United States
Environmental Protection
Agency
Total Maximum Daily Loads
Committed Landowner Implements and Advocates
Improved Grazing Practices in Nutrioso Creek,
Reducing Turbidity Levels to Attain Water Quality
TMDLataGlance:
Nutrioso Creek TMDLs—
Turbidity
(approved September 2000)
www.azdeq.gov/environ/water/assessment/download/
nutrioso.pdf
Factors causing impairment:
Elevated turbidity levels for aquatic and wildlife cold
water streams
Sources contributing to impairment:
Stream bank and channel erosion induced by
livestock grazing practices, livestock and wildlife
access to streams, and riparian vegetation loss
Restoration options:
Improve range management practices, exclude
livestock and wildlife from streams, re-vegetation of
riparian areas, conservation easements, and adopting
livestock, nutrient, irrigation, and pest management
strategies
Since the late 1800s, the Nutrioso Valley experienced heavy grazing that contributed
to excessive erosion and elevated turbidity levels. The excessive turbidity resulted in
unsuitable stream habitat for Nutrioso Creek's aquatic communities. As a result, the
Arizona Department of Environmental Quality (DEQ) placed a seven mile stretch of
Nutrioso Creek on the state's section 303(d) list of impaired waterbodies and developed
a turbidity TMDL approved in 2000. Although historic grazing practices were the
primary cause of impairment in Nutrioso Creek—it was progressive grazing
practices implemented by a committed local landowner that led to the restoration
of Nutrioso Creek. TMDL effectiveness monitoring data collected from 2004 to
2006 indicated that Nutrioso Creek met the TMDL load allocation and attained
water quality standards. In 2009, Nutrioso Creek was the first waterbody removed
from the Arizona's section 303(d) list of impaired waters due to implementation
activities.
How are TMDLs at work in Nutrioso Creek?
The ADEQ developed the turbidity TMDL for Nutrioso Creek to protect aquatic
wildlife, including the federally endangered Little Colorado spinedace, from
excessive sedimentation. Through the TMDL analysis, stakeholders were provided
with an understanding of the significant sources and critical flow conditions
contributing to the turbidity impairment in Nutrioso Creek. In addition, the
TMDL analysis provided a link between turbidity and total suspended solids,
providing stakeholders with an understandable and measurable end point for
assessing progress toward achieving the turbidity water quality standard. The final
TMDL report also provides a description of the effectiveness monitoring planned
to determine progress of TMDL implementation, along with a phased TMDL
implementation timeline, description of goals, and implementation milestones.
Stakeholder involvement:
EC Bar Ranch owner, local watershed residents, Little
Colorado River Watershed Partnership, Nutrioso
Creek Watershed Partnership, state and federal
agencies
Status of waterbody:
Full attainment of water quality standards; removed
from 303(d) list in 2009
Benefits to stakeholders:
Water quality, wildlife habitat, education, funding,
partnerships
Who were the participating stakeholders and key partners?
ADEQ is responsible for developing Arizona's TMDLs, including the Nutrioso
Creek turbidity TMDL, with participation from key partners and stakeholders.
Unlike TMDL development, TMDL implementation for nonpoint source-related
issues is in the hands of local stakeholders and partners. Local stakeholders that
initiated implementation activities, as well as participated in TMDL development,
What is a total maximum daily load (TMDL)?
It is a study or analysis that calculates the maximum amount of a pollutant that a waterbody can receive and still meet
water quality standards. The TMDL establishes a pollutant budget and then allocates portions of the overall budget to
the pollutant's sources. For more information on TMDLs, visit EPA's website at www.epa.gov/owow/tmdl.
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include members of the Nutrioso Creek Watershed Partnership and the Upper Little
Colorado River Partnership. A key stakeholder involved in TMDL implementation is
Jim Crosswhite, the owner of the E.G. Bar Ranch that contained 3 miles of the impaired
Nutrioso Creek. Key state partners, in addition to ADEQ, included the Arizona Game
and Fish Department (AGFD), Arizona State Land Department, Arizona Department of
Agriculture, and the Arizona Water Protection Fund. The U.S. Environmental Protection
Agency (EPA) is a key federal partner involved in both reviewing and approving the
turbidity TMDL for Nutrioso Creek and providing funding to support implementation.
Other key federal partners include the U.S. Forest Service, responsible for managing the
Apache-Sitgreaves National Forest that contained 4 miles of the impaired Nutrioso Creek,
as well as the U.S. Fish and Wildlife Service.
How did stakeholders participate in the TMDL process?
The overall TMDL process includes the following elements: section 303(d) listing
decisions, TMDL development, and TMDL implementation. Each element of the TMDL
process provided stakeholders with an opportunity to express concerns and share
information about the water quality problems in Nutrioso Creek with the ADEQ and
other key partners. A description of each element of the TMDL process is provided below.
Section 303(d) Listing Decisions
If a waterbody does not meet water quality standards (i.e., numeric or narrative criteria)
for one or more pollutants, it goes on a state's 303(d) list. Impaired waterbodies on this
list require a TMDL for each pollutant contributing to the impairment. Stakeholders have
the opportunity to provide input during the 303(d) listing process. ADEQ placed Nutrioso
Creek on the states's 303(d) list in 1996 . To verify and identify the turbidity impairment,
ADEQ conducted three-days of intensive watershed-wide turbidity sampling in 1999 and
in 2000 in addition to targeted monitoring.
TMDL Development
ADEQ initiated the development of the Nutrioso Creek turbidity TMDL due to turbidity
levels in a seven-mile stretch of the creek that exceeded the turbidity water quality
standard for aquatic and wildlife cold water streams. The turbidity water quality standard
of 10 Nephelometric Turbidity Units (NTU) is an indirect measure intended to protect
aquatic and wildlife designated uses from excessive sedimentation. Therefore, the ultimate
goal of restoring the condition of the biological communities and in-stream habitat in
Nutrioso Creek is linked to reducing the amount of sediment entering Nutrioso Creek
from the identified sources.
Although turbidity is a useful indirect measure for the purposes of water quality
standards, it is challenging to use in the context of TMDL development. The TMDL
framework requires a pollutant quantified using a measure of mass to develop a daily load.
The unit used to measure turbidity—NTU—measures light refraction. As a result, ADEQ
needed to identify a related surrogate for turbidity for calculating a pollutant load. ADEQ
selected total suspended solids (TSS) as the surrogate for turbidity and established a
quantifiable, statistical relationship between turbidity values and TSS values. ADEQ used
this relationship to understand how reductions in TSS would translate into reductions
in turbidity levels, allowing them to identify the TSS value that would correlate to the
turbidity water quality standard. The final TMDL report stated that the turbidity water
quality standard of 10 NTUs is equivalent to a TSS target value of 7.91 milligrams per
liter (mg/L) and a TSS target load of 183 pounds per day (Ibs/day).
The TMDL development process revealed that excessive turbidity levels in Nutrioso
Creek are due to suspended solids resulting from excessive sediment loads. Factors
contributing to the excessive sediment loads include streambank erosion due to stream
channel degradation, loss of floodplain, and lack of adequate riparian vegetation. ADEQ
NlltriOSO CrOBk — 2 determined that Nutrioso Creek has no point sources of turbidity. As a result, the TMDL
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report contains a load allocation for nonpoint sources and a wasteload allocation of zero
for point sources.
Through the TMDL analysis, ADEQ identified the period from February to May as the
critical season for sediment loading in Nutrioso Creek. These months are critical because
they are characterized by high spring flows from snow melt and rainfall. The final TMDL
report states that the measured load of TSS is 1,020 Ibs/day (44 mg/L) with a critical
flow in Nutrioso Creek of 4.3 cubic feet per second (cfs). To achieve the turbidity water
quality standard in Nutrioso Creek, the TMDL analysis assigned a TSS load allocation to
nonpoint sources in Nutrioso Creek of 154.8 Ibs/day, an allocation to background sources
of 5 Ibs/day, and a margin of safety of 23.2 Ibs/day (15 percent of the load allocation), for
a total TSS target load of 183 Ibs/day. Because the existing measured TSS load during the
critical flow period was 1,020 Ibs/day, ADEQ determined that a TSS load reduction of
837 Ibs/day would be necessary to achieve the turbidity water quality standard in Nutrioso
Creek.
Once developed, ADEQ made the draft Nutrioso Creek turbidity TMDL available
for a public comment period lasting 30 days. Public notice of the availability of the
draft document was disseminated through a local newspaper (The Observer), email
notifications, phone calls, and webpage postings. ADEQ also presented the draft TMDL
at a meeting of the Upper Little Colorado Watershed Group to obtain additional public
comments.
TMDL Implementation
The Nutrioso Creek turbidity TMDL discusses implementation-related issues, including
best management practices (BMPs), effectiveness monitoring, timeline, and milestones.
The final TMDL report presents the following implementation goals:
1) Increase education and public awareness to local landowners through the public
participation process and watershed group activities
2) Create milestones for each BMP project and reevaluate the effectiveness as necessary
3) Decrease Stream Velocities during critical flow events utilizing
a) Willow vegetation
b) Stream grade stabilization structures
c) Increased flood plain (addition of point bars), natural creation preferred
4) Decrease sheet flow and wind erosion contributions to Nutrioso Creek by
a) Removing Rabbitbrush
b) Increasing density of grasses as land cover
c) Promoting BMPs
5) Stop downcutting of the stream channel and promote stabilization of the channel by
a) Removing cattle and wildlife from the stream channel during critical flow periods
b) Allowing cattle to graze in the dormant winter months, under a range management
system
c) Revegetating the stream channel
d) Allowing time for stabilization of stream banks to occur
e) Promoting BMPs
f) Using stream restoration techniques to speed up recovery of stream corridor
sections
The final TMDL report discusses strategies that could help to reduce sediment loads along
the 7 mile impaired stretch of the creek—4 miles flowing through the Apache-Sitgreaves
National Forest administered by the U.S. Forest Service (USFS) and 3 miles flowing
Nutrioso Creek-3
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through the privately-owned lands. The USFS implemented several BMPs to address the
sources of sediment from the Apache-Sitgreaves National Forest affecting turbidity levels
in Nutrioso Creek. These BMPs included reductions in timber cutting, road closures, and
cattle grazing allotment revisions.
According to the final TMDL report, the 3-mile stretch of Nutrioso Creek through private
lands had the highest turbidity levels based on data collected during the TMDL sampling
activities. These privately-owned lands were characterized by historic overgrazing
and poor range management practices. TMDL implementation efforts were led by Jim
Crosswhite, the owner of the EC Bar Ranch and one of the three landowners in this
stretch of Nutrioso Creek. Crosswhite changed his range management practices and used
state and federal funding to implement several BMPs suggested in the final TMDL report.
BMPs implemented by Crosswhite include fencing out elk from the riparian corridor on
his property and limiting cattle grazing to the dormant winter months; revegetating the
riparian corridor with willow plantings and grass seeds; and adopting the conservation
plan developed by the Natural Resources Conservation Service (NRCS) for Nutrioso
Creek. Crosswhite's implementation activities cost approximately $2 million, with funding
from ADEQ, NRCS, wildlife agencies and other key partners. Crosswhite also provided
personal resources to fund these implementation efforts by matching 60 percent of the
public funding.
What is the current status of Nutrioso Creek as a result of the TMDL
process?
The final TMDL report describes the use of a phased-implementation approach,
dependent on the availability of funding for implementation projects. In 2000, before
implementation projects were initiated, Nutrioso Creek had a measured turbidity level of
55 NTU, equivalent to a measured TSS load of 1,020 Ibs/day at the critical flow of 4.3 cfs
ADEQ estimated that Nutrioso Creek would require 5-20 years to meet the turbidity
water quality standard. Effectiveness monitoring conducted between 2004 and 2006,
demonstrated the success of implementation activities in decreasing turbidity levels and
associated TSS levels in Nutrioso Creek. In the January 2007 Nutrioso Creek Turbidity
TMDL Effectiveness Monitoring Report, ADEQ presents data that indicates TSS levels in
Nutrioso Creek fall below the TMDL TSS target load of 183 Ibs/day. Therefore, Nutrioso
Creek turbidity levels were well below the turbidity water quality standard of 10 NTU.
During the 2004-2006 monitoring period, the measured turbidity level in Nutrioso Creek
dropped to 5.68 NTU, equivalent to a TSS load of 138.65 Ibs/day at the same critical flow.
As a result of successful implementation efforts illustrated through the effectiveness
monitoring, ADEQ recommended delisting Nutrioso Creek from the state's section 303(d)
list of impaired waters. The 2007 ADEQ report acknowledges that measured water quality
data are not the only indicator of stream health and that future water quality standards,
such as biocriteria, might require ADEQ to reassess the conditions and status of Nutrioso
Creek.
How did local stakeholders benefit from the TMDL process?
The most significant benefit of the TMDL process has been the attainment of the turbidity
water quality standard and the removal of Nutrioso Creek from the Arizona section
303(d) list of impaired waters. While attaining water quality standards is the primary goal
of the TMDL process, stakeholders benefitted from the efforts in Nutrioso Creek. Benefits
from TMDL implementation included the following:
O Increased wildlife populations and improved wildlife habitat. Water quality
improvements led to significant increases in Little Colorado spinedace populations
upstream of the previously impaired Nutrioso Creek segment. Improved riparian
vegetation and habitat is anticipated to benefit the Southwest Willow Flycatcher, a
federally endangered bird species of Arizona.
Nutrioso Creek-4
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O Increased public education and awareness. Through
Crosswhite's outreach efforts, other local and regional ranch
owners have an increased understanding about the benefits
of conservation practices to Nutrioso Creek and other
waterbodies.
O Effective local partnerships and leveraged financial
resources. Crosswhite's initiative, coupled with the
involvement of the Nutrioso Creek Watershed Partnership,
established an effective local partnership with other key
partners at the state and federal level. Through these
partnerships, Nutrioso Creek benefitted from a $2 million
restoration effort that leveraged private and public financial
resources.
"If other landowners in Nutrioso and elsewhere in
Arizona cooperate with governmental agencies to
meet public policy goals, they can improve their
property and enhance natural resources just like I
have. Clearly, conservation pays off."
—Jim Crosswhite,
Nutrioso resident, owner of EC Bar Ranch
(September 2006 press release, E.G. Bar Ranch)
&EPA
December 2009 • EPA841-F-09-002Q
For more information on the Arizona TMDL Program, contact
Jason Suffer, ADEQ, Sutter.jason@azdeq.gov, (602) 771-4468
or visit www.azdeq.gov/environ/water/assessment/tmdl.html
Nutrioso Creek-5
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