The value of a stream.

Transcription

1 The value of a stream. Rusty Wenerick DHEC Water Quality Certification & Wetlands Program 43 rd Annual Meeting of the SOUTHEAST WATER POLLUTION BIOLOGISTS ASSOCIATION Asheville, NC / November 7-10, 2016

2 USACE 404 Permit/DHEC 401 WQC authorized impacts: 92-acre / 1,094 MG drought storage reservoir 1,000 linear feet of 2 nd -order stream filled for 500,000 cubic yard embankment 6,320 linear feet of 1 st - and 2 nd -order stream acre of wetland flooded 0.02 acre (975 ft. 2 ) of riverbed filled for intake DHEC 401 WQC special conditions: ~ 50,000 stream wetland CREDITS minimum flow release below dam monitoring below dam: hydrology, WQ, and biology legal protection in perpetuity - mitigation and reservoir site including WQ buffers limit on river withdrawal during low flow

3 Compensating for Stream Impacts in SC Federal rule divides restoration into two categories: Reestablishment = gain in quantity (area) and function Rehabilitation = gain in function Assess stream at compensatory mitigation site prior to restoration actions Assess reference stream(s)/condition (this is the target) Difference translates to CREDITS Credits represent potential functional lift Mitigation banks sell credits (after attainment of performance standards, etc.) to permittees so they can offset losses from authorized unavoidable impacts

4 USEPA Assessment Intensity Framework Assessment Method Categories Office, Coarse, Least Time Field - No Samples Field - Samples, Rigorous, Most Time Rusty Wenerick (DHEC 401 Program) - Pee Dee River floodplain Southeastern Floodplains and Low Terraces - Marion County, SC Photo by David Eargle Source: USEPA Elements of a State Water Monitoring and Assessment Program for Wetlands.

5 DHEC Study - Objectives Evaluate level 1 and 2 assessment methods: Do level 1 and 2 data give the same picture as level 3 data? Do different level 2 methods give similar results? What about spatial scale of level 1 data? Mark Giffin (DHEC 401) Rocky Creek - Carolina Slate Belt - McCormick County, SC Photo by Rusty Wenerick

6 DHEC Study - Objectives continued Evaluate performance standards for stream restoration: Do typical metrics correlate with other level 3 data? Source: unpublished SC Interagency Review Team (SCIRT) guidance Alicia Rowe (DHEC 401) and David Eargle (DHEC Aquatic Biology) Golden Creek - Southern Inner Piedmont Pickens County, SC Photo by Rusty Wenerick.

7 DHEC Study Sites 13 small streams, upstream of NPDES dischargers, where DHEC has long-term biological data from required monitoring 0- to 3rd-order perennial streams (1:100 K NHD), w/ drainage areas ranging from < 1 sq. km to > 55 Michele Culbreath (DHEC 401) - Big Brushy Creek Southern Outer Piedmont - Anderson County, SC Photo by Rusty Wenerick.

8 DHEC Study - Data Level 1 USEPA ORD StreamCat Extensive database of landscape metrics for stream segments and their associated riparian areas, catchments (i.e., the nearby landscape flowing directly into streams) and full upstream watersheds Data corresponds to stream segments from the National Hydrography Dataset Plus Version 2 (1:100k) Catchment Watershed Monitoring Station Riparian Area Source: Read Me file, ftp://newftp.epa.gov/epadatacommons/ord/nhdpluslandscapeattributes/streamcat/welcomepage.html Hill, Ryan A., Marc H. Weber, Scott G. Leibowitz, Anthony R. Olsen, and Darren J. Thornbrugh, The Stream-Catchment (StreamCat) Dataset: A Database of Watershed Metrics for the Conterminous United States. Journal of the American Water Resources Association (JAWRA) 52(1):

9 DHEC Study - Data continued Level 2 Rapid Assessment Methods (3) 1. DHEC Aq. Biol. Program s Simplified Habitat Assessment, 1997 Does not classify streams = 1 class. 7 metrics assess instream habitat, hydrology and hydraulics/geomorphology. Visual-based, consensus of team, minutes to complete. Output = total = numeric score. Habitat data permits visualization of the assessment site when biological data are analyzed, which may aid in understanding the presence or absence of certain taxa. In addition, habitat data can be used to cluster stations according to shared habitats when comparisons are made among stations. Methods: Velocity/Flow and Sedimentation were converted to numeric scores (5, 2.5, and 0 so all 7 metrics were equally weighted), then all scores were summed for an overall score that could range from 0 to 35.

10 Level 2 continued Rapid Assessment Methods (3) continued 2. EPA RBP Habitat Assessment Chapter 5 Classifies streams as low or high gradient = 2 classes. 10 metrics assess in-stream habitat and riparian zone structure/condition. (L & R banks and L & R riparian zones are evaluated separately.) Visual-based, consensus of team, minutes to complete. Output = numeric score of 7 to metrics can range from 1-20, and 3 are split L & R and can range from ASSESS ALL 3 Guidelines for Preparing a Compensatory Mitigation Plan IMPACT SITE Score Existing Condition factor + sum of other factors x linear feet = required credits MITIGATION SITE Net Improvement factor + sum of other factors x linear feet = credits produced REFERENCE SITE(S) Difference in Scores

11 Level 2 continued Rapid Assessment Methods (3) cont. 3. NC Stream Assessment Method, Version 2, February 2014 Classifies streams by ecoregion (4), valley-type (1-2), and watershed size (4) = 28 classes + tidal marsh streams = 29 classes. 25 metrics assess structure/condition/ function, stressors, and opportunities for WQ improvement. Visual-based, one or more assessors, 15 minutes to complete. Methods: Class 2 function ratings were converted to numeric scores (3, 2, or 1), then equally weighted by Class 1 and 2, and then summed for an overall numeric score that could range from Output = high, medium or low rating. Overall rating + ratings for 3-4 levels of subcategories. Major subcategories are hydrology, WQ, and habitat.

12 DHEC Study Data Level 3 Geomorphological measurements and calculated metrics including metrics that are typical stream restoration performance standards and monitoring requirements from unpublished SC Interagency Review Team guidance. BHR = low bank height/maximum bankfull depth -Indicates degree of incision, floodplain connectivity -Dimensionless ETR = width of flood prone area/bankfull width -Indicates vertical containment, floodplain connectivity -Dimensionless MWR = meander belt width/bankfull width -Indicates lateral containment, lateral stability -Dimensionless Pool to Pool Spacing (P2P) = Length between pool maximum depths/bankfull width -Indicates frequency of pools, bedform diversity -Dimensionless Percent Riffle/Pool = length of riffle or pool/length of reach x 100 -Indicates bedform diversity -Dimensionless Source: unpublished SCIRT guidance Depth Variability Index (DVI) = max pool depth/mean riffle depth -Indicates bedform diversity, bedform complexity -Dimensionless Woody Debris Index (WDI) = # large woody debris/length of reach -Indicates bedform diversity, bedform complexity, habitat -Standardized

13 DHEC Study - Data Level 3 continued In-situ physicochemical WQ Dr. Jim Glover (Manager, DHEC Aq. Biol.) Unnamed 1 st -order tributary (urban) Sandhills Richland County, SC Photo by Rusty Wenerick

14 DHEC Study - Data continued Level 3 cont. Historical biological assessments = the truth Biotic Index, EPT and SC Bioclassification Raw data taxa list and numbers 1 to 7 years Biotic Index: based on assigned pollution tolerance and relative abundance of taxa; 0 to 10 (most impaired). EPT: total # of EPT taxa; 0 to? Bioclassification: based on combination of equally weighted BI & EPT, adjusted for region. 5 = Excellent 4 = Good 3 = Good-Fair 2 = Fair 1 = Poor For aquatic life uses, the goal of SC WQ standards is the protection of a balanced indigenous aquatic community. DHEC generally considers biological data as the deciding factor for aquatic life use support, regardless of chemical conditions. Scott Castleberry (DHEC Aquatic Biology) Wateree River floodplain Southeastern Floodplains and Low Terraces Sumter County, SC Photo by Rusty Wenerick

15 DHEC Study - Results Level 1 versus Level 3 Pool to Pool Spacing (P2P) = Length between pool maximum depths/bankfull width % Riffle = length of riffle/length of reach x 100 Depth Variability Index (DVI) = max pool depth/mean riffle depth Woody Debris Index (WDI) = # large woody debris/length of reach EPT can range from 0 to? SC Bioclassification can range from 1/poor to 5/excellent 1. Riparian area within 100 m of each side of NHD line ranged from 12 to 26% of entire watershed. 2. Sum of Developed, Open-, Low-, Medium- and High-Intensity.

16 DHEC Study Results continued Level 1 versus Level 2 No significant relationships found between level 1 and level 2 parameters. Level 2 versus Level 3 Pool to Pool Spacing (P2P) = Length between pool maximum depths/bankfull width -Indicates frequency of pools, bedform diversity -Dimensionless

17 DHEC Study Results continued Level 2 versus Level 2

18 DHEC Study Results continued Level 3 versus Performance Standards Pool to Pool Spacing (P2P) = Length between pool maximum depths/bankfull width Depth Variability Index (DVI) = max pool depth/mean riffle depth Woody Debris Index (WDI) = # large woody debris/length of reach EPT can range from 0 to? SC Bioclassification can range from 1/poor to 5/excellent

19 DHEC Study - Conclusions Level 1 versus Level 2 versus Level 3: Some relationships need more data Different Level 2 Methods: Strong relationships need more data at high and low end Spatial Scale of Level 1 Data: Some indication this is important need more data Performance Standards versus Level 3: Some relationships need more data

20 Hot off the Presses Results of Google Scholar search on Rapid Stream Assessment since 2016: North Carolina Doll, B., Jennings, G., Spooner, J., Penrose, D., Usset, J., Blackwell, J., & Fernandez, M. (2016). Can Rapid Assessments Predict the Biotic Condition of Restored Streams?. Water, 8(4), 143. Doll, B., Jennings, G., Spooner, J., Penrose, D., Usset, J., Blackwell, J., & Fernandez, M. (2016). Identifying Watershed, Landscape, and Engineering Design Factors that Influence the Biotic Condition of Restored Streams. Water, 8(4), 151. Canada Gazendam, E., Gharabaghi, B., Ackerman, J. D., & Whiteley, H. (2016). Integrative neural networks models for stream assessment in restoration projects. Journal of Hydrology, 536, Virginia Sweeten, S.E. and W.M. Ford Validation of a stream and riparian habitat assessment protocol using stream salamanders in the southwest Virginia coalfields. Journal of The American Society of Mining and Reclamation 5:45-46

21 What next? Source: Palmer, M.A.* and J.B. Ruhl Aligning restoration science and the law to sustain ecological infrastructure for the future. Frontiers in Ecology and the Environment 13: *Dr. Margaret Palmer, Director, National Socio-Environmental Synthesis Center Professor, Department of Entomology, University of Maryland Professor, Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science

22 What next? continued Stream Restoration Guidelines for Preparing a Compensatory Mitigation Plan IMPACT SITE Score Existing Condition factor + sum of other factors x linear feet = required credits MITIGATION SITE Net Improvement factor + sum of other factors x linear feet = credits produced REFERENCE SITE(S) Difference in Scores Consider reference condition biology as the target. Consider developing/improving performance standards for hydrology, hydraulics, water quality and biology in addition to geomorphology. What about other processes? Consider that the present and future condition of a stream s watershed limits ecological restoration potential. What is the proposed condition? Consider that increasing the fraction of a watershed s stream network subject to restoration actions will mitigate the above. Headwaters! Consider credit for watershed actions associated with stream restoration to facilitate restoration of natural hydrologic regimes. Stormwater runoff! Ecological Restoration So - not just geomorphology think about instream biology. Furthermore, not just the channel and riparian area think about the watershed and all the processes it has to support and sustain.

23 Acknowledgements This study would not have been possible without funding from a Wetland Program Development Grant from the U. S. Environmental Protection Agency s Region 4 and the training and technical expertise provided by personnel who were part of the NC Stream Functional Assessment Team, responsible for developing and testing the North Carolina Stream Assessment Method, including: John Dorney, formerly manager of the NC Division of Water Quality s Program Development Unit, and currently with Moffatt & Nichol; Leilani Paugh, NC Dept. of Transportation s Natural Environment Unit; and, Sandy Smith, Axiom Environmental. Chuck Hightower, Project Supervisor and Manager of DHEC s 401 Program; Heather Preston, Director of DHEC s Division of Water Quality; Dr. Jim Glover, Manager of DHEC s Aquatic Biology Program; and Dianna Woods, Grant Technical Officer with USEPA Region 4 s Water Protection Division, provided advice and guidance throughout the project. Numerous DHEC Bureau of Water staff attended training and/or assisted with field work including: Michele Culbreath, Mark Giffin, Chuck Hightower, Erin Owen, Don Padget, and Alicia Rowe from the DHEC 401 Program; and, Scott Castleberry, David Eargle, Maggie Emmons, Justin Lewandowski, and Michelle Scott from the DHEC Aquatic Biology Program.

24 Rusty Wenerick (803)