W2012L2-0001 and It Was Approved on June 13, 2019

Dominion Diamond Mines ULC 900-606 4 Street SW Calgary, Alberta T2P 1T1 (403) 910-1933 www.ddmines.com

28 January 2020

Joseph Mackenzie, Chair Wek’èezhìi Land and Water Board #1, 4905 – 48th Street Yellowknife, NT, X1A 3S3

Dear Mr. Mackenzie:

Re: Cujo Lake Outflow Special Study Technical Memorandum

Dominion Diamond Mines ULC (Dominion) is pleased to provide the Wek’èezhìi Land and Water Board (the Board) with the Cujo Lake Outflow Special Study Technical Memorandum (the Memo). The Memo provides the results of the field surveys completed in 2019 as part of the Cujo Outflow Special Study Design (Study Design). The Study Design was submitted on January 30, 2019 in accordance with requirements of Part J, Condition 15 of the amended Ekati mine Water Licence W2012L2-0001 and it was approved on June 13, 2019. The purpose of the Study was to complete field surveys within streams B2, B3, and B4 in the King-Cujo watershed to confirm that flows and water levels without seasonal Discharge from the King Pond Settling Facility to Cujo Lake are sufficient for maintaining access to spawning habitats for spring spawning fish species, with a focus on Arctic Grayling.

Dominion trusts that you will find this information to be clear and informative. Should you have any questions, please contact Laura Pacholski, Environment Advisor – Fisheries and Aquatics, at [email protected] or 403 910-1933 ext 2404 or the undersigned at Harry.O’[email protected] or 867-445-3185.

Sincerely,

Original signed by Harry O’Keefe.

Harry O’Keefe Superintendent – Environment Operations

Record #:HSE RCD ENV 1345; Document Owner: Environment Department; Date: 28-Jan-2020 Template # EKA TEM 1852.13

DATE January 23, 2020 Project No. 19116503-4100 / DCN-19014

TO Laura Pacholski Dominion Diamond Mines ULC CC Harry O'Keefe, Giovanna Diaz

FROM Kasey Clipperton, Kristine Mason, and EMAIL [email protected] Monica Redmond EKATI DIAMOND MINE – CUJO OUTFLOW FIELD PROGRAM

1.0 INTRODUCTION The Misery Underground (MUG) Project is located at the Dominion Diamond Mines ULC (Dominion) Ekati Diamond Mine (Ekati mine) in the Northwest Territories (NWT) approximately 320 km northeast of Yellowknife. As part of Part J, Condition 15 of the Ekati mine Water Licence amended to include the MUG Project, Dominion was required to submit the Cujo Outflow Special Study Design to the Wek'èezhìi Land and Water Board (WLWB) for approval. The Study Design was submitted to the WLWB on January 30, 2019 and approved on June 13, 2019. The purpose of the Study was to complete field surveys within streams B2, B3, and B4 in the King-Cujo watershed to confirm that flows and water levels without seasonal Discharge from the King Pond Settling Facility (KPSF) to Cujo Lake are sufficient for maintaining access to spawning habitats for spring spawning fish species, with a focus on Arctic Grayling. The Cujo Lake outlet flows in a northerly direction through a series of small streams and lakes into Christine Lake which ultimately flows into Lac du Sauvage (Map 1).

This technical memorandum summarizes the Study conducted by Golder Associates Ltd. (Golder) within the Cujo Lake outflow at streams B2, B3, and B4 during spring 2019 on behalf of Dominion (Map 1 to Map 4). The objectives of the 2019 Study consisted of the following:  Conduct a desktop review to develop criteria for fish passage for Arctic Grayling and other spring-spawning fish.  Identify, map, and describe if barriers to Arctic Grayling movement in streams B2, B3, and B4 are present based on direct observation at a range of flow conditions expected to occur under MUG Project operating conditions when there is no Discharge from KPSF.  Establish a relationship between streamflow and the onset of potential barrier formation (specific to each barrier identified), based on direct observations and measurements of depth and velocity, and standard fish passage criteria.

Golder Associates Ltd. 9, 4905 - 48 Street, Yellowknife, Northwest Territories, X1A 3S3, Canada T: +1 867 873 6319 F: +1 867 873 6379

Golder and the G logo are trademarks of Golder Associates Corporation golder.com

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

The Study compares physical streamflow characteristics such as velocity, channel depth, and connectivity documented at the flow conditions encountered during the field surveys to the timing and frequency of flow conditions expected under future operations and the flows monitored during the 2019 Aquatic Effects Monitoring Program. Direct observations and measurements of fish habitat conditions when Discharge from KPSF is not occurring will provide quantitative data to represent conditions that would be expected under future MUG Project operations.

Direct measurements of habitat and passage conditions under no-Discharge conditions will validate whether outflows will be sufficient to provide access to spawning habitats for spring-spawning species. The results will outline what flow conditions will allow access to suitable Arctic Grayling spawning habitats within the King-Cujo watershed.

536000 538000 540000 542000 LEGEND WATERCOURSE

EKATI MINE FOOTPRINT

KING-CUJO WATERSHED (SUB-BASIN B)

WATERBODY

B1 STREAM OR LAKE NAME

Lac du Sauvage B19

9 1 B B 1 8 B18

B 1 5 0

2 B28 B 7164000 7164000

0 B Christine Lake B1 (Lake B1) Ac35 B15

B 2 B17 4 B17 B29

Stand B25 3 Pond B

B16 (Lake B2)

B16 Shining Pond (Lake B3)

B10 B4 B26

Cujo Lake (Lake B4) 0 500 1,000 7162000 7162000

1:25,000 METRES B5

B8 B 7

King Pond

REFERENCE(S) 1. CANVEC © NATURAL RESOURCES CANADA, 2012 2. NATURAL RESOURCES CANADA, CENTRE FOR TOPOGRAPHIC INFORMATION, 2012 DATUM: NAD83 PROJECTION: UTM ZONE 12N

CLIENT

Misery Operation

PROJECT CUJO LAKE OUTFLOW SPECIAL STUDY

TITLE 7160000 7160000 KING-CUJO WATERSHED Misery Pit IF THIS MEASUREMENT DOES NOT MATCH WHAT ANSI B IS SHOWN, THE SHEET SIZE HAS BEEN MODIFIED FROM: THIS MEASUREMENT WHAT IF DOES NOT MATCH CONSULTANT YYYY-MM-DD 2019-11-15 25mm DESIGNED MR

PREPARED ANK

REVIEWED KC

APPROVED KM PROJECT NO. PHASE REV. MAP

536000 538000 540000 542000 19116503 4100 0 PATH: G:\CLIENTS\DOMINION\DDEC Projects\Figures\19116503_JayStage7\4100_CujoLakeOutflowFieldProgram\Map1_19116503-4100_CujoLake_Outflow.mxd and Jay Lynx PATH: 1 0 538900 539000 LEGEND

!( SPAWNING HABITAT

!( TRANSECT

FLOW DIRECTION

ARCTIC GRAYLING OBSERVATIONS

Shining Pond (Lake B3)

TRIP 1

TRIP 2

TRIP 3 7162500 7162500

B4-T1 !(

B4-T2B !( B4-T2A !(

B4-SH1 !(

B4-SH2 0 15 30 !( 1:775 METRES

B4-T3 !(

CLIENT

PROJECT CUJO LAKE OUTFLOW SPECIAL STUDY

TITLE STREAM B4

Cujo Lake (Lake B4) IF THIS MEASUREMENT DOES NOT MATCH WHAT ANSI B IS SHOWN, THE SHEET SIZE HAS BEEN MODIFIED FROM: THIS MEASUREMENT WHAT IF DOES NOT MATCH CONSULTANT YYYY-MM-DD 2019-11-15 25mm DESIGNED MR

PREPARED ANK

REVIEWED KC

APPROVED KM PROJECT NO. PHASE REV. MAP

538900 539000 19116503 4100 0 PATH: G:\CLIENTS\DOMINION\DDEC Projects\Figures\19116503_JayStage7\4100_CujoLakeOutflowFieldProgram\Map2_19116503-4100_StreamB4.mxd and Jay Lynx PATH: 2 0 538800 539000 539200 LEGEND

!( SPAWNING HABITAT

!( TRANSECT

FLOW DIRECTION

ARCTIC GRAYLING OBSERVATIONS

TRIP 1

TRIP 2

TRIP 3

Stand Pond (Lake B2) B3-SH2 !(

B3-T1 !(

B3-SH3 !( B3-T2 !(

B3-SH1 !( B3-SH4

7163000 !( 7163000

!( B3-T3

0 25 50

1:1,500 METRES

CLIENT

PROJECT CUJO LAKE OUTFLOW SPECIAL STUDY

TITLE STREAM B3 IF THIS MEASUREMENT DOES NOT MATCH WHAT ANSI B IS SHOWN, THE SHEET SIZE HAS BEEN MODIFIED FROM: THIS MEASUREMENT WHAT IF DOES NOT MATCH CONSULTANT Shining Pond (Lake B3) YYYY-MM-DD 2019-11-15 25mm DESIGNED MR

PREPARED ANK 7162800 7162800 REVIEWED KC

APPROVED KM PROJECT NO. PHASE REV. MAP

538800 539000 539200 19116503 4100 0 PATH: G:\CLIENTS\DOMINION\DDEC Projects\Figures\19116503_JayStage7\4100_CujoLakeOutflowFieldProgram\Map3_19116503-4100_StreamB3.mxd and Jay Lynx PATH: 3 0 539000 LEGEND

Christine Lake (Lake B1) !( SPAWNING HABITAT

!( TRANSECT

FLOW DIRECTION

ARCTIC GRAYLING OBSERVATIONS

TRIP 1

TRIP 2 !( B2-T1 TRIP 3

B2-SH1 !(

!( B2-T2

B2-T3 !( B2-SH2 !(

7163200 7163200 0 15 30

1:750 METRES

B2-SH3 !(

CLIENT

PROJECT CUJO LAKE OUTFLOW SPECIAL STUDY

TITLE STREAM B2 IF THIS MEASUREMENT DOES NOT MATCH WHAT ANSI B IS SHOWN, THE SHEET SIZE HAS BEEN MODIFIED FROM: THIS MEASUREMENT WHAT IF DOES NOT MATCH Stand Pond (Lake B2) CONSULTANT YYYY-MM-DD 2019-11-15 25mm DESIGNED MR

PREPARED ANK

REVIEWED KC

APPROVED KM PROJECT NO. PHASE REV. MAP

539000 19116503 4100 0

PATH: G:\CLIENTS\DOMINION\DDEC Projects\Figures\19116503_JayStage7\4100_CujoLakeOutflowFieldProgram\Map4_19116503-4100_StreamB2.mxd and Jay Lynx PATH: 4 0 Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

2.0 FISH PASSAGE CRITERIA 2.1 Desktop Review Criteria for fish passage was developed during a desktop review prior to the field program for Arctic Grayling and other spring-spawning fish to compare measured field conditions. Supportive literature (Golder 2016, 2018; Katopodis and Gervais 2016) was reviewed prior to the field program to identify conditions where fish passage could become restricted based on the size range of fish expected in the King-Cujo watershed. Areas of concern may include stream sections with increased velocity or confined flow or where flow passes through a boulder garden. Passage criteria include:  minimum depth;  velocity maxima; and,  vertical drop and/or obstruction. Key resources included fish swimming performance data and life history habitat requirements for Arctic Grayling and other spring-spawning fish species. 2.2 Habitat Access for Spring-Spawning Fish Species The fish community of Cujo Lake is comprised of Round Whitefish, Lake Trout, Arctic Grayling, and Slimy Sculpin (DDEC 2014; ERM 2019a). Of these species, Arctic Grayling are expected to be the primary species that will use the stream habitats of the King-Cujo watershed for spawning and rearing. Round Whitefish and Lake Trout are salmonids with similar swimming ability to Arctic Grayling, but these species spawn in lakes during the fall, and therefore, would not be making spring migratory movements in the streams of the King-Cujo watershed. Passage criteria for Slimy Sculpin are not represented in the fish swimming performance database (Katopodis and Gervais 2016) or on Department of Fisheries and Oceans’ Swim Performance Online Tool (http://fishprotectiontools.ca/), so habitat preferences of the species was considered instead.

Slimy Sculpin can be found in a variety of habitat that range from deeper sections of lakes to cool streams and rivers, and typically prefer rocky or gravelly substrate (Evans et al. 2002; Scott and Crossman 1973). In various North American streams, Slimy Sculpin have been captured in streams in depths of 0.10 m to 0.30 m and with moderate to relatively high-water velocities up to 1.72 metres per second (m/s; Baldigo and Lawrence 2001; Evans et al. 2002). Young-of-the-year Slimy Sculpin have been reported as common in depths of 0.05 to 0.25 m with a velocity of 0.2 m/s, and juvenile were common at 0.1 to 0.3 m with a velocity of 0.05 to 0.4 m/s (Evans et al. 2002). These environmental factors are within the expected range of depths and velocities of the King-Cujo watershed. Although possible for Slimy Sculpin to use streams B2, B3, and B4, it is unlikely that this species is undertaking a seasonal migration, as Slimy Sculpin have high site-fidelity and have a median annual travel of approximately 1 to 30 m per year (Gray et al. 2018). Slimy Sculpin are not equipped with a swim bladder and are considered to be poor swimmers (Weinstein et al. 2019). Although Slimy Sculpin can be found in high velocity habitats, they occupy the stream bottom and hide amongst boulders and cobbles, which provide cover from high velocity. As streams B2, B3, and B4 do not provide any overwintering habitat due to their shallow depths that freeze to the bottom with steep or vertical natural obstacles, resident populations of Slimy Sculpin are unlikely to be making extensive spawning migrations within these stream systems.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

2.3 Habitat Access for Arctic Grayling 2.3.1 Depth Minima Available guidelines and identified thresholds for depth minima are closely aligned with the body depths of the species targeted for mitigation. Based on available literature for fish passage of medium to large-bodied salmonids, recommended minimum depths to achieve fish passage are typically in the range of 20 to 30 cm (20 cm identified in Dryden and Stein [1975]; Webb [1975]; Bell [1986]; Government of British Columbia [2013]; 20 to 30 cm identified in State of California [2003]). For example, the recommended 30 cm depth minimum for culverts in the State of California (State of California 2002) aligns with the maximum body depths of adult anadromous species that may use the culvert (e.g., 30 cm for Chinook Salmon, 15 cm for juvenile salmonids). Consistent with that approach, a shallower water depth would be effective for Arctic Grayling because the species is characterized by maximum adult body depths of up to 7 cm based on observations and field measurements from field programs in the NWT (Golder, unpublished data). Using a factor of 1.5 times body depth, a 10-cm minimum water depth threshold should be sufficiently conservative for maintaining passage of adult Arctic Grayling. This depth target is considered conservative as it is intended to provide for passage in a culvert, where extended areas of uniform depth would be present, whereas short distances of shallower depths (i.e., areas of less than 10 cm depth) in natural streams are likely passable by Arctic Grayling. 2.3.2 Velocity Maxima Fish speed and stamina, locomotion, and the mechanics of fish swimming are important considerations in determining fish passage through channels with mixed channel conditions (Katopodis and Gervais 2016). To determine whether Arctic Grayling are able to navigate streams B2, B3, and B4 during seasonal flow conditions, a previously developed fatigue curve (or formula) for a range of salmonid species (Katopodis and Gervais 2016) was first applied to generate endurance values (seconds) and distances (m) at a range of swimming speeds. Selected parameter coefficients for the formula were those for the upper 75% boundary because Arctic Grayling have been described as very efficient swimmers, capable of swimming fast over long periods of time (Deegan et al. 2005). The fatigue equation was defined by the following relationship between dimensionless (fish speed [U*]) and dimensionless endurance time (t*; Katopodis and Gervais 2016):

. 𝑈∗ 5.897𝑡∗

Where: 𝑈 and 𝑡 ∗ ∗

Where: U = fish swimming speed t = endurance time (seconds) l = fish length (m) g = gravitational acceleration (9.81 metres per second squared [m/s2])

Results from the application of the fatigue equation show that, for example, an adult Arctic Grayling can maintain a swim speed of 1.0 m/s for 2,693 seconds, covering a distance of 2,693 m in zero water velocity before fatigue; whereas juvenile Arctic Grayling can swim at 1.0 m/s for 665 seconds, covering a distance of 665 m in zero water velocity (Table 1). Predictions for endurance times and distances prior to fatigue under a range of selected swim speeds are provided in Table 1.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Table 1: Predicted Endurance and Distance for a Range of Swimming Speeds for Arctic Grayling (Assumes Zero Water Velocity) Swim Speed Adult (35 cm length(a)) Juvenile (20 cm length(a)) Endurance Time(b) Distance(c) Endurance Time(b) Distance(c) [m/s] [s] [m] [s] [m] 0.6 20,777 12,466 5,129 3,077 0.8 6,574 5,259 1,623 1,298 1.0 2,693 2,693 665 665 1.2 1,299 1,558 321 385 1.4 701 981 173 242 1.6 411 657 101 162 1.8 257 462 63 114 2.0 168 337 42 83 2.2 115 253 28 62 2.4 81 195 20 48 2.6 59 153 15 38 2.8 44 123 11 30 3.0 33 100 8 25 3.2 26 82 6 20 3.4 20 69 5 17 3.6 16 58 4 14 3.8 13 49 3 12 4.0 11 42 3 10 (a) A body size equal to 35 cm was chosen to be representative of adult fish swimming performance; a body size equal to 20 cm was chosen to be representative of juvenile fish swimming performance; however, fish swimming performance is variable based on body size and will be variable across the entire size distribution of the population. (b) Endurance time has been rounded to the nearest second. (c) Calculated by multiplying swim speed by endurance time. m/s = metres per second; s = second.

To determine the maximum swimming distance prior to fatigue in flowing water, predicted endurance times were multiplied by the ‘actual swim speed’ (swim speed minus water velocity). The relationship between water velocity and maximum swimming distance prior to fatigue is illustrated in Figure 1.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Figure 1: Predicted Fatigue Curve for Arctic Grayling Under a Range of Water Velocities that can be Expected in The King-Cujo Outlet Streams

m/s = metres per second.

The fatigue formula calculates that under modest water velocities (e.g., 1.0 m/s), adult Arctic Grayling can swim for distances of 218 m, and juvenile Arctic Grayling can swim for distances of 54 m before fatigue. Under high velocities (1.9 m/s), adult Arctic Grayling can swim for a distance of 17 m, and juvenile Arctic Grayling can swim for a distance of only 4 m before fatigue.

The fatigue formula also predicts successful passage of adult fish over short distances of 50 m if water velocities remain below 1.45 m/s, 100 m if water velocities remain below 1.22 m/s, and 500 m if water velocities remain below 0.81 m/s. For juvenile Arctic Grayling, the fatigue formula predicts successful passage over short distances of 50 m if water velocities remain below 1.0 m/s, 100 m if water velocities remain below 0.86 m/s, and 500 m if water velocities remain below 0.57 m/s. The approximate lengths of streams B2, B3, and B4 are 245 m, 289 m, and 113 m respectively.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

2.3.3 Vertical Drop and/or Obstruction Fish such as Arctic Grayling require upstream passage and dispersal within a watershed for various life history requirements. Adult fish return to spawn in streams and juveniles migrate from lakes into tributaries for the open water seasons and return in the fall to overwintering areas. Natural features such as cascades and step-pool features can cause upstream and downstream fish passage obstructions. Juvenile fish and species with lower swimming capabilities have increased difficulty navigating these obstructions because of their mode of swimming (McCleary et al. 2004). Criteria for fish passage at road crossings were developed by McCleary et al. (2004) and confirmed to suit Arctic Grayling swimming criteria by Hurkett and Redman (2016). The criteria for fish passage were developed based on fish using culverts during road crossings. As the uniformity of velocity within culverts results in little to no resting areas for fish during moderate to high flow and depths too shallow to pass during low flow (Larinier 2002), the use of these criteria structured for passage of fish through road crossing structures is well-suited for this Study. Criteria for fish passage through areas with vertical drop is outlined in Table 2.

Table 2: Fish Barrier Parameters Used to Determine Potential Barriers to Fish Passage within the King-Cujo Watershed Full Barrier Potential Barrier No Barrier Vertical drop height > 0.6 m Vertical drop height < 0.59 m No drop – pool habitat The presence of a natural occurring barrier, Plunge pool depth is less than such as a boulder garden or a waterfall No presence of a boulder garden or Temporary or seasonal barriers 1.25ℎ other natural permanent barriers (shallow depths, dispersed flow during low (i.e., waterfalls) flow conditions, dry channel) Where ℎ = the vertical drop in height Source: Hurkett and Redman 2016, McCleary et al. 2004. > = greater than; < = less than or equal to.

3.0 FIELD PROGRAM The field program occurred during the 2019 spring freshet period and was timed to capture as wide a range of Cujo Lake outflow conditions as possible. The field program timing was determined by available regional hydrologic modelling for the Cujo Lake outlet (DDEC 2014), which predicted lower and upper quartile of flows (0.047 cubic metres per second [m3/s] and 0.146 m3/s) in June. Adult Arctic Grayling normally move from larger rivers or lakes into clear, cool tributaries during or shortly following the break-up of ice and are later followed by juveniles (Hubert et al. 1985). Spawning usually occurs shortly after ice-out from mid-May to mid-June (Stewart et al. 2007) but can be variable depending on annual weather conditions and the timing of ice-free conditions.

The field program was executed over three trips from June 18 to July 5, 2019. The program was extended by one day, on July 5, to accommodate weather and to complete sampling goals. The program started later than originally predicted from historical ice-out dates because of the late spring observed in 2019.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

3.1 Methods 3.1.1 Site Reconnaissance The entire length of streams B2, B3, and B4 were walked on the first day of Trip 1 of the field program. Areas where a potential barrier to fish passage or had the potential to form under different flow conditions were identified. The fish passage criteria followed the depth minima of 0.10 m for adult Arctic Grayling and 0.06 m for juvenile Arctic Grayling, the velocity maxima curve (Katopodis and Gervais 2016), and the fish barrier parameters outlined in Table 2.

During the reconnaissance, the streams were observed for any potential Arctic Grayling spawning habitat. Small, shallow tributary channels with fast and clear water are often the preferred Arctic Grayling spawning habitat (Stewart et al. 2007). Although Grayling favour gravel substrate to spawn over, they have also been observed to spawn over vegetated mud-bottomed pools, upstream of rapids, and in shallow backwaters (Hubert et al. 1985). Sections of stream that were moderately deep (less than 1.0 m), had clean and unembedded gravel or cobble substrates, and a velocity of less than 1.5 m/s, were considered for potential spawning habitats (Hubert et al. 1985; Stewart et al. 2007).

A minimum of two and up to four monitoring transects were established within each stream. The location of the transects were first placed at each potential barrier to fish passage and then supported by sections of stream that were wadable and had limited to no instream boulders that may disrupt flow. Transects were established by completing the following actions:  rebar or wooden stakes were placed on both shores of the site;  sites were visually marked with flagging tape;  a UTM coordinate was collected; and,  representative photos were taken at each transect (upstream, downstream, right downstream bank, and left downstream bank). 3.1.2 Transect Surveys Each transect was monitored once per trip with a total of three monitoring events throughout the field program. The following information was collected at each transect site. 3.1.2.1 Stream Habitat Data Supporting environmental data were gathered at each field visit, including water temperature (degrees Celsius [°C]) measured with a water quality multi-meter. Water depth, wetted width, substrate composition, and cover were recorded, and stream habitat was classified according to Golder standard protocols. Qualitative observations, such as undercut banks and whether a drop was well-stepped, were recorded. 3.1.2.2 Barrier Assessment Each transect was assessed for connectivity throughout the site. Both the vertical distance of a drop of the stream surface and the depth of the associated plunge pool were recorded to later assess the swimming ability of a fish to pass the obstacle. Channel characteristics such as water depth, substrate, and flow were used to determine the passage of fish throughout the site.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

3.1.2.3 Streamflow Monitoring Point velocity and depth measurements were collected using a Marsh McBirney flow meter, wading rod, and 30 m measuring tape along the set transect. A minimum of two and a maximum of six point-velocity measurements were collected at each transect. The number of measurements was determined by the stream flow and conditions at the time of the survey. The objective was to capture the minimum and maximum velocities, the velocities of the left and right downstream bank, and an average transect velocity. 3.1.3 Arctic Grayling Observations and Spawning Habitat The streams were monitored throughout the field program for Arctic Grayling migration and spawning activity. The lengths of streams were walked carefully multiple times throughout each field visit in order to visually confirm the presence of Arctic Grayling and any spawning activity. Polarized lenses were worn for greater visibility and photos were taken with an underwater camera of fish observations when possible (Appendix 1).

Arctic Grayling spawning occurs over unembedded gravel, sand, or rubble in clear, relatively shallow (less than 1.0 m) and moderate velocity (less than 0.15 m/s) streams at water temperatures ranging between 4°C and 16°C (Stewart et al. 2007). Spawning activity included recording the location of any Arctic Grayling that were quivering prior to and during release of eggs and milt, territorial behaviours, fish paired up, holding, and/or travelling along the streams. The streams were monitored for change in channel characteristics during the various flow conditions, such as a change in depth and velocity conditions, or newly exposed areas of gravels caused by increased scouring during higher flow conditions. Coordinates were recorded at all potential or confirmed Arctic Grayling spawning habitats, and these sites were monitored again the following trip. Areas where spawning habitat was identified, and Arctic Grayling passive observations are indicated in Map 2 to Map 4. 3.2 Results 3.2.1 Transect Selection Transects were first established at all potential barriers to upstream passage which followed criteria based on findings during the desktop review. Supplemental sites were chosen based on accessibility and monitoring suitability (i.e., no or few boulders within the transect area, continuous channel features). A total of ten transects were established within streams B2, B3, and B4 in the King-Cujo watershed: four at Stream B2, three at Stream B3, and three at Stream B4 (Table 3; Map 2 to Map 4). Eleven areas for potential spawning habitat were identified and monitored for Arctic Grayling spawning activity throughout the field program (Table 3, Map 2 to Map 4).

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Table 3: Coordinates of the Cujo Outflow Special Study, 2019 Potential Barrier Potential Spawning Habitat Stream UTM Coordinate (12 W) UTM Coordinate (12 W) Identifier Identifier Easting Northing Easting Northing B2-T1 538903 7163276 B2-SH1 538924 7163263 B2-T2 538934 7163252 B2-SH2 538950 7163243 B2 B2-T3 538938 7163246 B2-SH3 538985 7163184 B2-T4 538987 7163172 B2-SH4 538987 7163172 B2-SH5 538987 7163172 B3-T1 538989 7163049 B3-SH1 538990 7163007 B3-T2 538972 7163029 B3-SH2 539015 7163062 B3 B3-T3 538985 7162977 B3-SH3 538985 7163028 B3-SH4 538996 7162997 B4-T1 538947 7162483 B4-SH1 538936 7162457 B4-T2A 538946 7162471 B4-SH2 538922 7162425 B4 B4-T2B 538944 7162476 B4-T3 538913 7162410 Coordinates recorded with the UTM system using NAD83. UTM = Universal Transverse Mercator; NAD = North American Datum; W = west.

3.2.2 Stream Habitat Characteristics Data were collected at each transect three times (i.e., once per field visit) during the field program. Qualitative observations of each transect are provided in Table 4, and representative photos are included in Appendix A.

The mean water temperature of Stream B2 ranged from 5.8°C to 13.1°C. The average wetted width of Stream B2 was 1.15 m with a range from 0.53 m to 2.30 m. The dominant substrate of Stream B2 was boulder (53%), followed by gravel (25%), and sand (11%). Subdominant substrate included organics (9%) and cobble (2%). The dominant cover type for Stream B2 was depth and/or turbulence (53%), and overhanging vegetation (25%). Some woody debris (17%) and aquatic vegetation (5%) cover was present.

The mean water temperature of Stream B3 ranged from 7.2°C to 13.0°C. The average wetted width of Stream B3 was 0.99 m with a range from 0.67 m to 1.68 m. The dominant substrate of Stream B3 was gravel (60%) and Sand (18%). Subdominant substrate was organics (9%), cobble (5%), boulder (5%), and silt (3%). The dominant cover type for stream B3 was depth and/or turbulence (66%), and undercut banks (16%). Some aquatic vegetation (11%) and overhanging vegetation (7%) was present.

The mean water temperature of Stream B4 ranged from 4.9°C to 14.0°C. The average wetted width of Stream B4 was 1.01 m and ranged from 0.50 m to 2.26 m. The dominant substrate of Stream B4 was gravel (43%), cobble (23%), and sand (20%). Subdominant substrate was organics (12%) and boulder (4%). The dominant cover type for Stream B4 was depth and/or turbulence (38%), aquatic vegetation (27%) and overhanging vegetation (22%). Some woody debris (12%) and undercut banks (1%) were present.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Table 4: Qualitative Descriptions of Streams B2, B3, and B4 in the King-Cujo Watershed Stream Transect Photos(a) Description Overflow during freshet B2-T1 A-1 to A-5 Densely covered by willows The transect was set between two channels that converged with the main channel The water flowed over an elevation drop at the convergence of the two channel braids B2-T2 A-6 to A-11 The downstream-most channel was fish passable where it converged with the main B2 channel as it is well-stepped with a slight gradient There was an overflow channel adjacent to the main channel B2-T3 A-12 to A-15 This transect is along one-half of two braided channels The step feature has three stacked vertical drops B2-T4 A-16 to A-22 A side-channel is present along the left downstream bank of the feature and allows for fish passage at high flows A well-defined and well-scoured channel B3-T1 A-23 to A-27 Undercut bank along the right downstream bank is approximately 25 cm deep A well-defined and well-scoured channel B3-T2 A-28 to A-30 B3 Very little overhanging cover A well-defined and well-scoured channel B3-T3 A-31 to A-34 Absence of overhanging cover A large and deep (> 1.0 m) plunge pool A vertical drop is present at the location of the transect B4-T1 A-35 to A-38 Turbulent water follows the drop Heavy willow cover The right downstream channel of two channel braids B4-T2A A-39 to A-40 A secondary channel to B4-T2B A shallow channel with potential seasonal flow The left downstream and main channel braid B4 Well-defined banks and well-scoured B4-T2B A-41 to A-44 Immediately downstream of a draw and downstream of braided channels Densely covered by willows No step-pool features Just downstream from Cujo Lake outflow B4-T3 A-45 to A-48 Absence of dense willow cover Confined flow with well-defined banks The inflow of the channels is typically less dense with willow cover and relatively well- confined. The channel beds are generally poorly scoured within the upstream sections of the streams. Cujo-King Watershed A-49 to A-53 The downstream sections of streams B2 and B4 are very dense with willows and consist of braided channels. Scouring is more present in the downstream sections. Stream B3 has relatively homogenous stream channel characteristics throughout. a) Photos are provided in Appendix A.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

3.2.3 Barrier Assessment Potential for fish passage was calculated according to environmental data gathered during the field program. The lowest water depth recorded was 0.11 m and the highest velocity measured at a potential barrier was 1.24 m/s, which were both measured at Transect B2-T3. Vertical drops were observed at several locations and were comprised of woody debris-jams that formed across the channel causing flow to overtop the debris. These vertical drops are not likely permanent and may shift in location but were considered representative of the conditions that could be expected in the system over time. There may have been passage possible through the debris-jams, but for the purpose of the analysis, it was assumed passage was only possible over top of the barrier. The greatest vertical drop to pool depth ratio was observed at Transect B2-T1. The quantitative barrier monitoring results are in Table 5.

Table 5: Quantitative Assessment of Barrier to Fish Passage Potential Pool Depth Trip Minimum Maximum Vertical 𝟏. 𝟐𝟓𝒉 Pool Barrier to Transect > Number Depth (m) Velocity (m) Drop(a) (m) (b) Depth(c) (m) Fish 𝟏. 𝟐𝟓𝒉 Passage 1 B2-T1 0.28 0.13 0.16 0.2 Yes 2 B2-T1 0.29 0.68 0.25 0.31 0.19 No Yes 3 B2-T1 0.25 0.19 0.24 0.21 No 1 B2-T2 0.59 0.15 0.19 0.49 Yes 2 B2-T2 0.49 0.54 0.58 0.73 0.42 No No(d) 3 B2-T2 0.53 0.52 0.65 0.37 No 1 B2-T3 0.14 0.36 0.45 0.27 No 2 B2-T3 0.11 1.24 0.38 0.48 0.11 Yes No(e) 3 B2-T3 0.11 0.34 0.43 0.22 No 1 B2-T4 0.44 0.14 0.18 0.18 Yes 2 B2-T4 0.44 0.57 0.23 0.29 0.29 Yes No 3 B2-T4 0.44 0.21 0.26 0.28 Yes 1 B3-T1 0.5 0 0 0 Yes 2 B3-T1 0.42 0.9 0 0 0 Yes No 3 B3-T1 0.45 0 0 0 Yes 1 B3-T2 0.19 0 0 0 Yes 2 B3-T2 0.18 0.96 0 0 0 Yes No 3 B3-T2 0.17 0 0 0 Yes 1 B3-T3 1.03 0.15 0.19 1.03 Yes 2 B3-T3 1.08 1.08 0.18 0.23 1.08 Yes No 3 B3-T3 1.07 0.12 0.15 1.08 Yes 1 B4-T1 0.25 0.17 0.21 0.29 Yes 2 B4-T1 0.3 1.13 0.27 0.34 0.37 Yes No 3 B4-T1 0.28 0.23 0.29 0.29 Yes 1 B4-T2A 0.12 0 0 0 Yes 2 B4-T2A 0.13 0.23 0 0 0 Yes No 3 B4-T2A 0.18 0 0 0 Yes

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Table 5: Quantitative Assessment of Barrier to Fish Passage Potential Pool Depth Trip Minimum Maximum Vertical 𝟏. 𝟐𝟓𝒉 Pool Barrier to Transect > Number Depth (m) Velocity (m) Drop(a) (m) (b) Depth(c) (m) Fish 𝟏. 𝟐𝟓𝒉 Passage 1 B4-T2B 0.24 0 0 0 Yes 2 B4-T2B 0.23 0.66 0.1 0.13 0.23 Yes No 3 B4-T2B 0.23 0.1 0.13 0.23 Yes 1 B4-T3 0.35 0 0 0 Yes 2 B4-T3 0.3 0.25 0 0 0 Yes No 3 B4-T3 0.31 0 0 0 Yes (a) The drop with the least height was chosen when multiple drops were horizontal to one another. The drop with the greatest height was chosen when multiple drops were present in succession. (b) The value h represents the vertical change in height. This is the factor for fish passage in the criteria outlined in Table 2 (Hurkett and Redman 2016; McCleary et al. 2004) (c) The depth of the pool that was associated with the highest drop was used when multiple drops were stacked vertically. (d) Although the transect location is a potential barrier according to the criteria, there is a secondary access point that is fish-passible approximately 7 m downstream of the transect within the braided channel (Table 3, Transect B2-T2) (e) Although the transect location is a potential barrier according to the criteria, this transect is located along one-half of a braided channel. Fish have alternative passage.

3.2.4 Stream Flow of the King-Cujo Watershed Stream flow discharge measurements collected for the Aquatic Effects Monitoring Program at the Cujo Outflow hydrology station were provided by the Ekati mine Environment team and show the daily mean flow discharge from June 5 to September 2, 2019 (Figure 2). Discharge from Cujo Lake dropped from 0.063 m3/s to 0.056 m3/s during the June 18 to June 21, 2019 field program. During the June 25 to June 27 field program, the discharge from Cujo Lake dropped from 0.048 m3/s to 0.045 m3/s, and the July 2 to July 5 field program had a range from 0.048 m3/s to 0.053 m3/s. There was no Discharge pumping from King Pond into Cujo Lake for the duration of the 2019 open-water season, and therefore, stream flow discharge measurements are reflective of conditions expected under the MUG Project during periods of no Discharge during the spring freshet.

Figure 2: Mean Flow Discharge of The King-Cujo Watershed as Provided by The Ekati Mine Environment Department

Note: The green section indicates the timeframe of the field monitoring program. m3/s = cubic metres per second.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

3.2.5 Arctic Grayling Observations and Spawning Habitat Arctic Grayling were observed using a variety of habitat within streams B2, B3, and, B4 throughout the King-Cujo watershed during the field program and all age classes were observed (Table 6). On June 26, young juvenile and young-of-year fish were seen grouping at the outflows of streams in the shallow protected waters of the lakes (Photo 1), while older juveniles and adults were observed holding in undercut banks, travelling within the streams, and, holding in larger pools.

The most Arctic Grayling observations occurred during Trip 2 where fish of all size classes were observed throughout all the streams (i.e., B2-T2, B2-T3, B4-SH2) rather than just at the outflow and inflow of the streams (Table 6; Map 2 to Map 4). These observations validated that fish had access to all habitats between Christine Lake and Cujo Lake within the observed flow conditions (0.045 m3/s to 0.048 m3/s).

Arctic Grayling spawning activities were recorded on June 20, 2019 in a pool just upstream of Transect B2-T2 (Photo 2). These spawning activities included fish grouping and pairing up, and observations of male and female quivering prior to the release of eggs and milt.

In total, eleven potential Arctic Grayling spawning areas were identified during the site reconnaissance: five in Stream B2, four in Stream B3, and, two in Stream B4. Adult and juvenile Arctic Grayling were observed in three of these potential spawning habitats.

Table 6: Arctic Grayling Observations within the King-Cujo Watershed UTM Coordinate (12 W) Identifier Trip1 Trip 2 Trip 3 Easting Northing B2 Outflow 538898 7163281 - Juvenile - B2-T1 538903 7163276 Adult - - B2-SH1(a) 538925 7163257 - Juvenile - B2-T2 538934 7163252 - Juvenile - B2-T3(b) 538936 7163248 - Juvenile, Adult - B2-SH3(c) 538977 7163191 - Juvenile Adult B2-T4 538987 7163172 - Juvenile Juvenile B3 Outflow 539015 7163062 - - Adult B3-T1(d) 538994 7163054 Adult - - B3-T3 538985 7162977 - - Juvenile B3 Inflow 538941 7162856 - Juvenile - B4-SH2 538922 7162425 - Adult(e) Juvenile B4-T3 538913 7162410 - Adult - (a) Located approximately 5 m upstream from B2-SH1. (b) Located approximately 2 m downstream from B2-T3. (c) Located approximately 10 m downstream from B2-SH3. (d) Located approximately 7 m downstream from B3-T1. (e) Located approximately 10 m upstream from B4-SH2. UTM = Universal Transverse Mercator; W = west; - = no fish observed.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo 1: Juvenile Arctic Grayling in the B2 Outflow just downstream of Transect B2-T1, June 26, 2019.

Photo 2: Adult Arctic Grayling in a pool just upstream of Transect B2-T2, June 20, 2019.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

4.0 SUMMARY The evaluation of streams B2, B3, and B4 in the King-Cujo watershed during the 2019 field season provided an estimation of the potential fish passage for local spring spawning fish, such as Arctic Grayling, during the migratory open-water season that would occur under MUG Project operations. All identified potential barriers to fish passage were assessed and found that all transects within streams B2, B3, and B4 met the criteria for the minimum acceptable depth for Arctic Grayling adults of 0.10 m. The minimum depth recorded was 0.11 m at Transect B2-T3 with a point velocity of 0.98 m/s, which was observed at a flow of 0.045 during Trip 2. This corresponds to conditions that represent the lower quartile flows for June (0.047 m3/s), which would be indicative that passage will be possible under the vast majority of spring flows predicted during MUG Project operations. The potential for a barrier may increase at lower flows, however these conditions would still be in the natural range of flows expected at this site; the Cujo Lake outlet has been noted to experience intermittent flows in dry years from past sampling efforts (ERM 2019b). It is unlikely that resident Slimy Sculpin in the watershed are making extensive spawning migrations as this species has a high site fidelity and streams B2, B3, and B4 do not provide overwintering habitat.

The highest velocity measured at a potential barrier was 1.2 m/s, which allows a passage distance of 1,299 m for adult Arctic Grayling and 321 m for juvenile Arctic Grayling before fatigue (Table 1; Figure 1). As the distance where high velocity was encountered was very localized (i.e., a few metres), no velocity barriers are expected at the observed flows, or under high flow conditions within the King-Cujo watershed.

The height of the vertical drops at all of the transect sites were compared against the depth of the associated plunge pools and results showed that all transects were free of barriers, with the exception of Transect B2-T1, B2-T2, and B2-T3. Of these three barriers, it was determined that fish still had passage through the system at Transects B2-T2 and B2-T3, as these potential barriers were identified along one of two braids of a channel where the second braid allowed unimpeded fish access. As a result, these barriers may be restrictive to fish movements, but are not complete barriers. Observations of fish above and below these transects during the field program was further evidence that barriers to fish passage were not present under the observed flow conditions.

During the time of the field visits, adult and juvenile Arctic Grayling were observed within streams B2, B3, and B4, which indicates that Arctic Grayling were able to travel from an overwintering lake (either Lake B2, B3, or B4) to habitat located within a stream. The observations of Arctic Grayling do not confirm unimpeded access from the outflow of Stream B2 to the upper reaches of Stream B4; however, the distribution of the observations would indicate habitat for spawning and juvenile rearing throughout the watershed is accessible. Of all transects assessed, B2-T1 showed the greatest potential for a barrier to upstream fish passage during low flow conditions; however, fish observations above Transect B2-T1 would be an indication it is not a barrier during the spring freshet conditions observed in 2019. Transect B2-T1 may become a barrier later in the season as flows continue to decline; however, since this barrier location was due to a vertical drop rather than shallow depth, downstream movements would still be possible. Fish would not be impeded from moving upstream to spawning habitats during the natural lower quartile flows and would be able to move downstream to overwintering habitat.

During the 2019 field program, fish passage conditions were observed under the lower quartile flows predicted for MUG Project operations, and passage and spawning activities were confirmed at these conditions; therefore, conclusions remain valid that Arctic Grayling passage and spawning would still be possible during MUG Project operations.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

5.0 CLOSURE We trust the information contained in this memorandum is sufficient for your present needs. If you require any further information, please do not hesitate to contact the undersigned.

Yours Truly,

GOLDER ASSOCIATES LTD.

Kasey Clipperton, MEDes, PBiol Kristine Mason, MSc, PBiol Principal, Senior Fisheries Biologist Principal, Senior Fisheries Biologist

Monica Redmond, BSc Fisheries Biologist

KC/KM/MR/crm/al

21 Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

6.0 REFERENCES Baldigo BP and Lawrence GB. 2001. Effects of stream acidification and habitat on fish populations of a North American river. Aquat. Sci. 63: 196-222

Bell MC (Ed). 1986. Fisheries handbook of engineering requirement and biological criteria. Report No. NTIS AD/A167-877. Fish Passage Development and Evaluation Program, U.S. Army Corps of Engineers, North Pacific Division, Portland, Oregon USA.

Deegan LA, Golden HE, Harrison J, Kracko K. 2005. Swimming performance and metabolism of 0+ year Thymallus articus. Journal of fish biology 67:910-8.

DDEC (Dominion Diamond Ekati Corporation). 2014. Developer’s Assessment Report for the Jay Project. Prepared by Golder Associates Ltd., October 2014. Yellowknife, NWT, Canada.

Dryden RL, Stein JM. 1975. Guidelines for the protection of the fish resources of the Northwest Territories during highway construction an operation. Technical Report No. CEN/T-75-1. Department of the Environment, Fish and Marine Service.

Evans CL, Reist JD, Minns CK. 2002. Life history characteristics of freshwater fishes occurring in the Northwest Territories and Nunavut, with major emphasis on riverine habitat requirements. Can. Manuscr. Rep. Fish. Aquat. Sci. 2641: viii + 169 p.

ERM (ERM Consultants Canada Ltd.). 2019a. Ekati Diamond Mine 2018 Aquatic Effects Monitoring Program Part 1 – Evaluation of Effects. March 2019.

ERM (ERM Consultants Canada Ltd.). 2019b. Ekati Diamond Mine: 2019 Aquatic Effects Monitoring Program Re-evaluation and the Proposed 2020 to 2022 AEMP Plan. Prepared for Dominion Diamond Mines ULC by ERM Consultants Canada Ltd.: Yellowknife, Northwest Territories.

Golder. 2016. Arctic Grayling Passage Evaluation for the Jay Project. Prepared for Dominion Diamond Corporation Ekati Jay Project. Golder Doc. No. 16021; 19 September 2016. 17 pp.

Golder. 2018. Arctic Grayling Passage Evaluation for the Sub-Basin B Diversion Channel. Prepared for Dominion Diamond Corporation Ekati Jay Project. Golder Doc. No. 17040; 19 January 2018. 19 p.

Government of British Columbia. 2013. Culvert and fish passage. British Columbia Ministry of Transportation and Infrastructure. Updated May 2013. 9 pp.

Gray MA, Curry RA, Arciszewski TJ, Munkittrick KR, Brasfield SM. 2018. The biology and ecology of slimy sculpin: A recipe for effective environmental monitoring. FACETS 3: 103-127.

Hubert WA, Helzner RS, Lee LA, Nelson PC. 1985. Habitat suitability index models and instream flow suitability cures: Arctic grayling riverine populations. U.S. Fish Wildl. Serv. Biol. Rep. 82 (10.110). 34 pp.

Hurkett, B and Redman L. 2016. Swan River Arctic Grayling and watercourse crossing assessment. Data Report, D-2016-104, produced by Alberta Conservation Association, Lethbridge, Alberta, Canada. 21 pp + App.

Katopodis C and Gervais R. 2016. Fish swimming performance database and analyses. Department of Fisheries and Oceans. Can. Sci. Advis. Sec. Res. Doc. 2016/002. Vi + 550 p.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Larinier M. 2002. Fish passage through culverts, rock weirs and estuarine obstructions. Bulletin Francais de Peche et Pisciculture. 364(18), 119-134.

McCleary R, Wilson A, Spytz C. 2004. A stream crossings remediation planning process and example application in the Foothills Model Forest, Alberta. In Proceedings from the 2003 Access Management Conference. Edited by H. Epp. Alberta Society of Professional Biologists.

Scott WB and Crossman EJ. 1973. Freshwater fishes of Canada. Bull. Fish. Res. Board. Can. 184: xi + 1-966.

State of California. 2002. Culvert criteria for fish passage. Resources Agency, Department of Fish and Game. May 2002. 17 pp.

Stewart DB, Mochnacz NJ, Reist JD, Carmichael TJ, Sawatzky CD. 2007. Fish life history and habitat use in the Northwest Territories: Arctic Grayling (Thymallus arcticus). Can. Manuscr. Rep. Fish. Aquat. Sci. 2797: ci +55 p.

Webb PW. 1975. Hydrodynamics and energetics of fish propulsion. Bulletin of the Fisheries Research Board of Canada. 190: 159.

Weinstein S, Coombs J, Nislow K, Riley C, Roy A, Whiteley A. 2019. Evaluating the effects of barriers on Slimy Sculpin movement and population connectivity using novel sibship-based and traditional genetic metrics. Transactions of the American Fisheries Society. https://doi.org/10.1002/tafs.10202. November 2019. 1117-1131 pp.

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

APPENDIX A Photo Journal

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-1. An upstream view of Transect B2-T1, Photo A-2. An upstream view of Transect B2-T1 at June 26, 2019 the gaps and pool, June 20, 2019

Photo A-3. A downstream view of Transect B2-T1 Photo A-4. The right downstream bank of Transect and the outflow of Stream B2 as it flows into B2-T1, June 20, 2019 Christine Lake, June 20, 2019

Photo A-5. The left downstream bank of Transect Photo A-6. Arctic Grayling documented just B2-T1, June 20, 2019 upstream of Transect B2-T2, June 20, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-7. An upstream view of the spawning pool Photo A-8. The downstream view of the at Transect B2-T2, June 20, 2019 downstream channel converging into the main channel at Transect B2-T2, June 20, 2019

Photo A-9. The right downstream bank of Transect Photo A-10. The right downstream bank of the B2-T2, June 20, 2019 upstream channel converging into the main channel at Transect B2-T2, June 20, 2019

Photo A-11. A downstream view of the channel Photo A-12. An upstream view of Transect B2-T3, convergence at Transect B2-T2, June 20, 2019 June 20, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-13. A downstream view of Transect B2-T3, Photo A-14. The right downstream bank of Transect June 26, 2019 B2-T3 and the overflow channel, June 20, 2019

Photo A-15. An upstream view of the pool just Photo A-16. An upstream view of Transect B2-T4 upstream of Transect B2-T3 and the potential and the step-pool feature, June 20, 2019 barrier, June 20, 2019

Photo A-17. A downstream view of Transect B2-T4, Photo A-18. A view of the right downstream bank of June 20, 2019 Transect B2-T4, June 20, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-19. A view of the left downstream bank of Photo A-20. The representative gravel substrate of Transect B2-T4, June 20, 2019 Transect B2-T4, June 20, 2019.

Photo A-21. A photo of the two lower step-pool Photo A-22. A photo of the third and upstream- features of Transect B2-T2, June 20, 2019 most step-pool feature of Transect B2-T2 and an upstream view of Stream B2, June 20, 2019

Photo A-23. An upstream view Transect B3-T1, Photo A-24. A downstream view of Transect B3-T1, June 20, 2019 June 20, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-25. A view of the right downstream bank of Photo A-26. The left downstream bank of Transect Transect B3-T1, June 20, 2019 B3-T1, June 20, 2019

Photo A-27. Representative gravel substrate of Photo A-28. An upstream view of Transect B3-T2, Transect B3-T1, June 20, 2019 June 20, 2019

Photo A-29. A downstream view of Transect B3-T2, Photo A-30. A view of the right downstream bank of June 20, 2019 Transect B3-T2, June 20, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-31. An upstream view of Transect B3-T3, Photo A-32. A downstream view of Transect B3-T3, June 20, 2019 June 20, 2019

Photo A-33. The right downstream bank of Transect Photo A-34. The left downstream bank of Transect B3-T3, June 20, 2019 B3-T3, June 20, 2019

Photo A-35. An upstream view of Transect B4-T1, Photo A-36. A downstream view of Transect B4-T1 June 26, 2019 as the stream flows into Lake B3, June 26, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-37. The right downstream bank of Transect Photo A-38. An upstream view of a side-channel B4-T1, June 26, 2019 converging with the main channel along the left downstream bank of Transect B4-T1, June 26, 2019

Photo A-39. An upstream view of Transect B4-T2A, Photo A-40. A downstream view of Transect B4- June 26, 2019 T2A, June 26, 2019

Photo A-41. An upstream view of Transect B4-T2B, Photo A-42. A downstream view of Transect B4- June 26, 2019 T2B, June 26, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-43. A view of the right downstream bank of Photo A-44. The left downstream bank of Transect Transect B4-T2B, June 26, 2019 B4-T2B, June 26, 2019

Photo A-45. An upstream view of Transect B4-T3 Photo A-46. A downstream view of Transect B4-T3, and the inlet of Stream B4 flowing from Cujo Lake, June 26, 2019 June 26, 2019

Photo A-47. The right downstream bank of Transect Photo A-48. The left downstream bank of Transect B4-T3, June 26, 2019 B4-T3, June 26, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Photo A-49. An aerial view of Stream B4 as it flows Photo A-50. An aerial view of Stream B3 as it flows to the right, June 21, 2019 to the right, June 26, 2019

Photo A-51. An aerial view of the downstream Photo A-52. An aerial view of Stream B2 as if flows portion of Stream B2 as it flows into Christine to the left, June 21, 2019 Lake, June 21, 2019

Laura Pacholski Project No. 19116503-4100 / DCN-19014 Dominion Diamond Mines ULC January 23, 2020

Christine Lake (Lake B1)

Lake B2

Lake B3

Cujo Lake (Lake B4)

Photo A-53. An aerial downstream view of Cujo Lake, Lake B3, Lake B2, and Christine Lake, June 21, 2019