Kangra Discard Facility

Transcription

1 Reuse and recycling of dirty water - regulations stipulate a clear hierarchy of water use. First reuse any captured dirty water. Recycle as much water as possible. Minimise the import and use of clean water resources. Excess water released from a dirty water area must be treated to a standard agreed to by the regulator (DWA) and any plan to treat and release excess water must be approved and licensed; Preventing the pollution of water resources - exposure between water and potential pollutants should be reduced to a minimum. Special precautions may be required to prevent the transport of pollutants in water. Oil traps should be specified below workshops, fuel depots and vehicle wash-bays to prevent the flow of hydrocarbons into PCDs. Silt traps may be constructed where surface runoff is likely to lead to the transport of suspended sediments and the like. Showers in a change-room at a coal mine may yield heavy concentrations of coal dust that would reduce the efficiency of a sewage treatment plant. Under similar circumstances, wash-water should be separated from conventional water-borne sewage, and treated separately, and Reducing dirty water areas - special attention should be paid to early rehabilitation of mining and other dirty water areas to reduce the dirty water footprint area to an absolute minimum. This will reduce the total volumes of dirty water and simplify the final measures to be taken at mine closure. Part of any SWMP will include processes that identify and implement opportunities to reduce the dirty water footprint areas. 7.2 Clean and Dirty Water Catchment Delineation Areas that pose pollution threats were delineated separately from clean water areas, as it should be ensured that water flowing from dirty areas is collected, stored and cleaned prior to release into the natural water system, in accordance with GN704 regulations. Please Note: The information provided in this section was adapted from a report that was undertaken by Geo Tail (Pty) Ltd. for Kangra Coal, titled Kangra Pollution Control Dam and Storm Water Channel Sizing (See Appendix B) (Geo Tai l(pty) Ltd, 2014) May 2015 Page 28

2 7.3 Clean water diversion Clean water should be collected from the catchment surrounding the proposed area of development and should be diverted away from the dirty areas. This will be achieved through the use of earth channels and berms (See Figure 7-1). The earth channels and drainage berms should be designed such that water from clean water areas should be diverted away from dirty water areas and should be allowed to pass through to downstream users (NWA, 1998). FIGURE 7-1 CROSS SECTION OF THE PROPOSED EARTH CHANNEL AND BERM Since the clean water flowing off the surrounding fields is expected to be carrying sediments, it is advisable that the drainage channel be designed with a gravel bed. The size of the channel should be specified using Manning s Equation (See Equation 1) assuming a manning s coefficient of for an excavated drainage channel with a gravel bed. Design flow rates for 1:50- and 1:100-year storm-water inflow into earth channel drains were calculated. The SANRAL Drainage Manual (SANRAL, 2007) recommends that the side slopes of an earth channel have a ratio of 1:1.5, and for diversion purposes, a berm should be constructed with a similar slope of 1: (1) Based on the plan layout of the discard facility and the contours of the entire area, it was recommended that a diversion channel and a berm should be constructed on the eastern side of the discard facility, from South to North as indicated Error! Reference source not found.. Preliminary dimensions of the diversion channel were calculated, using the peak flow value calculated from sub-catchment W51B, which has an area of ha, the results indicated that from a 1:50-year flood the peak flow is 4.7 m 3 /s (See May 2015 Page 29

3 Table 7-1) May 2015 Page 30

4 TABLE 7-1 LTD, 2014] SUMMARY OF FLOOD PEAK CALCULATIONS [ADAPTED FROM: GEO TAIL (PTY) Sub Catchment Parameter Value Clean water area Catchment size 32.9 ha Runoff coefficient 0.32 Time of concentration 0.28 hours Peak rainfall intensity 162 mm/hr 50-yr flood peak 4.7 m 3 /s Dirty water area Catchment size 4.9 ha Runoff coefficient 0.32 hr Time of concentration 0.17 to 0.25 used Peak rainfall intensity 174 mm/hr 50-yr flood peak 0.8 m 3 /s Based on the abovementioned values, Equation 1 and assumed values, the bottom width of the channel was calculated at mm, which is equal to the flow depth (See Table 7-2). Three culverts will be required to cross under the three access ramps. In order to handle the design flow of 4.7 m 3 /s, installed culverts should have a diameter of mm, with energy dissipaters to reduce the effect of scouring of the channels and erosion (See Figure 7-2). In addition, both the clean water and dirty water channels should be constructed with berms on the downstream side of the channel for clean water channel and on the upstream side of the channel for dirty water channels. Within the clean water channel, the inclusion of a berm will increase its capacity while for dirty water channel it will provide greater certainty that no clean water will flow into the dirty water area. TABLE 7-2 CHANNEL SIZING AND PARAMETERS Parameter Value Shape Trapezoidal Base width 1 m Side slopes 1:1.5 (V:H) Flow depth 0.83 m Channel depth 1.1 m Max flow velocity 3.7 m/s Flow type at max velocity Supercritical May 2015 Page 31

5 Figure 7-2 Sketch depicting the proposed culvert 7.4 Dirty water containment The whole area that falls within the layout of the proposed discard facility was considered to be dirty as indicated in FIGURE 7-3. Therefore all rain that falls within the discard facility must be collected and discharged at the proposed pollution control dam at the lowest point on the site, as indicated in FIGURE 7-3. Table 7.3 summarises the results of the calculations that were undertaken to determine the size required for the clean water channel. It is recommended that the dirty water channel be lined in order to minimise seepage of dirty water into underground water resources. A minimum of 300 mm was added to the calculated flow depth in order to accommodate for wave action and flow surge. From these calculations, it is concluded that a pollution control dam would be big enough to be able to hold a minimum effluent volume of Mm 3. In order to allow for a large evaporation surface, the pollution control dam should be not more than two meters deep plus 0.8 m freeboard. It was also recommended that the pollution control dam should be lined in order to reduce seepage. The HDPE liner absorbs heat, therefore increasing the surrounding temperature and consequently increasing the rate of evaporation May 2015 Page 32

6 Table 7-3 Channel sizing and parameters Parameter Value Shape Trapezoidal Base width 1 m Side slopes 1:1.5 (V:H) Flow depth 0.48 m Channel depth 0.8 Max flow velocity 2.7 m/s Flow type at max velocity Supercritical 7.5 Soil erosion measures From Error! Reference source not found. it can be seen that the topsoil that will be stripped during construction will be stockpiled next to the dump. This soil should be preserved since it will be utilised during the rehabilitation phase and eroded topsoil should be kept out of the storm water channels, however, these stockpiled soils will be susceptible to erosion due to both wind and runoff. Therefore, it is recommended that appropriate soil erosion prevention measures should be established and applied, please see below for some of the erosion prevention measures; Construct retaining walls around the topsoil stockpiles to prevent or minimize erosion; Plant vegetation, this is the simplest and most natural method of conserving soils; Stockpile slopes should be kept at 1:3 at minimum and the height of the stockpile wall should not exceed m; Plant tree line windbreaks, and Plant grasses and small trees on those steep slopes. In addition, the proposed storm water channels will be subject to flow velocities of 2.7 m/s that are supercritical and can cause erosion on the channels if earth channels are used. Therefore, it is recommended that the channels be lined with concrete in order to prevent erosion from occurring, this will also assist in limiting the seepage rate May 2015 Page 33

7 Kangra Figure Layout indicating proposed storm water infrastructure 13 May 2015 Page 34

8 8 WATER BALANCE The WB was based on the Process Flow Diagram (PFD) which can be seen in Figure 8-1. This PFD was based on previous reports (Geo Tail, 2014; Ilanda, 2014) and reasonable assumptions were made and calculations were undertaken to fill identified gaps. The assumptions made are described in the following paragraphs. A simulation of water movement within the entire discard facility was conducted, assuming that the facility has been filled and surfaces fully rehabilitated. (See Table 8-1). Drain and storm water inflows from the discard facility, direct rainfall on the surface of the PCD, limited seepage through the lining and evaporation from the PCD surface were balanced. Based on the results of the WB, it is recommended that the required PCD should have a capacity of m 3, assuming that the entire discard facility is in operation and that there is no return to the plant. This figure is in the same order of magnitude as the m 3 that was proposed by Ilanda (2014). Some m 3 /annum (long-term average) of water would need either to be treated and discharged, or transferred to evaporators during the operation of the discard facility (understood to be Kangra s preferred option) May 2015 Page 35

9 Figure 8-1 Kangra discard dump process flow diagram May 2015 Page 36

10 Table 8-1 Annual average water balance May 2015 Page 37

11 It is anticipated that, at some point in time, backfilled mining pits located to the east of this discard facility will fill and start to decant. Additional pollution control facility capacity will be required to capture and deal with this long-term decant water. This anticipated decant was included in the water balance simulation and it is recommended that a PCD with a minimum capacity of m 3 should be constructed in order to account for this additional volume. The aforementioned PCD capacity is thus considered adequate for the purposes of the proposed Kangra Discard Dump May 2015 Page 38

12 9 RISK ASSESSMENT This risk assessment exercise involves identification and description of risks to the environment and to people emanating during each phase of the project cycle. 9.1 Surface Water Impacts Assessment The risk rating matrix methodology used within this study is based on the following quantitative measures: The probability of impact occurrence; The frequency of impact occurrence; The spatial extent of impact occurrence; The intensity of impact occurrence, and Duration of impact occurrence. The ratings are combined to determine the risk significance points for the impact according to the following equation: Risk significance value = (magnitude + duration + Scale) x probability The maximum value is 60 risk points and ratings are scaled from high, medium to low in respect of their environmental impact. The ranking system used in the study is presented in and Table May 2015 Page 39

13 Table 9-1 and Table May 2015 Page 40

14 Table 9-1: Risk Assessment Significance Value The maximum value that can be achieved is 100 Significance Points (SP). Environmental effects were rated as follows: Significance Environmental Significance Points Colour Code High (positive) >60 H Medium (positive) 30 to 60 M Low (positive) <30 L Neutral 0 N Low (negative) >-30 L Medium (negative) -30 to -60 M High (negative) <-60 H May 2015 Page 41

15 Table 9-2: Risk Rating Matrix Status of Impact +: Positive (A benefit to the receiving environment) N: Neutral (No cost or benefit to the receiving environment) -: Negative (A cost to the receiving environment) Magnitude:=M Duration:=D 10: Very high/don t know 5: Permanent 8: High 4: Long-term (ceases with the operational life) 6: Moderate 3: Medium-term (5-15 years) 4: Low 2: Short-term (0-5 years) 2: Minor 1: Immediate 0: Not applicable/none/negligible 0: Not applicable/none/negligible Scale:=S Probability:=P 5: International 5: Definite/don t know 4: National 4: Highly probable 3: Regional 3: Medium probability 2: Local 2: Low probability 1: Site only 1: Improbable 0: Not applicable/none/negligible 0: Not applicable/none/negligible 9.2 Key Issues and Scenarios The Risk Assessment addressed impacts associated with general catchment characteristics, runoff characteristics and the quality and quantity of surface water resources. Detailed descriptions of these risk assessment and mitigation measures can be seen in TABLE 9-3 to TABLE 9-5. The following subsections to describe the identified risks May 2015 Page 42

16 Changes to water quality of the rivers Surface water quality in the Egude River to the left and its tributary to the right of both the Discard Dump and the PCD (see Figure 4-1) may be impacted upon. This could occur as a result of: Mobilisation of sediments from areas cleared ahead of mining; Mobilisation of sediments from over-burden and residue deposits; Release of chemicals associated with mining; The construction of haul roads and transport of product material could increase the quantity of airborne sediments. This dust would settle on the ground surface where it would present additional sediments to nearby streams during rainfall events. Truck and machinery oils and fuel could spill to water resources. All oils and fuels must be stored in banded areas and any spillages must be managed immediately in accordance with the site s emergency response plan. The emergency response plan must be provided by contractors. This will reduce the risks from medium to low. Disturbance to the Discard Dump and PCD during the Operational Phase could cause faults or cracks resulting in more seepage to surface and groundwater resources. Any seepage must be contained according to design criteria. The stormwater diversion channels and berms must be constructed as shown in FIGURE 7-3 to separate clean water from dirty water at this site. This will reduce the risks from medium to low. Changes in catchment runoff characteristics The risk assessment has revealed that, during the construction phase, the overburden resulting from excavation and land clearing will alter runoff characteristics of the footprint area (See TABLE 9-3). Therefore, it is recommended that the overburden should be spread and rehabilitated with consideration of the drainage plan or SWMP for the site. It is recommended that erosion measures be implemented on topsoil stockpile areas in order to prevent topsoil loss, since this soil will be used for rehabilitation and eroded topsoil should be kept out of the storm water channels. The proposed storm water channels will be subject to supercritical flow velocities, which can cause erosion if earth channels are used. Therefore, it is recommended that the channels be lined with concrete in order to prevent erosion from occurring, this will also assist in limiting the seepage rate May 2015 Page 43

17 Changes in Catchment Characteristics The catchment characteristics of the site will be altered by the Discard Dump and PCD construction since these will result in a general change of the site s landscape. The footprint catchment can be regarded as dirty due to the quality of material and effluent associated with the Discard Dump and PCD structures. Surface water runoff from this Discard Dump catchment should be collected, contained (See FIGURE 7-3) and recycled (where possible) in order to: Reduce the extent of contaminated areas; Prevent effluent overflows and limit seepage losses (It is understood that the PCD and Discard Dump will be lined), thus avoiding further deterioration of water quality May 2015 Page 44

18 Table 9-3 Construction phase risk assessment ENVIRONMENTAL SIGNIFICANCE BEFORE MITIGATION ENVIRONMENTAL SIGNIFICANCE AFTER MITIGATION POTENTIAL ENVIRONMENTAL IMPACT ACTIVITY M D S P TOTAL STATUS RECOMMENDED MITIGATION ACTION PLAN PERSON MEASURES SP M D S P TOTAL STATUS SP CONSTRUCTION PHASE ACTIVITIES: SITE PREPARATION & FOOTPRINT CLEARANCE, DISCARD DUMP & PCD CONSTRUCTION, WASTE HANDLING KANGRA MINE ACTIVITY AREAS: 1.DISCARD DUMP 2.PCD 3. DIVERSION CHANNELS SURFACE WATER Siltation of surface water resources & associated soil erosion Footprint Clearance & Construction - Soil disturbance during excavation, vehicle & machinery movement will cause siltation to the nearby streams H Limit vegetation clearance and soil disturbance to footprint area. Machinery and vehicle movement should be confined to designated roads. Adhere to Soil Stripping, Soil Stockpiling and Soil Management Plan Environmental Officer L Reduced runoff to surface water resources Overburden resulting from excavation and clearance of footprint areas (Discard Dump & PCD) will obstruct drainage thereby altering runoff pathways and rates to the streams H Overburden should be spread and rehabilitated with drainage plans in place. Adhere to Soil Stripping, Soil Stockpiling and Soil Management Plan Environmental Officer L Increased runoff to surface water resource Access and Haul Roads- Surface compaction will increase surface runoff H Enforce the use of only designated roads on site. Adhere to SWMP Environmental Officer L Waste Handling - litter and building rubble M Builder's contracts should stipulate the appropriate storage and removal of builders' waste. Adhere to Construction Plan Adhere to Waste Storage and Handling Plan Environmental Officer L Surface water contamination Waste Handling -Waste water, fuel and oil spills M Prevent seepage of wastewater and spillage of fuel and oils. Adhere to Waste Storage and Handling Plan Adhere to Spill Management Plan Environmental Officer L Waste Handling - Runoff to surface water resources from waste disposal areas M Design criteria of Discard Dump and PCD should prevent or minimise seepage by liners. Adhere to SWMP Environmental Officer L May 2015 Page 45

19 Table 9-4 Operational phase risk assessment POTENTIAL ENVIRONMENTAL IMPACT ACTIVITY ENVIRONMENTAL SIGNIFICANCE BEFORE MITIGATION M D S P TOTAL STATUS ENVIRONMENTAL SIGNIFICANCE AFTER MITIGATION RECOMMENDED ACTION PLAN PERSON MITIGATION MEASURES SP M D S P TOTAL STATUS SP OPERATIONAL PHASE ACTIVITIES: PRODUCT PROCESSING, PRODUCT TRANSPORTATION, WASTE HANDLING SURFACE WATER Surface water quality Deterioration of surface water quality Siltation of water resources Structural failures KANGRA MINE ACTIVITY AREAS: 1.DISCARD DUMP 2.PCD 3. DIVERSION CHANNELS Product Stockpiling - result in contaminated runoff Waste Handling - Handling of waste and transport of operation material can cause spills (e.g. hydrocarbons)which can contaminate streams Discard Dump material result in poor quality seepages and overflow Mine Effluent Deposition in PCD- spills and seepages contaminate surface & groundwater resources Haul roads - exposure of soil surfaces accelerate soil erosion. PCD failure due to extreme rainfall events H M H M M H Consider runoff from stockpiles and infrastructure as dirty water. Maintain all water control infrastructure. Consider runoff from these area as dirty water. Prevent run-off of water with high suspended solid content. Install oil traps below workshop, fuel depots and vehicle wash bays to prevent flow of hydrocarbons Conduct regular inspection and consider runoff from the waste dump as dirty. Seepage and runoff water must be contained in the PCD Conduct immediate cleanups in the event of spillages and liners in PCDs minimise seepage risks. Ensure that design structures (e.g. PCD) have at least a 0.8m freeboard to contain water during occurrence of extreme rainfall events. Maintain storm water infrastructure, ensure effective rehabilitation. Prevent run-off of water with high suspended solid content. Design PCDs to contain the 1:50 year flood event. Conduct check-ups to ensure that the PCD and associated channels are still durable and working well. Adhere to SWMP Adhere to SWMP Adhere to SWMP and Structure Inspection Plan Adhere to SWMP Adhere to SWMP Adhere to SWMP Environmental Officer Environmental Officer Environmental Officer Environmental Officer Environmental Officer Environmental Officer L M M M L L Surface water quantity Pollution control dams- intercept rainfall-runoff which should report to streams, thus reducing stream flows M Minimise dam surface area. Avoid further reduction of streamflow by making use of PCD return flow for processes such as dust depression if the quality meets required standards. Adhere to SWMP Environmental Officer L May 2015 Page 46

20 Table 9-5 Closure phase risk assessment ENVIRONMENTAL SIGNIFICANCE BEFORE MITIGATION ENVIRONMENTAL SIGNIFICANCE AFTER MITIGATION POTENTIAL ENVIRONMENTAL IMPACT ACTIVITY M D S P TOTAL STATUS RECOMMENDED MITIGATION MEASURES ACTION PLAN PERSON SP M D S P TOTAL STATUS SP DECOMISSIONING and CLOSURE ACTIVITIES: REMOVAL OF INFRASTRUCTURE AND REHABILITATION OF DISTURBED AREAS KANGRA MINE ACTIVITY AREAS: 1.DISCARD DUMP 2.PCD 3. DIVERSION CHANNELS SURFACE WATER Removal of infrastructure - improper waste handling and fuel/oil spills M All infrastructure will be enclosed in berms to contain any accidental spills of hazardous material. Manage waste effectively to prevent pollution of water resources Adhere to Rehabilitation Plan Adhere to Water Monitoring Programme Environmental Officer L Pollution of water resources PCD - poor quality seepages and overflow H Line dams and design to 1:50 year flood peaks with sufficient freeboard to prevent spills in extreme rainfall events Adhere to Rehabilitation Plan Adhere to Water Monitoring Programme Environmental Officer L Surface water quality Runoff and drainage from stockpiles and Discard Dump continue to yield polluted water H Maintain dirty water separation systems until the site is rehabilitated and free draining Adhere to Rehabilitation Plan Adhere to Water Monitoring Programme Environmental Officer L Siltation of water courses Removal of infrastructure - including water and TSF pipelines M Rehabilitate as soon as possible, maintain erosion control for the duration of rehabilitation Adhere to Rehabilitation Plan Adhere to Water Monitoring Programme Environmental Officer L May 2015 Page 47

21 10 CONCLUSIONS AND RECOMMENDATIONS The study area is located in quaternary catchment areas W52A and W51B, and the MAP of the study area is mm. The MAE of the study area was calculated at mm. The conceptual SWMP, which adheres to the GN 704 guidelines as stated in Section 7.1, highlights that the proposed PCD should have a 2 m depth and that a capacity of m 3 is required to evaporate the storm water generated from the site and remain in compliance with GN704. As the discard facility is located close to local watersheds and catchments are small, the storm water channels are small (Geo Tail, 2014). It was recommended that concrete, lined channels and berms be constructed around the discard facility, to help contain dirty water and divert clean water around the discard facility. It was estimated that the overall development of the discard facility will cause only a 0.7% stream flow reduction (GCS, 2013). The water balance was calculated on the basis that the PCD should have a capacity of m 3. It was anticipated that, at some point in time, backfilled mining pits located to the east of this discard dump will fill and start to decant. This anticipated decant was included in the simulation and can be contained in the recommended PCD capacity. The flood lines analysis concluded that the 100m buffer zone, serving as the Exclusion Zone as described in GN704, will apply to all rivers for the protection of watercourses close to infrastructure. According to GN 704 either the flood lines or the 100m buffer area will ultimately be used to protect water resources on site. Calculations show that flood levels will not reach a distance of 100m on either side of the flood plains. Since the flood lines are less than the 100m buffer distance in this instance, the 100m buffer area will serve as the Exclusion Zone around all streams, within which no development is permitted. The water samples taken at the Kangra Maquasa site in general indicated good quality water in terms of compliance to the SAWQG and SANS standards. Samples Maq-SW1, 2 and 3 are directly relevant to the discard facility site. Sample Maq-SW 2, however, indicated an impact from mining with non-compliant sulphates and salts. This sample site should be investigated and the appropriate water management measures put in place to prevent the seepage of contaminated water into the environment May 2015 Page 48

22 The risk assessment identified potential risks which include possible contamination of water resources through spillages of oils and liquid fuels by machinery and vehicles. Spillages, overflows and seepages of contaminated effluent from the Discard Dump and PCD during the Operational Phase are also noted as risky areas. Adherence to waste disposal plan and to SWMP are thus emphasized in order to minimise the aforementioned impacts. The SWMP should also help to deal with impacts that emanate from sediment transport and deposition into nearby water courses. As far as possible, all operations during the construction Phase of the Discard Dump and PCD should be confined to the footprint area in order to ensure that impacts are localised and thus prevented from spreading to other areas within or close to the Kangra Coal Mine site. It is recommended that erosion measures be implemented on topsoil stockpile areas in order to prevent topsoil loss, since this soil will be used for rehabilitation and eroded topsoil should be kept out of the storm water channels. The proposed storm water channels will be subject to supercritical flow velocities, which can cause erosion if earth channels are used. Therefore, it is recommended that the channels be lined with concrete in order to prevent erosion from occurring, this will also assist in limiting the seepage rate. The SWMP should be complemented with an on-going surface water monitoring programme and resources management strategies should be established in order to ensure that the water quality changes are detected throughout the mine life May 2015 Page 49

23 11 REFERENCES DWA. (2006). Best practice guidelines for water resources protection in the South African mining industry. BPG G2: Water and Salt Balance. Pretoria: DWA. GCS. (2013). Maquasa extension hydrology investigation. Johanessburg: GCS Water and Environment (Pty) Ltd. Geo Tail. (2014). Kangra Project: Design for New Maquasa East Coal Discard Dump. Pretoria: Unpublished Report. GeoTail(Pty)Ltd. (2014). KANGRA POLLUTION CONTROL DAM AND STORM WATER CHANNEL SIZING. Johannesburg: ilanda Water Services CC. Ilanda. (2014). Kangra Pollution Control Dam and Storm Water Channel Sizing. Johannesburg: Unpublished Report No : 0119-Rep-001 submitted to Geo Tail (Pty) Ltd. NWA. (1998). NATIONAL WATER ACT (Act No 36 of 1998). Pretoria: Department of Water Affairs. Regulations on use of water for mining and related activities aimed at the protection of water resources. (1999, June 4). Government Notice 704, 408(20119), 4. SANRAL. (2006). Drainage Manual. Pretoria: The South African Natinal Road Agency Ltd. South Africa. (1998). The South African National Water Act. South Africa. US Army Corps of Engineers. (1995). HEC RAS Hydraulic Modelling Software. Version 4.1. USA: USGS May 2015 Page 50

24 APPENDIX A: PROFILE AND CROSS SECTIONAL PLOTS Stream 3 Plan: Stream /11/21 Legend WS 1:50 WS 1:100 Ground Bank Sta Stream 3 Plan: Stream /11/ Leg end EG 1:100 EG 1:50 Crit 1:100 Elevation (m) Crit 1:50 WS 1:100 WS 1:50 Ground Main Channel Distance (m) Stream 3 Plan: Stream /11/ Legend EG 1:100 EG 1: Crit 1:100 Crit 1:50 WS 1: WS 1:50 Ground Bank Sta Elevation (m) Station (m) May 2015 Page 51

25 Stream 6 Plan: Stream /11/ Legend EG 1:100 EG 1:50 WS 1:100 Elevation (m) Crit 1:100 WS 1:50 Crit 1:50 Ground Main Channel Distance (m) Stream 8 Plan: Stream /11/21 1 Legend WS 1:50 WS 1:100 Ground Bank Sta May 2015 Page 52

26 1464 Stream 8 Plan: Stream /11/ Legend EG 1:100 EG 1:50 WS 1:100 Crit 1:100 WS 1:50 Crit 1:50 Ground Bank Sta Elevation (m) Station (m) Stream 10 Plan: Stream /11/21 Legend WS 1:50 WS 1:100 Ground Bank Sta 2 Stream 10 Plan: Stream /11/ Leg end EG 1:100 EG 1:50 Crit 1:100 Elevation (m) Crit 1:50 WS 1:100 WS 1:50 Ground Main Channel Distance (m) May 2015 Page 53