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Home My WebLink AboutMary_Davis(slides 1-96)Environmental Flow Science: Lessons Learned from Selected Environmental Flow Programs NC Environmental Flow Science Advisory Board November 15, 2011 Mary M. Davis, Ph.D. Southern Instream Flow Network “Hydrologic regimes are the master variables in aquatic ecosystems.” Poff et al. 1997 Southern Instream Flow Network Purpose ‐To facilitate protective instream flow policies and practices in 15 southern states by providing science-based resources and opening lines of communication. More information at: www.southeastaquatics.net/programs/sifn/ Presentation Overview 1. Review of science‐based methods to determine IF needs 2. Methods used by select states to determine IF needs 3. IF resources for North Carolina Science‐based Methods to Determine Instream Flow Needs •Instream Flow Incremental Method (IFIM) •Ecologically Sustainable Water Management (ESWM) •Ecological Limits of Hydrologic Alteration (ELOHA) Instream Flow Incremental Method (IFIM) Source: http://www.fort.usgs.gov/Products/Software/ifim/5phases.asp 0 5,000 10,000 15,000 20,000 25,000 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 WU A ( s q . f t . p e r 1 0 0 0 f t ) Discharge (cfs) ROCKY RIVER - REDBREAST SUNFISH HABITAT vs. DISCHARGE Adult Juvenile Fry Spawning 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 HS I DEPTH (ft) HABITAT SUITABILITY INDICES - DEPTH GUILD=SHALLOW-SLOW with WOOD… 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 HS I VELOCITY (fps) HABITAT SUITABILITY INDICES - VELOCITY GUILD=SHALLOW-SLOW with WOOD… Field Study Physical Modeling Habitat Modeling Habitat vs. Flow for each organism Hydrologic Modeling •Time Series Analysis •Flow Alternatives •Recommendations Requires time and $ IFIM Process: Site‐and Project–specific Evaluations IFIM Process: Water management alternatives are the basis for a negotiated solution. IFIM Essentials •Well‐established methodology developed in the 1980s and 1990s •Applies (usually) species‐specific models at site‐ specific level •Based on population responses to natural variation in velocity, depth, cover, and area •Negotiated instream flow solutions Ecologically Sustainable Water Management (ESWM) Ecosystem Flow Requirements Human Needs Areas of Incompatibility Collaborative Dialogue Water Experiments Adaptive Management Ecological Conceptual Model Source: Susquehanna River Commission 2011 Savannah River Ecosystem Flow Workshop Participants JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 4,000‐5,000 cfs; •Sturgeon spawning 6,000‐10,000 cfs, with 6,000 cfs as baseflow >2,700 cfs; • Juvenile Outmigration >2,700 cfs | >2,000 cfs | >2,700 cfs >5,000 cfs; •Sturgeon spawning 4,000‐6,000 cfs, 4,000 cfs as baseflow >16,000 cfs; 1‐2 days, 1‐2 pulse 20,000‐40,000 cfs; 2‐3 days, 1/month Ecosystem Flow Recommendations: Building Block Method Augusta Shoals on the Savannah River Low Flows High Flow Pulses Floods • Herring passage over NSBLD • Morone egg suspension 20,000‐40,000 cfs; 2‐3 days, 1/month | 14 days, 1/month Jan & Feb | Mar & Apr • Shad, striped bass, robust redhouse spawning and habitat 6,000‐10,000 cfs, with 6,000 cfs as baseflow •protect spider lily from deer grazing >2,700,000 cfs • Resident fish habitat • Juvenile fish out‐migration 4,000‐5,000 cfs; 4,000‐5,000 cfs; No flood flow recommendations provided for the Shoals 20,000 cfs; 2‐3 days, 1 pulse •Sturgeon spawning Key Dry Year Avg Year Wet Year ESWM Essentials •Developed in 1990s by The Nature Conservancy •Applied at watershed level to improve flow regimes and restore ecological function •Based on existing data and expert knowledge of ecological relationships with natural hydrologic regimes •Integrates societal values with ecological needs Ecological Limits of Hydrologic Alteration (ELOHA) http://conserveonline.org/workspaces/eloha (Poff et al. 2010) Bi o t i c in d i c a t o r Hydrologic alteration Ecological Limits of Hydrologic Alteration (ELOHA) http://conserveonline.org/workspaces/eloha (Poff et al. 2010) Output from The Nature Conservancy’s Indicators of Hydrologic Alteration (IHA) software Calculation of Flow Alteration Flow‐Ecology Relationships from Literature Source: McManamay et al. 2011 Flow‐Ecology Relationships from Existing Data Source: Potomac River Commission Watershed Assessment 2011 Characteristic species Thriving species 1.0 0.9 ‐ 0.8 ‐ 0.7 ‐ 0.6 ‐ 0.5 ‐ 0.4 ‐ 0.3 ‐ 0.2 ‐ 0.1 ‐ 0.0 Pr o p o r t i o n of in i t i a l fi s h po p u l a t i o n me t r i c Proportion of index flow removed 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Adverse resource impact Acceptable resource impact Michigan’s Screening Tool for Ground‐Water Withdrawals ECOLOGI CAL COND I TION Ecological Response to Flow Alteration ELOHA Essentials •Newly established method (Poff et al. 2010) •Uses existing data to develop flow‐ecology relationships for classes of rivers •Based on ecological responses to flow alteration of natural hydrologic regime •Integrates societal values with ecological values Presumptive Flow Standard for Environmental Flow Protection (Richter et al. 2011) Presentation Overview 1. Review of science‐based methods to determine IF needs 2. Methods used by selected programs to determine IF needs 3. IF resources for North Carolina Approaches for Determining IF Standards •Minimum flow threshold –7Q10 (e.g., AL, LA, MS) –Modified Tennant (e.g., AR, GA, SC) •Statistically based standards (e.g., FL St Johns WMD, Potomac River Commission) •Percent of flow approaches (e.g., FL SW Florida and Suwannee River WMDs, TN Presumptive WQ Standard) Under development in SE: TX, NC, VA IF Methods Used by Selected Programs •Florida •Michigan •Potomac River Commission •Texas, if time allows Slides courtesy of Marty Kelly, DirectorSWFWMD MFL Program Florida – Instream Flow Protection Policy and Management Programs http://www.swfwmd.state.fl.us/projects/mfl/ SJRWMD NWFWMD SRWMD SFWMD Minimum Flows and Levels ‐Florida Statutes, Section 373.042 ‐ The minimum flow for a given watercourse shall be the limit at which further withdrawals would be significantly harmful to the water resources or ecology of the area A MFL is set by the Water Management Districts for each of their priority streams, rivers, lakes, and aquifers. MFLs are used in •water management allocation planning, •surface and groundwater withdrawal permit conditions, and •recovery plans. •Building Block Method •PHABSim-style methodology •Percent of Flow Reduction Approach •‘Significant Harm’ threshold = 15% reduction in available habitat for most conservative target 0 500 1000 1500 2000 2500 0 100 200 300 Day of Year Fl o w ( c f s ) Block 1 Block 2Block 2 Block 3 SWFWMD Instream Flow Program Physical Habitat Simulation System Used for Blocks 1 and 2 • Depth •Velocity • Substrate Floodplain Snags Exposed Roots Long-Term Inundation Analysis Used for Blocks 2 and 3 Low Flow Threshold - Wetted Perimeter Used for All Blocks Low Flow Threshold -Fish Passage Used for All Blocks 0 400 800 1200 1600 2000 0 50 100 150 200 250 300 350 Fl o w ( c f s ) 10% 8% 13% 18% LFT = 67 cfs Flow Prescription Percent of Flow and Seasonality of allowable cumulativewithdrawals Day of Year • Best Available Information • Peer Review Process Block Rivers Upper Alafia Braden Myakka Peace Hillsborough Hi Lo Hi Lo Hi Lo Hi Lo Hi Lo 1 (April 20‐June 24)8 10101015158108 10 2 (Oct 28 –Apr 19)815101155818811 3 (Jun 25 –Oct 27)8 13 10 19 7 16 8 13 8 13 SWFWMD MFLs Range of Percent Allowable Withdrawals (Significant Harm Threshold < 15% habitat loss) Source: http://www.swfwmd.state.fl.us/projects/mfl/ SWFWMD MFL Essentials •MFL set for each water body (i.e., no classification needed) •Flow requirements based on most sensitive ecological response to flow alteration (i.e., fish, coarse woody debris, floodplains, organic soils, etc.) •Estimate habitat loss based on cumulative depletion of the natural daily flow regime •MFLs for medium size, coastal rivers show a small range of allowable depletions. IF Methods Used by Programs •Florida –using similar methods as NC; finding similar standards within river class •Michigan •Potomac River Commission Environmental Flow Standards in Michigan Slides courtesy of Paul Seelbach, USGS and Richard Bowman, TNC Spatial framework Reach attribution MI fisheries classification Coordination is good Well-established conceptual framework tested and implemented over past 15 years by TNC, USGS Regional Aquatic GAP, and a few states. Provides for multi- state coverage. Zoogeographic Region (WWF) Ecological Drainage Unit (EDU) Aquatic Ecological System (AES) Ecological Segment NHD+ Reach Michigan River Classification Approach Spatial framework Reach attribution MI fisheries classification Coordination is good Key landscape and riverine attributes for every reach came from existing map-level data and state-level models. Examples: flow, temperature, slope, and elevation. 0 - 0.10.1 - 0.2130.213 - 0.334 0.334 - 0.468 0.468 - 0.631 0.631 - 0.826 0.826 - 1.294 Yield (cfs/sq. mi) Spatial framework Reach attribution MI fisheries classification Coordination is good Summer temperature Fi s h a b u n d a n c e Cold fishes Warm fishes Cold Cold transition Warm transition Warm Spatial framework Reach attribution MI fisheries classification Coordination is good Streams Cold Warm Trans Warm Lg RiversSm Rivers Cold Trans 11 river classes based on flow and temperature Spatial framework Reach attribution MI fisheries classification Coordination is good Simple. Familiar. Fish values. Incredibly powerful in policy development. “Map that changed the world.” Map is central to state water law. Is in minds and language of policy leaders and users. Is useful to many other river management programs. Can drill into database for more details. m river river am ll river e river 100 Ecological targets Statewide habitat suitability info: flow and temperature Rank scores per normal distribution; 60+ species 0 0.05 0.1 0.15 0.2 0.25 2 3.6 5.2 6.8 8.4 10 11.6 13.2 14.8 16.4 18 Pr o b a b i l i t y D e n s i t y Normal (Gaussian) Distribution Ab u n d a n c e Habitat Gradient (Flow or Temperature for instance) Optimum Habitat ‘4’ represents ‘best’ conditions ‘4’ is ±0.5 SD ‘3’ is ± 0.5 to 1.0 SD ‘2’ is ± 1.0 to 1.5 SD ‘1’ is ± 1.5 to 2.0 SD ‘0’ is ± > 2.0 SD Reference flows River types Ecological response curves Degree flow alteration Enviro. flow targets Implement program For representative sites per river type: Considered initial “characteristic” species Ran withdrawal simulations and followed scores common shiner white sucker longnose dace rainbow darter 0102030405060 44 4 3332 4 333222 33 22200 22 10000 Percent flow reduction Reference flows River types Ecological response curves Degree flow alteration Ecological targets Enviro. flow targets Implement program Variation in fish assemblage response curves for each of 15 representative sites within one river type. The mean response (dark line) was used in the water management program, and policy safeguards were used in recognition of the degree of variation. Reference flows River types Degree flow alteration Ecological targets Enviro. flow targets Implement programEcological response curves Summaries of simulations create early warning and total impact curves (for assemblage) Reference flows River types Ecological response curves Degree flow alteration Ecological targets Enviro. flow targets Implement programEcological response curves Cool Small Rivers 0 0.2 0.4 0.6 0.8 1 0 0.25 0.5 0.75 1 Early warning response curve Assemblage response curve Pr o p o r t i o n i n t a c t Proportion of index flow removed Curves and target zones per each ecological river type. Geographies of biological response and social values. Allowable cumulative withdrawal (% median August) Michigan’s Screening Tool for Ground‐Water Withdrawals Characteristic species Thriving species 1.0 0.9 ‐ 0.8 ‐ 0.7 ‐ 0.6 ‐ 0.5 ‐ 0.4 ‐ 0.3 ‐ 0.2 ‐ 0.1 ‐ 0.0 Pr o p o r t i o n of in i t i a l fi s h po p u l a t i o n me t r i c Proportion of median August flow removed 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Adverse resource impact Acceptable resource impact • River classification informed by fish assemblages •PHABSim-style methodology •Percent of Flow Reduction Criteria Michigan Instream Flow Program IF Methods and Approaches Used by Advanced State Programs •Florida – similar standards within river class •Michigan –river classification informed by fish assemblages; similar standards within river class •Potomac River Commission Middle Potomac Watershed Assessment: Environmental Flows •Follows ELOHA framework •Multistate watershed •www.potomacriver.org Slides courtesy of Carlton Haywood, PRC Bi o t i c in d i c a t o r Hydrologic alteration Ecological Limits of Hydrologic Alteration (ELOHA) http://conserveonline.org/workspaces/eloha (Poff et al. 2010) Hydrologic Data Hydrologic Metrics Hydrologic Metrics Middle Potomac – Biological Data Biotic Metrics Classification Classification Flow‐Ecology Relationships Flow‐Ecology Relationships Flow‐Ecology Relationships Flow‐Ecology Relationships IF Methods and Approaches Used by Advanced State Programs •Florida – similar standards within river class •Michigan –river classification informed by fish assemblages; similar standards within river class •Potomac River Commission – demonstrated ecological impairment due to flow alteration in addition to other sources of stress Presentation Overview 1. Review of science‐based methods to determine IF needs 2. Methods used by select states to determine IF needs 3. IF resources for North Carolina and the SE region Southern Instream Flow Network Purpose ‐To facilitate protective instream flow policies and practices in 15 southern states by providing science-based resources and opening lines of communication. More information at: www.southeastaquatics.net/programs/sifn/ •Problem:The limited focus on research and funding for instream flows has resulted in a lack of science to support protective instream flow standards. •Objective:to highlight research needs and coordinate sources of funding and research to address these needs. •Goal:to ensure that instream flow research is focused on the needs of water resource managers for scientifically credible and protective state instream flow standards and practices. Southern Instream Flow Research Agenda www.southeastaquatics.net/programs/sifn 1. Develop a regional river classification system 2. Identify commonalities in ecosystem responses to flow alterations 3. Compile regional aquatic ecology data sets 4. Develop hypotheses for regional ecological responses to flow alteration 5. Perform field studies to test ecological responses to altered flow regimes Southern Instream Flow Research Agenda Priority Research Topics Integration of Instream Research Agenda Products To Develop Flow‐Ecology Relationships Ec o l o g i c a l Co n d i t i o n Hydrologic Alteration + + ‐ ‐0 Hydrologic Models Ecological Condition Assessment Aquatic Conservation Priority Areas Sources of Flow Alteration River Classification Hypothetical Flow‐ Ecology Relationships Quantify Flow Alteration Ecological Metric Re s e a r c h Pr i o r i t i e s an d Va l i d a t i o n Ec o l o g i c a l Da t a SE River Classification •Utilizing existing classifications •Hierarchical scales for geomorphology, hydrology, and biota •Principals: John Faustini, USFWS and Chris Konrad, USGS Preliminary SE Flow‐Ecology Relationships Source: McManamay et al. 2011 Compile regional aquatic ecology data sets Multistate Aquatic Resources Information System www.marisdata.org Integrating State Data into the National Fish Habitat Assessment MARIS States (2010) SARP Flow Alteration Assessment Approach –Qualitatively assess sources, spatial distribution, and relative magnitude of hydrologic alteration from water consumption, impervious cover, and dams. In conclusion: Generally, instream flow science is progressing and is resulting in more protective policies and management practices. From the case studies: •River classification works well where there is a clear relationship with biota. •‘Flow‐ecology’ relationships help guide selection of hydrologic and biotic metrics •Demonstrated ecological impairment due to flow alteration provides a strong basis for instream flow criteria. If we had more time: •Scientific certainty should be balanced with policy development. •Presumptive standards may provide a protective option until more studies can be completed. Environmental Flows Allocation Process in Texas Slides Courtesy of Kevin Mayes Director, EF Program •Flow Regime –Integration of Ecological Flow Components •IFIM-style methodology •Statistically-based approach for recommendations •Sound ecological management target Texas EF Program Clear definitions and process Well‐defined stakeholder/public involvement process Integration framework ties flow components and disciplines Approved by National Research Council Texas Environmental Flow Program Priority Study River Segments Data Integration to Generate Flow Conditions Reconnaissance and Information Evaluation Study Design Multidisciplinary Data Collection and Evaluation Goal Development Consistent with Sound Ecological Environment Stakeholder Input Peer Review Draft Study Report Final Study Report Next Steps: Implementation, Monitoring, and Adaptive Management Stakeholder Input Stakeholder Input Stakeholder Input Stakeholder Input Peer Review Peer ReviewSB2 ends Post SB2 TIFP Process (National Research Council 2005) Instream Flow Components Primary Disciplines Hydrology & Hydraulics Physical Processes (Geomorphology) Biology Water Quality Connectivity Key Species and/or Habitat Diversity Hydrology-Based Environmental Flow Regime (HEFR) Basics • Uses hydrologic data • Computations are rapid • Populates a flow regime matrix (1) Select Flow Gage (2) Select Period of Record (3) Separate (parse) Hydrograph into Flow Components (4) Generate Statistical Summaries in Excel Identify Biological Considerations Calculate Low Flow Statistics Identify Water Quality Constituents of Concern Conduct Water Quality Modeling Studies Assess Low Flow ‐Water Quality Relationship Subsistence Flows Other Biological Considerations Primary Discipline Hydrology/Hydraulics Biology Geomorphology Water Quality Subsistence Flows Assess Bedform and Banks Model Hydraulic Characteristics in Relation to Flow Determine Habitat Criteria Describe Wet, Normal, and Dry Years Calculate Base Flow Statistics Collect Biological Data Assess Habitat‐Flow Relationships, including Diversity Consider Water Quality Issues Consider Biological and Riparian Issues Base Flows Identify Biological Issues and Key Species Base Flows Primary Discipline Hydrology/Hydraulics Biology Geomorphology Water Quality Assess Active Channel Processes Develop Sediment Budgets Assess Channel Adjusting Flow Behavior High Flow Pulses Calculate High Flow Statistics Consider Water Quality Issues Consider Biological IssuesDescribe Significant Habitat Conditions High Flow Pulses Primary Discipline Hydrology/Hydraulics Biology Geomorphology Water Quality Assess Overbank Flow Behavior Overbank Flows Model Extent of Flood Events Conduct Riparian StudiesConsider Biological Issues Estimate Riparian Requirements Consider Water Quality Issues Calculate Flood Frequency Statistics Assess Active Floodplain and Channel Processes Overbank Flows Primary Discipline Hydrology/Hydraulics Biology Geomorphology Water Quality Integration to Generate a Flow Regime Integration of Flow Components Overbank Flows High Flow Pulses Base Flows Subsistence Flows JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 35 ‐55 cfs Maintain water quality (35 cfs) and key habitats in May (55 cfs) 40‐50 cfs Fish habitat 90‐100 cfs Fish habitat 150‐300 cfs Spring spawning 100‐150 cfs Fish habitat 300‐450 cfs maintain biodiversity and longitudinal connectivity 700‐1500 cfs for 2‐3 days 2‐3 X per year every year Sediment transport Lateral connectivity Fish spawning 1800 cfs for 2 days 1 X per yr every other year “Big River fish” spawning between Jul 15 ‐Aug 15 4,000‐10,000 cfs for 2‐3 days Once every 3‐5 years Channel Maintenance Riparian Connectivity, Seed dispersal Flooplain habitat Wet year Average year Dry year Texas Environmental Flows Process (Stakeholder process under SB3) Stakeholder environmental flow recommendations (instream flows and freshwater inflows to bays and estuaries): 1. Sabine‐Neches‐Sabine Lake 2. Trinity‐San Jacinto‐Galveston Bay 3. Colorado and Lavaca Rivers and Matagorda and Lavaca Bays Basin and Bay 4. Guadalupe, San Antonio, Mission, and Aransas Rivers 5. Mission, Copano, Aransas, and San Antonio Bays Basin and Bay Analyses and draft reports in prep: •Rio Grande, Rio Grande Estuary, and Lower Laguna Madre •Brazos River and Associated Bay and Estuary System •Nueces River and Corpus Christi and Baffin Bays. Texas Instream Flow Program (Environmental studies under SB2) Interim report: 1. Lower San Antonio River Multidisciplinary studies underway in: •lower San Antonio River •middle and lower Brazos River •lower Sabine River Status of Texas Environmental Flow Process •Parts 3 and 4 –this is the most important part. Take care to focus on the science as much as possible, and if talking about the approach a state settled on, point out changes that were made based on other factors (economics, politics etc.) •With regards to the science and what other states are doing, here are some questions: –Are they classifying/sorting streams? How? –How are they coming up with ecological response relationships? What metrics are they evaluating? If working with biological databases, how are they isolating flow effects from water quality effects and effects downstream of big dams not related to flow? –How are they evaluating degree of hydrologic alteration against which biological data is being contrasted? What metrics for flow alteration? • Develop testable ideas about flow-ecology relations •many possible ecological responses •multiple plausible hydrologic drivers Freeman and Marcinek 2006