Drawdown
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DRAWDOWN: SHALLOW WEATHERED KAROO AQUIFER (Figure 1) <Double-click here to enter title> L EGEND VIER AIRI A P! Springs G E 27°11'0"S S Rivers and Streams AS Non-Perennial Perennial Road Network National Route Main Road Secondary Road 27°12'0"S Site Footprint Study Area Underground Mine Area Faults P! Drawdown (m/d) 2 - 4 4 - 9 27°13'0"S P! Wetlands P! P! E N A P! L D N P! A KW W E A A GOQWAN P! M 27°14'0"S E S A Z P! U K P! P! M R33 UVN2 P! P! R35 ! PIET RETIEF P! P! P! R543 27°15'0"S P! N11 V P! U MPUMALANGA R23 VOLKSRUST P! ! ! Charlestown ND KWAZULU-NATAL LOV IN I Utrecht R33 R34 R34 ! Data Sources:Data ! ! ! ! GoogleEarth™ mapp ingservice: 2017 27°16'0"S P! P P! ImageryDate:30/03/2017 0 0.5 1 2 Kilometers A SCALE: 000 1:50 OL AB M FIGURENO.: - MAPNU MBER: 17-1127-14 P! CHETT P. Y JOHNSTONEA DRAWNBY: REVIEWEDBY: GIS SPECIALIST GIS MANAGINGDIRECTOR DATU M: WGS84 DATE: NOVEMBER29 2017 PROJECTION: GEOGRAPHIC MABOLAPROT ECTEDENV IRONMENTREVIEW OF2015 PROJECT: 27°17'0"S WETL ANDASSESSMENT CLIENT : CENTFOR REENV IRONMENT ALRIGHT NPC S R543 63 Wessel63 Road Woodm ead POBox Rivonia2597 2128 SouthAfrica T el: +27 (0) 11 803 5726803 11 T(0) +27 el: P! 5745803 11 (0) +27Fax: P! E-mail:jhb @gc s-sa.biz ± www.gc s-sa.biz 30°14'0"E 30°15'0"E 30°16'0"E 30°17'0"E 30°18'0"E 30°19'0"E 30°20'0"E 30°21'0"E 30°22'0"E DRAWDOWN: DEEP FRACTURED KAROO AQUIFER (Figure 2) <Double-click here to enter title> L EGEND IVIER P! Springs AIR A G Rivers and Streams E 27°11'0"S SS A Non-Perennial Perennial Road Network National Route Main Road Secondary Road Site Footprint 27°12'0"S Study Area Underground Mine Area Faults Wetlands P! Drawdown (m) 5-10 27°13'0"S 10-20 P! 20-30 P! 30-40 40-50 P! E N A P! L D N A K P! W W E A A GOQWAN P! M 27°14'0"S E S A Z P! U K P! P! M R33 UVN2 P! P! R35 ! PIET RETIEF P! P! P! R543 27°15'0"S P! N11 V P! U MPUMALANGA R23 VOLKSRUST P! ! ! Charlestown ND KWAZULU-NATAL LOV IN I Utrecht R33 R34 R34 ! Data Sources:Data ! ! ! ! GoogleEarth™ mapp ingservice: 2017 27°16'0"S P! P P! ImageryDate:30/03/2017 0 0.5 1 2 Kilometers A SCALE: 000 1:50 OL AB M FIGURENO.: - MAPNU MBER: 17-1127-13 P! CHETT P. Y JOHNSTONEA DRAWNBY: REVIEWEDBY: GIS SPECIALIST GIS MANAGINGDIRECTOR DATU M: WGS84 DATE: NOVEMBER29 2017 PROJECTION: GEOGRAPHIC MABOLAPROT ECTEDENV IRONMENTREVIEW OF2015 PROJECT: 27°17'0"S WETL ANDASSESSMENT CLIENT : CENTFOR REENV IRONMENT ALRIGHT NPC S R543 63 Wessel63 Road Woodm ead POBox Rivonia2597 2128 SouthAfrica T el: +27 (0) 11 803 5726803 11 T(0) +27 el: P! 5745803 11 (0) +27Fax: P! E-mail:jhb @gc s-sa.biz ± www.gc s-sa.biz 30°14'0"E 30°15'0"E 30°16'0"E 30°17'0"E 30°18'0"E 30°19'0"E 30°20'0"E 30°21'0"E 30°22'0"E Simulated groundwater table drawdown in the shallow weathered Karoo acquifer (Figure 3 - Delta H, p 52) Figure 8.2: Simulated groundwater table drawdown in the shallow weathered Karoo aquifer (mapped springs indicated in red). The simulated extent of the (steady-state) zone of impact (5m cut-off to account for higher uncertainty in simulations) of the underground workings on the deeper fractured aquifer extends predominantly above and around 2 km downstream or N of the mine (Figure 8.3). The deeper fractured aquifer is considered to be less sensitive to a drawdown of the water table and significant impacts with drawdowns above 20m are likely to be limited to an area immediately above the underground mine workings. Yzermyn Groundwater Model 52 Simulated table drawdown in the deep fractured Karoo acquifer (Figure 4 - Delta H, p 53) Figure 8.3: Simulated groundwater table drawdown in the deep fractured Karoo aquifer (mapped springs indicated in red). It must be emphasised that the simulated steady-state cones of dewatering due to inflows into the final mine voids present an unlikely worst case scenario, as a steady-state cone of dewatering develops only after numerous years to decades of unimpeded groundwater inflows into the mine. The currently foreseen 15 years of life of mine are therefore likely to be exceeded before a steady-state drawdown is established, by which time the mine is no longer actively dewatered and the water table at least partially likely to recover (though not to pre-mining levels). Groundwater dependant eco-systems and yields of (water supply) springs located within the significant zone of dewatering of the shallow aquifer, limited to the site boundaries, could be negatively impacted and some may dry up during the life of mine. Springs located within the cone of dewatering of the deeper fractured aquifer, also limited to the site boundaries, are on the other hand unlikely to be impacted upon due to the limited hydraulic connection of the shallow and deep aquifer systems. Yzermyn Groundwater Model 53 CATCHMENTS (Figure 5) 27°3'0"S <Double-click here to enter title> LEGEND Rivers and Streams K Non-Perennial L E I N Perennial - V A A Road Network L R I VI National Route ER Main Road DU N 27°6'0"S U P Secondary Road M Catchments A N Site Footprint A F IV O AIR IE R543 Study Area EGA R P ASS M Underground Mine Area 27°9'0"S NTA NTA M A N GU LA NE 27°12'0"S E M N S A IB L A KU D N Z WAN D A A LU S M E T I M U A R P B S O D R33 N L UVN2 A A S R35 27°15'0"S BE ! OM T PIET RETIEF NDL N R543 O WA VI K N I N11 U V MPUMALANGA R23 VOLKSRUST ! ! Charlestown KWAZULU-NATAL Utrecht R33 R34 R34 ! 27°18'0"S Data Sources:! ! ! ArcGIS Basemap - Topography Catchments Generated from SRTM Sourced Data WAKKERSTROOM 0 1 2 4 Kilometers SCALE: 1:144 476 FIGURE NO.: - MAP NUMBER: 17-1127-16 NGOLO P. CHETTY A JOHNSTONE O DRAWN BY: REVIEWED BY: PH GIS SPECIALIST MANAGING DIRECTOR A DATUM: WGS84 27°21'0"S N DATE: 27 NOVEMBER 2017 A PROJECTION: GEOGRAPHIC W MABOLA PROTECTED ENVIRONMENT REVIEW OF 2015 D PROJECT: N WETLAND ASSESSMENT M A CLIENT: CENTRE FOR ENVIRONMENTAL RIGHTS NPC C N 63 Wessel Road Woodmead E PO Box 2597 Rivonia 2128 South Africa A B IB S Tel: +27 (0) 11 803 5726 T H Fax: +27 (0) 11 803 5745 AK E-mail: [email protected] ± A www.gcs-sa.biz 30°6'0"E 30°9'0"E 30°12'0"E 30°15'0"E 30°18'0"E 30°21'0"E 30°24'0"E 30°27'0"E.