Benchmarking Watershed Condition for Aquatic Biointegrity Outcomes and Nutrient Criteria Development Paul E. Stacey NAB Conference Principal Scientist 5 March 2020 Footprints In The Water LLC Newport, RI [email protected] Management Perspective for Changing Times: Value of Nature to Canadians Study Taskforce. 2017. Management Perspective for Changing Times: Value of Nature to Canadians Study Taskforce. 2017. An Ecosystem Approach A social-ecological system framework for both analysis and management that accounts for the complex interrelationships of human society, economics, and the environment GOAL – Achieve Structural and Functional Integrity: The Path to Making Nature Great Again is Fostering ECOSYSTEM RECOVERY “NOBODY KNEW ECOSYSTEMS COULD BE SO COMPLICATED.” DPSIR Framework in the SES Context: DRIVER Land Cover Change, Climate Change D Agriculture, Habitat Destruction PRESSURE Forcing Factors (Stressors): P Chemical, Physical, Biological Chemical, Physical, STATE S Biological Condition Loss of Structural and IMPACT I Functional Integrity R Management RESPONSE Action - Smeets and Weterings (1999) Assessing Collective Stress: Five Major Factors that Determine Biological Condition USEPA. 2016. Assessing Collective Stress: Five Major Factors that Determine Biological Condition D P S/I USEPA. 2016. GOAL – Achieve Structural and Functional Integrity: The Path to Making Nature Great Again is Fostering ECOSYSTEM RECOVERY “NOBODY KNEW ECOSYSTEMS COULD BE SO COMPLICATED.” “NOBODY KNOWS ECOSYSTEMS BETTER THAN NATURE… THAT’S WHY NATURE ALONE CAN FIX THEM.” BCG Pressure-Response in SES: X Axis (Pressure): ➢ Ecosystem Stress Level (GS) 1 ➢ Percent Natural Cover ➢ Watershed Structure POPULATION ➢ Watershed Condition Index (WCI) Y Axis (Response): ➢ Biological Condition ➢ Ecosystem Integrity (WFI) Index ➢ Watershed Function Index (WFI) Ecosystem Integrity Ecosystem Integrity BiologicalCondition Watershed Function Watershed 0 1 0 WatershedEcosystemPercentWatershed Condition Natural Stress Structure CoverLevel Index (GS) (WCI) USEPA. 2016. A Practitioner’s Guide to the Biological Condition Gradient BCG Pressure-Response in SES: X Axis (Pressure): ➢ Ecosystem Stress Level (GS) 1 ➢ Percent Natural Cover ➢ Watershed Structure ➢ Watershed Condition Index (WCI) SITE-SPECIFIC NATURAL VARIATION Y Axis (Response): ➢ Biological Condition ➢ Ecosystem Integrity (WFI) Index ➢ Watershed Function Index (WFI) Ecosystem Integrity Ecosystem Integrity BiologicalCondition Watershed Function Watershed 0 1 0 WatershedEcosystemPercentWatershed Condition Natural Stress Structure CoverLevel Index (GS) (WCI) USEPA. 2016. A Practitioner’s Guide to the Biological Condition Gradient BCG Pressure-Response in SES: X Axis (Pressure): ➢ Ecosystem Stress Level (GS) 1 ➢ Percent Natural Cover ➢ Watershed Structure ➢ Watershed Condition Index (WCI) ➢WCI = STRESSOR Y Axis (Response): ➢ Biological Condition ➢ Ecosystem Integrity (WFI) Index ➢ Watershed Function Index (WFI) Ecosystem Integrity Ecosystem Integrity BiologicalCondition Watershed Function Watershed ➢WFI = RESPONSE 0 1 0 WatershedEcosystemPercentWatershed Condition Natural Stress Structure CoverLevel Index (GS) (WCI) USEPA. 2016. A Practitioner’s Guide to the Biological Condition Gradient SES Along the BCG: HIGH Natural Assets LOW 1 HIGH Ecosystem Approach 0.8 Conservation Watershed Structure 0.6 is the Independent Variable Management 0.4 (Pressure Metric) Mitigation 0.2 Watershed Function Natural Functions (WFI) is the Dependent LOW Variable 0 1.0 0.8 0.7 0.5 0.3 0.2 0.0 (Response Metric) HIGH Watershed Natural Structure (WCI) LOW Setting Land Cover – Biointegrity Benchmarks: > 80% > 50% Biointegrity Threshold: • Buffers • >80% Tree Cover • Watershed • >50% Tree Cover < 5% • Impervious Cover • <5% IC Goetz et al. 2003 GOAL – Achieve Structural and Functional Integrity: The Path to Making Nature Great Again is Fostering ECOSYSTEM RECOVERY “ NOBODY KNEW ECOSYSTEMS COULD BE SO COMPLICATED.” “NOBODY KNOWS ECOSYSTEMS BETTER THAN NATURE… THAT’S WHY NATURE ALONE CAN FIX THEM.” “IT’S A PERFECT CALL!” Benchmarks in BCG Context: HIGH Natural Assets LOW 1 HIGH Useful Benchmarks: WS Index Function (WFI) Historical Reference 0.8 Historical Reference WCI = 1.0 0.6 Threshold WCI = 0.5 0.4 Threshold 0.2 LOW 0 1.0 0.8 0.7 0.5 0.3 0.2 0.0 HIGH Watershed Condition Index (WCI) LOW Benchmarks in BCG Context: HIGH Natural Assets LOW 1 HIGH WS Function Index WS Index Function (WFI) Useful Benchmarks: 0.8 Historical Reference WCI = 1.0 0.6 Threshold BAC WCI = 0.5 Current Condition Target Condition 0.4 WCI = 0 – 1.0 Management Target WCI = Current + Increase Current Condition 0.2 Best Attainable Condition (BAC) WCI = Current + Recovery LOW Potential 0 1.0 0.8 0.7 0.5 0.3 0.2 0.0 HIGH Watershed Condition Index (WCI) LOW Natural Cover WCI Assessment: 10 Football Fields/Day ! Watershed Condition Analysis: Watershed Size Distribution 50000 45000 40000 CT 35000 NY 30000 25000 20000 15000 Watershed Size (acres) Size Watershed 10000 Long Island Sound 5000 0 1 26 51 76 101 126 151 160 Connecticut Coastal Watersheds Benchmarking Watershed Conditions Watershed Benchmarking Reference Historical Historical Threshold 157 151 145 139 133 WCI for 160 CT Coastal Watersheds CTCoastal 160 for WCI 127 121 : 115 109 103 Watersheds 97 91 85 79 73 67 61 55 49 43 37 31 25 19 13 7 1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Watershed Condition Index (WCI) Index Condition Watershed Benchmarking Town Conditions: WCI for Coastal Towns Watershed Watershed Condition Index (WCI) Historical 1.0 Reference 0.9 0.8 0.7 0.6 Threshold 0.5 0.4 0.3 0.2 0.1 0.0 9 7 5 3 1 35 33 31 29 27 25 23 21 19 17 15 13 11 Towns Benchmarking Town Conditions: WCI for Coastal Towns Watershed Watershed Condition Index (WCI) Historical 1.0 Reference 0.9 0.8 Mitigation (BMPs) 0.7 0.6 Threshold 0.5 0.4 Conservation 0.3 0.2 Management (Recovery) 0.1 0.0 9 7 5 3 1 35 33 31 29 27 25 23 21 19 17 15 13 11 Towns What About Nitrogen? Five Major Factors that Determine Biological Condition USEPA. 2016. What About Nitrogen? Five Major Factors that Determine Biological Condition NITROGEN ? BIOINTEGRITY or “WFI” USEPA. 2016. LIS Applications: LONG ISLAND SOUND STUDY – NITROGEN MANAGEMENT STRATEGY Tetra Tech, Inc. 2018. Pressure-Response Framework: LISS –0.53 NITROGEN MANAGEMENT STRATEGY 0.30 0.76 0.10 (One Size Fits All) Tetra Tech, Inc. 2018. Pressure-Response Framework: LISS –0.53 NITROGEN MANAGEMENT STRATEGY 0.30 0.76 Type I Error 10 (One Size Fits All) Type II Error Tetra Tech, Inc. 2018. Watershed Condition Index: Condition Watershed Threshold 157 151 145 139 133 WCI for 160 CT Coastal Watersheds CTCoastal 160 for WCI 127 121 115 109 103 Watersheds 97 91 85 79 73 67 61 55 49 43 37 31 25 19 13 7 1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Watershed Condition Index (WCI) Index Condition Watershed Nitrogen! At last: Calculated Nitrogen Loads from WCI 20 20 y = 16.499e-2.883x R² = 0.9851 16 16 ) ) yr yr - - 12 12 /acre Current = Calculated from WCI /acre lbs lbs Target (TMDL) = Calculated from WCI 8 8 Recovery (BAC) = Calculated from Recovery Potential WCI N Yield ( Yield N N Yield ( Yield N Threshold = 4 + 1 ? 4 4 Current “Current” Reference = 2 Reference Historical Reference = 1 0 0 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 Watershed Condition Index (WCI) Managing Nitrogen in SES Context: TMDL NPS/SW + PT S = TMDL REDUCTION TARGET (LA) (WLA) TARGET Fractional Area Current Reference Threshold WCI Current Land Current Point Land + Point Watershed Below/Above Area (acres) Forest Urban (Natural) Load (WCI = 5.0)0.5) Load (Tons Load (Tons Load (Tons Agric Threshold (With Point Sources) (>0.50) (>0.30) (Tons TN/yr) (Tons TN/yr) TN/yr) TN/yr) TN/yr) (Tons TN/yr) Pawcatuck River 166626 0.78 0.10 0.12 83 416 190 77 267 150 (Enrichment Factors) 1.0 5.0 2.3 3.2 Fully Natural Using “Enrichment Reference Factors” the Threshold Exports Load is 5X the 1 lb N/acre-yr Threshold Condition Natural Reference (50% Natural Cover) Load or “Dose” This approach establishes a site-specific Exports 5 lb N/acre-yr Assessment of loading, scalable and Applicable to any watershed or segment. It is harmonized with ecosystem functional Conditions and loads can be estimated in Mass units/time unit (e.g., tons N/yr used Here) or as a normalized “dose” by using Enrichment factors relative to the Reference load, e.g., the EF for the Threshold condition = 416 tons/83 tons = 5 Managing Nitrogen in SES Context: TMDL NPS/SW + PT S = TMDL REDUCTION TARGET (LA) (WLA) TARGET Fractional Area Current Reference Threshold WCI Current Land Current Point Land + Point Watershed Below/Above Area (acres) Forest Urban (Natural) Load (WCI = 5.0)0.5) Load (Tons Load (Tons Load (Tons Agric Threshold (With Point Sources) (>0.50) (>0.30) (Tons TN/yr) (Tons TN/yr) TN/yr) TN/yr) TN/yr) (Tons TN/yr) Pawcatuck River 166626 0.78 0.10 0.12 83 416 190 77 267 150 Niantic Bay (Enrichment Factors) 18821 0.74 0.10 0.16 1.09 5.047 2.325 0 3.225 22 Mystic Harbor 16598 0.70 0.15 0.15 8 41 24 9 33 9 Saugatuck Estuary 55723 0.67 0.13 0.20 28 139 91 5 96 43 Stonington Harbor 1531 0.61 0.15 0.24 1 4 3 1 4 0 Stony Brook Harbor 4915 0.57 0.13 0.30 4 22 11 0 11 11 Farm River 16648 0.54 0.21 0.25 8 42 38 0 38 3 Southport Harbor/Sasco Brook 27565 0.52 0.22 0.26 14 69 66 0 66 2 Norwalk Harbor 38409 0.52 0.15 0.33 19 96 98 134 232 -136 Oyster Bay/Cold Spring 16500 0.50 0.19 0.31 8 41 43 10 53 -12 Byram River 17364 0.48 0.25 0.27 9 43 46 5 52 -8 Port Jefferson Harbor 3829 0.48 0.12 0.40 2 10 11 18 29 -20 Mt.