National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center 

Assessment of Riparian-Wetland Conditions and 

Recommendations for Management 

Pueblo Colorado Wash, Hubbell Trading Post National Historic Site, 

Arizona 

Natural Resource Report NPS/NRPC/NRR—2010/213 
ON THE COVER 

Recovering riparian-wetland ecosystem in Pueblo Colorado Wash (2007) 

Photograph by: Joel Wagner, NPS-NRPC, Water Resources Division 
Assessment of Riparian-Wetland Conditions and 

Recommendations for Management 

Pueblo Colorado Wash, Hubbell Trading Post National Historic 

Site, Arizona

Natural Resource Report NPS/NRPC/NRR—2010/213 

Joel Wagner 

National Park Service 

Natural Resource Program Center 

Water Resources Division 

P.O. Box 25287 

Denver, Colorado 80225 

Richard Inglis 

National Park Service 

Natural Resource Program Center 

Water Resources Division 

1201 Oak Ridge Drive, Suite 250 

Fort Collins, CO 80525

June 2010 

U.S. Department of the Interior 

National Park Service 

Natural Resource Program Center

Fort Collins, Colorado 
ii 

The National Park Service, Natural Resource Program Center publishes a range of reports that 

address natural resource topics of interest and applicability to a broad audience in the National 

Park Service and others in natural resource management, including scientists, conservation and 

environmental constituencies, and the public. 

The Natural Resource Technical Report Series is used to disseminate results of scientific studies 

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reporting of the data, and whose background and expertise put them on par technically and 

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Views, statements, findings, conclusions, recommendations, and data in this report are those of 

the author(s) and do not necessarily reflect views and policies of the National Park Service, U.S. 

Department of the Interior. Mention of trade names or commercial products does not constitute 

endorsement or recommendation for use by the National Park Service. 

This report is available from the Natural Resource Publications Management website 

(http://www.nature.nps.gov/publications/NRPM). 

Please cite this publication as: 

Wagner, J. I. and R. Inglis. 2010. Assessment of riparian-wetland conditions and 

recommendations for management: Pueblo Colorado Wash, Hubbell Trading Post National 

Historic Site, Arizona. Natural Resource Report NPS/NRPC/NRR—2010/213. National Park 

Service, Fort Collins, Colorado. 

NPS 433/103717, June 2010 
iii 

Contents 

 Page 

Figures .................................................................................................. iv

Appendix .............................................................................................. v

Executive Summary ................................................................................... vi

Acknowledgments .................................................................................... viii 

Introduction ............................................................................................ 1 

Monitoring Well Network Installation ............................................................. 2 

Functional Condition of the Riparian-Wetland System .......................................... 4 

 Downstream Reach ............................................................................ 5 

 Upstream Reach ............................................................................... 6

Recommendations for Pueblo Colorado Wash Management Goals and the 

Revegetation Program ............................................................................... 7

What should be the long-term goal(s) for the Pueblo Colorado Wash 

riparian area within HUTR? Can the wash support a self-sustaining 

wetland-riparian vegetation community? .................................................... 7

What is required to meet these goals? At what point should the park 

stop planting wetland-riparian vegetation? ................................................. 8

 

Literature Cited ....................................................................................... 11 
iv 

Figures 

 Page

Figure 1. Location of Hubbell Trading Post National Historic Site............................ 12 

Figure 2. Photo pair of Pueblo Colorado Wash within HUTR, 1997 and 2007, 

 looking west toward Hubbell Hill.................................................................. 13 

Figure 3. Photo pair of Pueblo Colorado Wash within HUTR, 1997 and 2010, 

 looking west toward Hubbell Hill................................................................... 14 

Figure 4. Locations of observation well transects installed June 24-26, 2008 ............... 15

Figure 5. The Pueblo Colorado Wash maintained its basic channel form and 

riparian-wetland vegetation community even after this large runoff event in 

fall 2007 ............................................................................................. ... 16 
v 

Appendix 

PFC riparian system standard checklists and notes for downstream and 

 upstream reaches of Pueblo Colorado Wash within HUTR .................................. 17
vi 

Executive Summary 

Pueblo Colorado Wash is an integral feature of the cultural landscape preserved at Hubbell 

Trading Post National Historic Site (HUTR). During the 1970s and 1980s, exotic shrubs 

(tamarisk and Russian olive) invaded the wash. By about 1990, these shrubs had formed dense 

thickets that crowded out native vegetation and created a fire hazard that threatened the park’s 

invaluable cultural features. At about this same time, a deep gully formed in the wash, further 

diminishing its natural and cultural resource functions and values. By the late 1990s, these threats 

prompted some critical resource management actions. Exotic shrubs were removed and small inchannel structures were installed to encourage development of a more stable channel form. 

Cottonwoods and willows were planted and livestock were excluded to help establish a healthy, 

native riparian-wetland plant community. 

In 2008, the park superintendent asked the NPS Water Resources Division (WRD) to assess the 

condition of the riparian-wetland system in response to these and other restoration and 

management activities. During June 24-26, 2008, WRD staff used the Bureau of Land 

Management’s Proper Functioning Condition method to evaluate the condition of the riparian 

zone. The lower half of Pueblo Colorado Wash (downstream reach) was rated “Functional – At 

Risk” with an upward trend. This riparian segment was considered marginally functional in that it 

has many of the vegetation and hydrology characteristics of a properly functioning riparian system. 

However, factors such as lack of a diverse, soil-binding wetland plant community and excess 

sediment inputs from headcuts upstream placed this reach in the “At-Risk” category. The 

upstream reach was also rated “Functional – At Risk” with an upward trend. In addition to having 

the same risk factors as the downstream reach, this segment exhibited inadequate riparian-wetland 

vegetative cover to protect banks and dissipate energy during high flows. These persistent risk 

factors leave the entire wash vulnerable to future channel and floodplain destabilization and 

degradation in larger storms. 

Based on this condition assessment, the superintendent asked WRD to provide recommendations 

for addressing the immediate risk factors. This report recommends planting six herbaceous 

wetland species and several woody species to increase native plant diversity and cover. This 

would enhance wildlife functions and values by increasing the variety of habitats available for 

feeding, nesting, and so on, and would increase site stability and functionality by having multiple 

native plant species stabilize the channel and banks. 

Park management also asked for recommendations for longer-term riparian area management in 

Pueblo Colorado Wash. Specifically, the superintendent posed two sets of questions: 

1. What should be the long-term goal(s) for the Pueblo Colorado Wash riparian area within 

HUTR? Can the wash support a self-sustaining wetland-riparian vegetation community? 

2. What is required to meet these goals? At what point should we stop planting wetland-riparian 

vegetation, i.e., how do we know when we are done with the revegetation effort? 

Detailed responses to these questions, and recommendations for management, are provided in this 

report. However, some of the questions can’t be fully answered without additional data collection 
vii 

and analysis. The Southern Colorado Plateau I&M network (SCPN) is currently establishing a 

long-term program to monitor vegetation, channel morphology, and hydrologic conditions in 

Pueblo Colorado Wash. Prior to this site visit, WRD and SCPN staff met to discuss ongoing 

monitoring and to determine what additional information would be needed to address these 

questions. We decided to install a network of shallow observation wells in the wash during this 

site visit so we could monitor seasonal and inter-annual water table fluctuations. These data will 

be useful in determining if appropriate conditions exist to support a self-sustaining riparianwetland plant community and in identifying appropriate areas for additional riparian-wetland 

vegetation plantings. 
viii 

Acknowledgments 

We thank park Superintendent Anne Worthington for her extraordinary efforts in coordinating 

the management, restoration and monitoring of the Pueblo Colorado Wash. The work described 

in this report was conducted at her request and with her able assistance. Steve Monroe, Ellen 

Soles, and Jodi Norris of the NPS Southern Colorado Plateau Inventory and Monitoring Network 

(SCPN) played a huge role in installing the water table observation wells described in this report. 

They are among the hardest working and professional people we’ve worked with in the NPS, and 

were also very enjoyable companions during our field work and dinners together. A Southwest 

Conservation Corps crew (including Adrian Dineyazhe and Marcello Roanhorse) and a crew of 

Navajo Nation interns helped with well installation. They worked hard, were fun to work with, 

and were very much appreciated! 
1 

Introduction 

Pueblo Colorado Wash is an integral feature of the cultural landscape at Hubbell Trading Post 

National Historic Site (HUTR). The historic site is managed by the National Park Service and is 

located in northeastern Arizona, just west of the town of Ganado (Figure 1). During the 1970s 

and 1980s, the wash was invaded by exotic shrubs (tamarisk and Russian olive). By about 1990, 

these shrubs had formed thickets in the wash area that crowded out native vegetation and created a 

fire hazard threatening HUTR’s invaluable cultural features. At about the same time as the exotic 

shrub invasion, a deep gully formed along the length of the wash within the park (Shaw et al. 

2005). Factors contributing to the gully formation are complex and not fully understood, but 

likely include exotic shrub invasion, presence of an upstream dam that alters natural hydrology and 

sediment processes, climate cycles, grazing practices, and natural arroyo processes that can move 

sediment downstream in pulses through alternating episodes of channel filling and incision. 

By the late 1990s, threats to the park’s cultural resources by expanding tamarisk and Russian olive 

thickets and worsening erosion in Pueblo Colorado Wash led to some critical resource 

management decisions. Removal of exotic shrubs from the wash area began in the late 1990s. 

Once that process was underway, William (Bill) Zeedyk, a retired US Forest Service biologist and 

now an environmental consultant from Sandia, NM, supervised installation of small, in-channel 

structures made of locally available rock (and later wood and rock). These hand-built structures, 

which were designed to encourage formation of meanders in the bottom of the straight, incised 

channel, were evaluated in a 2000 WRD trip report (Inglis). The structures are built low in the 

channel to allow lower flows to cut the gully walls, while flood flows would overtop the structures, 

leaving them intact. The idea was to slow channel flow by providing a wider floodplain, which 

would encourage deposition of sediment, raise the water table, provide sites for riparian vegetation 

to establish, and ultimately raise the elevation of the streambed and floodplain to reverse the 

incision process. Cottonwoods and willows were planted on the edges of the channel and on the 

adjacent terraces to help recovery of the riparian system, slow flood flows, accumulate sediment, 

and enhance wildlife values. Livestock grazing was excluded from the area to promote natural 

vegetation recovery and to allow new plantings to become established. 

An upstream structure diverts flow into Ganado Lake, mostly during spring runoff (personal 

communication, Theresa Showa, Navajo Nation Department of Water Resources, July 2008). 

Sediment is trapped in a settling basin near the diversion structure and is flushed periodically back 

into the wash. This dam was renovated in the mid-1990s, and came back into use in 1998. Some 

irrigation releases are sent down Pueblo Colorado Wash; however, it is unknown how frequently 

this flow reaches HUTR. 

Figure 2 shows a 1997 and 2007 photo pair of Pueblo Colorado Wash. The 1997 photo shows a 

straight channel undergoing active incision (note vertical, unvegetated banks, unvegetated channel 

bottom, and large rock/debris that was either transported to this location or exposed by high 

velocity flows). By 2007, after management actions were taken, the channel has aggraded 

significantly, the banks have flattened, and native riparian and wetland vegetation cover is 

increasing in the channel and on the floodplain. One of Bill Zeedyk’s channel structures can be 

seen in the 2007 photo. Figure 3 shows a 1997 and 2010 photo pair of the wash, illustrating the 

response of the channel to these management actions farther downstream. 
2 

Riparian vegetation, channel morphology, and hydrologic conditions of Pueblo Colorado Wash 

were monitored by two investigators from 1998 through 2004 (Baker 2005; Zeedyk 2004). 

Zeedyk established and surveyed five cross-sections across the wash, creating a baseline for 

monitoring changes in channel and floodplain morphology. He also installed two water table 

monitoring wells. Even though these wells were measured infrequently and their spatial 

coverage of the wash is limited, they provide data describing a significant change (rise of greater 

than 2 meters) in riparian area ground water levels over a 10 year period of time. 

During a brief site visit by WRD staff (Wagner) in summer 2007, park superintendent Anne 

Worthington explained that the Southern Colorado Plateau I&M network (SCPN) is establishing 

a long-term program in Pueblo Colorado Wash to monitor vegetation, channel morphology, and 

hydrologic conditions. This program is incorporating Zeedyk’s cross-sections and wells into a 

more comprehensive monitoring system. At that time, we discussed the ongoing riparianwetland revegetation work in the wash area and formulated two related sets of questions: 

1) What should be the long-term goal(s) for the Pueblo Colorado Wash riparian area within 

HUTR? Can the wash support a self-sustaining wetland-riparian vegetation community? 

2) What is required to meet these goals? At what point should the park stop planting wetlandriparian vegetation? 

Anne submitted a 2008 technical assistance request to the Natural Resource Program Center for 

help with these complex questions. In February 2008, Rick Inglis, Joel Wagner, and Steve Monroe 

met to discuss ongoing monitoring in Pueblo Colorado Wash by the SCPN and to determine what 

additional information would be needed to address these questions. We decided to install a 

network of shallow observation wells in the wash so we could monitor seasonal and interannual 

water table fluctuations. These data would be useful in determining if appropriate conditions exist 

to support a self-sustaining riparian-wetland plant community and to identify appropriate areas for 

additional riparian-wetland vegetation plantings, if needed. We also decided to evaluate the 

current condition of the riparian system using the Bureau of Land Management’s process for 

assessing the “Proper Functioning Condition” of riparian areas (USDI, 1998). This rapid 

assessment method involves evaluation of 17 hydrology, vegetation, and stream morphology 

factors to determine if a riparian system is in Proper Functioning Condition (PFC). It can also be 

used to identify characteristics of nonfunctional riparian systems that need to be addressed to move 

a site toward PFC. 

 

On June 24-26, 2008 we worked with SCPN and park staff, a Southwest Conservation Corps crew, 

and a crew of Navajo Nation interns to complete the well installations. During this same time 

period we performed the riparian condition assessments. 

Monitoring Well Network Installation

We installed a total of 11 shallow observation wells along the Pueblo Colorado Wash floodplain. A 

12th well, installed by a contractor for the Bureau of Indian Affairs in September 2007, was 
3 

incorporated into the monitoring system as well #10A. The wells were located along four transects 

that had been established previously by SCPN to monitor channel cross sections. These transects 

are oriented perpendicular to the channel and are spaced roughly evenly along the length of the 

wash within the HUTR boundary (transects 2, 4, 7, and 10 in Figure 4). Each transect is composed 

of three wells, with two on the south bank and one on the north bank. We had planned to place 

two wells on each side of the stream (total of four per transect), but in all cases the potential 

riparian area was relatively wide on the south side of the channel and very narrow (approx. 10-15 

feet wide) on the north side. We felt that a single well on the narrow north floodplain at each 

transect was sufficient to evaluate water table fluctuations in those areas. Wells were labeled with 

the transect # and A-C from south to north, and are shown in Figure 4. 

Wells were installed by hand using a 3.5 inch diameter bucket auger with 4 foot extensions. Holes 

were augered to approximately 4-5 feet below the top of the water table at each location. Since 

this was a relatively dry time of year (between spring snowmelt/rains and the monsoon season), we 

felt this depth was sufficient to measure March-October water levels, except perhaps in significant 

droughts. A well log was created for each installation to document soil types and characteristics 

encountered. Once each hole was augered to the appropriate depth, a well casing was quickly 

inserted and pushed to the maximum depth possible. 

Each well casing was constructed using a 5-foot section of pre-slotted (0.02 in.), 2-inch diameter 

Schedule 40 PVC pipe. Unslotted 2-inch PVC riser pipe was attached to the top of the slotted 

section to achieve the necessary length for each well. A PVC cap was placed on the bottom of the 

casing to prevent sand from entering as it was inserted into the augered hole. Small holes were 

drilled in these end caps to allow water to drain out of them as water tables fall below the bottoms 

of the wells. The annular space around each slotted section of pipe was backfilled with 

commercial coarse filter sand, and river sand was used to backfill the rest of the space to within 

approximately two feet of the ground surface. Bentonite was then placed in the annular space to 

within about 6-12 inches of the surface, and concrete was then poured to bring the annular space up 

to the ground surface. A notch was made at the top of each well, which will serve as a permanent 

measuring point. The tops of the wells (at the measuring points) and ground surface elevations 

were surveyed to a common datum with a GPS and a total station. SCPN will provide these 

elevations at a later date. 

We trained Adrian Dineyazhe and Marcello Roanhorse in operation and maintenance of an 

electronic tape measure that they will use to measure depths to the water table. Wells will be 

monitored every week during the growing season. They will record the data on the datasheets 

provided and will fax them to the Water Resources Division for entry in an Excel spreadsheet. The 

data will be graphed, checked for consistency, and forwarded regularly to SCPN staff and the park. 

SCPN staff will periodically monitor the well network and check the condition of the wells when 

they need to service continuous recording equipment or collect other monitoring data at HUTR. 

We recommend monitoring for at least two full growing seasons (March – October), and longer if 

possible. WRD and SCPN staff will work together to analyze the hydrologic data and will make 

recommendations regarding future plantings and the ability of the system to support a selfregenerating woody riparian plant community. 
4 

Functional Condition of the Riparian-Wetland System 

We used BLM’s process for assessing “Proper Functioning Condition” of riparian areas (USDI 

1998) to evaluate the functional condition of the Pueblo Colorado Wash riparian zone. Possible 

riparian condition ratings include “Proper Functioning Condition,” “Functional At-Risk” or 

“Nonfunctional” (see definitions below). The proper functioning condition of a riparian area refers 

to the stability of the physical system, which in turn is dictated by the interaction of geology, soil, 

water, and vegetation. A riparian area in PFC is in dynamic equilibrium with its streamflow forces 

and channel processes. The system adjusts to handle larger runoff events with limited change in 

channel characteristics and associated riparian-wetland plant communities. Because of this 

resiliency, riparian areas in PFC can maintain aquatic habitat, water quality enhancement, and 

other important ecosystem functions, even after larger storms. In contrast, nonfunctional systems 

in the same storms might exhibit excessive erosion and sediment loading, loss of aquatic and 

wetland habitat, and so on. 

Based on assessment of 17 hydrologic, vegetation, and geomorphology elements of the riparian 

area, the team assigns one of the following three functionality ratings to a site: 

Proper Functioning Condition: Streams and associated riparian areas are functioning properly 

when adequate vegetation, landform, or large woody debris is present to: 

1. Dissipate stream energy associated with high water flows, thereby reducing erosion and 

improving water quality; 

2. filter sediment, capture bedload, and aid floodplain development; 

3. improve floodwater retention and groundwater recharge; 

4. develop root masses that stabilize stream banks against cutting action; 

5. develop diverse ponding and channel characteristics to provide habitat and the water depths, 

durations, temperature regimes, and substrates necessary for fish production, waterfowl 

breeding, and other uses; and 

6. support greater biodiversity. 

Functional-At Risk: These riparian areas are in functional condition, but an existing soil, water, 

vegetation, or related attribute makes them susceptible to degradation. For example, a stream 

reach may exhibit attributes of a properly functioning riparian system, but it may be poised to 

suffer severe erosion during a large storm in the future due to likely migration of a headcut or 

increased runoff associated with recent urbanization in the watershed. When this rating is 

assigned to a stream reach, then its “trend” toward or away from PFC is assessed. 

Nonfunctional: These are riparian areas that clearly are not providing adequate vegetation, 

landform, or large woody debris to dissipate stream energy associated with high flows, and thus 

are not reducing erosion, improving water quality, sustaining desirable channel and riparian 

habitat characteristics, and so on as described in the PFC definition. The absence of certain 

physical attributes such as a floodplain where one should exist is an indicator of nonfunctioning 

conditions. 
5 

After examining site characteristics via aerial photography and on the ground, we divided Pueblo 

Colorado Wash into two assessment reaches. Width and vegetation cover of the riparian zones and 

sinuosity of the channel appeared to be different in the two reaches. The downstream reach 

extended from SCPN cross-section #1 to cross-section #6, and the upstream reach extended from 

cross-section #6 to cross-section #11 (Figure 4). Data sheets showing the results of the 

evaluations and detailed supporting notes are found in the Appendix. 

Downstream Reach 

This reach has shown dramatic improvements in channel and floodplain form since the riparian 

management activities discussed previously were implemented. The channel has aggraded from its 

former deeply-incised condition and the floodplain is now inundated in relatively frequent runoff 

events. Sinuosity is increasing somewhat, but this process is still ongoing. The channel is not yet 

considered “in-balance” with the sediment provided (it is actively aggrading and 

channel/floodplain form is still developing), but the direction is positive. 

Riparian-wetland vegetation recovery has been dramatic since a site visit in 1997 (Figures 2 and 3). 

Cottonwood and willow plantings appear healthy, and coyote willow (Salix exigua) is spreading 

clonally and providing important stability to many upper streambank areas. Common three-square 

(Schoenoplectus pungens) has invaded much of the stream channel bottom and lower banks. 

These species are helping to slow velocities and dissipate stream energy, stabilize channel bottoms 

and banks, trap sediment, and perform other beneficial riparian functions. The system is clearly 

recovering from the non-functional condition observed here in the late 1990’s to one that is more 

stable and developing more habitat values. 

Several concerns were noted, however, with respect to riparian-wetland vegetation. We saw 

absolutely no evidence of cottonwood or willow recruitment from seed, even in the channel or on 

the lower banks. Cottonwood plantings over the last 10 years provide a scattered sapling age class, 

but it is unknown whether there will be establishment from seed in the future, or if plantings will 

always be necessary to provide new recruitment to replace aging and decadent trees. Similarly, 

willow plantings appeared vigorous, but only coyote willow has the capacity to spread clonally and 

stabilize additional streambank areas beyond the original plantings. If willows can’t establish from 

seed along this reach, then more plantings will be needed to dissipate energy, provide bank 

stability and enhance riparian habitat values. 

Another significant vegetation concern is the lack of species diversity in both the herbaceous 

wetland and woody riparian communities. There is a near monoculture of common three-square 

(S. pungens) in the channel and on the lower banks, with only a couple of small patches of 

hardstem bulrush (Schoenoplectus acutus). Lack of herbaceous wetland plant diversity is a 

threat to channel stability and function. If S. pungens dies off due to disease, insect infestation, 

drought, or other reasons, there will be no other species present to contribute to these critical 

functions. Coyote willow (Salix exigua) is by far the predominant willow on the channel banks, 

but there are only very isolated shining willow (Salix lucida) and bluestem willow (Salix 

irrorata) plants present. This lack of diversity in upper channel bank species is a threat for the 

same reason as described above for the herbaceous plant community. If there is a dieback of 

coyote willow for any reason, then there will be no other species to stabilize the upper channel 
6 

banks, trap sediment, dissipate energy, and provide the habitat functions offered by healthy 

willow communities. 

The downstream reach was rated “Functional – At Risk” with an upward trend. It was considered 

marginally functional in that it has many of the vegetation and hydrology characteristics of a PFC 

system. In fact, it withstood large flood flows in fall 2007 (see photo in Figure 5), dissipating the 

energy of that event with apparently limited change in channel characteristics and associated 

riparian-wetland plant communities. But several factors clearly place the reach in the “At-Risk” 

category: 

1. The effects of the diversion at Ganado Lake on downstream riparian areas (including HUTR) 

have not been analyzed, but thus far they have not prevented the riparian recovery observed to 

date. However, if farming increases in the area and there are greater demands for irrigation, more 

water may be diverted into Ganado Lake, including during the monsoon season. This could 

deprive downstream riparian areas (including HUTR) of water needed for establishment and 

maintenance of healthy and functional riparian-wetland vegetation. 

2. Lack of diversity in herbaceous wetland plant species and willows creates risk that disease, 

drought, or insect damage could wipe out vegetation critical to riparian system recovery, stability 

and function. 

3. If lack of cottonwood and willow reproduction from seed continues over the long term, then 

plantings will continue to be necessary to provide recruitment of new plants to replace those that 

are lost (see additional discussion in following section). Future managers at HUTR may not make 

planting in the riparian area as high a priority as the current and previous superintendent. 

 

4. Active side channel headcuts upstream produce sediment that is handled now by the reach, but 

this sediment source will likely become a problem (excess sediment) in the future. The causes of 

the headcuts should be investigated and appropriate treatments should be implemented to stop 

excessive sediment delivery to the wash. We recommend that HUTR should request additional 

technical assistance from the NPS Natural Resource Program Center on this issue. 

Continued positive developments including increasing native riparian-wetland vegetative cover, 

increasing channel sinuosity, and development of an appropriate channel/floodplain form (recovery 

from deep channel incision of the recent past) are reasons to identify the trend as “upward.” 

Upstream Reach 

The hydrology, vegetation and geomorphology characteristics and PFC ratings of the upstream 

reach were very similar to the downstream reach. Therefore, rather than repeat all of the above 

discussion, we provide only a short summary here and point out any differences. The full PFC 

documentation and notes for both reaches are found in the Appendix. 

The upstream reach was rated “Functional – At Risk” with an upward trend. The only difference 

in the rating factors between the two reaches was for factor #11 (Adequate riparian-wetland 

vegetative cover is present to protect banks and dissipate energy during high flows). In the 
7 

upstream reach, we noticed some significant stretches of exposed (unvegetated) banks that are 

susceptible to erosion during bankfull or larger flows, and so recorded a “no” response. We 

recommend planting native wetland-riparian species on these unvegetated banks (see section 

below). 

Regarding wetland-riparian vegetation, one notable difference was the addition of another 

herbaceous wetland plant species, saltgrass (Distichlis spicata). This native, soil-stabilizing grass 

was observed along the upper streambanks in only a couple of isolated locations (e.g., on the north 

bank between transects 10 and 11). However, its presence indicates that it tolerates these site 

conditions, and it should be considered as a potential species for introduction to increase 

herbaceous wetland plant diversity and enhance channel bank stability. 

A second notable vegetation difference was that cottonwoods were more numerous on the 

floodplain, presumably because of more plantings in this reach. However, as with the downstream 

reach, there was no evidence of establishment from seed. 

The reasons for classifying this reach as “At-Risk” are the same as those listed above for the 

downstream reach, except we add a fifth factor of significant stretches of unvegetated channel 

banks that are vulnerable to excessive erosion. 

 

 

Recommendations for Pueblo Colorado Wash Management 

Goals and the Revegetation Program 

What should be the long-term goal(s) for the Pueblo Colorado Wash riparian area 

within HUTR? Can the wash support a self-sustaining wetland-riparian vegetation 

community? 

There does not appear to be conclusive evidence regarding the “natural” or “pre-Anglo” channel 

form or riparian-wetland community in Pueblo Colorado Wash (Shaw et al. 2005). Therefore, 

park management must use its best judgment regarding the “desired condition” for Pueblo 

Colorado Wash, within the context of park purposes. We suggest that goals or desired conditions 

should include: 1) establish and maintain a riparian system that is in proper functioning condition 

(as defined previously); and 2) maintain a self-sustaining (i.e., self-reproducing), diverse, native 

wetland-riparian plant community that provides site stability and increased wildlife habitat values. 

We assessed the status of this first suggested goal using the BLM’s process for assessing “Proper 

Functioning Condition” of riparian areas (USDI 1998), and found that both stream reaches within 

HUTR are rated “Functional – At Risk.” Recommendations for improving vegetation community 

diversity and other recommendations provided in this report should help move Pueblo Colorado 

Wash further toward the goal of “Proper Functioning Condition” and the second goal of a diverse 

native wetland-riparian plant community that increases wildlife values. However, whether the 

woody riparian community being established here will be “self-sustaining” is an open question that 

needs further explanation. 
8 

Cottonwood and willow seeds are released in late spring or early summer. In order to germinate 

and become established, these wind-borne seeds must fall on moist, bare soil surfaces in areas 

where the water table remains relatively close to the surface. The seeds are only viable for a short 

period (~1-2 weeks), so the linkage between timing of seed dispersal and availability of moist, bare 

seed beds on the upper channel banks and floodplain by spring or early summer is critical. 

Monsoon season storms in mid-July or later may produce appropriate substrates, but the seeds are 

no longer available to land and germinate. (Tamarisk has several competitive advantages over 

native woody riparian species, including an ability to produce seed throughout most of the growing 

season. Therefore, it can establish after monsoon season storms when cottonwood and willow 

seeds are no longer available to compete.) 

Once cottonwood and willow seeds germinate, it is critical that the water table does not drop more 

than about 6 mm/day. This is because in order to become established, the seedling taproots must 

be in constant contact with the water table, and therefore must grow fast enough to keep pace with 

the falling water level. As a result, cottonwoods and willows generally will not establish from seed 

where water tables fall more than about 1 meter below the ground surface during the summer. The 

well network that we installed during this trip, along with the water level recorders and the stream 

channel crest gage installed by SCPN will give us a good idea if the basic water table 

characteristics exist to support establishment from seed in the future. If possible, we also suggest 

monitoring the timing of willow and cottonwood “seed rain” in the spring and early summer so we 

can see how seed availability and water levels match up. This can be as simple as identifying a 

few female cottonwoods and willows on site and recording dates when significant seed release 

begins and ends. WRD can provide further information for doing this, upon request. 

The fact that we saw no cottonwood or willow establishment from seed is of some concern, but it 

doesn’t mean such establishment can’t occur here. The interval for cottonwood establishment 

along free-flowing rivers averages about 10 years (Lytle and Merritt, 2004), but may be much 

longer in some watersheds. For example, a site with a rapidly falling water table may require a 

rare sequence of events for cottonwoods or willows to establish, such as an unusually rainy 

summer that sustains an abnormally high water table for an extended period. Since recovery of the 

Pueblo Colorado Wash channel incision and development of potential establishment sites only 

occurred in the last few years, it is too early to determine if establishment from seed will occur in 

the future to replace older, decadent trees. 

 

Extensive and expanding cover of common three-square (S. pungens) in the channel bottom and on 

the lower banks indicates that sufficient moisture exists to support a self-sustaining herbaceous 

wetland plant community. The issue for this community at HUTR is more about the lack of 

diversity, which minimizes wildlife values (e.g., limited food sources and habitat types) and is a 

risk to site stability, as explained previously. Recommendations for increasing native plant 

diversity and cover are found in the following section. 

What is required to meet these goals? At what point should the park stop planting 

wetland-riparian vegetation? 

If the goal is to establish a riparian system that is in proper functioning condition and has a selfsustaining, diverse native wetland-riparian plant community with increased wildlife habitat values, 
9 

then we strongly support continued planting of native cottonwoods, willows, and herbaceous 

wetland plants in the wash. 

For cottonwoods, recruitment from seed is not yet occurring, so the planting program provides 

substitute recruitment of new plants to replace dying trees. Cuttings from Rio Grande cottonwoods 

(Populus deltoides ssp. wislizeni) should be used. Since these trees are dioecious (individual trees 

are either male or female), it is critical to make sure that poles of both sexes are planted to assure 

seed sources into the future. Poles should be inserted to a depth of 2 feet below the lowest 

expected water table in the growing season. (This information will be available as soon as we can 

collect a season or two of water table data from the newly installed wells.) Pole plantings should 

be located about 1-3 feet above the elevation of the channel bank so root systems can avoid longterm inundation (this is also the likely elevation zone for establishment from seed). They can be 

planted at higher elevations to achieve a desired landscape appearance, but poles will need to be 

quite long to meet the planting depth described above. 

Unfortunately, there is no formula to determine when the number of planted cottonwoods is 

sufficient, and there is probably no such thing as “too many.” We suggest planting in irregular 

clusters on the floodplain and leaving open areas without cottonwoods to provide diversity in 

habitat structure. On-center distances of 4-5 ft (1 pole per 2-3 square yards) within the clusters or 

groves would be a reasonable goal. The 2007 photo in Figure 2 shows this approximate planting 

density, and also shows them planted at the appropriate elevation with respect to the channel bank. 

During our visit it appeared that the planting effort has been more focused on the upstream reach. 

If the water table data support it, we suggest more new plantings in the downstream reach as well. 

For willows, the ultimate goal should be to establish them along nearly all upper channel bank and 

adjacent low overbank areas. We suggest planting cuttings with on center distances of 1-3 feet for 

shrubby willows such as coyote willow (S. exigua) and bluestem willow (S. irrorata), interspersing 

the species. Although shining willow (Salix lucida) is found on site and plants are healthy, this is 

may be a little low in elevation for that species (personal communication, Dr. David Cooper, 

Colorado State University, July 2008). We suggest also considering planting Goodding’s willow 

(Salix gooddingii). Because this is a tree species, it should be planted much farther apart than the 

shrubby willow species, at the tops of the banks or in low overbank areas. Again, these are 

dioecious plants, so care should be taken to obtain cuttings from many different plants to assure a 

mix of males and females. 

For the herbaceous wetland plant community, we recommend planting more appropriate native 

species to increase diversity. This would enhance wildlife functions and values by increasing the 

variety of habitats available for feeding, nesting, and so on, and would increase site stability and 

functionality by having multiple species stabilize the soil. Discussions with several qualified 

vegetation ecologists and botanists working in the region indicated that the following species 

should be considered for introduction in Pueblo Colorado Wash: 

Mountain rush (Juncus arcticus) – reported to exist in comparable riparian areas in the region 

(personal communication, Daniela Roth, Navajo Nation Department of Fish and Wildlife) 

Chairmaker’s bulrush (Schoenoplectus americanus) - reported in previous vegetation studies at 

HUTR 
10 

Common spikerush (Eleocharis palustris) – “Eleocharis sp.” is on SCPN species list for HUTR 

Nebraska sedge (Carex nebrascensis) 

Scratchgrass (Muhlenbergia asperifolia) - reported present at HUTR in previous studies 

Saltgrass (Distichlis spicata) - observed in a few patches in the upstream reach at HUTR 

All of these species are reported to occur in Apache County, AZ according to the USDA PLANTS 

database (http://plants.usda.gov/index.html) and would contribute to site stability, wildlife values, 

and ecosystem function. All can tolerate the slightly brackish conditions found at this site 

(specific conductance in the range of approximately 600 – 800 microsiemens/cm was measured in 

the channel by the USGS in 1998 - 2000). WRD can provide additional assistance with species 

selection, planting densities and locations, sources of plants, potential funding sources, and so on 

upon request. 

At a basic level, the goals will be met when Pueblo Colorado Wash can be rated as being in Proper 

Functioning Condition. At that point, there will be an adequate channel form and at least the 

minimum native plant diversity, cover, and age class structure necessary to provide site stability 

and maintenance of wildlife habitat, even after large storms. Beyond that point, we would have to 

defer to the SCPN vegetation monitoring program to evaluate whether plant diversity is 

appropriate, and to wildlife experts to determine if additional habitat enhancements are appropriate 

and necessary. 
11 

Literature Cited 

Baker, M. 2005. Analysis of Streamside Vegetation within Hubbell Trading Post Historic Site, 

Apache County, Arizona, Interim Report: Summary of 2004 Sampling. Report submitted to 

National Park Service, Hubbell Trading Post National Historic Site. 

Lytle, D.A. and D.M. Merritt. 2004. Hydrologic Regimes and Riparian Forests: A Structured 

Population Model for Cottonwood. Ecology, Vol. 85, No. 9, pp. 2493-2503. 

Shaw, H.G., P.M. Woodruff and W. Zeedyk. 2005. Natural History of a Small Place: An 

Ecological History of Pueblo Colorado Wash at Hubbell Trading Post National Historic Site, 

Ganado, Arizona. The Juniper Institute, Hillsboro, NM. 89 pp. (Final report submitted to 

HUTR) 

U.S. Department of the Interior, Bureau of Land Management. 1998. Riparian Area Management: 

A User Guide to Assessing Proper Functioning Condition and the Supporting Science for Lotic 

Areas. TR 1737-15. BLM National Applied Resource Sciences Center. Denver, CO. 126 pp. 

Zeedyk, W. 2004. Final Report: Geomorphological Monitoring and Instream Structure 

Installations. 72 pp., including appendix. (Final report submitted to HUTR) 
12 

 

Figure 1. Location of Hubbell Trading Post National Historic Site 
13 

 

Figure 2. Photo pair of Pueblo Colorado Wash within HUTR, 1997 and 2007, looking west 

toward Hubbell Hill. Note in-channel deflection structure in 2007 photo (yellow arrow points to 

center of triangular structure). Photos by Joel Wagner, NPS. 

1997 

2007 
14 

 

Figure 3. Photo pair of Pueblo Colorado Wash within HUTR, 1997 and 2010, looking west 

toward Hubbell Hill. (Note failed rock gabion check dam in center of 1997 photo, since 

removed.) Photos by Joel Wagner, NPS.

1997 

2010 
15 

Figure 4. Locations of observation well transects installed June 24-26, 2008.

N 
16 

Figure 5. Pueblo Colorado Wash maintained its basic channel form and riparian-wetland 

vegetation community even after this large runoff event in fall 2007. Photo by Anne 

Worthington, NPS. 
17 

Appendix: PFC riparian system standard checklists and notes for downstream and upstream 

reaches of Pueblo Colorado Wash within HUTR 
18 
PFC Lotic (Riparian) Standard Checklist 

Name of Riparian Area: HUTR, Pueblo Colorado Wash near Ganado, AZ 

Date: 6-26-2008 Segment/Reach ID: Downstream reach, from SCPN crosssection #1 to cross-section #6 

Miles: approx. 385 meters Acres: 

ID Team Observers: J. Wagner, R. Inglis 

Yes No N/A HYDROLOGY 

X 1) Floodplain above bankfull is inundated in “relatively frequent” events 

 X 2) Where beaver dams are present they are active and stable 

 X 3) Sinuosity, width/depth ratio, and gradient are in balance with the 

landscape setting (i.e., landform, geology, and bioclimatic region) 

X 4) Riparian-wetland area is widening or has achieved potential extent 

X 5) Upland watershed is not contributing to riparian-wetland degradation 

Yes No N/A VEGETATION 

 X 6) There is diverse age-class distribution of riparian-wetland vegetation 

(recruitment for maintenance/recovery) 

 X 7) There is diverse composition of riparian-wetland vegetation for 

maintenance/recovery) 

X 8) Species present indicate maintenance of riparian-wetland soil 

moisture characteristics 

X 9) Streambank vegetation is comprised of those plants or plant 

communities that have root masses capable of withstanding highstreamflow events 

X 10) Riparian-wetland plants exhibit high vigor 

X 11) Adequate riparian-wetland vegetative cover is present to protect 

banks and dissipate energy during high flows 

 X 12) Plant communities are an adequate source of coarse and/or large 

woody material (for maintenance/recovery) 

Yes No N/A EROSION/DEPOSITION 

X 13) Floodplain and channel characteristics (i.e., rocks, overflow channels, 

coarse and/or large woody material) are adequate to dissipate energy 

 X 14) Point bars are revegetating with riparian-wetland vegetation 

 X 15) Lateral stream movement is associated with natural sinuosity 

 X 16) System is vertically stable 

 X 17) Stream is in balance with the water and sediment being supplied by the 

 watershed (i.e., no excessive erosion or deposition) 

 (Revised 1999) 

 
Remarks (numbers correspond to checklist items) 

3. This system is responding to 10 years of management activities designed to aid recovery 

of the degraded riparian system of the late 1990s to one that is more stable and has higher 

habitat value. Actions have included exclusion of livestock, removal of tamarisk and 

Russian olive, planting of native willows and cottonwoods, and installation of in-channel 

rock and wood deflection structures. The channel and floodplain are actively aggrading 

and sinuosity is increasing. It is not yet considered “in-balance” but the direction is 

positive. 

 4. Common three-square (Schoenoplectus pungens) is growing nearly bank to bank in many 

areas. The riparian area is widening in these areas as the channel narrows. 

 5. The upland watershed may be aiding the improvement based on channel and floodplain 

aggradation and establishment of wetland vegetation (reach is not degrading). Side 

channel formation to the north in the upstream reach associated with concentrated 

highway runoff may become a threat (excess sediment delivery) at some point unless 

treated. 

 6. No evidence of cottonwood or willow recruitment from seed, even in the channel or on 

the lower banks. (Salix exigua is spreading clonally). Cottonwood plantings over the last 

10 years provide a scattered sapling age class, but it is unknown whether there will be 

establishment from seed in the future, or if plantings will always be necessary to provide 

recruitment. Herbaceous riparian-wetland vegetation is essentially a monoculture of 

Schoenoplectus pungens. This species is spreading aggressively in the channel bottom 

and on lower banks. Both herbaceous and woody species are necessary for achieving 

PFC here. 

 7. Herbaceous species: a near monoculture of Schoenoplectus pungens in the channel and 

lower banks, with a couple of small patches of Schoenoplectus acutus in the channel 

thalweg. Lack of herbaceous wetland plant diversity is evident, and there is a threat to 

channel stability if S. pungens dies back. 

 Woody species: coyote willow (Salix exigua) is by far the predominant willow on the 

channel banks and it is spreading clonally. Very isolated (though healthy) plants of 

shining willow (Salix lucida) and bluestem willow (Salix irrorata) present, likely from 

plantings. Scattered planted cottonwoods (Populus sp.) exist on the floodplain. Lack of 

diversity of upper channel bank species (willows) is a threat if there is a dieback of 

coyote willow. 

 16. Channel and floodplain actively aggrading and therefore not vertically stable. Episodes 

of mid-channel scour were reported by park staff this spring, but channel refilled soon 

afterwards. 

 17. Channel is actively aggrading. 

 

Summary Determination 

Functional Rating: Trend for Functional – At Risk: 

 Proper Functioning Condition Upward __X_ 

 Functional – At Risk __X__ Downward _____ 

 Nonfunctional _____ Not Apparent _____ 

 Unknown _____ 

Notes: Reach is considered functional in that it has many of the vegetation and hydrology 

characteristics of a PFC system. It withstood a very high flow event in fall 2007, dissipating the 

energy of that event with limited change in channel characteristics and associated riparian-wetland 

plant communities. But several factors place the reach in the “At-Risk” category: 
1) An upstream dam diverts flow into Ganado Lake, mostly during spring runoff. Sediment is 

trapped in a settling basin near the diversion structure. Settling basin is flushed periodically, 

returning sediment to Pueblo Colorado Wash. Effects of these practices on downstream riparian 

areas (including HUTR) have not been analyzed, but may create risk. Also, if farming increases in 

the area and there are greater demands for irrigation, more water may be diverted into Ganado Lake, 

including during the monsoon season. This could deprive downstream riparian areas (including 

HUTR) of water needed for establishment and maintenance of stabilizing riparian-wetland 

vegetation. 

2) Lack of diversity in herbaceous wetland plant species and willows creates risk that disease, 

drought, or insect damage could wipe out vegetation critical to riparian system stability and 

recovery. 

3) If lack of cottonwood and willow reproduction from seed continues over the long term, then 

plantings will continue to be necessary to provide recruitment of new plants to replace those that are 

lost. Future managers at HUTR may not make planting in the riparian area as high a priority as the 

current and previous superintendent. 

4) Active side channel headcuts upstream produce sediment that is handled now by the reach, but 

could become excessive. 

Continued positive developments including increasing native riparian-wetland vegetative cover, 

increasing sinuosity, aggradation of the channel and floodplain formation (recovery from past deep 

channel incision) are reasons to identify the trend as upward. 

Are factors contributing to unacceptable conditions outside the control of the manager? 

 Yes __X_ 

 No ____ 

If yes, what are those factors? 

 _X_ Flow regulations (dam) ___ Mining activities ___ Upstream channel conditions 

 ___ Channelization ___ Road encroachment ___ Oil field water discharge 

 ___ Augmented flows _X_ Other (specify) active headcutting in side channels 

 upstream

PFC Lotic (Riparian) Standard Checklist 

Name of Riparian Area: HUTR, Pueblo Colorado Wash near Ganado, AZ 

Date: 6-26-2008 Segment/Reach ID: Upstream reach, from SCPN cross-section 

#6 to cross-section #11 

Miles: approx. 350 meters Acres: 

ID Team Observers: J. Wagner, R. Inglis 

Yes No N/A HYDROLOGY 

X 1) Floodplain above bankfull is inundated in “relatively frequent” events 

 X 2) Where beaver dams are present they are active and stable 

 X 3) Sinuosity, width/depth ratio, and gradient are in balance with the 

landscape setting (i.e., landform, geology, and bioclimatic region) 

X 4) Riparian-wetland area is widening or has achieved potential extent 

X 5) Upland watershed is not contributing to riparian-wetland degradation 

Yes No N/A VEGETATION 

 X 6) There is diverse age-class distribution of riparian-wetland vegetation 

(recruitment for maintenance/recovery) 

 X 7) There is diverse composition of riparian-wetland vegetation for 

maintenance/recovery) 

X 8) Species present indicate maintenance of riparian-wetland soil 

moisture characteristics 

X 9) Streambank vegetation is comprised of those plants or plant 

communities that have root masses capable of withstanding highstreamflow events 

X 10) Riparian-wetland plants exhibit high vigor 

 X 11) Adequate riparian-wetland vegetative cover is present to protect 

banks and dissipate energy during high flows 

 X 12) Plant communities are an adequate source of coarse and/or large 

woody material (for maintenance/recovery) 

Yes No N/A EROSION/DEPOSITION 

X 13) Floodplain and channel characteristics (i.e., rocks, overflow channels, 

coarse and/or large woody material) are adequate to dissipate energy 

 X 14) Point bars are revegetating with riparian-wetland vegetation 

 X 15) Lateral stream movement is associated with natural sinuosity 

 X 16) System is vertically stable 

 X 17) Stream is in balance with the water and sediment being supplied by the 

 watershed (i.e., no excessive erosion or deposition) 

 (Revised 1999) 

 
Remarks (numbers correspond to checklist items) 

3. This system is responding to 10 years of management activities designed to aid recovery 

of the degraded riparian system of the late 1990s to one that is more stable and has higher 

habitat value. Actions have included exclusion of livestock, removal of tamarisk and 

Russian olive, planting of native willows and cottonwoods, and installation of in-channel 

rock and wood deflection structures. The channel and floodplain are actively aggrading 

and sinuosity is increasing. It is not yet considered “in-balance” but the direction is 

positive. 

 4. Common three-square (Schoenoplectus pungens) is growing nearly bank to bank in many 

areas. The riparian area is widening in these areas as the channel narrows. 

 5. The upland watershed may be aiding the recovery based on channel and floodplain 

aggradation and establishment of wetland vegetation (reach is not degrading). Side 

channel formation to the north associated with concentrated highway runoff may become 

a threat (excess sediment delivery) at some point unless treated. 

 6. No evidence of cottonwood or willow recruitment from seed, even in the channel or on 

the lower banks. (Salix exigua is spreading aggressively vegetatively). Cottonwood 

plantings over the last 10 years provide a significant sapling age class, but it is unknown 

whether there will be establishment from seed in the future, or if plantings will always be 

necessary to provide recruitment. Herbaceous riparian-wetland vegetation is essentially a 

monoculture of Schoenoplectus pungens. This species is spreading aggressively in the 

channel bottom and on lower banks. Both herbaceous and woody species are necessary 

for achieving PFC here. 

 7. Herbaceous species: a near monoculture of Schoenoplectus pungens in the channel and 

lower banks, with a couple of small patches of Schoenoplectus acutus in the channel 

thalweg. Lack of herbaceous wetland plant diversity is evident, and there is a threat to 

channel stability if S. pungens dies back. 

 Woody species: coyote willow (Salix exigua) is by far the predominant willow on the 

channel banks and it is spreading clonally. Very isolated (though healthy) plants of 

shining willow (Salix lucida) and bluestem willow (Salix irrorata) present, likely from 

plantings. Good numbers of planted cottonwoods (Populus sp.) exist on the floodplain. 

Lack of diversity of upper channel bank woody species (willows) is a threat if there is a 

dieback of coyote willow. 

 11. Some stretches of exposed (unvegetated) banks remain in portions of this reach. 

 14. Minor development of point bars but still in transition. 

 15. Some meanders forming but not stabilized and not yet affecting overall sinuosity/channel 

form. 

 16. Channel and floodplain actively aggrading and therefore not vertically stable. Episodes 

of mid-channel scour were reported by park staff this spring, but channel refilled soon 

afterwards. 

 17. Channel is actively aggrading. 

 

Summary Determination 

Functional Rating: Trend for Functional – At Risk: 

 Proper Functioning Condition Upward __X_ 

 Functional – At Risk __X__ Downward _____ 

 Nonfunctional _____ Not Apparent _____ 

 Unknown _____ 

Notes: Reach is considered functional in that it has many of the vegetation and hydrology 

characteristics of a PFC system. It withstood a very high flow event in fall 2007, dissipating the 
energy of that event with limited change in channel characteristics and associated riparian-wetland 

plant communities. But several factors place the reach in the “At-Risk” category: 

1) An upstream dam diverts flow into Ganado Lake, mostly during spring runoff. Sediment is 

trapped in a settling basin near the diversion structure. Settling basin is flushed periodically, 

returning sediment to Pueblo Colorado Wash. Effects of these practices on downstream riparian 

areas (including HUTR) have not been analyzed, but may create risk. Also, if farming increases in 

the area and there are greater demands for irrigation, more water may be diverted into Ganado Lake, 

including during the monsoon season. This could deprive downstream riparian areas (including 

HUTR) of water needed for establishment and maintenance of stabilizing riparian-wetland 

vegetation. 

2) Lack of diversity in herbaceous wetland plant species and willows creates risk that disease, 

drought, or insect damage could wipe out vegetation critical to riparian system stability and 

recovery; 

3) If lack of cottonwood and willow reproduction from seed continues over the long term, then 

plantings will continue to be necessary to provide recruitment of new plants to replace those that are 

lost. Future managers at HUTR may not make planting in the riparian area as high a priority as the 

current and previous superintendent. 

4) Active side channel headcuts upstream produce sediment that is handled now by the reach, but 

could become excessive. 

5) Some stretches of exposed (unvegetated) banks remain in portions of this reach, leaving them 

vulnerable to excessive erosion. 

Continued positive developments including increasing native riparian-wetland vegetative cover, 

increasing sinuosity, aggradation of the channel and floodplain formation (recovery from past deep 

channel incision) are reasons to identify the trend as upward. 

Are factors contributing to unacceptable conditions outside the control of the manager? 

 Yes __X_ 

 No ____ 

If yes, what are those factors? 

 _X_ Flow regulations (dam) ___ Mining activities ___ Upstream channel conditions 

 ___ Channelization ___ Road encroachment ___ Oil field water discharge 

 ___ Augmented flows _X__ Other (specify)_active headcutting in side channels

20 

The Department of the Interior protects and manages the nation’s natural resources and cultural heritage; provides scientific and 

other information about those resources; and honors its special responsibilities to American Indians, Alaska Natives, and affiliated 

Island Communities. 

NPS 433/103717, June 2010 
National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center

1201 Oakridge Drive, Suite 150 

Fort Collins, CO 80525 

www.nature.nps.gov 

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