Kimberly Meitzen, Ph.D.
A presentation to the NC Ecological Flows Science Advisory Board, February 19th
TNC Freshwater Resilience Project 1. Linear and lateral functional connectivity 2.Diversity of geophysical riverine habitats 3. Water quality and riparian land use/cover 4. Natural flow patterns and flow alterations Environmental flow assessment
Goal is to identify stream reaches with the greatest resiliency and conservation potential for supporting healthy biodiverse freshwater ecosystems.
E‐Flows: Cape Fear Little Tennessee, Tar Pamlico, Roanoke
TNC Environmental Flow Project Outline 1. Conduct literature review to develop flow-ecology relationships for NC riverine biota and physical stream processes
2. Analyze changes
in (a.) flow patterns and (b.) biota over recent history of flow impacts
3a. Identify patterns of biotic changes 3b. Identify spatial and temporal patterns of flow changes
4. Develop flow-ecology criteria and flow recommendations to protect riverine ecosystem integrity characteristic of NC’s biotic and physiographic diversity (Decision Support System for Environmental Flows DSSEF)
5. Identify areas of conservation priority relative to freshwater ecosystem resilience and vulnerability 6. Provide information and resources to the EFSAB to assists their environmental flow recommendation process
Creek chub sucker
Biological Data Evaluation NCDWQ wadeable streams Fish > 2 survey dates per site, 1990 ‐ 2011 Benthos > 3 survey dates per site 1982 ‐ 2010
Tar River spinymussel
Biological Data Evaluation Fish data: sites with > 2 survey samples Benthos data: sites with > 3 surveys Species distribution by ecoregion NMS community ordination of species and sites:
coastal plain (red), piedmont (yellow), and blue ridge (green), black dot represent species River Basin
Fish Sites
Fish Diversity
Fish Density
Benthos Sites
Benthos Diversity
Benthos Density
Roanoke
27
58
1,218
23
338
4,938
Cape Fear
69
68
2,650
136
464
28,032
Tar Pamlico
33
59
1,740
25
330
5,887
Little Tennessee
12
36
415
50
350
12,043
Fish Distribution by Guilds Count Total % 14 17 10 2 1 50 5 64 37 3 6 2 2 1
pool‐run pool‐run; backwater pool‐run; pool pool‐run; riffle‐run riffle riffle; riffle‐run riffle‐run riffle‐run; pool‐run riffle‐run; riffle riffle‐run; riffle; pool‐run
41 1 2 6 12 3 19 2 3 1
50
15 25
29
9
14
Spawn backwater backwater; pool
Count Total % 20 22 13 2
Pool Pool‐Run Riffle‐Run
pool pool; backwater pool; margin pool; pool‐run pool‐margin pool‐margin; pool‐run pool‐run pool‐run; backwater pool‐run; margin pool‐run; riffle‐run riffle riffle; riffle‐run riffle‐run riffle‐run; pool‐run riffle‐run; riffle
29 4 2 1 3 2 32 1 2 7 13 8 41 2 4
Riffle 36
21
5
3
42
24
21
12
47
27
Margin Backwater
Depth
Adult/Juvenile backwater backwater; pool backwater; pool‐margin pool pool; backwater pool; pool‐margin pool; pool‐run pool‐margin
Guilds developed by WRC for NC
Velocity
Calculated from fish presence data for Little Tennessee, Cape Fear, Tar‐Pamlico, and Little Tennessee
Biological analysis: biotic changes over time Fish and benthos diversity and abundance changes over time Graphs for 141 fish sites and 234 benthos sites Calculated Coefficient of Variation (CV = st.dev/mean) to show
30
1200
25
1000
20
800
15
600
10
400
5
200
0
0
Cape Fear Fish OID 18
Diversity
R² = 0.6867
Count
R² = 0.1636
Count
Diversity
variation in diversity and abundance among sample surveys Contemporary conditions and patterns of change
Biotic changes over time: Fish Diversity Variation overtime between survey dates Coefficient of Variance, CV= standard deviation/mean Lower values = less change and higher values = more
CV
Low
High
(0)
(0.5)
Biotic changes over time: Fish Abundance Variation overtime between survey dates Coefficient of Variance, CV= standard deviation/mean Lower values = less change and higher values = more
CV
Low
High
(0)
(0.5)
Biotic changes over time: Benthos Diversity Variation overtime between survey dates Coefficient of Variance, CV= standard deviation/mean Lower values = less change and higher values = more
CV
Low
High
(0)
(0.99)
Biotic changes over time: Benthos Abundance Variation overtime between survey dates Coefficient of Variance, CV= standard deviation/mean Lower values = less change and higher values = more
CV
Low
High
(0)
(0.99)
Fish diversity
Fish abundance
Benthos Diversity Low
High
Benthos Abundance Low
High
Low
High
USGS Stream Flow Gages 34 gages with 36 years of record, 1976‐2011 Period 1 (recent historic conditions): 1976‐1994 Period 2 (current contemporary conditions) : 1994‐2011
What are the changes in flow patterns over recent history (1976‐ 2011)? How do they vary spatially (among gaging sites) and temporally (months)? Contemporary conditions and patterns of change
Examining spatial and temporal patterns of flow changes will inform management decisions on sustainable water use and environmental flow protection.
USGS Stream Flow Gages Station ID 03504000 03500240 03500000 03512000 03503000 03513000 02102908 02093800 02097517 02097314 02102192 02094500 02100500 02108000 02106500 02096960 02102000 02102500 02105500 02105769 02084557 02084160 02081500 02082950 02081747 02083000 02082506 02082585 02083500 02077200 02077670 02077303 02071000 02080500
Basin Little Tennessee Little Tennessee Little Tennessee Little Tennessee Little Tennessee Little Tennessee Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Cape Fear Tar‐Pamlico Tar‐Pamlico Tar‐Pamlico Tar‐Pamlico Tar‐Pamlico Tar‐Pamlico Tar‐Pamlico Tar‐Pamlico Tar‐Pamlico Roanoke Roanoke Roanoke Roanoke Roanoke
Longitude ‐83.61900 ‐83.39430 ‐83.37960 ‐83.35350 ‐83.52680 ‐83.44740 ‐79.17750 ‐79.95310 ‐79.01920 ‐78.96580 ‐78.97340 ‐79.61670 ‐79.65530 ‐77.83300 ‐78.28890 ‐79.13360 ‐79.11590 ‐78.81310 ‐78.82390 ‐78.29360 ‐76.74660 ‐77.22830 ‐78.58310 ‐77.87580 ‐78.29640 ‐77.69270 ‐77.86550 ‐77.78720 ‐77.53300 ‐79.19700 ‐78.87220 ‐78.99640 ‐79.82610 ‐77.63450
Latitude 35.12700 35.15870 35.14980 35.46150 35.33650 35.42790 35.18180 36.17290 35.89350 35.88490 35.55960 36.17540 35.72620 34.82790 34.75490 35.76350 35.62740 35.40630 34.83490 34.40430 35.73040 35.56320 36.19490 36.18570 36.09290 36.15100 35.89960 35.95430 35.89410 36.39930 36.54070 36.52350 36.41260 36.46050
Station Name NANTAHALA RIVER NEAR RAINBOW SPRINGS, NC CARTOOGECHAYE CREEK NEAR FRANKLIN, NC LITTLE TENNESSEE RIVER NEAR PRENTISS, NC OCONALUFTEE RIVER AT BIRDTOWN, NC LITTLE TENNESSEE RIVER AT NEEDMORE, NC TUCKASEGEE RIVER AT BRYSON CITY, NC FLAT CREEK NEAR INVERNESS, NC REEDY FORK NEAR OAK RIDGE, NC MORGAN CREEK NEAR CHAPEL HILL, NC NEW HOPE CREEK NEAR BLANDS, NC BUCKHORN CREEK NR CORINTH, NC REEDY FORK NEAR GIBSONVILLE, NC DEEP RIVER AT RAMSEUR, NC NORTHEAST CAPE FEAR RIVER NEAR CHINQUAPIN, NC BLACK RIVER NEAR TOMAHAWK, NC HAW RIVER NEAR BYNUM, NC DEEP RIVER AT MONCURE, NC CAPE FEAR RIVER AT LILLINGTON, NC CAPE FEAR R AT WILM O HUSKE LOCK NR TARHEEL, NC CAPE FEAR R AT LOCK #1 NR KELLY, NC VAN SWAMP NEAR HOKE, NC CHICOD CR AT SR1760 NEAR SIMPSON, NC TAR RIVER NEAR TAR RIVER, NC LITTLE FISHING CREEK NEAR WHITE OAK, NC TAR R AT US 401 AT LOUISBURG, NC FISHING CREEK NEAR ENFIELD, NC TAR R BL TAR R RESERVOIR NR ROCKY MOUNT, NC TAR RIVER AT NC 97 AT ROCKY MOUNT, NC TAR RIVER AT TARBORO, NC HYCO CREEK NEAR LEASBURG, NC MAYO CR NR BETHEL HILL, NC HYCO R BL ABAY D NR MCGEHEES MILL, NC DAN RIVER NEAR WENTWORTH, NC ROANOKE RIVER AT ROANOKE RAPIDS, NC
Drainage Size Area (mi2) Category Ecoregion 51.9 small Blue Ridge 57.1 small Blue Ridge 140.0 small Blue Ridge 184.0 small Blue Ridge 436.0 medium Blue Ridge 655.0 medium Blue Ridge 7.6 headwater Coastal Plain 20.6 headwater Piedmont 41.0 headwater Piedmont 75.9 small Piedmont 76.3 small Piedmont 131.0 small Piedmont 349.0 medium Piedmont 599.0 medium Coastal Plain 676.0 medium Coastal Plain 1275.0 large Piedmont 1434.0 large Piedmont 3464.0 large Coastal Plain 4852.0 large Coastal Plain 5255.0 large Coastal Plain 23.0 headwater Coastal Plain 45.0 headwater Coastal Plain 167.0 small Piedmont 177.0 small Piedmont 427.0 medium Piedmont 526.0 medium Coastal Plain 777.0 medium Coastal Plain 925.0 medium Coastal Plain 2183.0 large Coastal Plain 45.9 headwater Piedmont 53.5 small Piedmont 202.0 medium Piedmont 1053.0 medium Piedmont 8384.0 large Coastal Plain
Indicators of Hydrologic Alteration IHA • • •
•
Software for understanding hydrologic changes in ecologically relevant terms Developed by TNC to quantify flow patterns and flow alteration Metrics for Magnitude, Duration, Frequency, Timing, Rate of Change • 33 Metrics calculated for the period of record • 34 Environmental Flow Component (EFC) Metrics calculated for 5 discrete groups: Extreme Low Flows, Low Flows, High Flows, Small Floods, Large Floods Applied in numerous e‐flow studies nationwide Version 7.1 IHA software download: http://conserveonline.org/workspaces/iha/documents/index/view.html
IHA metrics for quantifying flow alteration between baseline and altered conditions •
Standard metrics
• • • •
•
Monthly metrics for the 10th, 25th, 50th, 75th, and 90th (60 metrics) 3, 7, 30, and 90 day minimums and maximums Low pulse count, low pulse duration High pulse count, high pulse duration
Environmental Flow Component Metrics
• • • • • • •
Extreme low flow peak, duration, frequency, and timing: High flow peak duration, frequency, and timing Small flood peak, duration, timing, and frequency Large flood peak, duration, timing, and frequency Extreme low flow, low flow, and high flow thresholds Small flood and large flood minimum peak flow Calculated annually and for 2 periods: July 1st –Sept. 30th and Oct. 1st‐June 30th
IHA Monthly Flow Duration Curves Exceedance Probabilities for the 90th, 75th, 50th, 25th, 10th %tile Flows CapeFear_02105769 Monthly Flow Duration Curves
Flow rate (cfs)
10,000
High Flows
Annual (1976-2011) October (1976-2011) November (1976-2011) December (1976-2011) January (1976-2011) February (1976-2011) March (1976-2011) April (1976-2011) May (1976-2011) June (1976-2011) July (1976-2011) August (1976-2011) September (1976-2011)
Wet Conditions 1,000
Mid‐Range Flows
5
10
90th
15
20
25
75th
30
35
40
45 50 55 Exceedance Probability
50th
60
Dry Conditions 65
70
75
25th
80
85
Low Flows 90
10th
95
Flow Duration, Percentile Changes Blue line: historic recent (1976‐1993) Black Line: contemporary conditions (1994‐2011) Graphs will be expressed as % change from historic to contemporary Positive change
Negative change
Changes to the 90th percentile: highest flows > 25 % (+ or ‐) represents significant amount of change, 25 % (+ or ‐) represents significant amount of change, 25 % (+ or ‐) represents significant amount of change, 25 % (+ or ‐) represents significant amount of change, 25 % (+ or ‐) represents significant amount of change, 50 mi2, Piedmont > 50 mi2 , Coastal Plain