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NONPOINT SOURCE SUCCESS STORY
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Installing Management Practices Improves the North Fork Virgin River
Waterbody Improved Fl°ocl-irrigated pastures grazed by cattle and wildlife contributed
to Escherichia coli exceedances in the North Fork Virgin River
watershed. As a result, the Utah Department of Environmental Quality (DEQ) included the upper
North Fork Virgin River on Utah's Clean Water Act (CWA) section 303(d) list of impaired waterbodies
in 2010 for failing to meet the E. coli standard for frequent primary contact recreation (2A),
The lower watershed was listed in 2012. Landowners and agencies collaborated to implement
recreational area improvements and best management practices in 2011-2017, and water quality
has improved. E. coli data have not exceeded the standard since 2015. The DEQ Division of Water
Quality (DWQ) will continue to collect data, and if no exceedances are observed, the North Fork of
the Virgin River could be delisted for E. coli as early as 2020.
Problem
The North Fork Virgin River watershed drains
approximately 360 square miles (230,390 acres) on
the Colorado Plateau in southwest Utah (Figure 1). The
river emerges as a spring at Cascade Falls and flows
for 16 miles before entering Zion National Park, The
North Fork Virgin River continues through the park for
several miles and combines with Deep Creek, Kolob
Creek, and several other tributaries to flow through
the famous Zion Narrows. The river flows for 25 miles
from Cascade Falls to the confluence with the East
Fork Virgin River in the town of Springdale.
Monthly E. coli data were collected at multiple sam-
pling sites in May through October, 2010-2017. E. coli
is an indicator of fecal contamination in a waterbody.
Exceedances of the standard were primarily driven
by return flows from flood-irrigated pastures grazed
by cattle and wildlife. Addressing the impairment by
developing a total maximum daily load (TMDL) was a
priority for DWQ due to the many people recreating
in the river in and near Zion National Park. Every year
thousands of people wade and swim in the river when
they hike the Zion Narrows trail.
North Fork Virgin River Watershed General Location ] n
UTAH
Long Valley
Junction
Story Highlights
Various agencies and landowners began working to
improve water quality by implementing best manage-
ment practices (BMPs) before the North Fork Virgin
River E. coli TMDL was completed in 2018. DWQ
awarded a nonpoint source grant to the Kanab Bureau
Figure 1. I he North Fork Virgin River is in southern Utah.
of Land Management (BLM) field office in 2011 to
install a vault toilet at the Chamberlain Ranch trail-
head, where the popular 16-mile Zion Narrows hike
begins. As a result, the amount of human waste scat-
tered about the trailhead has decreased and the over-
all conditions at the trailhead have greatly improved.

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North Fork Virgin River at BLM Boundary Fence below Chamberlain Ranch
Figure 2. A flow measurement device was added to
this irrigation diversion.
In an attempt to reduce E. coli loading from flood-
irrigated pastures in the upper watershed, a pre-
scribed grazing management plan was implemented
on 45 acres on private lands during the 2015 grazing
season. This plan helped identify how many animals
could graze on each individual pasture without overus-
ing the feed that was available in each pasture. It also
coordinated the timing of the grazing and irrigation.
Allowing the feces to dry for a period of days to weeks
before irrigation water was applied decreased the
amount of E. coli that was mobilized and entered the
stream.
The grazing management plan helped improve the
riparian area. Although no attempt was made to quan-
tify the increase in riparian vegetation, improvements
were visibly noticeable throughout the season. The
increase in riparian vegetation acts to slow overland
flow and reduce the pathogens entering the river from
the pastures during irrigation and precipitation events.
As part of the plan, approximately 200 feet of fences
and gates along several pastures were improved to
allow ease of hiker access while discouraging tres-
pass cattle from grazing on pastures that were being
actively irrigated.
Many of the pastures in the upper watershed are
irrigated through wild flood irrigation. Historically,
the landowners would divert the maximum amount
of water that their system would hold. This excess
of water increases the potential for bacteria-laden
irrigation return flows to enter the river, irrigators
throughout the watershed have been encouraged to
install measurement devices, and some already have
(Figure 2).



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9/1/2012 3/20/2013 10/6/2013 4/24/2014 11/10/2014 5/29/2015 12/15/2015 7/2/2016 1/18/2017 8/6/2017
~ E. coli MPN/lOOmL 	E. coli Not To Exceed Standard	E. coli Geomean Standard
Figure 3. E. coli concentrations have dropped in the North Fork
Virgin River.
Results
Through a collaborative effort between the DWQ,
Zion National Park and BLM, the North Fork Virgin
River watershed has been intensively monitored for
E. coli during the recreational season. The results
show that eliminating grazing, managing human waste
and improving irrigation water management has led
to improved water quality. As seen in Figure 3, E. coli
levels have not exceeded water quality standards since
BMPs were installed. DWQ will continue to collect
data, and if no exceedances are observed, the North
Fork of the Virgin River could be delisted for E. coli as
early as 2020.
Partners and Funding
Stakeholder participation was achieved through
multiple meetings and site visits over the past few
years. Approximately $30,000 has been spent on
improvements in the watershed, with funding coming
from state, federal and private sources: BLM ($1,600
for water measurement devices and gates/fencing),
Utah DWQ ($18,365 for installing a vaulted toiiet), and
Utah Department of Agriculture and Food ($10,000
for grazing management pian development). Other
partners included iocai landowners, Zion National
Park, Utah Association of Conservation Districts, and
Utah Division of Water Rights.
The most effective component has been the change
in land management by eliminating grazing, which
was accomplished by educating the landowners and
developing proper management plans. This is a water
quality success story that highlights the importance of
proper land use management, without a large amount
of funding needed to install expensive BMPs.
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©
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-18-Q01RR
December 2018
For additional information contact:
Amy Dickey
Utah Division of Water Quality
801-536-4334 • adickey@utah.gov

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