PEEL RIVER HEALTH ASSESSMENT

PEEL RIVER HEALTH ASSESSMENT CONTENTS SUMMARY... 2 Overall River Health Scoring... 2 Overall Data Sufficiency Scoring... 2 HYDROLOGY... 3 Overall Hydrology River Health Scoring... 3 Hydrology Data Sufficiency... 4 Long-Term Trends in Monthly Flow for the Peel River... 5 Recent-Term Trends in Monthly Flow for the Peel River... 7 Trends in Annual Flow for the Peel River Basin... 9 Hydrological Alteration in the Peel River Basin... 10 WATER QUALITY... 12 Overall Water Quality Health Scoring... 12 Water Quality Data Sufficiency... 12 FISH... 21 Overall Fish Health Scoring... 21 Fish Data Sufficiency... 21 BENTHICS... 22 Overall Benthic Health Scoring... 22 Benthic Data Sufficiency... 22

SUMMARY OVERALL RIVER HEALTH SCORING Indicator Hydrology Health Category Basin Poor Hydrology Hydrology Score Water Quality Health Category 1 Fair Water Quality Water Quality Health Score Benthic Health Category 2 Very Good Benthic Macro-Invertebrates Benthic Health Score Fish Health Category 4 Data Deficient Fish Fish Health Score Data Deficient Total Score Total Available Score Percentage of Maximum Score Overall Health Category 7 12 58.3% Fair OVERALL DATA SUFFICIENCY SCORING Hydrology Indicator Data Sufficiency Category Basin Partially Sufficient Data Sufficiency Score 1 Water Quality Data Sufficiency Category Partially Sufficient Data Sufficiency Score 1 Overall River Health Benthic Macro- Invertebrates Data Sufficiency Category Partially Sufficient Data Sufficiency Score 1 Fish Data Sufficiency Category 0 Data Sufficiency Score 0 Total Score Total Available Score Percentage of Maximum Score Overall Data Sufficiency Category 3 12 25.0% Partially Sufficient

HYDROLOGY OVERALL HYDROLOGY RIVER HEALTH SCORING Hydrology Long-Term Trends in Monthly Flow Recent-Term Trends in Monthly Flow Long-Term Trends in Annual Flow Pre- vs. Post- Dam or Recent vs. Historical Analsis of Monthly Flow Indicator percentage change in median monthly flow, measured as the relative change in median monthly flow per year, reported as an average across studied stations and weighted by the median annual flow per station. percentage change in median monthly flow, measured as the relative change in median monthly flow per year, reported as an average across studied stations and weighted by the median annual flow per station. percentage change in median annual flow, reported as an average across studied stations and weighted by the median annual flow per station. Percentage of total months, for all stations analyzed, with significantly different variance in monthly flow pre- vs. post-dam operation or for historical vs. Recent time periods in undammed systems. Percentage change in median monthly flow pre-and post-dam or for historical vs. Recent time periods in undammed systems, averaged across studied stations by mean annual flow. Period of Study 1969-2012 Stations 2 Value 0.38 Health Category Good Health Score 3 Period of Study 1985-2012 Stations 2 Value 0.86 Health Category Good Health Score 3 Period of Study 1969-2012 Stations 2 Value 1.3 Health Category Fair Health Score 2 Period of Study Stations Various 2 Value 64.8% Health Category Very Poor Health Score 0 Period of Study Stations Various 2 Value 32.2% Health Category Fair Health Score 2 Total Score 10 Maximum Available Score Basin 20 Hydrology Score Percentage of Maximum Score Hydrology Health Category 50.0% Poor Hydrology Score 1

HYDROLOGY DATA SUFFICIENCY Data Sufficiency Indicator Value Total number of sub-basins 3 Total number of dams (>10m) 0 Year of earliest dam operation - Year of earliest available continuous flow monitoring 1968 monitoring stations available for earliest, continuous flow monitoring 1 sub-basins with monitoring stations 1 Number if monitoring stations on river downstream of dams - Data Sufficiency Category Partially Sufficient Hydrology Year of long-term continuous flow monitoring monitoring stations available for continuous flow monitoring analysis sub-basins with monitoring stations 1969 2 2 monitoring stations on river downstream of dams - Data Sufficiency Category Partially Sufficient Year of widespread, continuous flow monitoring 1985 monitoring stations available for continuous flow monitoring analysis 2 sub-basins with monitoring stations 2 monitoring stations on river downstream of dams - Data Sufficiency Category Moderately Sufficient Overall Data Sufficiency Category Data Sufficiency Score Partially Sufficient 1

LONG-TERM TRENDS IN MONTHLY FLOW FOR THE PEEL RIVER MAP 10. RESULTS OF A SERIES OF TREND ANALYSES OF MEDIAN MONTHLY FLOW IN THE PEEL RIVER BASIN FOR THE PERIOD 1969 TO 2012.

TABLE. RESULTS OF LONG-TERM TREND ANALYSES FOR MEDIAN MONTHLY FLOW IN THE PEEL RIVER. Month Theil-Sen Slope Mann-Kendall p-value 10MA001 Start Year of Monitoring 1969 Annual Flow (m 3 /s) 50.05 Monthly Flow Percentage Change in Monthly Flow* Peel River Theil-Sen Slope Mann-Kendall p-value 10MC002 Start Year of Monitoring 1969 Annual Flow (m 3 /s) 181.25 Monthly Flow October 1.000 0.051 93.50 1.000 0.051 374.50 Percentage Change in Monthly Flow* November 0.502 0.014 * 50.70 0.99 0.502 0.014 * 179.75 0.28 December 0.329 0.006 ** 37.15 0.89 0.329 0.006 ** 124.00 0.27 January 0.312 6.94E-05 *** 27.15 1.15 0.312 6.94E-05 *** 98.58 0.32 February 0.308 9.75E-05 *** 23.00 1.34 0.308 9.75E-05 *** March 0.200 0.002 ** 21.15 0.95 0.200 0.002 ** 83.90 0.24 90.58 April 0.161 0.056 20.75 0.161 0.056 85.45 May 7.500 0.038 * 301.50 2.49 7.500 0.038 * 1025.00 0.73 June -6.98E+00 0.002 ** 394.75 1.77-6.98E+00 0.002 ** 1715.00 0.41 July 1.842 0.182 243.00 1.842 0.182 1015.00 August 0.800 0.687 252.50 0.800 0.687 970.25 September 2.563 0.014 * 239.50 1.07 2.563 0.014 * 827.25 0.31 for all months, for each station 0.71 142.05 0.89 0.71 549.10 0.24 percentage change in median monthly flow for all months, weighted by median annual flow 0.38 0.34 * Percentage change in median monthly flow is only calculated for months with a statistically significant trend over time. For months without a significant trend, a value of zero is assigned for calculation of the overall station score.

RECENT-TERM TRENDS IN MONTHLY FLOW FOR THE PEEL RIVER MAP. RESULTS OF A SERIES OF TREND ANALYSES OF MEDIAN MONTHLY FLOW IN THE PEEL RIVER BASIN FOR THE PERIOD 1985 TO 2012.

TABLE. RESULTS OF RECENT-TERM TREND ANALYSES FOR MEDIAN MONTHLY FLOW IN THE PEEL RIVER BASIN. Peel River 10MA001 Start Year of Monitoring 1985 Annual Flow (m 3 /s) 50.05 10MC002 Start Year of Monitoring 1985 Annual Flow (m 3 /s) 181.25 Month Theil-Sen Slope Mann-Kendall p-value Monthly Flow Percentage Change in Monthly Flow* Theil-Sen Slope Mann-Kendall p-value Monthly Flow Percentage Change in Monthly Flow* October 1.000 0.051 93.50 3.529 0.012 * 374.50 0.94 November 0.502 0.014 * 50.70 0.99 1.886 0.003 ** 179.75 1.05 December 0.329 0.006 ** 37.15 0.89 1.277 6.04E-05 *** 124.00 1.03 January 0.312 6.94E-05 *** 27.15 1.15 1.159 5.00E-05 *** 98.58 1.18 February 0.308 9.75E-05 *** 23.00 1.34 1.130 2.29E-05 *** March 0.200 0.002 ** 21.15 0.95 1.044 2.05E-05 *** 83.90 1.24 April 0.161 0.056 20.75 1.090 2.26E-05 *** 85.45 1.28 May 7.500 0.038 * 301.50 2.49 4.000 0.513 1025.00 June -6.98E+00 0.002 ** 394.75 1.77-3.06E+01 4.38E-04 *** 1715.00 1.79 July 1.842 0.182 243.00 2.700 0.653 1015.00 August 0.800 0.687 252.50-2.92E+00 0.515 970.25 September 2.563 0.014 * 239.50 1.07 3.567 0.286 827.25 0.43 for all months, for each station 0.71 142.05 0.89-1.01 549.10 0.85 percentage change in median monthly flow for all months, weighted by median annual flow 0.86 90.58 1.25

TRENDS IN ANNUAL FLOW FOR THE PEEL RIVER BASIN TABLE. RESULTS OF LINEAR REGRESSION ANALYSES FOR LONG-TERM TREND ANALYSIS OF MEDIAN ANNUAL FLOW IN THE PEEL RIVER, BY STATION. Station Start Year Intercept Intercept Standard Error Intercept T- Test Statistic Intercept T- Test p-value Slope Slope Standard Error Slope T- Test Statistic Slope T-Test p-value Adjusted R- Squared F-Test Static 10MA001 1969-1859.916 949.06587-1.9597338 0.0566849 0.968646 0.4777689 2.0274356 0.0489946 * 0.0161557 1.7225232 0.0489946 * 10MC002 1969-7365.972 2113.2204-3.4856618 0.0011631 3.809194 1.0618483 3.5873239 0.0008652 *** 0.1397331 7.0099069 0.0008652 *** F-Test p-value TABLE. RESULTS OF MANN-KENDALL NON-PARAMETRIC LONG-TERM TREND ANALYSIS OF MEDIAN ANNUAL FLOW IN THE PEEL RIVER, BY STATION. Station Start Year Theil -Sen Slope Mann- Kendall Test Statistic Mann-Kendall Test p-value Annual Flow (m 3 /s) 10MA001 1969 0.1922 79 0.4300 50.05 Percentage Change in Annual Flow 10MC002 1969 2.8889 380 0.0001 *** 181.25 1.59 Weighted Between Stations 1.25 FIGURE. TIME-SERIES OF LONG-TERM TRENDS IN MEDIAN ANNUAL FLOW FOR THE PEEL RIVER BASIN, BY STATION.

HYDROLOGICAL ALTERATION IN THE PEEL RIVER BASIN TABLE. NON-PARAMETRIC COMPARISON OF VARIANCE FOR RECENT VS. HISTORICAL MONTHLY FLOW IN THE PEEL RIVER BASIN. Historic Recent Fligner-Killeen Mann-Whitney Station Month Years of Sampling Monthly Flow (m 3 /s) Absolute Deviation in Monthly Flow (m 3 /s) Years of Sampling Monthly Flow (m 3 /s) Absolute Deviation in Monthly Flow (m 3 /s) Test Statistic p-value Test Statistic p-value Percentage Change in Monthly Flow Between the Two Time Periods Percentage Across Months* Annual Flow (m 3 /s) Weighted Across Basin June 23 535 256.4898 15 401 197.1858 9.2340 0.0024 ** 183970.0 0.0000 *** 25.0% July 22 235 87.4734 15 268 127.5036 31.8499 0.0000 *** 122519.0 0.0000 *** 14.0% Augus t 23 243 113.4189 15 270 124.5384 0.1682 0.6818 143799.5 0.0028 ** 11.1% September 23 219 75.6126 15 269 93.4038 16.3935 0.0001 *** 107623.0 0.0000 *** 22.8% October 23 92.5 40.6232 14 104 60.7866 33.5657 0.0000 *** 136668.0 0.0601 12.4% 10MA001 November 23 47.9 13.6399 13 52.5 12.8986 0.5392 0.4628 106190.5 0.0000 *** 9.6% December 23 32 8.8956 13 36.8 8.8956 0.0002 0.9882 86905.0 0.0000 *** 15.0% 26.3% 50.05 January 22 23 5.2632 14 28.6 4.5961 0.2520 0.6157 61853.5 0.0000 *** 24.3% February 22 19.9 3.8548 14 25.9 4.4478 8.5197 0.0035 ** 44539.5 0.0000 *** 30.2% March 22 18.7 2.5204 15 24.7 3.7065 55.7966 0.0000 *** 63608.0 0.0000 *** 32.1% April 22 19.7 4.0030 15 24.4 6.5234 64.3709 0.0000 *** 81151.0 0.0000 *** 23.9% May 20 202 261.6789 15 420 455.1582 1.5748 0.2095 114336.5 0.0000 *** 107.9% September 21 753 286.1418 22 868.5 309.1221 1.5897 0.2074 172780.5 0.0001 *** 15.3% 32.2% October 21 328 152.7078 22 402.5 166.7925 7.8736 0.0050 ** 170848.0 0.0000 *** 22.7% November 21 148 42.9954 21 178 68.1996 97.1703 0.0000 *** 127915.5 0.0000 *** 20.3% December 21 103 25.2042 21 126 25.2042 35.8610 0.0000 *** 80983.5 0.0000 *** 22.3% January 20 81.15 12.8245 21 109 24.3146 92.4739 0.0000 *** 58925.5 0.0000 *** 34.3% 10MC002 February 20 73.6 11.2678 21 97.5 22.5355 126.1856 0.0000 *** 43903.5 0.0000 *** 32.5% March 20 70 12.4538 22 88.8 17.0499 50.1085 0.0000 *** 58287.0 0.0000 *** 26.9% 33.8% 181.25 April 20 70.45 14.3071 22 91.9 22.2390 68.8131 0.0000 *** 66761.5 0.0000 *** 30.4% June 19 2220 1008.1680 22 1700 785.7780 15.2840 0.0001 *** 220162.5 0.0000 *** 23.4% July 19 1060 475.9146 22 1020 414.3867 3.8314 0.0503 205729.0 0.3363 3.8% Augus t 20 947 412.1628 22 999.5 453.6756 3.7306 0.0534 207470.5 0.3639 5.5% May 17 552 708.6828 22 1530 1994.8383 2.9521 0.0858 149528.0 0.0002 *** 177.2% *Percentage change in median monthly flow is only calculated for months with a statistically significant difference between the two time periods. For months without a siginificant trend, a value of zero is assigned for calculation of the overall score.

FIGURE. ANALYSIS OF VARIANCE IN MONTHLY FLOW FOR RECENT VS. HISTORICAL TIME PERIODS IN THE PEEL RIVER BASIN, BY STATION. FIGURE. PERCENTAGE CHANGE IN MEDIAN MONTHLY FLOW FOR RECENT VS. HISTORICAL TIME PERIODS IN THE PEEL RIVER BASIN, BY STATION.

WATER QUALITY OVERALL WATER QUALITY HEALTH SCORING Water Quality Exceedance of water quality guidelines for aquatic life Indicator Exceedance of water quality thresholds. Weighted average of exceedances of three thresholds: water quality guidelines,90th percentile and 77th percentile. Expressed as a proportion of total measurements. Reported as a weighted average for the most recent five years. Value Year 2009-2013 Stations 5 Value 0.3 Water Quality Health Category Water Quality Health Score Fair 2 Significant Mann-Kendal timeseries test to determine directional trend in proportion of exceedance of water quality thresholds. Time Period 1960-2013 Trend None WATER QUALITY DATA SUFFICIENCY Data Sufficiency Indicator Total number of sub-basins Value 3 Year of earliest available monitoring 1960 Water Quality monitoring stations available for earliest monitoring sub-basins with earliest available monitoring stations Year of most recently available monitoring monitoring stations available within last five years sub-sub-basins within last five years years of sampling in last 10 years Percentage of samples with at least 10 elements measured within last 5 years. Overall Data Sufficiency Category Data Sufficiency Score 1 1 2013 5 1 10 44.00% Partially Sufficient 1

MAP. ADHERENCE TO WATER GUIDELINES FOR MONITORING STATIONS IN THE PEEL RIVER BASIN FOR THE MOST RECENT YEARS AVAILABLE.

FIGURE. WATER QUALITY IN THE PEEL RIVER BASIN BASED ON PROPORTION OF EXCEEDANCE OF THREE THRESHOLDS: PROVINCIAL WATER QUALITY GUIDELINES, 75TH PERCENTILE OF HISTORICAL DISTRIBUTION, AND 90TH PERCENTILE OF HISTORICAL DISTRIBUTION. REPORTED BY YEAR AND DATA SOURCE. Year Source Contaminants Measured Total Sites Measurements Total Guidelines Exceedances Proportion of Guideline Exceedance Total 90th Percentile Exceedances Proportion of 90th Percentile Exceedance Total 75th Percentile Exceedances Proportion of 75th Percentile Exceedance Weighted Exceedance 5-Years Weighted Exceedance 2013 Environment Canada 9 1 32 10 0.31 4 0.13 6 0.19 0.23 2013 NWT-Wide Communitybased Water Quality Monitoring Program 16 4 192 74 0.39 30 0.16 52 0.27 0.29 2012 Environment Canada 9 1 63 25 0.40 18 0.29 35 0.56 0.39 2012 NWT-Wide Communitybased Water Quality Monitoring Program 16 1 47 22 0.47 10 0.21 18 0.38 0.37 2011 Environment Canada 9 1 90 44 0.49 14 0.16 23 0.26 0.34 2010 Environment Canada 9 1 61 16 0.26 13 0.21 18 0.30 0.25 2009 Environment Canada 9 1 36 13 0.36 5 0.14 10 0.28 0.27 2008 2007 1999 Canadian Aquatic Biomonitoring Network Canadian Aquatic Biomonitoring Network Aboriginal Affairs and Northern Development Canada 2 25 50 1 0.02 3 0.06 5 0.10 0.05 2 23 46 0 0.00 9 0.20 23 0.50 0.17 15 14 196 18 0.09 59 0.30 96 0.50 0.23 0.30

FIGURE. ANALYSIS OF VARIANCE IN EXCEEDANCE OF WATER QUALITY THRESHOLDS OVER TIME FOR MONITORING STATIONS IN THE PEEL RIVER BASIN, BY SUB-BASIN. FIGURE. ANALYSIS OF VARIANCE IN EXCEEDANCE OF WATER QUALITY THRESHOLDS OVER TIME FOR MONITORING STATIONS IN THE YUKON PORTION OF THE PEEL RIVER BASIN, BY CONTAMINANT.

FIGURE. ANALYSIS OF VARIANCE IN EXCEEDANCE OF WATER QUALITY THRESHOLDS OVER TIME FOR MONITORING STATIONS IN THE NORTHWEST TERRITORIES PORTION OF THE PEEL RIVER BASIN, BY CONTAMINANT.

TABLE. RESULTS OF MANN-KENDALL NON-PARAMETRIC TREND ANALYSIS OF ANNUAL EXCEEDANCE OF WATER QUALITY THRESHOLDS OVER TIME FOR MONITORING STATIONS IN THE PEEL RIVER BASIN, BY DATA SOURCE.

FISH OVERALL FISH HEALTH SCORING Indicator Basin Period of Study 1998-2010 Sites 41 Fish Change in Native Fish Species Richness Presence of statistically significant decline in number of total species observed per year. Presence of statistically significant decline in median species richness for the basin. Trend Trend Data Deficient Data Deficient Fish Health Category Data Deficient Fish Health Score Data Deficient FISH DATA SUFFICIENCY Data Sufficiency Indicator Total number of sub-sub-basins Basin 3 Year of earliest available monitoring 1998 sampling locations available for earliest monitoring 3 sub-sub-basins with earliest available sampling locations 3 Earliest year of continuous monitoring 1998 Fish sampling locations available for first year of continuous monitoring sub-sub-basins for first year of continuous monitoring 3 1 Year of most recently available monitoring 2010 monitoring stations available within last five years 51 sub-sub-basins within last five years 3 years of sampling in last 10 years Overall Data Sufficiency Category Data Sufficiency Score 3 Insufficient 0

BENTHICS OVERALL BENTHIC HEALTH SCORING Basin Indicator Value Benthic Macro- Invertebrates Index of benthic community composition based on sensitivity to disturbance Hilsenhoff Biotic Index (HBI) score for the basin. Reported as a weighted average for the most recent five years. Significant Mann-Kendal timeseries test to determine directional trend in HBI over time. Year 2005-2008 Sites 58 Value 4.01 Benthic Health Category Benthic Health Score Very Good Time Period - Trend - 4 BENTHIC DATA SUFFICIENCY Data Sufficiency Indicator Total number of sub-basins Value 3 Year of earliest available monitoring 1998 Benthic Macro-Invertebrates monitoring stations available for earliest monitoring sub-basins with earliest available monitoring stations Year of most recently available monitoring monitoring stations available within last five years sub-sub-basins within last five years 6 1 2008 24 1 years of sampling in last 10 years 3 Overall Data Sufficiency Category Data Sufficiency Score Partially Sufficient 1

MAP. HILSENHOFF'S BIOTIC INDEX SCORES FOR BENTHIC MACRO-INVERTEBRATE COMMUNITIES IN THE PEEL RIVER.

Table. HILSENHOFF'S BIOTIC INDEX VALUES FOR BENTHIC MACRO-INVERTEBRATE COMMUNITIES SAMPLED IN THE PEEL RIVER BASIN, BY YEAR, AND DATA SOURCE. Source Sub-basin Year Number of Sites HBI Value CABIN-BISY CABIN-YTG 10MA 2005 3 3.88 1998 6 5.40 10MB 2005 3 3.14 10MC 2005 4 3.70 10MA 2008 24 4.64 2007 15 4.48 10MB 2007 8 4.81 FIGURE. ANALYSIS OF VARIANCE FOR HILSENHOFF'S BIOTIC INDEX VALUES FOR BENTHIC MACRO-INVERTEBRATE COMMUNITIES SAMPLED IN THE PEEL RIVER BASIN. FIGURE. TREND ANALYSIS FOR HILSENHOFF'S BIOTIC INDEX VALUES FOR BENTHIC MACRO-INVERTEBRATE COMMUNITIES SAMPLED IN THE PEEL RIVER BASIN.