Introduction
The Recommended Plan includes a “Cumulative Effects Framework” which is described in Chapter 4 of the Plan.
The Dawson Region is an active landscape that hosts many activities including mining, traditional economy, forestry, recreation, tourism, and other activities. It is also an important cultural landscape and important habitat to fish and wildlife.
Cumulative effects are the net changes to values in the environment, society and economy that result from a land use activity in combination with other past, present, and future activities. With all these interests on the landscape, we need to monitor the cumulative effects of different activities on the region’s values, and their relationship to and with each other.
Indicators
The short term requirement of this Plan is for cumulative effects to be managed based upon two indicators: 1) surface disturbance and 2) linear features.
Surface disturbance
Surface disturbance will be measured as the percentage of a Land Management Unit that is disturbed. The amount of surface disturbance refers to the area of land physically disturbed by human activities. This includes activities such as tree cutting, soil changes, hydrology changes, structures, and cleared sites (e.g., placer mine sites, gravel quarries, drill pads, helicopter pads). These disturbance footprints represent a decrease in habitat.
The following are not included in the surface disturbance measurement:
- Areas of previous disturbance considered “reclaimed” or “recovered”.
- Areas of wildfire disturbance.
- Undisturbed areas that are tenured or permitted. For example, if a placer claim exists but not cleared. Disturbance within highway corridors (300 meters either side of centreline); to reduce encroachment in areas of undisturbed habitat.
- Roads, trails, seismic lines (these are calculated under linear feature density). This is different than the North Yukon and Peel Watershed plans.
The above exclusions were considered when the threshold levels of this framework were set.
Linear Feature Density
The amount of linear feature density is the length of all human-created linear features (i.e., roads, seismic lines, trails) in a Land Management Unit. This is measured as kilometres of access per square kilometres of area.
How linear feature density is measured in this Plan can be understood as follows:
Example:
100 km of roads, trails, and cutlines in an LMU with an area of 500 km² has a linear feature density of 0.2 km/ km².
Linear feature density is important since it can be a measure of fragmentation and accessibility. As linear features increase, access increases. In turn, greater accessibility means added opportunities for wildlife harvesting, increased predation rates, and a change in how people and wildlife use the land.
Reclamation and Natural Recovery
To provide an incentive for industry and government to take action to mitigate ecological impacts of disturbance, reclamation activities are to be considered part of the cumulative effects framework. However, at this time, surface and linear disturbances do include reclaimed or naturally recovered areas. Once “reclaimed” and “recovered” have been defined by the Parties and a system to measure and track is in place, this may change.
Thresholds
Most simply stated, the Plan has set thresholds that are the acceptable level of development (including disturbance and access) that can happen in the different units in the planning region. Higher development areas have higher limits (or thresholds) of development. Lower development areas have lower limits (or thresholds). This approach allows decision makers to make consistent decisions across the region based upon how each Land Management Unit has been designated.
The recommended surface disturbance and linear feature density thresholds provide guidance on the acceptable limits of human-caused disturbance in each LMU. The four tiers of the Integrated Stewardship Areas (ISA 1 to 4) are differentiated by their cumulative effects thresholds and their management intent, as shown in the table below (Table 3-2 from the Recommended Plan). Thresholds are also applied to the Special Management Areas with the understanding that there may already be some level of activity in these areas.
These thresholds are proportional to the size of the LMU and are measured in the % of the LMU that can be disturbed (“Surface Disturbance”) and in km/km² (“Linear Disturbance Density”).
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Precautionary |
Cautionary |
Critical |
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Designation |
Management Intent |
Surface (%) |
Linear (km/km²) |
Surface (%) |
Linear (km/km²) |
Surface (%) |
Linear (km/km²) |
|
ISA 1 |
Lowest Development |
0.0625 |
0.0625 |
0.1875 |
0.1875 |
0.25 |
0.25 |
|
ISA 2 |
Low |
0.25 |
0.125 |
0.75 |
0.375 |
1.0 |
0.5 |
|
ISA 3 |
Moderate |
0.5 |
0.25 |
1.5 |
0.75 |
2.0 |
1.0 |
|
ISA 4 |
Highest Development |
1.0 |
0.5 |
3 |
1.5 |
4.0 |
2.0 |
Table 1: Four tiers of the Integrated Stewardship Areas (from Table 3-2 from the Recommended Plan)
The numbers in the tables above are all expressed relative to the size of the LMU. They don’t show disturbance amounts in units useful for “on the ground” or project-level decisions, like km, hectares or km2.
Example:
Two LMUs, sized 500 km² and 1000 km² respectively, are both zoned ISA 2. They therefore both have a Cautionary Surface Disturbance threshold of 0.75% (see table above). However, the first LMU would allow 3.75 km² (375 ha) of disturbance, while the second would allow double: 7.5 km² (750 ha).
There are are three tiers of thresholds for both indicators: precautionary, cautionary, and critical. If an threshold is exceeded, mitigating actions may be triggered. This is part of the plan’s adaptive management approach.
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Precautionary |
The precautionary level represents a point at which it is important to improve information collection and understanding of cumulative effects in an area. Above this level, activity can continue at the same pace, as long as measures are being taken to improve information and awareness. |
|
Cautionary |
When the cautionary level is reached, it means that disturbance indicators are close to reaching undesirable levels. Above this level, undertake actions that slow the pace and scale of impacts. Provides an early warning signal. Allows time for proactive management to avert or limit potential impacts. |
|
Critical |
Represents the point at which the indicators have reached acceptable levels. Projects that would surpass the critical threshold for that LMU will be found not to conform during the Plan conformity evaluation process. Before this level is reached, the Parties should take action that will limit further disturbance and access. This may include ceasing activities that create additional surface or linear feature density disturbance. |
Table 2: Intent and descriptions of the three thresholds tiers (from Table 3-3 from the Recommended Plan)
Disturbance Amounts
Current Situation
The Parties mapped all surface and linear disturbances apparent in satellite imagery from 2020 for the whole region. They also mapped the disturbances visible in 2010 and 2016 in a portion of the Indian River Valley. Once mapped, we determined the amounts of disturbance per LMU. Patterns and rates of disturbance were also described for the period of 2014-2020.
Potential Future: Scenarios
The Parties then worked with the DRPC, YLUPC and experts in placer and quartz (hard rock) mining in the Yukon as well as experts in cumulative effects to develop plausible mining scenarios. Two scenarios were developed; one describing lower development and therefore lower disturbance, and one describing high development. This project is described in more detail in our Exploring the Cumulative Effects of Future Land Use in the Dawson Planning Region available here. The Scenarios can be summarized as follows:
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Low Scenario |
High Scenario |
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Quartz Exploration and Mining |
· Construction of one mine (Brewery Creek) in next 5 years. · Two discovery / advanced exploration projects active per year over 20 years (2 * 20 = 40 project years of mineral exploration).
|
· 3 mines start (Brewery Creek, Coffee, and White Gold) in years 5-10 · 8 discovery/advanced exploration projects active per year 20 years (8*20 = 160 project-years of mineral exploration). · Northern Access Route required to support new mines. |
|
Placer Exploration and Mining |
· Disturbance rates were linked to gold production in the last decade · 65% of the average gold production over the last decade and the average of the 5 lowest years in the last 4 decades · 98% of future mining will be adjacent to currently active areas |
· Disturbance rates were linked to gold production in the last decade · 190% of the average gold production over the last decade · 90% of future mining will be adjacent to currently active areas |
Table 3: Overview development scenarios
Results
Table 4 below was developed using 2020 mapped disturbances, the development scenarios, the threshold table above (Table1) and the size and designations of the LMUs to see at a glance what if any thresholds have been met as of 2020. The units here are presented in units that make more sense for “on the ground” project-level decisions. Unlike Table 1 above, they are not relative to the size of the LMU but are absolute; in other words, linear disturbance are presented in kilometers, and surface disturbance in kilometers squared (multiply by 100 to get in hectares). To see the table in relative units (to better compare to Table 1 above), click here.
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Rec. Plan Zoning |
Rec. Plan threshold equivalent* |
Linear Feature Amount (km) |
Linear Disturbance Thresholds (km) |
Surface Disturbance (km2) |
Surface Disturbance Thresholds (km2) |
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Land Management Unit |
Current |
Pre-cautionary |
Cautionary |
Critical |
Current |
Pre-cautionary |
Cautionary |
Critical |
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|
(# and name) |
2020 |
|
|
|
2020 |
|
|
|
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1 Tthetäwndëk (Tatonduk) |
SMA |
ISA 1 |
159.2 |
497.5 |
1492.4 |
1989.8 |
0.0 |
5.0 |
14.9 |
19.9 |
||
|
2 The Horseshoe |
ISA 2 |
ISA 2 |
164.5 |
41.1 |
123.3 |
164.5 |
0.5 |
0.8 |
2.5 |
3.3 |
||
|
3 Chu Kon Dëk (Yukon River Corridor) |
SRPA |
ISA 2 |
84.6 |
48.1 |
144.3 |
192.4 |
0.4 |
1.0 |
2.9 |
3.8 |
||
|
4 Tsey Dëk (Fifteenmile) |
SMA |
ISA 1 |
386.5 |
172.5 |
517.6 |
690.2 |
0.0 |
1.7 |
5.2 |
6.9 |
||
|
5 Ddhäl Ch’ël (Tombstone) |
TTP |
ISA 1 |
105.4 |
131.7 |
395.1 |
526.8 |
0.0 |
1.3 |
4.0 |
5.3 |
||
|
6 Tr’ondëk (Klondike) |
ISA 2 |
ISA 2 |
263.7 |
103.0 |
309.0 |
412.1 |
2.2 |
2.1 |
6.2 |
8.2 |
||
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7 Wehtr’e (Antimony) |
ISA 1 |
ISA 1 |
42.9 |
134.0 |
402.0 |
536.0 |
0.0 |
1.3 |
4.0 |
5.4 |
||
|
8 Brewery Creek |
ISA 3 |
ISA 3 |
284.4 |
237.0 |
710.9 |
947.8 |
5.2 |
4.7 |
14.2 |
19.0 |
||
|
9 Clear Creek |
ISA 4 |
ISA 4 |
284.0 |
232.8 |
698.3 |
931.1 |
7.8 |
4.7 |
14.0 |
18.6 |
||
|
10 Tintina Trench |
SMA |
ISA 2 |
417.1 |
226.7 |
680.1 |
906.8 |
1.3 |
4.5 |
13.6 |
18.1 |
||
|
11 Goldfields |
ISA 4 |
ISA 4 |
4672.1 |
3073.8 |
9221.3 |
12295.1 |
143.9 |
61.5 |
184.4 |
245.9 |
||
|
12 Tr’ondëk täk’it (Klondike Valley) |
SRPA |
NA |
339.4 |
NA |
NA |
NA |
7.5 |
NA |
NA |
NA |
||
|
13 Ch’ë̀nyä̀ng (Dawson City) |
CA |
NA |
208.4 |
NA |
NA |
NA |
11.1 |
NA |
NA |
NA |
||
|
14 Tąy dë̀kdhät (Top of the World) |
ISA 2 |
ISA 2 |
487.9 |
196.7 |
590.2 |
786.9 |
5.7 |
3.9 |
11.8 |
15.7 |
||
|
15 Khel Dëk (Sixty Mile) |
ISA 3 |
ISA 3 |
1043.0 |
724.3 |
2172.9 |
2897.2 |
21.7 |
14.5 |
43.5 |
57.9 |
||
|
16 Wëdzey nähuzhi (Matson Uplands) |
SMA |
NA |
205.4 |
NA |
NA |
NA |
0.1 |
NA |
NA |
NA |
||
|
17 Nän dhòhdäl (Upper Indian River Wetlands) |
ISA 2 |
ISA 2 |
232.8 |
60.6 |
181.9 |
242.5 |
1.2 |
1.2 |
3.6 |
4.9 |
||
|
18 Ttthetryän dëk (Coffee Creek) |
ISA 3 |
ISA 3 |
159.7 |
249.5 |
748.4 |
997.8 |
4.1 |
5.0 |
15.0 |
20.0 |
||
|
19 Tädzan Dëk (White River) |
ISA 1 |
ISA 1 |
371.9 |
258.3 |
774.8 |
1033.0 |
1.2 |
2.6 |
7.7 |
10.3 |
||
|
20 Łuk tthe k’ät (Scottie Creek Wetlands) |
SMA |
ISA 2 |
142.3 |
44.5 |
133.4 |
177.9 |
1.1 |
0.9 |
2.7 |
3.6 |
||
|
21 Wedzey Tąy (Fortymile Caribou Corridor) |
ISA 2 |
ISA 2 |
606.2 |
252.6 |
757.7 |
1010.3 |
3.4 |
5.1 |
15.2 |
20.2 |
||
|
Regional totals |
|
|
10661.19 |
|
|
|
218.41 |
|
|
|
||
|
Regional totals (excluding LMU 13) |
|
|
10452.82 |
|
|
|
207.30 |
|
|
|
||
* From Special Management Directions for SMAs and SRPAs
|
Explanation of colours |
|
Below precautionary threshold |
|
Below cautionary threshold |
|
Below critical threshold |
|
Above critical threshold |
|
No threshold in plan |
Table 4: Current (2020) disturbance amounts and threhsolds, per LMU
Comment:
If you look at the disturbance amounts for LMU 1 in the table above, you’ll notice that there is linear disturbance but no surface disturbance. This seeming discrepancy can be explained two ways:
1. Surface disturbance in this plan has been defined as not including linear disturbances. In LMU 1, there are cut-lines but few cleared areas.
2. LMU 1 is very large, and cleared areas there (if any) would be insignificant (e.g., less than 0.005%).
This pattern is typical of areas with low or early development: first disturbances tend to be linear. Later in the development cycle, access is developed, mining occurs and surface disturbance increase. LMU 11 is and example of this.
Changes in Surface Disturbance
Under the high scenario, we are expecting surface disturbance to double for the whole region. The increase in surface disturbance expected in the low scenario is about one third those of the high scenario. As may be expected, LMUs expected to have new or resumed quartz mining under the high scenario showed some of the highest increases in surface disturbance (e.g. LMU 18/Coffee Creek: 268%; LMU 8.Brewery: 165%). Even more pronounced increases (by percentage) are observed for LMUs with relatively little current disturbance, but with expected increases in placer and quartz exploration activities (e.g. LMU 21/Fortymile Caribou Corridor: 465%; LMU 17/Upper Indian Wetlands: 412%; LMU 14/Top of the World: 208%). The biggest increases (i.e., not % increase) were in LMUs with established placer mining (e.g. LMU 9/Clear Creek, LMU 11/Goldfields, LMU 12/Klondike Valley). Because these LMUs have an established placer mining and consequently higher existing disturbance, their relative increase in surface disturbance (i.e., % increase) were more modest with an average increase of 73%.
Changes in Linear Disturbance
Increases to linear disturbance tend to be more modest than those of surface disturbance with a regional increase of 77% under the high scenario. Like surface disturbance, the increase in linear disturbance expected in the low scenario is about one third that of the high scenario. Most of the active mining areas identified in the previous section show ~100-150% increases in linear density under the high scenario. Two LMUs each with prospective mining interests with poor access show even higher increases (e.g. LMU 15/Sixty Mile: 183%; LMU 7/Antimony: 200%).
Linear vs Surface Disturbance
There is much variation between the two disturbance indicators around the region. In LMUs with higher levels of current disturbance, surface disturbance values tend to be larger than linear disturbance. Conversely, outlying LMUs with little development tend to indicate more linear disturbance that surface disturbance; access roads to relatively small exploration footprints likely drive this pattern. This variety supports the use of two indicators that, together, track disturbance patterns over the cycle of exploration and development. Further, it may suggest that, unlike in the North Yukon and Peel Watershed regional plans, linear disturbance thresholds should be set lower than surface disturbance thresholds.