Taseko Mines Limited

T 15th Floor; 1040 West Georgia St.a Vancouver, BC \‘6E 4111ta koiiilnes.com

June 20, 2013

Dr. Bill Ross, Panel ChairNew Prosperity Gold-Copper Federal Review PanelCanadian Environmental Assessment Agency160 Elgin Street, 22nd FloorOttawa, ON K1A 0H3

Re: Additional Information Requested by the Tsilhqot’in National Government

Dear Mr. Ross:

This letter is in response to yourJune l3~~ letter requesting two additional reports.

Specific to “The letter noted on page 6, Information Issue 4 (ElS 2.6.1.4 — Water Quality and Quantity /Appendix 2.6.1.4B A)”, the requested information is attached to this letter and is also posted as CEAR#1126 for the previous Prosperity Project.

Specific to “The companion study that assessed Rainbow Trout spawning habitat suitability in Reach 8 ofUpper fish Creek” noted on page 13, Information Issue 19 (ElS 2.6.1.5 Fish and Fish Habitat)”, the“companion study” was referred to on page 310 of the 2012 ElS submission and in Appendix 2.6.1.5-ARainbow Trout Distribution in Selected Fish Creek and fish Lake Tributaries. The “companion study” wasa field survey conducted on August 17, 2011 in Upper Fish Creek; a summary of this survey is attached tothis letter. Note that the attached is not in formal report format but rather a summary of field notescollected. This information was considered by Triton Environmental to supplement data collected in Julyfor the writing of their final report, which is Appendix 2.6.1.5-A dated November 2011.

We trust that the Panel and the TNG will find this information sufficient to address this request foradditional information.

Sincerely,

LIMITED

Katherine GizikoffDirector, Environment and Governmental Affairs

Brian Battison, Taseko VP Corporate AffairsTsilhqot’in National Government

Upper Fish Creek Survey Crew BR and RT Wx cloudy with showers Air temp 14 ° Water Temp 18 ° The objective of the survey was to collect habitat suitability data at flow that approximated those that will be experienced post project. These flows will be reduced from current values due to the placement of a tailings storage facility upstream of Fish Lake. The flow levels expected are: May - 0.15 m3/s to 0.43 m3/s June – 0.04 m3/s to 0.13 m3/s. A survey conducted by Triton on July 24 indicated that flow levels were at or above the upper limits of post project flows. Field work was scheduled to take place later to capture the lower bounds of the future flows. The survey was initiated on August17, 2011. When the crew arrived at Upper Fish Creek the discharge was 0. The channel showed indications of a recent and rapid flow recession. Algae mats on the dewatered riffles were wetted and grasses within dry channel area were still at repose. It is unclear how recently the flow recession had occurred but based on our observation it appeared to be in the range of days. It is also not clear why flow recession would have been as rapid as seemed to occur. A habitat assessment was undertaken to document the habitat strata in Upper fish Creek in the area downstream of the proposed tailings dam. The stream was walked from the mouth for a lineal distance of 1.95 km upstream based on GPS tracking from the mouth, which was estimated to be approximately 3-4 km of stream length. Habitat units were defined by distance upstream along with substrate within the units. Arial extents of potential spawning areas were estimated. Although there was no flow the channel was wetted in sections that were contained within riffle units that provided tailwater controls for the wetted sections. These sections were classified as pool/glide on the survey sheet but are likely primarily glides when continuous flows are present. Repeating sections of riffle and pool/glide would describe the overall stream morphology of upper fish creek (see attached spreadsheet). The riffles were comprised on small and large cobbles with some small boulders. A few of the riffles had some gravels but the smaller substrate fraction was generally absent. Riffle gradients varied from 1 to 4 %. Most of the riffles were completely dewatered although some were wetted to depths of 5 cm. Some riffles were short < 2 m in length and functioned as weirs providing local hydraulic control, while some riffles exceeded 30 m in length. The pools controlled by the riffles could be classified in three different substrate types. Lower pool/glides had primarily cobble boulder beds with overlying fines, some small pockets of gravel were observed but the area was limited. The mid survey area had smaller substrates and this is the area where the majority of the spawning potential was noted. The stream section located between 900m and 1.2 km from the mouth had areas of good spawning gravel and evidence of active spawning within these areas. Rainbow trout fry were also observed in this area although in low numbers.

Upstream of this section the pools/glides had primarily silty bottoms, with limited spawning potential. Several relic beaver dams were located along the channel. They appear to have been abandoned for several years but still pose passage problems. Redds and fry were located above the beaver dams suggesting spring freshette provides options for upstream passage. These could include bypass flows. These potential bypass flows may not be present post project and may exacerbate passage impacts. The observed spawning sites were located in what would be glide habitat. In the largest area at km 1.03 to 1.15 gravels were distributed downstream of a pool/glide below a riffle. Downstream of the pool the channel became constricted that resulted in localize velocity increases. The gravels there appeared to have had a heady concentration of spawners based on the disturbance noted. There does not appear to be much gravel recruitment to upper Fish Creek. What is there is maintained through the riffle/glide morphology of the system. Even with lower flows hydraulic conditions could be manipulated to provide the necessary spawning requirements. Provided there is no new recruitment of beavers perhaps the existing relic dams could be removed modified to mitigate the loss of high bypass flows.

Photos

Photo 1 Pool between riffles

Photo 2 typical cobble boulder riffle

Photo 3 Relic Beaver Dam

Photo 4 Large Relic Beaver Dam > m high

Photo Main spawning location gravels are present upstream and through the channel narrowing providing up to 100 m² of spawning habitat No flow at time of survey August 17, 2011 Prepared for: Taseko Mines Limited 1020 – 800 West Pender Street Vancouver, BC V6C 2V6 Prepared by: Triton Environmental Consultants Ltd. 1326 McGill Rd. Kamloops, BC V2C 6N6

Habitat Assessment of Upper Fish Creek August 17, 2011 Wx Cldy with showers Air Temp 15 ° Water Temp 18 ° Crew BR RT 

Started survey 0:900 hours 

Location   Habitat Unit  Substrate Spawning area m²  Comments 

Mouth   0 

1  0‐45  Lake backwater  Cobble Boulder interspaced with fines 

2  45 ‐50  Cobble Riffle  Large and small cobble   No flow in Creek 

3  50‐67  Pool/Glide  Cobble dominant substrate, limited gravels Pool at time of visit downstream riffle impounds water 

4  67‐70  Cobble Riffle  Large and small cobble   No flow through rifle 5  70‐76  Pool/Glide  Cobble dominant substrate, limited gravels 

6  76‐85 cobble/bldr riffle  Large and small cobble some small boulder  No flow through riffle 

7  85‐122  Pool/Glide Sands and some gravels (5²), with scattered boulders  5 

Pockets of potential spawning gravels 5 m² 

8  122‐141 cobble/bldr riffle  Large and small cobble some small boulder 

9  141‐157  Pool/Glide Sands and some gravels (5 m²) , with scattered boulders  5 

Pockets of potential spawning gravels 5 m² 

10  157‐159   Cobble Riffle  Large and small cobble  11  159‐170  Pool/Glide  Cobbles with some fines 

12  170‐174  Cobble Riffle Large and small cobble with some small boulders (1 m width) 

no spawning gravel noted.  Location of staff gauge 0.08 pool backwatered from DS weir 

13  174‐184  Pool/Glide  Cobbles with some fines 

Location   Habitat Unit  Substrate Spawning area m²  Comments 

14  184‐208  Cobble riffle Large and small cobble with some small boulders channel width 1m  

15  208‐215 

Split channel cobble riffles (2)  Large and small cobbles 

16  215‐230  Pool/Glide  Cobbles with some fines 

17  230‐232  Cobble riffle Large and small cobble with some small boulders  

18  232‐241  Pool/Glide  cobble and large boulder with covering fines 

19  241‐276  Cobble riffle Large and small cobble with some small boulders  

20  276‐300  Pool/Glide Fines and small gravel some spawning potential with appropriate velocities (5 m²)  5 

21  300‐305  Cobble riffle Large and small cobble with some small boulders  

22  305‐322  Pool/Glide Fines and small gravel some spawning potential with appropriate velocities (5‐7 m²)  7 

23  322‐331  Cobble riffle Large and small cobble with some small boulders  

24  331‐347  Pool/Glide Fines and small gravel some spawning potential with appropriate velocities (5‐10 m²)  10 

25  347‐373  Cobble riffle 

Large and small cobble with some small boulders  deposit of gravels at upstream end of riffle could be used for spawning with appropriate flows. 

26  373‐380  Pool/Glide  Cobbles and fines 

27  380‐382  Cobble riffle Large and small cobble with some small boulders  

28  382‐391  Pool/Glide  Cobbles and fines 29  391‐397  Cobble riffle  Large and small cobble  

Location   Habitat Unit  Substrate Spawning area m²  Comments 

30  377  Beaver dam  Relic dam 60 cm high veg growing on top 

31  377‐411  Pool/Glide Fine sediments overlaying cobble boulder vegetated with grasses 

32  411‐438  Cobble riffle  Large and small cobble  33  438‐447  Pool/Glide  cobble boulder with fines 34  447‐483  Cobble riffle  Large and small cobble  35  483  Beaver Dam   Relic dam 70 cm high 36  483‐513  Pool  Dry pond above relic beaver dam 37  513  Beaver dam  Relic keeping flows out of downstream pond 38  513‐551  Pool/Glide  cobbles fines 39  551‐573  Cobble riffle  Large and small cobble  40  573  Beaver dam   60 cm high looks like barrier 

41  573‐600  Beaver pond Predominantly fines with some cobbles at upstream end 

42  600‐608   Cobble Riffle  Large and small cobble  43  608‐614  Pool/Glide  cobbles fines 

44  614‐618  Cobble Riffle Cobles with some lateral gravel pockets (1‐2 m²)  2 

45  618‐621  Pool/Glide  cobbles fines 46  621‐625  Cobble Riffle  Large and small cobble  47  625‐634  Pool/Glide  cobbles and some gravels 3m²  3 48  634‐644  Cobble Riffle  Large and small cobble  49  644‐676   Pool/Glide  cobbles and some gravels 5m²  5 

50  676‐685  Cobble Riffle Large and small cobble heavily matted with algae 

51  685‐700  Pool/Glide  cobbles and fines 52  700‐703  Cobble Riffle  Large and small cobble  

53  703‐772 Long Pool/glide   cobbles and fines no spawning gravel found 

Location   Habitat Unit  Substrate Spawning area m²  Comments 

54  772‐780  Cobble Riffle  Large and small cobble  55  780‐800  Pool/Glide  cobbles and fines 56  800‐806  Cobble Riffle  Large and small cobble  57  806‐829  Pool/Glide  cobbles and fines 58  829‐838  Cobble Riffle  Large and small cobble  59  838‐905  Pool/Glide  Cobble Boulder fines 

60  905‐920 No defined channel  channel definition lost flows through grasses 

61  920‐925  Cobble Riffle  Large and small cobble  

62  925‐955  Pool/Glide spawning gravels present (50 m ²) depth 20 ‐30 cm   50 

63  955‐960  Cobble Riffle  Large and small cobble  

64  960‐978  Pool/Glide spawning gravels present (5 m ²) depth 20 ‐30 cm  

65  978‐981  Cobble Riffle  cobble gravel  saw rainbow trout fry in riffle 5 cm water depth ‐ no flow 

66  981‐995  Pool/Glide spawning gravels present (20 m ²) depth 20 ‐30 cm   20 

67  995‐1.03  Cobble Riffle  Large and small cobble  

68  1.03‐1.15‐  Pool/Glide  Sands gravels 100m² spawning gravels  100 

gravels on inside of meander bend and tail out of larger pool  redds present 

69  1.15 ‐1.20  Cobble Riffle  Large and small cobble  70  1.20‐1.28  Pool/Glide  fines  71  1.28‐1.32  Pool/Glide  fines channel has instream vegetation grasses 72  1.32‐1.35  Cobble Riffle  Cobbles and small boulders 3‐4% gradient 73  1.35‐1.39  Pool/Glide  cobble and fines 74  1.39‐1.42  Cobble Riffle  Large and small cobble  75  1.42  Beaver Dam  Relic dam 1 m high looks like barrier 

Location   Habitat Unit  Substrate Spawning area m²  Comments 

76  1.42‐1.49  Pool/Glide  fines 

77  1.49‐1.62  Cobble Riffle  Large and small cobble  Saw fry so fish can get above beaver dam likely at high flows 

78  1.62‐1.67  Pool/Glide  fines 79  1.67‐1.69  Cobble Riffle  Large and small cobble  80  1.69‐1.72  Pool/Glide  cobbles and fines 81  1.72‐1.73  Cobble Riffle  Large and small cobble  82  1.73‐1.81  Pool/Glide  fines braided area of channels 83  1.81‐1.82  Cobble Riffle  Large and small cobble  

84  1.82‐1.95  Pool/Glide Meandering silty channel with side channels and grassy banks 

End of survey  212 

Suite 1400 - 750 West Pender Street Vancouver, BC Canada V6C 2T8 File No.:VA101-266/9-A.01 Cont. No.:VA09-01164 Tel: 604.685.0543 Fax: 604.685.0147 www.knightpiesold.com

August 18, 2009 Mr. Roderick Bell-Irving Manager, Environmental Assessment Taseko Mines Limited Suite 300 - 905 West Pender Street Vancouver, BC V6C 1L6 Dear Rod, Re: Potential for Flow Losses in Fish Creek Concerns have been raised by various parties that a substantial amount of flow in Fish Creek may be going to ground and not resurfacing further downstream, thereby suggesting that the subsurface flows are instead being conveyed to neighbouring basins and water courses, most notably the Taseko River. This idea of a possible interbasin transfer of flows is based on some of the Fish Creek annual unit hydrograph plots presented in Appendix C of the Prosperity Project Hydrometeorology Report (Ref. No. VA101-00266/01-2, Dec. 3, 2007), which indicate substantial differences in unit area flows for different points on Fish Creek. For example, Figure C9 (shown in Appendix A of this letter), which presents unit flows for 1993 for Fish Creek stations H2, H3, and H4b, indicates that unit flows drop substantially between stations H2 and H3, and then only recover slightly between stations H3 and H4b, thereby demonstrating a net loss of unit flow between stations H2 and H4b. The locations of the stations, as well as other stations for which reasonable amounts of data are also available, are shown on Figure 1. The full descriptive names of these stations are as follows:

• Station H17 - Fish Creek upstream of Fish Lake • Station H2 - Fish Creek at the outlet of Fish Lake • Station H3 - Fish Creek upstream of the ore body • Station H6 - Fish Creek downstream of the ore body, and • Station H4 - Fish Creek upstream of the Taseko River. Please note that stations on Figure 1 that have the same number but different letter suffix are essentially located in same place. The letter simply indicates that the gauge was re-installed at some point. In an effort to assess the validity of interbasin groundwater flow supposition, all the available hydrology data were carefully examined, and it has been concluded that the surface flow loss pattern suggested by Figure C9 is almost certainly an artifact of data error. This conclusion is based on the following information: 1. A review of all the figures in Appendix C of the hydrometeorology report indicates that there are no

consistent patterns of relative unit flows. In years 1992, 1994, 1996, and 1997 there appears to be a net gain of unit flow between stations H2 and H4b, while for years 1993 and 1998 there appears to be a net loss, and in 1995 the unit flow was reasonably constant (except for clearly anomalous flows in November and December).

2 of 3 VA09-01164 August 18, 2009

2. A comparison of discharge measurements that were manually recorded at different locations on the same date also fails to indicate a consistent pattern of surface flow loss. The discharge measurements recorded in the 1990s are summarized in Table 1 and those recorded in the 2000s are in Table 2. Corresponding plots of unit runoff trends are shown on Figures 2 and 3. When viewing these data please keep in mind that the 2000 data are likely more accurate than the 1990 data.

The key points that come to mind when viewing these Tables and Figures are as follows: Table 1 and Figure 2 – The data are inconclusive. There does not appear to be any strong indication of a substantial loss of flow to ground that is available to feed a neighbouring basin. • H2 to H3 - There are no consistent trends. Stations H2 and H3 are located very close together

and should have very similar unit runoff, as they appear to do on the dates corresponding to the largest measured flows (4/7/1992 and 5/13/1994). For the remaining three dates when flows are concurrently measured at both sites the measurements indicate that the unit runoff essentially doubles as one progresses downstream, which is physically impossible unless there was massive seepage from the lake that was surfacing immediately downstream of the outlet, which is very unlikely. This pattern is most likely an artifact of flow measurement error.

• H3 to H6 - Once again the trends are not consistent. Two dates show a substantial decrease in flows, while the third date shows a minor increase. Overall, there appears to be a decrease in flows.

• H6 to H4b - There are only two dates with concurrent measurements. In both instances there appears to be an increase in flows.

Table 2 and Figure 3 - Overall, there appear to be higher unit flows at station H17b than at all stations downstream of Fish Lake, although trends between stations H17b and H6b appear to be confounded by the attenuating effect of the lake. There appears to be an increasing trend of unit flows between stations H6b and H4c. The latter pattern is generally consistent with the pattern detected in the 1990 flow data.

• H17b to H6b - Four dates indicate decreasing unit flows and three dates indicate increasing unit flows. The decreasing trends are substantially stronger and all occur in May, while the increasing trends all occur in June. This pattern is fairly consistent with the expected attenuating effect of Fish Lake.

• H6b to H4c - There is generally a trend of increasing unit flows in 2006, except during the very lowest flow periods when there appears to be a slight decreasing trend, although differences in the low flows are likely within the measurement error. In 2007, flows at the two sites appear to be very similar.

3. Figure 4 presents the unit runoff hydrographs for stations H17b, H6b, and H4c, for the most complete and reliable year of record available, which is 2007. This figure suggests that annual unit flows are very similar at H6b and H4c, but that H17b has substantially higher runoff. This pattern is consistent with the higher average basin elevation of H17b and correspondingly the expected enhanced precipitation during the winter months and reduced evapotranspiration during the summer months.

To conclude, there is no compelling hydrologic evidence to support the idea that Fish Creek is losing a substantial amount of surface flow to groundwater that is being conveyed to neighbouring drainages.

Date Year Month Day H2 H3 H6 H4b4/7/1992 1992 4 7 14.7 13.6 10.44/8/1992 1992 4 8 10.46/15/1992 1992 6 15 0.4 0.76/16/1992 1992 6 16 0.89/2/1992 1992 9 2 0.29/2/1992 1992 9 2 0.19/3/1992 1992 9 3 1.9

10/17/1992 1992 10 17 0.011/25/1992 1992 11 25 0.22/1/1993 1993 2 1 0.1 0.0 0.14/28/1993 1993 4 28 0.5 1.0 0.65/1/1993 1993 5 1 1.86/16/1993 1993 6 16 2.06/19/1993 1993 6 19 1.38/26/1993 1993 8 26 0.4 0.88/27/1993 1993 8 27 1.48/29/1993 1993 8 29 1.15/13/1994 1994 5 13 12.5 12.25/15/1994 1994 5 15 9.8 16.28/22/1994 1994 8 22 0.08/28/1994 1994 8 22 0.28/31/1994 1994 8 31 0.96/17/1995 1995 6 17 0.46/19/1995 1995 6 19 1.14/15/1996 1996 4 15 14.64/17/1996 1996 4 17 18.86/27/1996 1996 6 27 21.97/8/1996 1996 7 8 4.27/9/1996 1996 7 9 3.2 3.510/4/1996 1996 10 4 0.2 0.3

M:\1\01\00266\09\A\Data\Hydrology\Ratings_2006 - 2008\Measured Flow compare\1990s flows\[Gaugings Compare - 1990_VM.xls]Tab 1 - Summary H2H3H6H4b

NOTE:1. DATASETS WITH CONCURRENT DISCHARGES AT TWO OR MORE SITES ARE INDICATED WITH SHADING.

Print Aug/18/09 14:51:51

FISH CREEK MEASURED UNIT DISCHARGES (l/s/km2) 1992-1996

TABLE 1

TASEKO MINES LIMITED

PROSPERITY GOLD-COPPER PROJECT

0 05AUG'09 JGC CBISSUED FOR LETTER VA09-01164 JGCDATE DESCRIPTION PREP'D CHK'D APP'DREV

Date Year Month Day H17b H6b H4c5/9/2006 2006 5 9 4.15/9/2006 2006 5 9 4.0

5/10/2006 2006 5 10 3.15/10/2006 2006 5 10 3.35/23/2006 2006 5 23 1.8 1.1 2.05/23/2006 2006 5 23 1.9 1.1 1.96/6/2006 2006 6 6 3.26/6/2006 2006 6 6 3.66/7/2006 2006 6 7 2.6 3.26/7/2006 2006 6 7 2.6 3.0

6/20/2006 2006 6 20 2.3 0.9 1.66/20/2006 2006 6 20 2.3 0.8 1.57/4/2006 2006 7 4 0.07/5/2006 2006 7 5 0.2 0.17/5/2006 2006 7 5 0.1

7/18/2006 2006 7 18 0.1 0.07/18/2006 2006 7 18 0.1 0.010/2/2006 2006 10 2 0.0 0.010/2/2006 2006 10 2 0.0 0.0

10/17/2006 2006 10 17 0.05/14/2007 2007 5 14 42.1 36.6 37.45/14/2007 2007 5 14 45.3 36.3 35.45/14/2007 2007 5 14 35.25/14/2007 2007 5 14 31.95/31/2007 2007 5 31 10.2 8.4 10.05/31/2007 2007 5 31 10.7 9.3 10.36/14/2007 2007 6 14 7.1 8.3 8.36/14/2007 2007 6 14 6.9 8.2 7.86/25/2007 2007 6 25 3.2 3.36/25/2007 2007 6 25 3.1 3.76/26/2007 2007 6 26 3.146/26/2007 2007 6 26 3.13

11/15/2007 2007 11 15 0.549/19/2008 2008 9 19 0.02

M:\1\01\00266\09\A\Data\Hydrology\Ratings_2006 - 2008\Measured Flow compare\2000s flows\[Gaugings Compare - 2000s.xls]Tab 2 - Summary H17b H6B H4C

NOTE:1. DATASETS WITH CONCURRENT DISCHARGES AT TWO OR MORE SITES ARE INDICATED WITH SHADING.

Print Aug/18/09 14:51:51

FISH CREEK MEASURED UNIT DISCHARGES (l/s/km2) 2006-2008

TABLE 2

TASEKO MINES LIMITED

PROSPERITY GOLD-COPPER PROJECT

0 05AUG'09 JGC CBISSUED FOR LETTER VA09-01164 JGCDATE DESCRIPTION PREP'D CHK'D APP'DREV

M:\1\01\00266\09\A\Data\Hydrology\Ratings_2006 - 2008\Measured Flow compare\1990s flows\/Gaugings Compare - 1990_VM/Figure 2 8/18/2009 2:56 PM

4/7/1992

6/15/1992

2/1/1993

4/28/1993

8/26/1993

5/13/1994

5/15/1994

7/9/1996

0

2

4

6

8

10

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H2 H3 H6 H4b

Gauging Station

Flow

Mea

sure

men

t - U

nit D

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arge

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/km

2 )

UNIT RUNOFF IN FISH CREEKMOVING DOWNSTREAM FROM H2 to H3 to H6 to H4b

1992-1996 MEASUREMENTS

FIGURE 2

TASEKO MINES LTD.

PROSPERITY GOLD-COPPER PROJECT

REV0

P/A NO. VA101-266/9

REF NO.VA09-01164

0 01AUG'09 ISSUED FOR LETTER JGC CB JGCDATE DESCRIPTION PREP'D CHK'D APP'DREV

H2 - Fish Creek at outlet of Fish Lake H3 - Fish Creek upstream of the orebody H6 - Fish Creek downstream of the orebody H4b - Fish Creek near the Taseko River

NOTES: 1. COMPARATIVE PLOTS ARE PROVIDED FOR DISCHARGE VALUES MEASURED ON THE SAME DAY. MEASUREMENTS AT DIFFERENT LOCATIONS WERE NOT TAKEN AT IDENTICAL TIMES, SO SOME OF THE DIFFERENCES IN THE UNIT RUNOFF VALUES MAY BE ATTRIBUTED TO DAILY FLUCTUATIONS IN THE STREAMFLOW PATTERNS.

M:\1\01\00266\09\A\Data\Hydrology\Ratings_2006 - 2008\Measured Flow compare\2000s flows\/Gaugings Compare - 2000s/Figure 3 8/18/2009 2:52 PM

5/23/2006

6/7/20066/20/2006 7/5/2006

7/18/2006

10/2/2006

5/14/2007

5/31/2007

6/14/20076/25/2007

0

5

10

15

20

25

30

35

40

45

H17b H6b H4c

Gauging Station

Flo

w M

easu

rem

ent -

Uni

t Dis

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ge (l

/s/k

m2 )

UNIT RUNOFF IN FISH CREEKMOVING DOWNSTREAM FROM H17b to H6b to H4c

2006-2008 MEASUREMENTS

FIGURE 3

TASEKO MINES LTD.

PROSPERITY GOLD-COPPER PROJECT

REV0

P/A NO. VA101-266/9

REF NO.VA09-01164

NOTES: 1. COMPARATIVE PLOTS ARE PROVIDED FOR DISCHARGE VALUES MEASURED ON THE SAME DAY. MEASUREMENTS AT DIFFERENT LOCATIONS WERE NOT TAKEN AT IDENTICAL TIMES, SO SOME OF THE DIFFERENCES IN THE UNIT RUNOFF VALUES MAY BE ATTRIBUTED TO DAILY FLUCTUATIONS IN THE STREAMFLOW PATTERNS.

0 01AUG'09 ISSUED FOR LETTER JGC CB JGCDATE DESCRIPTION PREP'D CHK'D APP'DREV

H17 - Fish Creek upstream of Fish Lake H6b - Fish Creek downstream of the orebody H4c - Fish Creek near the Taseko River

M:\1\01\00266\09\A\Data\Hydrology\Ratings_2006 - 2008\Unit Runoff Comparison Chart\Unit Runoff Comparison Chart.xls Print 8/18/2009 2:53 PM

0 AUG06'09 ISSUED FOR LETTER CMB JGC JGCDATE DESCRIPTION PREP'D CHK'D APP'DREV

2007 UNIT RUNOFF HYDROGRAPHH17B, H6B & H4C

FIGURE 4

TASEKO MINES LTD.PROSPERITY PROJECT

REV0

P/A NO. VA101-266/9

REF. NO.VA09-01164

0

10

20

30

40

50

60

70

80

03/09/07 04/28/07 06/17/07 08/06/07 09/25/07 11/14/07 01/03/08

Uni

t Run

off (

l/s/k

m2 )

Station H17b

Station H6b

Station H4c

VA09-01164 August 18, 2009

APPENDIX A

FIGURE C9 – MEAN MONTHLY UNIT HYDROGRAPHS: FISH CREEK (H2, H3 & H4B) VS. BIG CREEK (08MB006)

(1 Page)

Print 8/18/2009 1:45 PMRev'd April 19/07

M:\1\01\00266\01\A\Data\EA 2007\Hydrology\KP 2007 Hydromet Report\[App C plots (1).xls]Fig C9

0

5

10

15

20

25

30

January February March April May June July August September October November December

Year - 1993

Uni

t Flo

w (l

/s/k

m2)

H2

H3

H4b

08MB006

Rev A - Issued in Draft

MEAN MONTHLY UNIT HYDROGRAPHSFISH CREEK (H2, H3 & H4b) vs. BIG CREEK (08MB006)

FIGURE C9

TASEKO MINES LIMITED

PROSPERITY GOLD-COPPER PROJECT

REV.A

PROJECT / ASSIGNMENT NO. VA101-266/1

REF NO.2Knight Piésold

C O N S U L T I N G