Section 319
NONPOINT SOURCE PROGRAM SOCGESS STORY
Restoration Efforts Improve Aquatic Life in Olentangy River
WatPrhndv Imnrnvpd Lowhead dam structures, failing home septic systems, and
' " increased agricultural and urban stormwater runoff had degraded
water quality in Ohio's Olentangy River. As a result, in 2002 the Ohio Environmental Protection
Agency (Ohio EPA) added a watershed-based unit of the river to the state's Clean Water Act
(CWA) section 303(d) list of impaired waters for failure to meet the water quality standards
associated with the unit's designated warm-water habitat (WWH) aquatic life use. Thanks to
work completed through the Olentangy River Restoration Project, approximately three miles of
the Olentangy River now fully attains the designated WWH aquatic life use. While additional
monitoring is required, Ohio EPA expects to remove flow alteration as a cause of impairment in
the watershed-based unit of Olentangy River on the state's 2014 list of impaired waters.
Problem
The rapidly developing Olentangy River watershed
is in central Ohio, north of the Columbus metropoli-
tan area. The 93-mile-long river originates near the
city of Gallon, flows through the city of Delaware
(Figure 1), and empties into the Scioto River in
downtown Columbus. The major land uses in the
watershed are cropland (56 percent), urban (14 per-
cent), forest (14 percent) and pasture (13 percent).
Data collected by Ohio EPA in 1999 identified water
quality problems in the Olentangy River. As a result,
Ohio EPA added a watershed-based unit of the river
to the state's 2002 section 303(d) list of impaired
waters for failure to meet standards for WWH aquat-
ic life use. In 2005, Ohio EPA collected additional
biological data at four Olentangy River monitoring
sites within the city of Delaware. Biological metrics
showed thatfish communities (Index of Biological
Integrity) and macroinvertebrate communities
(Invertebrate Community Index) were not meeting
the state's WWH standards; in addition, the physical
habitat conditions (Qualitative Habitat Evaluation
Index) were classified as relatively poor.
In 2007 Ohio EPA finalized a total maximum daily
load (TMDL) for the Olentangy River. The TMDL
report identified habitat alteration, hydromodifica-
tion, urban and agricultural runoff, and failing home
sewage treatment system (HSTS) units as the key
causes of impairment leading to partial attain-
ment or nonattainment of the river's designated
WWH aquatic life use. Lowhead dams blocked
fish migration and contributed to degraded water
quality within impounded pools. Failing HSTS units
Figure 1. The Olentangy River flows through the city of Delaware.
contributed nutrients to the river, and high-volume
stormwater flows contributed silt and sediment.
Project Highlights
Using CWA section 319(h) grant funds, the Friends of
the Lower Olentangy and the Olentangy Watershed
Alliance developed watershed action plans. Both
the watershed plans and the 2007 TMDL recom-
mended (1) removing all lowhead dams within the
city of Delaware, (2) replacing failing HSTS units
in the southern portions of Delaware County, and
(3) more effectively managing agricultural and urban
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Figure 2. Heavy machinery was
used to remove the River Street
Dam, one of four lowhead dams
removed from the Olentangy River
during the project period.
stormwater runoff. In
addition, because of rapid
residential development
observed in the area, the
TMDL report recommend-
ed that riparian buffers be
protected.
Multiple partners helped to
implement the Olentangy
River Restoration Project.
The City of Delaware
removed four lowhead dam
structures (Figure 2). The
Delaware County General
Health District worked
with homeowners to replace or repair 126 failing
HSTS units. Ohio EPA acquired conservation ease-
ments on approximately 235 acres of high-quality
riparian and headwater areas. The local soil and
water conservation districts, the Ohio Department
of Natural Resources' Division of Soil and Water
Resources (ODNR-DSWR), and the Olentangy River
watershed coordinator worked with landowners
to enroll more than 12,300 agricultural acres in
the U.S. Department of Agriculture's Conservation
Reserve Enhancement Program, which provided
financial incentives for converting cropland to native
grasses, trees and other vegetation. Finally, Ohio EPA
implemented a revised Olentangy River Construction
Stormwater Permit, which mandated more strin-
gent requirements for stormwater discharges from
construction activities in the watershed.
Table 1. Pre- and Post-Project Bioassessment Data for
the Olentangy River within the city of Delaware, Ohio
Results
Restoration efforts have improved water quality
in the Olentangy River. Bioassesment data col-
lected by Ohio EPA in 2009 showed that water
quality in a three-mile-long monitored segment of
the river meets WWH biocriteria (Table 1). Further,
all sites meet exceptional WWH standards for at
least one of the biocriteria used to assess fish
and macroinvertebrate community health. The
macroinvertebrate scores (ICI) show the most
dramatic increases—up by more than 40 percent
at some sites. Physical habitat conditions have also
increased considerably: Three of four sites exceed
the exceptional WWH standards.
Although these data show significant water qual-
ity improvement in the Olentangy River, Ohio EPA
continues to monitor throughout the watershed to
determine whether the entire assessment unit can
be removed from the state's list of impaired waters.
Sample
Location
River Mile
Aquatic
Life Use
Attainment
Status
Index of
Biotic
Integrity
(fish)
Modified
Index of
Weil-Being
(fish)
Invertebrate
Community
Index
Qualitative
Habitat
Evaluation
Index"
2005 Data
28.2
27.5
26.0
25.8
25.4
NON
PARTIAL
PARTIAL
PARTIAL
FULL
30
42
38
34
46
6.1
7.1
9.5
8.6
8.6
20
42
26
32
50b
55.5
81.0
45.5
49.0
84.0
2009 Data
27.5
26.0
25.8
25.4
FULL
FULL
FULL
FULL
46
48b
46
48b
9.4b
8.8
9.1
9.0
54b
44
52b
52b
70.0
62.5
54.4
63.0
Notes:
Bold indicates impairment, according to the state's WWH biocriteria.
a = Values > 60 are generally conducive to the establishment
of warm-water fauna; values > 75 often typify habitat
conditions that can support exceptional fauna.
b = Meets exceptional WWH standards.
Based on data collected so far, the state expects to
remove flow alteration as a cause of impairment for
the assessment unit when the 2014 list of impaired
waters is prepared.
Partners and Funding
Key partners included the City of Delaware,
Delaware County General Health District,
Preservation Parks, Ohio's Scenic Rivers, Ohio
Department of Transportation (ODOT), ODNR-DSWR
and Ohio EPA. Project funding was provided by the
U.S. Environmental Protection Agency, Ohio EPA,
the City of Delaware and ODOT. The city received
a $105,000 CWA section 104(b)(3) grant to help
support dam removals. Approximately $6.3 million
was provided through Ohio EPA's Water Resources
Restoration Program for land and conservation
easement acquisition. The Health District received
approximately $110,000 in CWA section 319(h)
funding to support HSTS inspections and replace-
ments. ODNR-DSWR received $405,000 in CWA
section 319(h) funding for converting an agricultural
ditch into a two-stage channel. In addition, $70,000
in Ohio EPA Surface Water Improvement funds was
awarded to the City of Delaware for additional dam
removal work. All monitoring was completed by
staff from Ohio EPA's Ecological Assessment Unit.
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-12-001L
June 2012
For additional information contact:
Russ Gibson
Ohio Environmental Protection Agency
614-644-2020
russ.gibson@epa.state.oh.us
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