Appendix C –Consistency with the Aquatic Conservation Strategy

Appendix C - Consistency with the Aquatic 

Conservation Strategy

Introduction

The Aquatic Conservation Strategy was developed to restore and maintain the ecological health of 

watersheds and aquatic ecosystems contained within them on public lands. A goal of this strategy is to 

maintain a "natural" disturbance regime. In addition, management activities must comply with nine 

objectives that are included in the strategy and any associated standards and guidelines. A variety of 

tactics to accomplish these goals and objectives are incorporated into four primary components. These 

components are:

• Riparian Reserves

• Key Watersheds

• Watershed Analysis

• Watershed Restoration

These four components, along with Late Successional Reserves, are designed to operate together to 

maintain and restore the productivity and resiliency of riparian and aquatic ecosystems (Record of 

Decision for Amendments to Forest Service and Bureau of Land Management Planning Documents 

Within the Range of the Northern Spotted Owl - USFS, BLM 1994, (ROD), pages B9-B12).

1. Riparian Reserves

The Northwest Forest Plan defined Riparian Reserves as “portions of watersheds where ripariandependent resources receive primary emphasis and where special standards and guidelines apply” 

(ROD page B12). Riparian Reserves include those portions of a watershed directly coupled to 

streams, ponds, lakes, and wetlands - that is, the portions of a watershed required for maintaining 

hydrologic, geomorphic, and ecologic processes that directly affect standing and flowing water (ROD 

pgs. B-12 and B-13).

The Riparian Reserve network in the South Fork McKenzie watershed totals over 65,570 acres which 

is over 47% of the entire land base (South Fork McKenzie Watershed Analysis 2010). The Watershed 

Analysis made no final recommendations to adjust Riparian Reserve widths for the streams in the 

watershed, retaining the initial reserve widths (of one site potential tree height) from the ROD for all 

streams.

The Lang Dam project area is 7,195 acres of which 2,443 acres are Riparian Reserves. At the unit 

level, there are a total of 645 acres of which 209 acres are Riparian Reserves. Of those 209 acres, the 

proposed action would thin 120 acres and not cut, or “skip,” 89 acres.

During the analysis for the Lang Dam Project, no reductions of Riparian Reserve widths along any 

streams were proposed. However, silvicultural treatments were proposed within Riparian Reserves 

for some units in order to improve structural diversity and vegetative diversity. Timber harvest is 

prohibited within Riparian Reserves but there are 3 exceptions provided in the ROD. One of which is 

Standard and Guideline TM-1(c). 
Appendix C –Consistency with the Aquatic Conservation Strategy

Standards and Guidelines (S&Gs)

TM-1(c). Apply silvicultural practices for Riparian Reserves to control stocking, reestablish and 

manage stands, and acquire desired vegetation characteristics needed to attain Aquatic 

Conservation Strategy objectives.

Standard and Guideline TM-1(c) in the Northwest Forest Plan (1994) provides direction on when 

silvicultural activities can take place in Riparian Reserves. Members of the interdisciplinary team

reviewed all the Riparian Reserves in the project units and conducted a “hardwood analysis” at the subwatershed level to determine if treatment is warranted. Based on this analysis recommendations for 

treatment were developed for each Riparian Reserve in project units. 

There are no-cut buffers of varying width (30 feet to 180 feet) depending on stream class, presence or 

absence of hardwoods, and density of the conifers in the Riparian Reserve. See Table 4 in Chapter 2 for 

the no-cut buffer widths for units with Riparian Reserves. Thinning Riparian Reserves means there will 

be an effect on the supply of coarse woody material and ACS objective 8 states that the Forest Service 

must maintain and restore amounts and distributions of coarse woody debris sufficient to sustain 

physical complexity and stability. The plantations where thinning is proposed are dense and there is a 

need to control stocking in order to maintain a healthy stand of trees. The number of total trees per acre 

(i.e. this number includes trees less than 7 inches in diameter) range from 234 to 503. Recent forest 

research in the Coast Range and Western Cascades indicates that existing old growth stands developed 

with natural stand densities of 40 to 60 conifers per acre (Tappeiner et al 1997; Poage & Tappeiner 

2002). Having a no-cut buffer adjacent to every stream would maintain a high level of trees per acre 

compared to what has been found in these studies. In the thinned areas, there would still be more trees 

per acre left after thinning than found in the studies. The previously harvested stands proposed for 

treatment in the Lang Dam Project Area were harvested and replanted using direction that pre-dates 

the Willamette Land and Resource Management Plan (1990) and the Northwest Forest Plan (1994). As a 

result, the majority of these forest stands were set on a management-induced trajectory that has led to 

artificially dense, conifer-dominated stands, with tree densities above the range of natural variability 

expected in this area. Per field investigations, the buffer was determined from stream size, stream class, 

gradient, channel complexity, and how functional the existing coarse woody material was in the stream 

channel. It is expected that the amount of woody material left in the no-cut buffer and the remainder of 

the Riparian Reserve would be sufficient to sustain physical complexity and stability. Fish bearing 

streams have wider no-cut buffers (i.e. from 30 to 180 feet) so thinning in these Riparian Reserves would 

have limited effects on fish and caddisflies.

The South Fork Watershed Analysis (SFWA) (1994) described past conditions, current conditions, and 

trends in riparian vegetation in the watershed. Fires, road construction, and timber harvest on some land 

types, and flooding can accelerate debris flow occurrence. Conditions of riparian stands will depend on 

previous timing of fires and pulses of debris flows. It is reasonable to speculate that the extensive fires of 

the mid-1800’s would have created open riparian stands in many of the South Fork’s drainages. Further, 

the fires combined with the great flood of 1861 would have triggered debris flows in many first to third 

order streams during that period, with some affecting larger streams. By the year 1900, many small 

riparian areas would have shown mixed conifer / red alder stands with conifer about to go into a period 

of rapid height growth. For larger streams recovering from the impacts of 1800’s fires and the 1861 

flood, some red alder, cottonwood, or willow may have persisted near the active channel shelf, but 

conifers would have established and by 1900 have overtopped the deciduous trees to dominate 
Appendix C –Consistency with the Aquatic Conservation Strategy

floodplains. By the time of the 1945 flood (25 year flood event), most of the stands would have lost 

remnants of red alder and little evidence of these events would remain. With fire suppression few large 

fires had occurred since the early 1900’s. It is estimated that 50 fires have been suppressed in the 

watershed since the arrival of the Civilian Conservation Corps (CCC) in the 1930’s with the majority being 

caused by lightning. 

The SFWA (1994) also discussed trends in riparian vegetation for the entire watershed. Given the 

Riparian Reserve network established by the Northwest Forest Plan (1994), the SFWA found that the 

riparian areas within the watershed will have an increase in conifer dominance tree communities. 

Unlogged areas will continue recovery from the 1964 flood (a 130-year flood event in the South Fork 

McKenzie). Alder stands initiated during the 1945 and 1964 floods will persist until the middle of the 

next century (i.e. 21st century) when they will decline under emerging conifers. Older floodplains reset 

during the 1861 flood will be old growth by that time. A major flood would reset succession along 

floodplains and would affect the least confined valleys the most. 

Cougar Dam, constructed in 1963, has had a significant impact on the riparian vegetation community 

downstream of the dam due to the changes in the flow regime, the sediment regime, and the large 

woody material (LWM) regime. The South Fork Watershed Analysis (1994) discussed trends in riparian 

vegetation below the dam. Riparian vegetation patterns below the dam are reacting to the flow and 

sediment deposition changes since construction of the dam. Vegetation communities once found near 

secondary channels, on depositional bars, and on floodplains are shifting due to natural successional 

processes as well as altered disturbance regimes. Data from a 962-foot long transect across the reach 

suggest trends in vegetation below the dam will be most significantly affected by: (1) abandonment of 

secondary channels; (2) transformation of depositional bars into floodplains; and (3) transformation of 

old floodplains into terraces. All of this will mean a reduction in hardwoods downstream of the dam.

A “hardwood analysis” was conducted for the South Fork McKenzie River-Cougar Creek watershed. For 

this analysis, satellite imagery (WorldView 2) and Google Earth imagery were used to determine the 

percentage of deciduous trees in Riparian Reserves. 

Table 1. Results of Hardwood Analysis for the Cougar Creek – South Fork McKenzie River 6th Field.

Class Name Acres Percent of the Riparian Reserve 

Network

Conifer 1,162.05 65.45

Mix 253.79 14.29

Deciduous 186.27 10.49

Water 46.83 2.64

Other 126.44 7.12

2. Key Watersheds

The Northwest Forest Plan created an overlay of Key Watersheds that are intended to provide refugia 

for at-risk stocks of anadromous salmonids and resident fish species. Refugia are a cornerstone of the 
Appendix C –Consistency with the Aquatic Conservation Strategy

conservation strategy for these species, consisting of watersheds that provide high quality habitat or are 

expected to provide habitat. There is no Key Watershed designation in the Lang Dam project area. 

3. Watershed Analysis and Watershed Restoration

South Fork McKenzie Watershed Analysis (WA) was prepared for the McKenzie River Ranger District in 

1994 and updated in 2010. The watershed was characterized in terms of past and current conditions, 

and a synthesis discussion was provided to guide development of management proposals to maintain 

and restore watershed conditions.

The Lang Dam Project has incorporated information from the WA into the project design. Current 

vegetative landscape patterns reflect past management activities that did not consider what the 

landscape might look like under natural disturbance regimes. The presence of Cougar Dam since 1963 

has affected the riparian plant community along the South Fork McKenzie below the dam. Many of the 

proposed projects seek to create vegetative patterns, late successional stand structures, increased 

hardwoods in the area, and fuel loadings that would have been typical of this landscape under the 

natural disturbance regimes that historically occurred in the area. 

Watershed restoration has been ongoing in the South Fork McKenzie River since 1994. For example, 

large wood placement project have been implemented since 1996 and 841 trees have been added to 

the channel upstream of Cougar Reservoir. In 2010, a Watershed Restoration Action Plan (WRAP) was 

developed for the Cougar Creek-South Fork McKenzie sub-watershed. Most of the essential projects 

recommended in the WRAP have been implemented. A project has been proposed – the Lower South 

Fork McKenzie River Floodplain Enhancement Project – that would implement the final projects 

proposed in the WRAP. That project would essentially spread water out over a greater area in the subwatershed which would hypothetically increase the number of hardwoods. Lang Dam would thin 120 

Riparian Reserve acres of out of a total of 1,775 Riparian Reserve acres in the sub-watershed. This, 

along with the floodplain enhancement project, would help to increase hardwoods in the subwatershed.

Aquatic Conservation Strategy Objectives

The previous discussions highlighted the consistency of the Lang Dam Project with the four components 

of the Aquatic Conservation Strategy. This section will outline how the activities proposed in the action 

alternative conforms to the nine objectives of the ACS. The information presented is summarized from 

Chapters 2 and 3 of the Environmental Assessment, where greater detail can be found if needed. 

Objective #1 - Maintain and restore the distribution, diversity, and complexity of watershed and 

landscape-scale features to ensure protection of the aquatic systems to which species, populations 

and communities are uniquely adapted.

Thinning treatments were developed so that they would, to the extent possible, emulate the effects of 

the natural fire regime that historically occurred in the vicinity as well as maintain existing habitat near 

streams and wetlands. Creating structural and species diversity within dense, homogenous Riparian 

Reserve stands were key drivers in the proposed treatments. The objective is to provide a balance 

between the maintenance of existing habitat for species, populations, and communities, with 
Appendix C –Consistency with the Aquatic Conservation Strategy

opportunities to develop landscape scale features with distribution, diversity and complexity of the 

historical landscapes. This includes aquatic and riparian elements of the landscape. 

Objective #2 - Maintain and restore spatial and temporal connectivity within and between 

watersheds. Lateral, longitudinal, and drainage network connections include floodplains, wetlands, 

upslope areas, headwater tributaries, and intact refugia. These network connections must provide 

chemically and physically unobstructed routes to areas critical for fulfilling life history requirements of 

aquatic and riparian-dependent species.

Riparian Reserves, as established by the Record of Decision for the Northwest Forest Plan and reassessed in the South Fork McKenzie Watershed Analysis have been incorporated into the design of all 

treatment units where streams occur. Treatments are proposed within Riparian Reserves, where they 

have the potential to enhance functions such as the development of future large wood, stand structural 

diversity, vegetative species richness and diversity, and other late successional characteristics. Road 

treatments include upgrade of stream crossings to accommodate 100 year flood events, so that these 

events can flow through the landscape unimpeded and without the risk of catastrophic fill failures.

The only man-made barrier in the sub-watershed is Cougar Dam. At present, it has an adult “trap and 

haul” facility at the base of the dam. Safe downstream passage has not been established at Cougar Dam 

but the Army Corps of Engineers has studied the need and is developing a plan to implement 

downstream passage.

Objective #3 - Maintain and restore the physical integrity of the aquatic system, including shorelines, 

banks, and bottom configurations.

All proposed treatments were designed with channel stability in mind. All harvest activities restrict the 

use of ground disturbing equipment in and around streams, and provide for retention of all vegetation 

that is contributing to the stability of banks and channels. Where aerial yarding methods are prescribed, 

full suspension is required when yarding over streams to prevent disturbance of stream banks and 

channels. Trees cut for skyline corridors within the Riparian Reserve would be retained on site as down 

woody material.

Roads are a known potential source of damage to stream habitat, where improper design or location, or 

inadequate maintenance results in failures or roadway erosion. The Lang Dam Project addresses this 

concern by not implementing permanent road construction and upgrading at least 11 culverts (4 stream 

crossing and 7 ditch relief). Approximately 11.5 miles of maintenance and reconstruction of portions of 

the existing road network that are in poor repair, replacement of undersized or old culverts, drainage 

improvement, and application of aggregate where necessary, will reduce chronic, low amplitude sources 

of fine sediment from the existing transportation system, and the potential of crossing fill failures. This 

will reduce the possibility of gravels and cobbles becoming embedded in fine materials in the stream 

channel bottoms. Approximately 2.2 miles of temporary roads will be constructed on stable locations, 

and all of these will be obliterated following harvest activities. Additionally, approximately 0.3 miles of 

existing permanent road (1900399 road) would be decommissioned and left in a hydrologically stable 

condition and 2.7 miles of open roads would be closed and put into storage with water bars and bermed 

at the entrances.
Appendix C –Consistency with the Aquatic Conservation Strategy

Objective #4 – Maintain and restore water quality necessary to support healthy riparian, aquatic and 

wetland ecosystems. Water quality must remain within the range that maintains the biological, 

physical, and chemical integrity of the system and benefits survival, growth, reproduction, and 

migration of individuals composing aquatic and riparian communities. 

The over-all objective of any treatment within the Riparian Reserves is to maintain compliance with the 

Regional TMDL Implementation Strategy so that stream temperatures are not detrimentally impacted. 

Where vegetative treatments are proposed within Riparian Reserves, effective stream shading is 

retained at levels sufficient to maintain water temperature. A minimum of 50% canopy closure 

(approximately 40% canopy cover) is preserved throughout the Riparian Reserve to maintain 

microclimates. No-harvest buffers were developed to preserve the primary shade zone. Most of the 

class 3 and all of class 2 streams have a minimum 180-foot no-harvest buffer and a few have a minimum 

of 60-foot no-harvest buffer. Class 4 streams have a 30 or 60 foot no harvest buffer with a few 

exceptions at 230 feet.

Objective #5 – Maintain and restore the sediment regime under which aquatic ecosystems evolved. 

Elements of the sediment regime include the timing, volume, rate, and character of sediment input, 

storage, and transport.

Project design elements are intended to maintain and restore the physical integrity of the aquatic 

system, including shorelines, banks, and bottom configurations, as discussed above under Objective 3. 

These design elements will also provide protection to water quality from the introduction of sediment 

into streams and resulting effects on stream turbidity.

As stated in #3 above, roads are a known potential source of damage to stream habitat, where improper 

design or location, or inadequate maintenance results in failures or roadway erosion.

All proposed treatments were designed with sediment transport potential in mind. All harvest activities 

follow Best Management Practices (BMP) guidelines and restrict the use of ground-disturbing 

equipment in and around streams. This reduces the potential of water routing along skid roads or the 

creation of overland flow due to high compaction levels. Where aerial yarding methods are prescribed, 

full suspension is required when yarding over streams to prevent disturbance of stream banks and 

channels. Trees cut for skyline corridors within the Riparian Reserve would be retained on site as down 

woody material. 

Objective #6 – Maintain and restore in-stream flows sufficient to create and sustain riparian, aquatic, 

and wetland habitats and to retain patterns of sediment, nutrient, and wood routing. The timing, 

magnitude, duration and spatial distribution of peak, high, and low flows must be protected. 

This alternative maintains current canopy cover at levels well above the maximum mid-point for

Aggregate Recovery Percentage (ARP). Therefore, no altered flows are anticipated from implementation 

of this alterative.

Objective #7 – Maintain and restore the timing, variability, and duration of floodplain inundation and 

water table elevation in meadows and wetlands.
Appendix C –Consistency with the Aquatic Conservation Strategy

Implementation of a landscape design that is intended to restore vegetative structures, landscape 

patterns, and disturbance regimes to a more natural condition will result in watershed conditions that 

more closely resemble those under which historic stream flow conditions developed. 

Floodplains and wetland areas were excluded from consideration for harvest activities and where 

treatment units occur adjacent to these features, ground-based equipment that could impact the soil 

and result in altered groundwater movement are restricted. 

Cougar Dam is the human created feature in the 6th field watershed that significantly impacts the flow 

regime and floodplain inundation. The Forest Service cannot do anything to remove Cougar Dam in 

order to restore the flow regime.

Objective #8 - Maintain and restore the species compositions and structural diversity of plant 

communities in riparian areas and wetlands to provide adequate summer and winter thermal 

regulation, nutrient filtering, appropriate rates of surface erosion, bank erosion, and channel 

migration and to supply amounts and distribution of coarse woody debris sufficient to sustain physical 

complexity and stability.

As discussed in the Riparian Reserve section of this ACS analysis, the vegetation in this sub-watershed 

has changed due to the presence of Cougar Dam. The Lang Dam project would increase the amount of 

hardwoods in the sub-watershed by thinning out overly-stocked conifers. This activity will have the short 

term effect (years to a couple of decades) of reducing coarse woody material loading in the Riparian 

Reserve outside the no-harvest buffer. However given the unnaturally over-stocked conditions of these 

managed stands, in the long term (decades to a century) there will still be adequate woody material to 

maintained volumes within the natural range of variability. 

Wetlands and floodplain areas that are critical to nutrient filtering are eliminated from treatment areas 

and use of ground disturbing equipment adjacent to them is restricted. New hardwood trees will help 

improve the nutritional quality of organic matter delivered to streams.

Use of low severity fire is restricted to the edges of Riparian Reserves where the risk of adverse effects 

on ground cover and duff retention cannot impact water quality. 

Objective #9 – Maintain and restore habitat to support well-distributed populations of native plant, 

invertebrate, and vertebrate riparian-dependent species.

This project complies with the Northwest Forest Plan and all of its applicable standards and guidelines. 

Option 9 was expected to maintain and restore late-successional and old-growth forest ecosystems, and 

provide adequate viability levels for all late successional species including species listed in the FEIS ROD 

Table C-3. As discussed in the other Objectives above, some stands in Riparian Reserves are proposed 

for treatment to encourage development of large wood and late successional stand structure. This 

would help to create a rich variety of habitats for native species. Adequate amounts of down woody 

debris will be retained on site.

The South Fork McKenzie and its numerous tributaries provide excellent habitat for native fish. This is 

due to the cold, clean water. This habitat will be maintained by the implementation of no-cut buffers 
Appendix C –Consistency with the Aquatic Conservation Strategy

along fish bearing streams. Additionally, upgrades to several culverts will provide better dispersal 

opportunities to aquatic invertebrates and salamanders. Roads that are decommissioned will restore 

stream channels so that there will be unobstructed passage at the former road crossing.

Map of Cougar Creek – South Fork McKenzie River Sub-watershed Hardwood Results

Cougar Creek – South Fork McKenzie River Sub-watershed Hardwood Results with Lang Dam Units