INTRODUCTION TO ENVIRONMENTAL FLOW ANALYSIS Thomas R. Payne Certified Fisheries Professional Normandeau Associates, Inc.

ENVIRONMENTAL FLOW TERMINOLOGY Environmental Flow is AKA: –Instream Flow –Ecological Flow –E-flow –Rarely “Minimum” Flow “Environmental flows are the quantity and timing of water flows required to maintain the components, functions, processes, and resilience of freshwater ecosystems and the goods and services they provide to people.”

HISTORY OF DAMS/RIVER REGULATION Egypt – 3000 BC Roman Empire – 500 BC to 500 AD Japan – 400 AD to 900 AD China – 833 AD (still there!) Great Britain – 1787 AD River Basin Development – 1930’s –TVA (US), Columbia River (US), Volga River (USSR), Snowy Mountains (Australia)

HISTORY OF DAMS/RIVER REGULATION 1800’s – Ten per year – Fifty per year – One hundred per year 1960’s – Five hundred per year 2000’s – Thousands per year Current Status of Dams –50,000 dams storing more than 1,00,000 m 3 –100,000 dams storing 100,000 m 3

TYPES OF ENVIRONMENTAL FLOW METHODS Hydrologic –Historic flows Hydraulic Rating –River channel characteristics Habitat Rating –Mechanistic/Observational Individual and Population Modeling –Population Dynamics/Interactions Professional Judgment –Economics/Environment

HISTORY OF ENVIRONMENTAL FLOW METHODS Late 1800s – United Kingdom –Navigation –Public health –Downstream users –Fisheries protection 1900s – United States (State Level) –Appropriation Doctrine –Riparian Doctrine –Reserve Doctrine

APPROACHES IN THE ‘50 S AND ‘60 S Hydrologic –7Q10 – Lowest seven days over ten years –Q90 – Ninety percent exceedance –Baxter’s percent of mean annual flow Hydraulic Rating –Wetted perimeter –Wetted usable width Professional Judgment –Managers “decide”, biologists “consult”

ENVIRONMENTAL FLOW BEFORE 1970 Minimum or Base Flow –Single Threshold –Often applied to summer season –Often resulted in constant minimum flow –Did not consider flow variability Result –Habitat Degradation! Consequence –Awareness, laws, regulations, methods

APPROACHES IN THE ‘70 S Research Driven by Consequences Hydrologic –Tennant Method  Percent of Mean Annual Flow  Summer season, winter season, flushing Habitat Rating –Washington habitat area method (1972) –Waters’ habitat discharge method (1976) –Physical Habitat Simulation (1978)

EXPLOSION OF APPROACHES 1980 – 16 Methods 1986 – 70 Methods 2002 – 207 Methods 2015 – ??? Methods

HYDROLOGIC (31 IN 2002) Tennant Modified Tennant New England Base Flow Flow Duration Curves Texas Method Basic Flow Method (Spain) Flow Translucency Approach (Australia) Range of Variability Approach

HYDRAULIC RATING (23 IN 2002) Wetted Perimeter R-2 Cross Washington Toe-Width Oregon Method Arkansas Method Colorado Method Standard Depth Approach One-Flow Method

HABITAT RATING (58 IN 2002) Physical Habitat Simulation (PHABSIM) River Simulation System (RSS – Norway) Evaluation of Habitat (EVHA – France) Computer Aided Simulation Model for Instream Flow Requirements (CASiMIR) Riverine Community Habitat Assessment and Restoration Concept (RCHARC) River2D MesoHABSIM

INDIVIDUAL/POPULATION DYNAMICS Individual Based Modeling (InSTREAM) Systems Impact Assessment Model (SIAM) Salmon Life Cycle Production Model (SALMOD) River Invertebrate Prediction and Classification System (RIVPACS) SALMOD II

PROFESSIONAL JUDGMENT (16 IN 2002) Instream Flow Incremental Methodology Building Block Methodology (BBM) Downstream Response to Imposed Flow Transformations (DRIFT) Demonstration Flow Approach (DFA) Expert Panel Assessment Method (EPAM) Ecological Limits of Hydrologic Alteration (ELOHA)

SO WHERE ARE WE NOW?

METHODS AND METHODOLOGIES Method (tools) A process by which a task is completed. Methodology (approaches) A guideline system for solving a problem, with specific components such as phases, tasks, methods, techniques and tools.

WHAT WE’RE MOSTLY DOING Methods –Tennant (and modifications) –Demonstration Flow Assessment –MesoHABSIM –Direct Habitat Mapping Methodologies –Instream Flow Incremental Methodology (IFIM) and PHABSIM (1D and 2D) –Ecological Limits of Hydrologic Alteration (ELOHA) –System for Environmental Flow Analysis (SEFA)

TENNANT (AND MODIFICATIONS) Percentage of Mean Annual Flow Narrative Description October-MarchApril-September Flushing or Maximum 200 Optimum range Outstanding 4060 Excellent 3050 Good 2040 Fair or degrading 1030 Poor or minimum 10 Severe degradation <10 Tennant, D.L Instream flow regimens for fish, wildlife, recreation and related environmental resources. USFWS, Billings, MT

TENNANT (AND MODIFICATIONS) SituationFlow Recommendation MMF < 40% MAF MMF MMF > 40% MAF and 40% MMF < 40% MAF 40% MAF 40% MMF > 40% MAF 40% MMF MMF = Mean Monthly Flow MAF = Mean Annual Flow Tessman, S.A Environmental assessment, technical Appendix E, western Dakotas region of South Dakota study. WRRI, Brookings, SD Others: Estes, C.C (Washington), 1998 (Alaska) Trihey, E.W (California) Bureau of Land Management (Oregon, California)

DEMONSTRATION FLOW ASSESSMENT (Railsback, S.F., and Kadvany, J. 2008) Step 1 – Frame the Decision –Clearly define the instream flow decision process Step 2 – Develop Conceptual Models of Flow Effects –Develop a shared understanding of important flow mechanisms Step 3 – Select Habitat Metrics –Define the specific measures to be observed and quantified Step 4 – Design and Conduct Field Observations –Observe and quantify or rate the selected habitat metrics Step 5 – Analyze Results –Rank alternative flows by the quantity or value of the metrics Step 6 – Negotiate Instream Flows

DEMONSTRATION FLOW ASSESSMENT (Railsback, S.F., and Kadvany, J. 2008)

MesoHABSIM (Parasiewicz, P. 2001)

DIRECT HABITAT MAPPING (McBain & Trush 2013) Habitat at 150 cfs DIRECT HABITAT MAPPING Habitat at 200 cfs

INSTREAM FLOW INCREMENTAL METHODOLOGY (Bovee et al. 1998)

Hydraulics Microhabitat area per unit length of stream Channel structure Microhabitat suitability criteria

HYDRAULIC HABITAT MODELING (PHABSIM)

HYDRAULIC HABITAT SIMULATION (PHABSIM) XSEC 1 XSEC 2 Hydraulic Model Velocity: v i Depth: d i Substrate: s i Biological Model Velocity Cv Sv i Sd i Ss i Substrate Cs Physical Habitat Index Flow AWS

1-D MODEL PHYSICAL REPRESENTATION

CROSS SECTION PROFILE AND VELOCITY

2-D MODEL PHYSICAL REPRESENTATION

1-D HABITAT REPRESENTATION O O O O O O O O O O O O O Data points O

O O O O OO O O O O O O O O 2-D HABITAT REPRESENTATION

T1 = 15% T2 = 35% T3 = 35% T4 = 15% T2 T3 T4 T1 Scaled & weighted data points, 3-axis frequency analysis N=132 Data Points Scaled by Suitability and Weight

PHABSIM 1-D OR 2-D HABITAT INDEX

ECOLOGICAL LIMITS OF HYDROLOGIC ALTERATION (ELOHA) (Poff et al. 2009) ELOHA is “a new framework for developing regional environmental flow standards” ELOHA Framework 1.Model hydrologic baseline and current hydrograph 2.Classify river segments by ecological characteristics 3.Determine the deviation of current flow from baseline 4.Develop flow alteration-ecological response relationships ELOHA should occur in a consensus context ELOHA should proceed in an adaptive management context

ECOLOGICAL LIMITS OF HYDROLOGIC ALTERATION (ELOHA) (Poff et al. 2009)

QUESTIONS AND DISCUSSION…