Fry, Johnson, Upper Johnson, Means, 1N/7E-26J1 340830116124201 03-30-94 2,510 239.41 2,271 R 401 277 401 P Pipes, Reche, Warren, Copper Mountain, Joshua Tree, Giant Rock, Emerson, Surprise Spring, Mesquite, Deadman, Twentynine 2,225 Well 3N/7E-31E1 Spring 1N/7E-28Q1 340819116145001 02-02-94 2,483 204.06 2,279 V 412 -- -- * 28F1 25G1 1N/7E-28R2 340819116145201 02-02-94 2,464 184.67 2,279 V 262 -- -- Palms, and Mainside Basins (fig. 2). The ground-water-basin boundaries shown in figure 2 are defined by faults, low-permeability 31C1 2,700 35F3 2,200 1N/7E-30K1 340831116172201 03-30-94 2,625 346.21 2,279 R 740 -- -- P

2,829 IN FEET ABOVE SEA LEVEL ALTITUDE, 2,800 2,718 32B2 2,861 1940 5045 6055 7065 8075 85 90 95 1N/7E-32C1 340801116163401 05-03-94 2,610 329.56 2,280 V ------rocks, and other ground-water barriers that generally restrict ground-water movement in the study area. 2,700 2,787 YEAR Extinct spring 1N/7E-34B1 340803116140601 02-28-94 2,489 216.15 2,273 V 590 527 590 1N/7E-34D1 340754116144501 02-02-94 2,543 262.59 2,280 V 396 261 391 Rabbit Lucerne Valley 1N/8E-09L1 341106116090001 03-01-94 2,180 324.61 1,855 R 386 342 386 The climate of the Morongo Basin is typical of the Mojave Desert. The area receives little precipitation, and recharge to ground Lake 1N/8E-12G1 341114116053301 03-02-94 1,973 200.78 1,772 V ------3K1 Johnson Valley Fault 1N/8E-30J1 340831116104201 01-04-94 2,353 168.83 2,184 R 600 80 390 water is minimal. Average annual precipitation on the basin floor ranges from 4 to 6 in. (Rantz, 1969). Recently, MWA has begun (Dry) 36R1 2,760 1N/8E-30J2 340831116104301 09-28-93 2,353 164.50 2,188 R 400 145 312 */P 2,842 2J1 2,704 2,740 Soggy Melville 2,225 1N/8E-30N1 340807116113101 02-17-94 2,490 307.67 2,182 R 400 200 400 P an artificial-recharge project in Yucca Valley (Warren Basin) and is planning an artificial-recharge project near Lucerne Valley 2,729 3P2 Lake 2,740 Lake 1N/8E-33A2 340804116083001 02-01-94 2,510 311.33 2,199 R 350 195 345 P 2,769 2,200 1N/8E-33A3 340803116082901 02-22-94 2,510 312.84 2,197 R 408 258 403 */P (Lucerne Basin). Local water districts, municipalities, the USMCAGCC, and private well owners rely on the local ground water 2Q2 2,860 1N/8E-33A4 340805116082901 02-27-94 2,510 307.58 2,202 R 530 318 510 */P Rabbit Springs 18C2 5P2 9D4 2,820 2,880 7G1 (Dry) (Dry) 2,810 Bullion Mountains 1N/8E-33A5 340804116082901 02-22-94 2,510 309.75 2,200 R 410 310 410 */P for municipal, domestic, and agricultural needs. 2,822 18C3 2,727 2,735 2,831 2,780 Emerson 2,175 ? 10H1 2,815 1N/8E-33J1 340731116084301 03-04-94 2,700 425.96 2,274 V 553 310 330 9N2 1N/8E-34M1 340731116082601 03-04-94 2,700 311.26 2,389 V 410 391 -- * 18 2,897 2,840 Lake U.S. Marine Corps 2,755 2,780 2,800 12R1 2,150 1N/8E-34N1 340722116081701 03-04-94 2,690 249.97 2,440 V 350 250 350 The basin is largely undeveloped desert except for the towns of Lucerne Valley, Yucca Valley, Joshua Tree, Landers, 7E1 13E1 9N2 1N/8E-36A1 340801116052401 01-18-94 2,130 185.66 1,944 R 292 -- -- P 12N2 2,835 2,895 2,840 2,700 (Dry) Air/Ground Combat Center and Twentynine Palms, and the main facility (Mainside) at the USMCAGCC. Agricultural development in the basin, with the 2,906 2,839 17C1 2,125 Well 2N/7E-2C1 1N/8E-36G1 340742116053201 01-04-94 2,158 218.58 1,939 R 430 220 420 P 2,898 7R1 10R1 14A2 16D1 1N/8E-36H2 340741116053201 08-31-93 2,160 217.08 1,943 R 337 52 337 */P 15R1 2,696 exception of Lucerne Valley, is minimal. 2,918 2,929 2,857 2,783 2,100 1N/9E-04C1 341226116024601 10-11-93 1,769 223.21 1,546 R 244 218 243 13M2 20E1 2,867 17H2 IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 1N/9E-04N3 341141116030901 03-03-94 1,787 16.90 1,770 V 500 390 495 2,894 1,875 1N/9E-11N2 341047116010501 05-27-94 1,790 253.58 1,536 S ------2,900 2,860 15J1 Means YEAR 2,936 2,884 18L1 1N/9E-16H4 341020116021901 03-03-94 1,795 15.76 1,779 V 55 -- -- 18Q1 Helendale 17L2 13P1 2,780 19B1 2,253 Well 3N/7E-36G1 2,920 21C1 2,887 Lake 1,850 1N/9E-17E1 341031116041401 03-02-94 1,870 109.88 1,760 V ------T4N 21J1 2,845 13M1 2,737 T4N 1N/9E-23D1 340953116005001 05-27-94 1,800 263.63 1,536 S ------21G1 2,882 2,949 2,840 2,880 23G1 (Dry) 1N/9E-27C1 340855116013601 03-03-94 1,867 84.63 1,782 V ------2,948 1,825 1N/9E-31A4 340755116042501 01-18-94 2,085 144.67 1,940 R 398 160 398 P 2,920 20Q1 27D1 30C1 2,777 2,977 1N/9E-31C1 340757116045601 01-18-94 2,105 158.50 1,947 R ------P Ord Mountains 2,963 2,900 2,882 1,800 1N/9E-32P1 340719116034901 01-20-94 2,140 177.42 1,963 R 320 220 320 P 2,940 18 29D1 2,260 1N/9E-33F5 340743116025502 03-03-94 1,981 17.60 1,963 V 22 20 22 ? 1,775 1N/9E-33H2 340741116022002 03-03-94 1,961 51.69 1,909 V 57 55 57 ? 26J1 2,740 1N/9E-33J3 340739116021701 03-03-94 1,972 17.83 1,954 V 35 33 35 * MountainsGranite 3,097 ? 3,000 1N/9E-33K5 340739116023004 03-03-94 1,973 23.33 1,950 V 28 26 28 * 2,960 27M1 1,750

ALTITUDE, IN FEET ABOVE SEA LEVEL ALTITUDE, 1N/9E-34A1 340808116012101 03-03-94 1,938 151.93 1,786 V ------27R2 3,200 Old 2,900 36B1 1940 5045 6055 7065 8075 85 90 95 2,980 32B1 2,264 YEAR 1N/9E-35F1 340756116004601 03-03-94 1,972 115.40 1,857 V ------3,228 1N/9E-35N1 340718116010301 03-04-94 2,081 115.62 1,965 V 260 147 247 3,000 Woman 32Q1 2,567 2,323 1,875 247 3,100 Springs 1S/5E-03D1 340717116271001 01-06-94 3,340 380.52 2,960 R 940 400 940 P Upper Johnson Fault 35J1 2,745 1S/5E-04A1 340706116273001 04-26-94 3,331 345.10 2,986 R 535 200 525 Bullion Mountains ? 1,850 Emerson 2,784 ? 1S/5E-04B1 340706116274401 04-26-94 3,339 379.22 2,960 R ------1S/5E-05A1 340700116283201 05-04-94 3,554 107.94 3,446 S 390 145 340 5K1 4K2 3C1 2J1 2,250 Lucerne 1,825 1S/5E-10D1 340614116272201 05-06-94 3,570 47.65 3,522 S 130 -- -- 18 Cushenbury Canyon 2R1 2,756 2,759 2,748 2,251 1S/9E-03D1 340714116020701 03-04-94 2,075 113.32 1,962 S 275 -- -- Lucerne Valley 2,786 2N/5E-01G1 341716116242901 05-25-94 3,010 100.42 2,910 S ------1,800 Mojave Water Agency 2,760 2N/5E-12B1 341643116243101 06-09-94 3,059 145.17 2,914 R ------P Means Wash Johnson Deadman 247 Well 3N/8E-29C1 2N/5E-12B2 341642116243001 06-09-94 3,055 138.92 2,916 R ------*/P Fry ? 2,250 ? 1,775 2N/5E-12N1 341600116250801 05-25-94 3,217 283.33 2,934 V 358 337 358 3,025 2,900 2N/5E-13A1 341549116241601 05-26-94 3,079 138.90 2,940 V 190 135 190 O at 155 ? 1,750 2N/5E-14M1 341520116261901 05-26-94 3,423 190.03 3,233 R 305 170 300 18 Well 4N/1W-21G1 Well 4N/1E-13M1 7R1 IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 2N/5E-22J1 341438116262801 06-09-94 3,503 257 3,246 R 785 250 775 P Giant Rock 3,000 2,875 YEAR 2N/5E-23M1 341438116261401 05-26-94 3,465 211.66 3,253 V 225 180 225 Surprise 2,765 12N1 Pipes 3,075 16A1 1,825 2N/5E-24H1 341444116241701 06-09-94 3,282 270.99 3,011 R 604 220 580 P California Spring 2,975 2,850 2,780 Deadman 2N/5E-27A1 341412116262201 05-05-94 3,470 219.76 3,250 S 485 443 485 O at 445 2,400 2,332 2N/5E-27K2 341343116263801 06-09-94 3,465 221.83 3,243 R 322 184 319 P San Bernardino MountainsLanders T3N ? 1,800 T3N Mainside 17L1 Lake 2N/5E-27K3 341343116263601 06-09-94 3,468 226.50 3,242 R 358 -- -- */P 2,950 2,825 20C1 ? Reche 2,246 1,803 2N/5E-27R1 341331116263201 06-09-94 3,470 221.08 3,249 R 475 260 470 P Note: Closely spaced data appear as solid lines on all (Dry) 1,775 2N/5E-34R2 341228116262301 05-26-94 3,550 163.29 3,387 S ------2,925 2,800 19N1 graphs; dashed lines represent periods of sporadic data 2,240 2N/5E-36C1 341319116244901 06-09-94 3,433 282.33 3,151 R ------2,247 29C1 28P3 1,750 2N/6E-11M1 341622116194601 03-23-94 2,803 482.85 2,320 V 790 750 -- Pipes 2,900 2,775 20M1 28D1 1,800

ALTITUDE, IN FEET ABOVE SEA LEVEL ALTITUDE, 2N/6E-18B1 341556116233401 05-26-94 3,087 221.90 2,865 V 310 187 305 P 1940 5045 6055 7065 8075 85 90 95 IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 1,801 Well 1N/8E-12G1 Mesquite 2,242 27H1 1,802 2N/6E-30L1 341345116234701 05-05-94 3,330 316.41 3,014 S 377 123 375 O at 350 YEAR YEAR 2,246 2,230 Study Copper Mountain 34D1 1,833 1,725 2N/6E-30N1 341332116241301 06-09-94 3,366 351.08 3,015 R 920 300 920 Twentynine ? 27B1 Area 247 29G1 2,231 2N/6E-31D1 341316116240101 05-05-94 3,395 316.69 3,078 S 358 337 358 Palms 2,334 28R1 34D1 1,700 2N/7E-02C1 341741116132501 03-23-94 2,272 135.22 2,137 V 398 149 377 O at 325 Los Angeles Yucca Valley 62 1,830 2,242 IN FEET ABOVE SEA LEVEL ALTITUDE, Joshua Tree Twentynine 2,231 29L1 1,800 1940 5045 6055 7065 8075 85 90 95 2N/7E-02D1 341732116132701 03-23-94 2,290 150.79 2,139 S 532 250 532 */P Palms 32D1 2,200 YEAR 2N/7E-03A1 341740116134201 03-23-94 2,301 160.54 2,140 S 560 210 550 */P

SAN BERNARDINO MERIDIAN 1,803 San Diego Warren Pinto 2,244 29R1 36G1 2N/7E-03B1 341736116141201 03-23-94 2,355 186.02 2,169 S 700 260 690 P Mountains 2,400 2,237 1,831 2N/7E-03E1 341723116143601 03-23-94 2,385 188.83 2,196 S 510 250 510 P ? 2,140 A’ 1,975 31E1 Surprise 33N1 2N/7E-04H1 341720116145601 03-23-94 2,442 216.02 2,226 V 481 300 420 Subbasin boundaries modified from California Department 5B1 32J1 2N/7E-05B1 341742116160701 08-23-94 2,587 356.16 2,230 V 405 385 405 34P1 2,260 Spring 31J3 1,801 1,950 0 10 MILES of Water Resources, 1964, French, 1978, Lewis, 1972, Mojave Water Agency 2,230 2,231 2N/7E-14K1 341520116130101 03-22-94 2,538 337.82 2,200 V 644 450 558 O at 500 Londquist and Martin, 1991, and Schaefer, 1978. 3,166 1,830 33H1 2N/7E-19A1 341501116170601 05-03-94 2,748 505.95 2,242 V 650 500 645 0 10 KILOMETERS 1G1 Homestead 1,925 2N/7E-36R1 341238116114301 03-01-94 2,305 291.85 2,013 V 462 305 462 Johnson Valley Fault 3B1 2C1 5A1 1,801 2,910 2,260 Mesquite Fault 2N/8E-04B1 341737116085501 03-01-94 2,005 204.41 1,801 R 227 202 227 Emerson Fault 2,169 2,137 Surprise Spring Fault 1,802 San Bernardino Mountains 3,200 4H1 1,900 2N/8E-04B2 341736116085401 12-29-93 2,008 208.16 1,800 R 226 202 226 * 2,950 4L3 4B1 2N/8E-04B3 341736116085901 03-05-94 2,010 209.28 1,801 R 230 204 229 * Figure 2. Location of study area and subbasins of Morongo Basin. Landers 2,226 Well 1N/9E-33H2 2N/8E-04D1 341739116092801 03-04-94 2,027 226.14 1,801 R 246 222 246 * Well 2N/6E-18B1 3E1 Elkins Fault 1,801 1,801 1,875 2,925 12B1 2N/8E-04D2 341738116092601 03-06-94 2,025 224.01 1,801 R 246 221 246 * 2,914 2,196 2N/8E-04D3 341735116092601 12-22-93 2,030 229.10 1,801 R 248 223 248 * 2,200 1,850 2,900 11M1 7K1 2N/8E-04D4 341737116092801 03-05-94 2,028 227.39 1,801 R 248 222 248 * T2N 12N1 12P1 IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 T2N 2N/8E-04F1 341725116090401 07-20-94 2,022 221.07 1,801 R 240 215 240 * 18B1 2,320 ? 1,829 2,934 1,656 YEAR 2N/8E-04L1 341709116090401 01-26-94 2,042 240.66 1,801 V 591 571 591 */M 2,875 2,865 2N/8E-04L2 341709116090402 01-26-94 2,042 240.65 1,801 V 380 360 380 */M Geohydrology 3,000 13A1 Fault 19D2 2N/8E-04L3 341709116090403 01-26-94 2,042 240.61 1,801 V 285 245 285 M 2,850 14K1 2N/8E-05A1 341735116093101 03-02-94 2,039 237.65 1,802 R 259 234 259 3,200 3,200 3,200 2,940 1,701 14M1 2,240USMCAGCC 2,200 1,550 2N/8E-05A2 341738116093401 03-02-94 2,036 235.42 1,801 R 254 228 253 * Non-water-bearing igneous and metamorphic rocks underlie the ground-water basin and form the mountains and hills that Note: Closely spaced data appear as solid lines on all 2,825 20G1 2N/8E-07K1 341621116110601 03-22-94 2,270 441.34 1,829 V 525 125 505 ALTITUDE, IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 3,233 20N2 2N/8E-12P1 341600116055501 02-22-94 1,848 192.3 1,656 R 212 186 211 3,100 3,100 3,100 graphs; dashed lines represent periods of sporadic data 19A1 1,548 surround the basin. These rocks contain virtually no water except where they are jointed or fractured. YEAR Mojave Water Agency 20A1 22H1 1,547 2N/8E-20A1 341454116094601 03-01-94 2,270 422.04 1,848 R 559 509 554 Well 1N/5E-36K1 22J1 23M1 2,242 1,848 2N/8E-22H1 341451116073901 03-01-94 2,125 328.82 1,796 R 390 340 390 24H1 1,796 19D4 29D1 2N/8E-32R1 341238116094101 05-30-92 2,210 342.00 1,868 R 489 -- -- 3,000 3,000 (destroyed) 3,000 3,246 3,253 19R2 Alluvial deposits of Quaternary and Tertiary age fill the Morongo ground-water basin to a maximum depth of 10,000 ft near 2,225 3,011 Arch 1,772 1,548 1,547 2N/9E-19D2 341502116050101 03-22-94 1,840 139.45 1,701 V ------27A1 30L1 2N/9E-19D4 341458116051601 03-22-94 1,860 88.21 1,772 V 519 259 519 Note: Closely spaced data appear as solid lines on all 1,860 Area 28L1 the eastern edge of the basin north of Deadman Lake (Moyle, 1984). In general, the deposits are unconsolidated at land surface 2,900 Well 1N/5E-36K2 2,900 27K2 3,250 30N1 Copper 29M1 2N/9E-19R1 341416116042501 01-26-94 1,768 220.77 1,548 V 460 440 460 */M 2,900 2,200 graphs; dashed lines represent periods of sporadic data 3,014 Well 1N/6E-31C1 3,243 3,015 1,547 1,547 2N/9E-19R2 341416116042502 01-26-94 1,768 220.36 1,548 V 310 290 310 M and become partly consolidated with depth. The unconsolidated deposits, where saturated, are the only deposits from which Well 1N/5E-34N1 36C1 of 2N/9E-20G1 341449116034201 01-26-94 1,921 373.00 1,548 V 440 400 440 27R1 ? Transverse 2,800 2,800 2,800 2,175 3,151 30P2 29R1 2N/9E-20N1 341419116040401 01-26-94 1,771 223.44 1,548 V 450 430 450 */M ALTITUDE, IN FEET ABOVE SEA LEVEL ALTITUDE, significant quantities of ground water can be obtained. IN FEET ABOVE SEA LEVEL ALTITUDE, 1,800 ALTITUDE, IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 1940 5045 6055 7065 8075 85 90 95 1940 5045 6055 7065 8075 85 90 95 3,249 1,758 1,546 Mesquite 2N/9E-20N2 341419116040402 01-26-94 1,771 224.34 1,547 V 270 250 270 M YEAR YEAR YEAR Perched 2N/9E-28L1 341341116024901 01-26-94 1,891 343.96 1,547 V 397 367 387 2,150 31D1 3,300 32R1 Lake 2N/9E-29D1 341402116040801 02-09-94 1,767 219.92 1,547 R 238 213 238 The Morongo Basin is crossed by several northwest-trending faults that show evidence of both lateral and vertical movement 3,078 29Q1 Water 2N/9E-29M1 341340116040501 01-26-94 1,760 213.26 1,547 V 410 390 410 M 2,125 3,400 Mesquite Well 1N/7E-23A1 1,868 (Dry) 2N/9E-29M2 341340116040502 01-25-94 1,760 185.62 1,575 V 250 220 250 */PW/M 247 3,100 36R1 1,547 (Bortugno, 1986). Large differences in water level across some of these faults suggest that they impede ground-water movement 34R2 Spring 32R1 4C1 2N/9E-29M3 341340116040503 01-26-94 1,760 75.13 1,685 V 90 70 90 */PW/M 29J3 2,100 3,000 Mountain2,180

36M1 IN FEET ABOVE SEA LEVEL ALTITUDE, 2,013 (F.S. Riley and G.F. Worts, Jr., USGS, written commun., 1953; Lewis, 1972; Schaefer, 1978; Londquist and Martin, 1991). The 1940 5045 6055 7065 8075 85 90 95 3,387 1,546 1,546 2N/9E-29Q1 341323116033801 02-09-94 1,765 218.12 1,547 R 238 213 238 2,820 36G2 2,915 2N/9E-29R1 341323116031601 02-23-94 1,767 220.67 1,546 R 256 236 256 YEAR barrier effect of the faults is believed to be caused by compaction and deformation of the water-bearing deposits immediately 28N1 36K2 2,877 36H2 28L2 2N/9E-29R2 341322116031501 02-05-94 1,769 221.91 1,546 R 254 234 254 * 1,760 1,540 2N/9E-29R3 341323116031501 01-10-94 1,769 222.32 1,546 R 254 218 254 * 3,528 2,888 2,902 ? adjacent to the faults and by cementation of the fault zone by mineral deposition (F.S. Riley and G.F. Worts, Jr., USGS, written 2,807 36K3 2N/9E-30P2 341323116045501 03-02-94 1,790 31.99 1,758 V ------commun., 1953; Schaefer, 1978; and Londquist and Martin, 1991). The Pinto Mountain Fault, its splays, and the mountain-front 36M6 2,856 Pipes Wash A 2N/9E-31C2 341321116050001 03-02-94 1,795 33.00 1,762 V ------* 2,000 12G1 2N/9E-32J1 341247116032601 03-22-94 1,758 72.90 1,685 R 86 65 85 */PW 34P4 34K1 34Q2 2,830 31C1 Mojave Water Agency 10B2 10N1 Fault 4N3 2N/9E-32J2 341245116032501 03-23-94 1,758 73.20 1,685 R 86 66 86 */PW faults of the San Bernardino Mountains near Lucerne Basin are the only east-west-trending faults that have been identified in the 2,375 ? 2,950 2,968 29R3 28N1 3,431 2,200 1,772 2N/9E-32J4 341246116032301 03-23-94 1,758 72.77 1,685 R 89 64 89 */PW study area. The Pinto Mountain Fault system also seems to be a barrier to ground-water movement. According to Bortugno 33J1 2,932 2,965 2,900 2,177 9L1 1,770 11N2 2,919 2,715 Well 1N/7E-32C1 1,855 1,780 1,536 2N/9E-32J5 341244116032601 01-19-94 1,758 72.82 1,685 R 90 64 89 */PW (1986), most of the faults have been tectonically active within the Quaternary period. 3,115 36M5 2,350 17A1 Coyote 16H4 2N/9E-32J6 341245116032301 03-24-94 1,758 72.92 1,546 R 80 60 80 */PW 2,760 3,011 17E1 1,779 2N/9E-32R1 341232116032201 02-27-94 1,759 212.58 1,546 V 470 450 470 PW/M T1N 31G1 2,325 Lake 1,760 T1N 2N/9E-32R2 341232116032202 02-27-94 1,759 189.11 1,570 V 255 235 255 */PW/M 2,935 2,800 247 (Dry) 2N/9E-32R3 341232116032203 02-27-94 1,759 65.27 1,694 V 80 60 80 */PW/M Barriers to ground-water flow are also formed by the generally non-water-bearing consolidated rocks that compose the 34N1 22D1 23D1 3N/3E-02R1 342216116374801 06-29-94 2,990 203.65 2,786 V -- 240 242 O at 240 31E1 2,300 2,955 2,950 2,960 36L1 2,171 3N/4E-03C1 342304116334401 05-24-94 2,840 92.10 2,748 S 137 107 137 mountain ranges and the antiformal bedrock structure (transverse arch) located in the southern part of the Surprise Spring Basin. 2,900 2,822 13R1 23A1 1,536 3N/4E-04K2 342229116341001 05-16-94 2,915 155.78 2,759 S 510 360 510 2,817 2,275 35P1 35K1 2,209 22L2 2,171 3N/4E-05K1 342224116350101 05-25-94 2,930 173.90 2,756 V 211 166 206 O at 186 2945 2,906 Yucca Valley 3N/4E-07R1 342120116355101 05-25-94 3,120 355 2,765 R 406 366 406 5A1 2,250 2,175 26J1 27C1 3N/4E-12N1 342117116311501 05-25-94 3,255 180.15 3,075 S 203 -- --

36M4 IN FEET ABOVE SEA LEVEL ALTITUDE, 1940 5045 6055 7065 8075 85 90 95 3,446 3D1 34Q1 23P1 2,271 30J1 1,782 3N/5E-34P1 341758116270501 05-25-94 3,309 143.47 3,166 S ------2,936 2,815 YEAR Pinto Mountain Fault ? 2,184 1,960 3N/6E-02J1 342221116190801 03-29-94 2,413 161.63 2,251 S ------4A1 2,960 36M1 36G2 29J3 2,178 34A1 3N/6E-16A1 342107116210401 03-28-94 2,507 174.56 2,332 S 295 275 295 36H2 30K1 36A1 Well-Numbering System 2,986 2,900 34Q2 28L2 28R2 33A2 Twentynine Palms 1,786 3N/6E-27B1 341925116202501 03-28-94 2,643 309.20 2,334 S 415 395 415 36K2 2,279 1,944 28N1 36M6 36K3 31C1 2,279 Joshua Tree 30N1 2,199 3N/7E-19N1 341939116174501 03-29-94 2,488 241.74 2,247 S 295 275 295 35F1 3N/7E-20C1 342111116174801 03-29-94 2,445 198.55 2,246 S 605 228 605 O at 212 4B1 62 31A4 3,000 34P4 34B1 Water Agency Mojave 2,182 Wells are identified and numbered according to their location in the rectangular system for the subdivision of public lands. 2,960 34K1 28N1 25K2 2,280 ? 1,857 3N/7E-20M1 341952116164601 03-29-94 2,458 211.54 2,246 S 295 275 295 10D1 33J1 32C1 2,273 2,200 31C1 1,940 3N/7E-27H1 341909116134101 03-29-94 2,240 407.05 1,833 V 587 472 572 3,522 25M3 2,283 34D1 33J1 1,900 Identification consists of the township number, north or south; the range number, east or west; and the section number. Each 0 2 MILES 34N1 36M5 29R3 2,280 34N1 36G1 1,947 32P1 33F5 3N/7E-28D1 341918116153001 03-24-94 2,473 230.57 2,242 V 618 418 598 2,282 2,280 35N1 3N/7E-28D2 341923116153201 05-24-94 2,473 233.20 2,238 V 600 390 580 *P section is divided into sixteen 40-acre tracts lettered consecutively (except I and 0), beginning with A in the northeast corner of 31G1 2,274 2,440 1,939 1,963 1,963 SAN BERNARDINO BASE LINE SAN BERNARDINO BASE LINE 1,965 1,960 3N/7E-28R1 341836116150501 03-22-94 2,521 290.21 2,231 V 600 390 580 P the section and progressing in a sinusoidal manner to R in the southeast corner. Within the 40-acre tract, wells are sequentially 3,400 0 2 KILOMETERS Yucca Valley 2,025 2,050 3N/7E-29F1 341905116163401 05-24-94 2,510 277.80 2,232 V 600 390 580 *P 35P1 36L1 3N/7E-29G1 341912116160801 03-24-94 2,501 258.17 2,242 V 351 312 348 O at 342 Scale 1 : 63,360 31E1 Well 1N/8E-36A1 3N/7E-29R1 341843116155201 03-24-94 2,520 283.55 2,236 V 600 390 580 P numbered in the order they are inventoried. The final letter refers to the base line and meridian. In California, there are three 03D1 35K1 2,000 2,025 33H2 3D1 ? Detail of inset map A 5A1 36M4 2,800 1,962 3N/7E-31E1 341823116175001 03-24-94 2,514 254.32 2,260 V ------base lines and meridians; Humboldt (H), Mount Diablo (M), and San Bernardino (S). All wells in the study area are referenced to 34Q1 2,900 Well 1S/9E-3D1 1,909 3N/7E-32D1 341826116164501 03-24-94 2,544 299.99 2,244 V 618 418 598 4B1 4A1 1,975 the San Bernardino base line and meridian (S). Well numbers consist of 15 characters and follow the format 004N004E36B001S. 3,000 2,000 3N/7E-32J1 341804116155101 03-24-94 2,548 316.61 2,232 S 600 390 580 P 10D1 3N/7E-34D1 341833116144201 08-22-94 2,501 270.32 2,231 V -- 270 -- In this report, well numbers are abbreviated and written 4N/4E-36B1. Wells in the same township and range are referred to by T1S 1,950 1,975 T1S 3N/7E-36G1 341809116115801 08-23-94 2,111 279.72 1,831 V -- 384 -- 3,400 3N/8E-17L1 342037116101101 03-29-94 1,850 47.81 1,803 S -- 248 -- only their section designation, 36B1. The following diagram shows how the number for well 4N/4E-36B1 is derived. Note: Closely spaced data appear as solid lines on all 3N/8E-28P1 341843116090401 01-26-94 1,832 30.90 1,801 V 395 375 395 */M Inset map A 1,925 1,950 graphs; dashed lines represent periods of sporadic data 3N/8E-28P2 341843116090402 01-26-94 1,832 30.85 1,801 V 180 160 180 */M 3N/8E-28P3 341843116090403 01-26-94 1,832 30.81 1,801 V 85 45 85 M 1,900 1,925

ALTITUDE, IN FEET ABOVE SEA LEVEL ALTITUDE, 3N/8E-29C1 341918116101501 03-29-94 1,891 88.43 1,802 S -- 500 684 O at 201 1940 5045 6055 7065 8075 85 90 95 IN FEET ABOVE SEA LEVEL ALTITUDE, RANGE 4N/4E-36B1 Little San Bernardino Mountains 1940 5045 6055 7065 8075 85 90 95 3N/8E-29L1 341845116100701 03-29-94 1,906 102.95 1,803 S 600 270 590 R3ER2E R4E R5E R6E YEAR YEAR 3N/8E-31J1 341801116104601 01-26-94 2,036 206.68 1,830 V 390 370 390 */M 3N/8E-31J2 341801116104602 01-26-94 2,036 206.63 1,830 V 320 300 320 */M T8N R4E D CB A R2W R1W R1E R2E R3E R4E R5E R6E R7E R8E R9E 3N/8E-31J3 341801116104603 01-26-94 2,036 206.59 1,830 V 250 210 250 M 3N/8E-32J1 341757116094701 04-07-94 2,000 203.43 1,797 S ------* 6 5 4 3 2 1 3N/8E-33H1 341814116083801 01-07-94 1,865 63.97 1,801 R 82 56 82 T7N E FG H Base from U.S. Geological Survey digital elevation data, 1:250,000, 1987, Faults modified from Bortugno, 1986; Londquist and Martin, 3N/8E-33H2 341822116083301 01-08-94 1,837 36.25 1,801 R 56 30 56 * and digital data, 1:100,000, 1981-89; Universal Transverse Mercator Projection, 0 2 4 6 8 10 MILES 1991; J.C. Matti, and G.I. Dixon, U.S. Geological Survey, 3N/8E-33H3 341819116083101 01-09-94 1,845 43.76 1,801 R 63 37 63 * 7 8 9 10 11 12 Zone 11. Shaded relief base from 1:250,000-scale Digital Elevation Model; sun written comnun., 1994; Schaefer, 1978 3N/8E-33N1 341751116092201 01-05-94 1,993 191.85 1,801 R 208 183 208 T6N 3N/8E-34D1 341823116082201 04-07-94 1,824 24.16 1,800 V -- 180 -- LM JK illumination from northwest at 30 degrees above horizon 3N/8E-33N2 341752116092501 01-04-94 1,992 190.66 1,801 R 210 185 210 * 18 17 16 15 14 13 0 2 4 6 8 10 KILOMETERS 4N/1E-02Q2 342732116504701 06-30-94 2,926 116.07 2,810 S ------TOWNSHIP T5N T4N 4N/1E-03P2 342735116521701 06-30-94 2,930 161.30 2,769 S ------19 20 21 22 23 24 NP Q R SCALE 1 : 125,000 4N/1E-05P2 342736116540401 05-16-94 2,910 183.40 2,727 V ------T4N 4N/1E-09D4 342728116531901 10-07-94 2,925 190.28 2,735 S 300 180 300 SECTION 36 4N/1E-09N2 342642116532701 04-01-92 2,965 210 2,755 R 298 -- -- 30 29 28 27 26 25 4N/1E-12R1 342638116492601 06-30-94 2,975 140.27 2,835 S 330 -- -- 4N/1E-13E1 342613116502201 07-22-94 3,000 161.04 2,839 S 505 220 488 31 32 33 34 35 36 4N/1E-13M1 342603116501801 05-16-94 3,014 174.42 2,840 S 270 -- -- Figure 1. Altitude of the water table in 1994 and water-level changes at selected wells. 4N/1E-15R1 342546116513901 08-29-94 3,062 195.03 2,867 S 405 240 340 4N/1E-17L2 342601116540701 10-07-94 2,990 144.51 2,845 S 250 -- -- 4N/1E-18C2 342627116551801 08-03-94 2,980 158.40 2,822 S 194 -- -- Well-numbering diagram 4N/1E-18C3 342633116551001 08-03-94 2,965 150 2,815 R 155 -- -- 4N/1E-20E1 342530116542101 10-07-94 3,020 136.10 2,884 S 280 -- -- GROUND-WATER LEVELS AND MOVEMENT--Continued HISTORICAL WATER-LEVEL CHANGES 4N/1E-20Q1 342501116535201 10-07-94 3,090 126.73 2,963 S 260 120 260 4N/1E-21C1 342545116530301 07-26-94 3,063 181.37 2,882 V ------4N/1E-27D1 342441116522201 10-07-94 3,225 248.15 2,977 S 425 240 418 4N/1E-27R2 342401116513401 07-01-94 3,381 153.33 3,228 S 200 -- -- Ground-Water Movement Available data for wells in the Morongo Basin were evaluated to determine water-level changes in different parts of the basin. References Cited--Continued 4N/1W-02J1 342744116565801 10-05-94 2,866 136.10 2,729 V ------Twenty-one long-term hydrographs for selected wells are shown on the large map. Water levels have remained relatively constant 4N/1W-03K1 342755116580301 07-22-94 2,860 17.53 2,842 S 404 -- -- Conversion Factors 4N/1W-07E1 342714117015601 07-26-94 2,950 44.52 2,906 S ------In general, the water-table map indicates that ground water flows eastward and northward from the San Bernardino Mountains. in the Deadman, Emerson, Mesquite, Mainside, Copper Mountain, Johnson, Upper Johnson, and Fry Basins, where the resident Lohman, S.W., and others, 1972, Definitions of selected ground-water terms--Revisions and conceptual 4N/1W-07R1 342639117005501 07-26-94 2,936 18.29 2,918 S 130 -- -- A A’ refinements: U.S. Geological Survey Water-Supply Paper 1988, 21 p. 4N/1W-10H1 342717116580001 10-06-93 2,910 12.69 2,897 S ------

Multiply By To obtain From Pipes Wash, flow is eastward toward the localized sinks in the water table at Deadman and Mesquite dry lakes. Ground water FEET Bend in section population is small and pumpage is minimal or nonexistent. Available data were insufficient to determine fluctuations of the water 4N/1W-10R1 342639116580001 05-16-94 2,946 17.53 2,929 S ------4,000 table in the Pipes, Emerson, or Giant Rock Basins. Water-table declines have occurred in parts of the Reche, Joshua Tree, Twenty- 4N/1W-13M2 342610116564101 05-17-94 2,934 56.22 2,936 V ------

pumping by the USMCAGCC in the Surprise Spring Basin has created a ground-water depression and has locally changed the Bend in section Londquist, C.J., and Martin, Peter, 1991, Geohydrology and ground-water-flow-simulation of the Surprise Spring Basin 4N/1W-13M3 342610116564102 11-18-93 2,990 55.15 2,935 S ------* foot (ft) 0.3048 meter direction of ground-water movement. From Cushenbury Canyon and other washes along the northern front of the San Bernardino nine Palms, Surprise Spring, and Warren Basins. In the Reche Basin, the water level has declined about 36 ft since 1963 at well 4N/1W-14A2 342629116564401 08-03-94 2,962 105.34 2,857 S ------aquifer system, San Bernardino County, California: U.S. Geological Survey Water-Resources Investigations Report 4N/1W-18Q1 342544117011501 05-16-94 3,000 79.54 2,920 S ------1N/5E-10B2 Pipes Wash foot per year (ft/yr) 0.3048 meter per year Mountains, flow is northeastward to the pumping depression in the Lucerne Basin, and to the Soggy, Melville, and Means dry lakes. 2N/6E-18B1, probably the result of pumpage to supply the town of Landers; in the Joshua Tree and Twentynine Palms Basins, 89-4099, 41 p. 4N/1W-21G1 342519116591401 05-17-94 3,121 173.07 2,948 S ------3,500 2N/6E-31D1 pumpage to supply the towns of Joshua Tree and Twentynine Palms has caused declines of about 25 ft since 1963 at well 4N/1W-21J1 342518116584901 03-21-94 3,138 189.00 2,949 R 330 -- -- As ground water moves eastward through the Morongo Basin, subsurface flow across faults is impeded, resulting in a steplike Bend in section 4N/1W-26J1 342416116564501 03-21-94 3,422 325.53 3,097 R 515 415 470 inch (in.) 25.4 millimeter decrease in water levels (fig. 3). For example, there is a water-level difference of more than 300 ft across the Surprise Spring Fault, 1N/7E-32C1, and about 54 ft since 1940 at well 1N/8E-36A1; in the Surprise Spring Basin, the water level has declined 110 ft 4N/2E-09N2 342643116471101 06-30-94 3,035 139.54 2,895 S ------Moyle, W.R., Jr., 1984, Bouguer gravity anomaly map of the Twentynine Palms Marine Corps Base and vicinity, 4N/2E-13P1 342551116434301 06-29-94 2,995 108.10 2,887 S ------Bend in section near extinct Surprise Spring. Between the faults, the hydraulic gradient is approximately constant and generally very low. The past Water table since 1960 at well 2N/7E-2C1 as a result of pumpage for the USMCAGCC; and in the Lucerne Basin, the water level has declined California: U.S. Geological Survey Water-Resources Investigations Report 84-4005, scale 1:62,500, 1 sheet. 4N/2E-17H2 342612116471601 06-30-94 3,030 135.95 2,894 S 200 -- -- 3,000 4N/2W-12N2 342637117025401 07-26-94 3,003 104.75 2,898 S 192 60 192

mile (mi) 1.609 kilometer (Projected) and present occurrence of springs at fault boundaries (Rabbit Springs, Old Woman Springs, Surprise Spring, and Mesquite Spring) 2N/6E-11M1 as much as 94 ft since 1954 at well 5N/1E-17D1, near the town of Lucerne Valley. 4N/3E-07G1 342708116422401 06-29-94 2,895 64.30 2,831 V 97 95 97 square mile (mi 2 ) 2.590 square kilometer indicates diversion of flow to the surface across faults at these locations, and emphasizes the importance of faults in controlling Rantz, S.E., 1969 (1972), Mean annual precipitation in the California region: U.S. Geological Survey Open-File 4N/3E-15J1 342600116385101 06-29-94 2,863 82.64 2,780 V 89 87 89 2N/7E-5B1 4N/3E-16D1 342631116405301 06-29-94 2,885 101.56 2,783 S 200 -- -- ground-water movement. Ground water leaves the basin across the Mesquite Fault in the southeastern part of the basin, and 2,500 The largest observed water-level decline in the study area is in the Warren Basin, at Yucca Valley, where the combined decline Report, 5 p., (includes two sheets, scale 1: 1,000,000). 4N/3E-23G1 342517116380601 06-29-94 2,850 72.72 2,777 V 154 76 150 O at 107 Bedrock 2N/7E-3B1 4N/3E-30C1 342448116424601 06-29-94 3,080 198.18 2,882 V ------ultimately moves eastward toward Dale Dry Lake (not shown) (F.S. Riley and G.F. Worts, Jr., written commun., 1953). Water table 2N/7E-2C1 since 1947 is 309 ft at well 1N/5E-36K1 (destroyed) and nearby well 1N/5E-36K2. The data for these two wells were combined to 4N/3E-35J1 342324116374901 01-02-94 2,920 136.05 2,784 S 512 200 512 Schaefer, D.H., 1978, Ground-water resources of the Marine Corps Base, Twentynine Palms, San Bernardino 4N/4E-17C1 342620116351701 05-25-94 2,735 38.95 2,696 V 61 59 61 O at 54 give a better indication of total decline in this area. In the western part of Warren Basin, the decline at well 1N/5E-34N1 is about 4N/4E-19B1 342533116360801 05-25-94 2,775 38.05 2,737 V 120 -- -- 3N/8E-31J1-3 County, California: U.S. Geological Survey Water-Resources Investigations Report 77-37, 29 p. Other patterns indicated by the contour lines and supported by previous findings are (1) northward flow from the Little San 2,000 Bedrock 178 ft since 1958. These large declines probably result from increased pumpage to supply the growing population of Yucca Valley. 4N/4E-29D1 342446116354101 05-24-94 2,770 29.96 2,740 V 47 45 47 4N/4E-32Q1 342306116350301 05-24-94 2,825 80.02 2,745 V 490 119 120 O at 118 3N/8E-34D1 Water Deadman Lake (Dry) Bernardino Mountains to the Pinto Mountain Fault (Lewis, 1972), (2) minor flow southward from the San Bernardino Mountains table The magnitude of those declines indicates small storage in compartments of the aquifer that are bounded by faults in combination 4N/4E-36B1 342350116305801 05-24-94 2,630 63.22 2,567 V 72 70 72 GROUND-WATER LEVELS AND MOVEMENT ------1979, Ground-water conditions and potential for artificial recharge in Lucerne Valley, San Bernardino into Warren Basin (Lewis, 1972), and (3) southward flow into Lucerne Basin from the Ord Mountains (Schaefer, 1979). Rates of with minimal natural recharge. 4N/6E-18L1 342547116234501 06-09-82 2,293 39.66 2,253 S 92 90 92 Z County, California: U.S. Geological Survey Water-Resources Investigations Report 78-118, 37 p. 4N/6E-27M1 342406116205501 03-28-94 2,350 86.18 2,264 S ------ground-water movement in areas of the basin unaffected by pumping are low--generally a few feet per year (French, 1978). 1,500 4N/6E-32B1 342337116223001 03-02-76 2,400 77.00 2,323 S 102 100 102 Z Water-level Measurements 5N/1E-10H3 343222116513001 07-21-94 3,030 239.65 2,790 S 260 -- -- References Cited 5N/1E-17D1 343153116542301 01-13-94 2,880 157.24 2,723 S ------Emerson Fault

Surprise Spring Fault 5N/1E-20Q1 343009116535001 07-21-94 2,863 147.30 2,716 S ------Elkins Fault Johnson Valley Fault Johnson Valley Fault Homestead Valley Ground-water depressions are present in the areas of highest historical and current pumpage: Warren, Lucerne, and Surprise Copper Mtn Fault Mesquite Fault Water-level data for this study (table 1) were collected from 248 wells during the period January-October 1994 to define the unnamed fault unnamed fault Vertical Datum 5N/1E-32B2 342910116534801 07-22-94 2,870 169.84 2,700 S 465 240 400 Spring Basins. Construction of water-table contours in Warren Basin was difficult because water levels vary considerably. To show 1,000 Bortugno, E.J., 1986, Map showing recency of faulting, San Bernardino Quadrangle, California: California Division 5N/1E-35F3 342851116510701 06-30-94 2,942 154.85 2,787 S 250 -- -- water-table surface and the direction of ground-water movement. The water table is the surface in an unconfined aquifer at which Vertical scale greatly exaggerated 5N/1W-12H2 343219116553701 07-21-94 2,872 151.16 2,721 S 230 80 230 Datum is sea level of Mines and Geology Regional Geologic Map Series, San Bernardino Quadrangle-map no. 3A, scale 1:250,000. the pressure is atmospheric, and it is defined by the levels at which water stands in wells that penetrate the water body (the zone small-scale variations, the Warren Basin area (inset map A) is enlarged to 1:63,360 scale. The variability might be due to (1) the 0 5 MILES 5N/1W-25G1 342943116555201 07-22-94 2,850 132.08 2,718 S ------Sea level: In this report, sea level refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)--a geodetic 5N/1W-28F1 342948116593301 07-22-94 2,865 35.77 2,829 S ------of saturation) just far enough to hold water (Lohman and others, 1972). Additional water-level data (from 11 wells) collected prior presence of faults that separate the area into small isolated compartments, and (or) (2) incomplete recovery of the water table in the 5N/1W-31C1 342916117012601 07-26-94 3,080 218.70 2,861 S 252 -- -- 0 5 KILOMETERS datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly public-supply wells at the time of measurement--even though pumping had ceased 24 hours prior to measurement. California Department of Water Resources, 1964, Names and areal code numbers of hydrologic areas in the Southern 5N/1W-36R1 342826116553901 07-22-94 2,861 156.98 2,704 S 468 148 468 O at 345 to 1994 also were used to construct map contours where current data could not be obtained or in areas of sparse data and little called Sea Level Datum of 1929. 6N/1W-05J1 343802116595901 07-21-94 3,220 115.35 3,105 S ------District: California Department of Water Resources Office Report, 57 p. 6N/1W-22P1 343513116582201 07-21-94 3,059 150.46 2,909 S 350 -- -- water-level fluctuation. For 87 wells where static water-level measurements were difficult to obtain, water levels reported by 6N/1W-27B1 343500116581401 07-21-94 3,040 141.56 2,898 S ------other agencies were used. The remaining water levels were measured by USGS personnel using steel or calibrated electric tapes. Perched water occurs in the Mainside Basin (under Mesquite Dry Lake) approximately 130 ft above the regional water table. 6N/1W-27R1 343417116574501 07-21-94 3,038 182.72 2,855 S 354 168 288 Figure 3. Hydrogeologic section A-A’ showing steplike decrease in water levels across faults. French, J.J., 1978, Ground-water storage in the Johnson Valley area, San Bernardino County, California: U.S. 6N/1W-36J1 343338116553801 07-21-94 2,948 197.53 2,750 S 266 226 266 Water-table altitude was calculated by subtracting the water-level measurement from the land-surface altitude (determined by Movement of this water seems to be southeastward, similar to that of the regional ground water below. The probable source of Geological Survey Water-Resources Investigations Report 77-130, 35 p. leveling survey or from topographic maps). Ground-water flow is from high to low water-level altitude and is perpendicular to this perched water is spreading ponds that are used for sewage-water treatment. lines of equal water-table altitude on the map (fig. 1). Arrows shown on the map indicate the approximate direction of movement. Lewis, R.E., 1972, Ground-water resources of the Yucca Valley-Joshua Tree area, San Bernardino County, California: U.S. Geological Survey Open-File Report, 51 p.

For sale by the For additional information write to: US. Geological Survey District Chief Earth Science Information Center U.S. Geological Survey Open-File Reports Section Federal Building Room W-2233 Regional Water Table (1994) and Water-Level Changes in the Morongo Basin, San Bernardino County, California Box 25286, MS 517 2800 Cottage Way Denver Federal Center Sacramento, CA 95825 By Carolyn R. Trayler and Kathryn M. Koczot, 1995 Denver, CO 80225