Section 319
NONPOINT SOURCE PROGRAM SUCCESS STORY
Controlling Sediment Improves a Native Cutthroat Trout Stream
Waterbody Improved
Historical overgrazing by cattle and elk herds damaged riparian
areas and streambanks along Comanche Creek. Water quality
surveys in 2000 and 2002 prompted the New Mexico Environment Department (NMED) to add the
creek to the state's Clean Water Act (CWA) section 303(d) list of impaired waters for sedimentation
and temperature. Reducing the number of cattle and implementing grazing management practices
have improved water quality and habitat for the native cutthroat trout. In 2008 NMED removed
sedimentation as a cause of the impairment of Comanche Creek on the state's list of impaired waters.
Although the creek is still impaired because of temperature, data show improvements.
Problem
Comanche Creek is a scenic trout stream in the
Valle Vidal unit of the Carson National Forest in
northern New Mexico (Figure 1). The 10.3-mile-long
creek drains a 43-square-mile watershed and emp-
ties into Rio Costilla (Costilla Creek), which flows
into the Upper Rio Grande watershed in southern
Colorado. The major land uses in the Comanche
Creek watershed are forest (66 percent) and
rangeland (33 percent). Today, the Forest Service
manages the entire watershed.
Until 1982 the Comanche Creek watershed was
under private ownership and subject to intense
grazing from cattle and elk herds. Substrate
analyses conducted in the creek by NMED in the
1990s recorded a high frequency of very small
sediment particles. A water quality survey con-
ducted in 2000 showed that the creek was failing
to support its high-quality aquatic life use because
of excessive sediment. New Mexico's general
narrative water quality standard for stream bot-
tom deposits requires that surface waters be free
of contaminants from other than natural sources
that will damage or impair aquatic life or signifi-
cantly alter the physical and chemical properties
of the bottom. At the time of the initial listing,
the state used a target maximum of 20 percent
fines (particles less than 2 millimeters in size) to
assess stream bottom deposits. On the basis
of the sediment data, NMED added a 4.3-mile
segment of Comanche Creek to the CWA section
303(d) list of impaired waters for sediment in 2000.
In 2006 the sediment-listed portion of the creek
was expanded to cover a 10.3-mile-long segment
(NM-2021.A 827).
Figure 1. A restored section of Comanche Creek in the
Valle Vidal unit of the Carson National Forest, 2012.
Water temperature data collected in 2002 indicated
that the creek exceeded the state's numeric water
quality criterion: Temperature must remain below
a maximum of 23°C (73°F). On the basis of these
data, in 2004 NMED added temperature to the list of
impairments on Comanche Creek. Rangeland graz-
ing from cattle and elk was listed as the probable
source of the impairments. NMED developed a total
maximum daily load (TMDL) for temperature for the
Upper Rio Grande (which includes Comanche Creek)
in 2004; no sediment TMDL was developed.
Project Highlights
In 1982 a private landowner, Pennzoil, donated
100,000 acres of its Vermejo Park Ranch property
to the Forest Service. The Forest Service immedi-
ately suspended domestic livestock grazing for two
years and established a new stocking rate to allow
-------
Figure 2. A cut bank on Comanche
Creek, before treatment.
vegetation to begin to
recover. Since then, the
Forest Service has closed
approximately 300 miles
of unpaved access road
in the Valle Vidal area.
In 1991 NMEDand
Carson National Forest
cooperated on a CWA
section 319 grant project
that stabilized erosion
along Comanche Creek.
In 2001 and 2004, NMED
awarded CWA section
319 grants to the Quivira
Coalition, a local nonprofit
organization, to imple-
ment restoration work
in Comanche Creek. The
projects included install-
ing more than 50 small
exclosuresto restrict
elk and cattle grazing,
130 post vanes (a series
of posts pounded into
the streambed to deflect
water flow away from the
streambank), several Zuni
bowl rock structures (rock-lined step pools) to arrest
headcut migration, and 75 upland structures to con-
trol erosion (Figures 2 and 3). Project partners also
improved drainage and culverts on eight miles of
road, planted willows and sedges, and conducted
planning, design, coordination and monitoring. The
Quivira Coalition conducts annual workshops that
engage volunteers in maintaining the exclosures
and other structures.
In 2008, similar restoration work in Comanche Creek
continued under the River Ecosystem Restoration
Initiative (RERI), a state-funded program patterned
after the CWA section 319 program. The RERI project
realigned the channel away from the bank to stop
erosion on a very high cut bank along a meander
bend. In addition, the Quivira Coalition initiated a new
project in 2012 to improve and protect wetlands on
slopes within the headwaters of Comanche Creek.
The Comanche Creek watershed restoration projects
have been conducted in the context of two water-
shed plans developed by the Quivira Coalition—the
Comanche Creek Watershed Preliminary Assessment
Report (2001) and the Comanche Creek Watershed
Restoration Action Strategy (2005).
Results
Figure 3. The same cut bank on
Comanche Creek, after installation of
post vanes.
Restoration projects have improved water quality
and habitat for the native cutthroat trout, which has
been reintroduced to Comanche Creek. The creek
was surveyed in 2000 and again in 2006. Pebble
counts showed that percent fines decreased from
44 percent to 3 percent over that period, indicating
significant sediment load reductions. Benthic mac-
roinvertebrate surveys were also conducted, but
the assessment methodology changed during the
course of restoration work, making before-and-after
comparison of bio-scores difficult. The bio-scores,
however, did change from an "impaired" category
before restoration to a "non-impaired, full support"
category after restoration. Furthermore, compari-
sons of cross sections before and after restoration
show a statistically significant decrease in bankfull
width and width-to-depth ratio, indicating a decline
in sedimentation. On the basis of these data, NMED
removed sedimentation as a cause of impairment
for the 10.3-mile segment of Comanche Creek on
the 2008 CWA section 303(d) list. Statistical tests
have indicated that summer maximum tempera-
tures in Comanche Creek have decreased as well.
The creek exceeds the state's current water quality
numeric criteria for temperature, however, and will
remain listed as impaired for temperature.
Partners and Funding
Key partners in the restoration effort were NMED,
the Forest Service's Carson National Forest and
the Quivira Coalition. Other partners included
the Albuquerque Wildlife Federation (contributed
volunteers for restoration work), New Mexico Game
and Fish (carried out Rio Grande Cutthroat Trout
reintroduction), Trout Unlimited (contributed vol-
unteers), the Santa Clara Fire Crew and the Gallup
Youth Conservation Corps.
Several CWA section 319 projects have taken place
in the watershed. In 1991 NMED and the Carson
National Forest cooperated on a $1,273,012 CWA
section 319 grant to implement erosion control. The
Quivira Coalition led two projects between 2001
and 2008 using $361,075 in CWA section 319 funds
(and another $317,262 in matching funds and in-kind
labor). State nonpoint source program members
had oversight responsibility and coordination roles
in each of these projects.
The Quivira Coalition also received state-supported
RERI funds in 2008 ($157,900) and 2011 ($199,171)
to conduct additional restoration projects.
I
o
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-13-001M
April 2013
For additional information contact:
Daniel Guevara, Environmental Scientist
New Mexico Environment Department
daniel.guevara@state.nm.us
505-476-3086
------- |