NONPOINT SOIREE  SICCESS  STOIY
Restoring Stream Channel and Riparian Areas Improves Aquatic
Habitat in Upper Big Darby  Creek
I           H
improved
                                Channelization, destruction of riparian habitat and road
                                construction degraded water quality in Upper Big Darby
Creek. As a result, this watershed assessment unit (AU), known as the Headwaters of Big Darby
Creek, was placed on the 2006 Clean Water Act (CWA) section 303(d) list of impaired waters for
failure to attain its exceptional warmwater habitat and coldwater habitat designated uses due to
hydromodification and habitat alteration. From 2007 to 2011, The Nature Conservancy worked on
more than a mile of Big Darby Creek, restoring riparian areas and stream hydrology. Water quality
and aquatic habitat have improved as a result; therefore, the Headwaters of Big Darby Creek
AU will be removed from the CWA section 303(d) impaired waters list for hydromodification and
habitat alteration in the 2016 integrated report.
Problem
The Big Darby Creek watershed covers about 555
square miles, beginning in Logan County before flow-
ing to the Scioto River in Pickaway County (Figure 1).
Some of the tributaries to the Big Darby are not meet-
ing attainment of their aquatic life designated uses,
partially due to habitat alteration. Portions of the
headwater reaches of Big Darby Creek are impaired
as a result of channelization, habitat alteration and
nutrient enrichment, which is degrading warm and
coldwater habitat.

Ohio Environmental Protection Agency (Ohio EPA)
measures designated aquatic life use using a set of
bioindicators. The Qualitative Habitat Index (QHEI)
measures physical habitat conditions. The Index of
Biological Integrity (IBI) measures relative health of
fish communities and the Invertebrate Community
Index (ICI) is a measure of the health of the macro-
invertebrates in a waterway. Ohio's water quality
standards for exceptional warmwater habitat require
ICI>46, and IBI>50 (indices measuring stream health
as indicated by benthic macroinvertebrates and fish,
respectively). Data collected by Ohio showed failure
to attain these standards in the  Upper Big Darby
Creek watershed, resulting in the addition of these
waters on the 2006 CWA section 303(d) list (listed as
the  Headwaters of Big Darby Creek AU: Waterbody
ID OH050600011901), for failing to attain warm and
coldwater habitat designated uses due to hydromodi-
fication and habitat alteration. A total maximum daily
load to restore these impaired designated uses was
completed for the watershed in 2006.
                                        roctor ^>-t6wer]
                                             Treacte
                                      Upper Treacle    V. _ BDC 3
                                       Upper LDC   Middle
                                                LDC
                                 Big Darby Sub-Watersheds
                                 I  I Upper Big Darby Creek
                                 I  [ Middle Big Darby Creek
                                 [  Lower Big Darby Creek
                                 Pn Little Darby Creek
                               Figure 1. The 555-square-mile Big Darby Creek
                               watershed, in central Ohio, includes four subwatersheds:
                               Little Darby Creek, and the Upper Big Darby, Middle Big
                               Darby, and Lower Big Darby creeks.

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          Figure 2. In 2011, partners completed a restoration
          project along this section of Big Darby Creek,
          establishing a newfloodplain along a formerly
          channelized, entrenched section.
                                             Figure 3. By 2015, grasses and other riparian
                                             vegetation had become re-established on the
                                             floodplain of Big Darby Creek, providing enhanced
                                             wildlife and aquatic habitat.
          Project Highlights
                                            Results
          In response to the impaired conditions of the
          headwaters of the Big Darby Creek watershed, The
          Nature Conservancy, in partnership with Ohio EPA
          via the CWA section 319(h) grants program and the
          Water Resources Restoration Sponsorship Program
          (WRRSP), completed restoration and re-naturalization
          of more than a mile of the headwaters of Big Darby
          Creek. The Nature Conservancy was the prime part-
          ner in the project.  Restoration work by TNC began in
          2007 and was completed in 2011. Specific restoration
          actions implemented by The Nature Conservancy
          included:
          • 5.7 acres of  riparian wetland restorations.
          • 7,086 linear feet  of stream restoration with recon-
            nection to channel floodplain and additional  hydro-
            logic features (riffle/pool sequences,  rootwads, etc)
            installed.
          • 24 acres of riparian area plantings (grasses and
            34,094 trees and shrubs).
          • Gravel grade control in three tributaries, including
            directing discharge to a wetland.
          • Public education and outreach project.
                                            As a result of the above restoration efforts, condi-
                                            tions have improved in the headwaters of Big Darby
                                            Creek. Riparian vegetation has recovered and
                                            flourished along the restored sections of the creek
                                            (Figures 2 and 3).

                                            Post-restoration QHEI scores ranged from just below
                                            60 up to 70 (QHEI > 60 is correlated to support of
                                            exceptional warmwater habitat). IBI and ICI indices
                                            in 2014 were all greater than 50 (out of a max of 60),
                                            indicating exceptional warmwater habitat. Based
                                            on these data, Ohio plans to delist the Headwaters
                                            of Big Darby Creek AU (19.2  square miles) for
                                            hydromodification and habitat alteration in the 2016
                                            integrated report.
                                            Partners and Funding
                                            The restoration of Upper Big Darby Creek was
                                            the result of collaboration between The Nature
                                            Conservancy, Ohio EPA and the WRRSP. The Nature
                                            Conservancy sponsored and implemented the resto-
                                            ration projects using $532,000 in CWA section 319
                                            grant funding and $1,000,000 in Ohio EPA's WRRSP
                                            funds.
yss
Ill
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U.S. Environmental Protection Agency
Office of Water
Washington, DC

EPA841-F-15-001ZZ
November 2015
For additional information contact:
Russ Gibson, Ohio EPA
Russ.gibson@epa.ohio.gov • 614-644-2020
Jeff De Shon, Ohio EPA
Jeff.deshon@epa.gov • 614-836-8780
Anthony Sasson, The Nature Conservancy
asasson@tnc.org  • 614-339-8123

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