A Riparian "Needs "Assessment for the

Beaver Valley Watershed

 

 

 

By

 

 

 

V.A. Poulin, R.P.Bio.

V.A. Poulin & Associates Ltd.

2153 West 46th Avenue,

Vancouver, B.C.

V6M 2L2

and

T. Johnson, R.P.F

T. Johnson and Associates

Box 4097

Smithers, B.C.

V0J 2N0

 

 

 

For

 

 

 

Weldwood of Canada Limited

Williams Lake, British Columbia

 

 

 

 

January 1998

TABLE OF CONTENTS

Page

Table of Contents .................................................................................................................. i

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

Needs Assessment ................................................................................................................ 1

Study Approach ................................................................................................................... 3

Office Preparation..................................................................................................... 5

Field Assessment........................................................................................................ 5

Results of Site Assessments................................................................................................. 7

Area 1. Solomon Creek Site 1..................................................................................... 7

Area 1. Solomon Creek Site 2..................................................................................... 8

Area 2. Gavin Lake Site 3........................................................................................... 10

Area 2. Gavin Lake Site 4........................................................................................... 11

Area 3. Jacobie Lake Site 5.......................................................................................... 12

Area 3. Jacobie Lake Site 6.......................................................................................... 12

Area 4. Antoine Lake Site 7........................................................................................ 12

Area 5. Macauley Lake............................................................................................... 13

Area 5. Parmiter Creek Site 8...................................................................................... 13

Area 6. Tyee Lake Site 9.............................................................................................. 14

Area 7. Beaver Creek.................................................................................................... 15

Other Considerations................................................................................................................ 15

Conclusion................................................................................................................................. 17

Appendix 1

Site location maps........................................................................................................... 18

Appendix 2

Photo mosaic plates........................................................................................................ 19

INTRODUCTION

The Beaver Valley Watershed was selected as a candidate area for an FRBC riparian assessment project by Weldwood of Canada Ltd. and Ministry of Environment. The project was to be undertaken following the procedures outlined in the latest version of the draft "Riparian Assessment and Prescription Procedures Field Guide" (June, 1997) which have formed the terms of reference for a number of FRBC projects awarded in 1997. The strategy outlined in the guide assumes that watersheds selected for assessment have gone through a sort of regional prioritization and are known to contain riparian stands that may be candidate areas for riparian restoration. The latter assumption is not well articulated in the draft guide and is a commonly misunderstood first step prior to awarding a contract. While the Beaver Valley Watershed area is recognized as a regionally significant area with high fisheries values it was not known prior to initiation of this project if the area in fact contained stand types that exhibited loss of riparian function due to timber harvesting. For this reason it was recommended by the contractors that the guidebook approach be modified and rather than going directly into an "Overview" Assessment that a preliminary "Needs" Assessment be undertaken as a first step to determine if stand conditions in the Beaver Valley area warranted the more detailed assessment as outlined by the guide.

Using a combination of colour themed maps showing age class of second growth stands, and knowledge of fisheries resources in the area (Maurice Laurette, pers. comm.) six areas were prioritized for inclusion in the needs assessment. These included riparian areas adjacent to Solomon Creek, streams tributary to Gavin Lake, Jacobie Lake, Antoine Lake, Macaulcy Lake, and Tyee Lake (Appendix 1). Nearly all of the riparian areas were adjacent to small streams. This is because most of the larger, "higher valued" fish streams in the watershed are situated on private land or they flow through areas that have not been logged. A good example is Beaver Creek itself which is situated almost exclusively on private land.

"NEEDS" ASSESSMENT

Summary of Results

Of the six areas visited none contained stand types that were suitable for rehabilitation or offered what we considered any meaningful opportunity for riparian work. All were revegetated with commercial plantings of coniferous trees, naturally restocked conifers, deciduous trees, shrubs and herbaceous plants in amounts and mixtures that will lead to restoration of riparian attributes without further stand treatments. Since the areas sampled were representative of the watershed at large, we concluded the more detailed overview called for in the draft guide was not warranted. Thus, we recommended to the contract authority that the remaining funding for this project be re-directed to other initiatives.

With the exception of private land adjacent to Beaver Creek, all of the sites examined achieved what we considered to be "proper functioning condition" or "functional - trending upwards". Areas were deemed to have achieved "proper functioning condition" when adequate riparian vegetation was present to provide for stable stream banks, shade over streams, continuous ground cover, and woody vegetation of sufficient size as to meet requirements for small or large woody debris as appropriate for the riparian stream class. Sites were considered to be "functional - trending upwards" when the site contained all of the necessary properties to have achieved a significant level of stability through revegetation of the site and the site was heading for a "desired future condition" without the need for restoration work.

A high degree of bank stability and plant community development was found at all the sites examined. As such, we considered riparian functions including stream shading, input of small woody debris (SWD), surface filtering of sediment laden water, bank and channel stability to be restored at all locations. Some functions are not possible to restore in the absence of time and this influenced the level of functionality ascribed to a site. Where large woody debris (LWD), coarse woody debris (CWD) or standing dead and dying trees were required to meet riparian objectives, and the species mix and stocking densities indicated large wood and old trees would be returned to the site without further restoration, the site was refereed to as "trending upwards". All of the riparian areas adjacent to fish streams in classes greater than S4 were assessed as "functional" and "trending upwards". The majority of streams visited were not dependent on LWD. Most were small, incised S4 or S6 channels that were dependent on cobbles and small boulders for stream morphology not woody debris. In these streams woody debris tends to rot and break-down long before being able to function as the hydraulic controls needed to influence pool and riffle development or sediment storage characteristics of a stream.

We further concluded that the plant communities present were sufficiently complex and vigorous as to achieve a "desired future condition" for the stands. Thus, we expect all preharvest riparian attributes to be restored over time. With respect to the watershed at large, we found past timber harvesting practices to have had a limited impact on riparian areas. Timber harvesting has been generally restricted to the removal of first pass timber and has occurred in portions of the watershed that do not support streams generally considered responsible for providing the bulk of the "higher-valued" fish habitats. Those areas that remain to be harvested will be subject to FPC regulations which require a high standard of vegetation management.

The same can not be said for agricultural development, road access, cattle grazing and placer mining in the watershed. Many of the "higher-valued" fish streams are contained in valley bottoms where range use has resulted in loss of riparian vegetation, damage to stream channels and increased erosion. Most stream crossings in the area use pipe culverts. A number of these were found perched above the water surface elevation of the streams they drain and passing high water velocities. These conditions effectively limit adult fish passage and most assuredly prevent the upstream movement of juvenile fish. Land clearing for hay and farming has encroached close to the banks of valley streams leaving the riparian corridors to depend on small trees, shrubs and grass for retention of riparian attributes.

STUDY APPROACH

The purpose of this relatively quick and concise assessment was to ensure that unnecessary funding was not expended conducting a more costly overview assessment prior to determining if there was a need for riparian assessment in the first place. The study team consisted of Tom Johnson, R.P.F, and V.A. Poulin, R.P. Bio. Tom Johnson is co-author of the latest version of the riparian assessment field guide and Vince Poulin is working with the guidebook team and WRP staff in Vancouver finalizing the field assessment procedures. The "Needs" Assessment was undertaken on August 21 - 25, 1997. Specific objectives of the field portion of the study were to determine if any of the stand conditions present in the watershed were indicative of the types illustrated in Figure 1. These include:

1. Poorly stocked plantations on moist, rich sites,

2. Over-stocked plantations on mesic sites,

3. Over-topped conifers on moist, rich sites; and,

4. Deciduous dominated pole sapling stands lacking conifers on moist, rich sites.

If any of these conditions were present then justification would have been provided to initiate the more detailed overview assessment as outlined in the draft field guide.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1. Types of stand conditions which typify areas that should be examined as potential candidates for riparian restoration.

Office Preparation

The project was completed over a span of 4 days with 1/2 of the first day allocated for identification of study sites and completing interviews with MOE and company staff in Williams Lake. During the office session the following materials were compiled and steps completed:

1. Map of assessment area for Beaver Valley

2. Recreation map of Caribou Region Forest

• transferred assessment area boundaries to define area of interest

3. 1:50 000 scale development maps showing location of harvested areas

• located all major streams and lakes in the development area

• identified areas where riparian restoration may be required based on logging history

• compiled notes for later reference including comments on amount of area logged, date of logging, timber type, age of stand, and any other pertinent detail pertaining to the character of the site

4. Transferred potential areas of interest to recreation map

• identified field route to be used and noted other relevant access information

• used map to help find appropriate flight lines for gathering aerial photographs

5. Selected and pulled aerial photographs for in-house examination (file photos used)

6. Examined photographs to identify areas of interest and preliminary site selection

• listed aerial photographs needed for the field

• returned originals to in-house files

7. Meet with MOE representative to discuss fish values and obtain other suggestions

• reviewed preliminary site selections relative to known fishery values

• modified field plan to include recommendations provided

8. Obtained colour copies of aerial photographs for field use

Field Assessment

The field portion of the survey consisted of an examination of six areas adjacent to Solomon Creek, streams tributary to Gavin Lake, Jacobie Lake, Antoine Lake, Macaulcy Lake, and Tyee Lake (Appendix 1). At each location representative sections of the RMAs were traversed and assessed. Unlike the more rigorous field procedures outlined in the field guide, a form of checklist approach was used to swiftly ascertain if a site was a candidate or not for restoration. These included answers to the following questions:

Yes No N/A RIPARIAN VEGETATION

q q q Site adequately stocked with a diverse composition of deciduous and coniferous tree species

q q q Distribution of trees and age-class structure indicative of good future stand structure

q q q Stream bank vegetation comprised of plants that have or will have root masses capable of withstanding high streamflow events for the size of stream

q q q Plants exhibit good vigor and lack significant disease or insect damage

q q q Adequate vegetative cover present to protect banks and dissipate energy during high flows

q q q Where necessary plant communities in the riparian area will provide an adequate source of large and coarse woody debris

q q q Site sufficiently vegetated as to provide good shade cover over temperature sensitive streams

Yes No N/A CHANNEL STABILITY

q q q Stream channel stable lacking evidence of erosion or channel widening

q q q Pool/riffle ratio, gradient and sinuosity in balance with watershed area/biogeoclimatic zone

q q q Terrain stability elsewhere in the watershed not contributing to riparian degradation

 

In addition to answering the above questions an evaluation of vegetation cover characteristics was made to verify tree and shrub species present, height of trees, and percent cover characteristics. Estimates of the number of well spaced stems per hectare in the RMA was noted by species and used as a measure of the sites ability to meet stocking standards considered acceptable for the recovery of riparian function and to achieve a desired future condition for the stand. Stocking densities were estimated from vegetative cover plots taken at random locations in the RMA. These plots were standard silvicultural plots of 3.99 meters radius. Within the plots the number of free-growing conifers were counted and extrapolated to give the number of stems per hectare for the site (Figure 2). Photo documentation of site conditions was also provided. If the site was not a likely candidate for restoration no other information was collected. Information was placed directly into field notebooks. No formal data forms were used. The success of this type of survey is directly related to the capability of the individuals responsible for the survey. In this case the sites were examined by two qualified individuals who can quickly and decidedly assess a site.

 

 

Figure 2. Vegetation cover plot showing how stocking density was derived for coniferous trees present within the RMA of streams sampled in the Beaver Valley Watershed.

 

RESULTS OF THE SITE EVALUATIONS

Area 1. Solomon Creek Site 1. Date Surveyed: 08/22/97

Riparian Stream Class: S3 Treatment: None required

Riparian Status: Functional - trending upwards

Solomon Creek is a major tributary to Big Lake and is known to support rainbow trout. The creek was examined at two locations. The first section was located immediately north of the main access road which runs parallel and south of Big Lake (Appendix 1a). The second is located approximately 1 km downstream of the first location. Fish were observed immediately downstream of the road culvert, but species could not be determined.

Solomon Creek in the vicinity of the first location has an average channel width of 2.0 m. Stream gradient is 5%. Bed material consists predominantly of a cobble/boulder substrate having a D90 of 0.35 m, D75 of 0.2 m, and a D50 of 0.1 m. The stream lacked a component of LWD due in large part to a relatively incised channel and the presence of coarse substrates that resist the embedment of logs into the streambed. The RMA adjacent to the stream is shown in photo mosaic Plate 1. The area shown is typical of the vegetation encountered throughout the riparian area. The site is well vegetated with alder, herbaceous plants and scattered spruce adjacent to the stream. This material serves as a source of small woody debris, provides shade, and contributes to minor changes in stream morphology. Spruce seedlings within 5 m of the stream have achieved a height of 1.7 m and a stocking density of approximately 300 stems/hectare.

On the sides of the draw and on flats situated above the slope break conifer stocking levels increase. The sides of the draw are stocked with an 80:20 mix of spruce and pine seedlings amounting to 800 well spaced stems per hectare. Of these well spaced stems, 600 stems per hectare are free growing at an average height of 1.7 meters. Competing vegetation is 0.6 m and consists largely of fireweed (60% cover). The remaining seedlings on the site are estimated to be free growing in four years. On the flat ground above the draw the stand is composed of pine with a 10% component of aspen. Trees in this area are free growing and vigorous.

Based on the well stocked conifers, good diversity of tree species, and continuous ground cover of riparian and forest vegetation the site was deemed to be functional and trending in an upward or positive direction with respect to restoration of preharvest riparian attributes. Current conifer stocking densities were considered adequate to satisfy future CWD requirements within the RMA and in time mature trees will be present within the riparian reserve zone to provide future opportunities for maintenance of wildlife trees and to contribute to LWD loading to the stream. No rehabilitation activities were recommended.

Area 1. Solomon Creek Site 2. Date Surveyed: 08/22/97

Riparian Stream Class: S3 Treatment: None recommended

Riparian Status: Functional - trending upwards

At site 2 (Appendix 1a) stream gradient averages 4% and stream morphology is increasingly controlled by LWD owing to a smaller substrate size (D90 of 0.25 m, D50 of 0.10 m) and an increase in sediment availablity to the stream. The stream consists of 70% riffle and 30% pool habitat with some undercut bank. Juvenile rainbow trout were observed in several pools. Grazing is frequent in this area and cattle have both hindered and aided in the restoration of riparian functions. Grazing has caused banks to collapse in some areas and portions of banks have been exposed to mineral rich soils that are being used as licks by cattle. Bank damage has contributed to a high sediment loading that starts upstream of the logged area. In other areas the presence of cattle have been responsible for helping to control competing vegetation and conifer seedlings to become established.

The RMA on the westerly side of the stream is characterized by higher ground and relatively well drained fine textured silt/loam soils. Grass and twinberry competition is high with 30 - 40% of the cover consisting of these plants. Conifer stocking densities are approximately 1000 stems per hectare. Seedlings are spruce with an average height of 1.0 m and 0.2 m leaders. Old gall aphid damage was found on 70% of the seedlings. It was estimated that within three years, 60% of the spruce seedlings will be free growing and stocking targets for LWD and CWD will be achieved.

The RMA on the easterly side of the stream is shown in photo mosaic Plate 2. The area is lower in elevation and contains silt/loam soils with a high soil moisture content. The terrain is indicative of a middle bench floodplain area. Twin berry and grass occur on elevated sites and alder and willow thickets are present in the depressions. In this area spruce densities fall to 400 stems per hectare, but they are well growing with an average height of 1.3 m and leaders of 0.3 m. Vigour is good and it is anticipated that in two years the trees will meet free growing criteria.

Further north the RMA is comprised of a sedge dominated wetland. In this area willows are the principal streamside vegetation. This area contained spruce prior to logging, but the subhydric moisture regime following logging has inhibited the establishment of spruce after logging.

On the more well drained, higher bench sites adequate stocking of conifers and deciduous trees were found and cattle grazing was considered to be doing a good job in controlling competing vegetation. The riparian functions of stream shading and SWD inputs have returned and provisions of LWD and CWD within the RMA will be satisfied at current stocking densities. On the middle bench sites stocking is patchy due to the undulating nature of the terrain. It would be possible to increase stocking by scarifying clusters every 100 meters and fill planting but, this is not recommended. Several points were considered:

• Any work on the site will result in damage to the existing plantation which is almost free growing and plantable spots available for establishment of clusters are beyond the effective distance of LWD. The effective distance for LWD on this interior site is estimated at 15 m from the stream bank.

• The fine textured silt soils on the site would be vulnerable to compaction and any exposure of mineral soil may cause reduced root egress and survival.

• Although conifer stocking densities were low they were still considered adequate to yield a well growing stand that will recruit CWD and LWD to the site.

• A more open grown stand on this wetter section may yield a more windfirm reserve zone when consideration is given to harvesting the second growth stand.

• Conifer stocking levels on the opposite side of the stream are high.

Within the sedge wetland no options for increased conifer stocking are available due to the high soil moisture regime which will prevent establishment of conifer seedlings. Within this area the only option for riparian restoration is to wait for natural processes to take their course.

Area 2. Gavin Lake Site 3. Date Surveyed: 08/23/97

Riparian Stream Class: S4 Treatment: None required

Riparian Status: Functional - trending upwards

Gavin Lake sites 3 and 4 (Appendix 1b) contain the principal inlet stream to Gavin Lake. The stream is located near the southeast shore of the lake and it is known to be used by rainbow trout for spawning. Juvenile rainbow trout were observed throughout the stream during the survey. The stream has an average channel width of 1.3 m and a stream gradient of 6%. Bed material is similar to that of Solomon Creek consisting of a cobble/boulder substrate having a D90 of 0.35 - 0.4 m, D75 of 0.2 m, and a D50 of 0.1 m. Stream morphology is not dependent on wood owing to the presence of the larger substrates and relatively incised channel that flows through a steep sided draw. The area was logged, broad cast burned, and planted in the late 1960’s. In 1978, a portion of the stream nearest Gavin Lake was harvested and burned in 1979. This portion of the block was found to be NSR in 1991. It was subsequently mechanically site prepared in 1992 and fill planted in 1993.

Two sites were examined. The first is situated in the area first harvested (Site 3) and the second occurs below the road where harvesting was completed in 1978 and subsequently mechanically site prepared and planted in 1992 and 1993 (Site 4). The RMA adjacent to Site 3 is shown in photo mosaic Plate 3. Immediately adjacent to the stream the site is well vegetated with alder, cottonwood, aspen, birch, willow and herbaceous plants. Scattered spruce at a density of approximately 300 stems per hectare are present amoungst these plants and increase to 450 acceptable well spaced trees per hectare on the sidewalls of the draw where the slope extends for an average of 10 m to the break. Within the remainder of the 30 m RMA total conifer stocking levels rise to 1200 stems (cedar, spruce, and pine) per hectare. Spruce present on the site exhibited damaged from white pine terminal weevil, gall aphid, and frost, but current growth did not appear to be significantly affected by these pests. It is expected that over time the majority of the spruce will outgrow the weevil attacks and there will be little impact on stocking. The cedar and subalpine fir present on the site were heavily browsed and exhibited poor form.

The riparian functions of stream shade and SWD input have been restored to the site and given the diversity of trees present, good growth of key tree species, total ground cover by vegetation and a stable stream system the site was deemed to be functional and trending in an upward or positive direction with respect to restoration of preharvest riparian attributes. Consequently, rehabilitation is not prescribed for this site.

Area 2. Gavin Lake Site 4. Date Surveyed: 08/23/97

Riparian Stream Class: S4 Treatment: None required

Riparian Status: Functional - trending upwards

In this section, the RMA on the west side of the stream was mounded to provide elevated microsites and improve seedling survival. Site preparation was completed to within 10 m of the channel. Mounds were planted with lodgepole pine and survival has been high. Current stocking is estimated at 1600 stems per hectare. Pine seedlings will be free growing in three years. Site preparation has shifted competing vegetation from a fireweed dominated community to a grass dominated community. This shift has no special consequences to the restoration of the RMA as trees are currently at equal height to the grass at this time.

Within 10 m of the stream stocking is lower ranging from 200 to 500 acceptable stems per hectare. In this area conifers consist of spruce and fir. The majority of these trees are 5 cm in diameter and well established. There are an additional 100 spruce per hectare which exhibit unacceptable pine terminal weevil damage. On the east side of the stream stocking is similar but density averages 600 stems per hectare in the RMA.

Although stocking is patchy adjacent to the creek, conifers are well established and will likely reach maturity. Like the upstream section of stream, the riparian functions of stream shade and SWD input are fulfilled by alder and herbaceous cover adjacent to the stream and the channel is not LWD dependent. Existing stocking will meet CWD and LWD requirements for wildlife and localized complexing of the stream. Thus, the RMA was deemed to be functional and trending in an upward or positive direction with respect to restoration of preharvest riparian attributes. No rehabilitation activities are recommended for the site.

Area 3. Jacobie Lake Site 5 Date Surveyed: 08/23/97

Riparian Stream Class: S6 Treatment: None required

Riparian Status: Proper Functioning Condition

Two streams were assessed in the Jacobie Lake area (Appendix 1b). The first site was a small S6 tributary stream located on the east side of the lake. It drains out of a large clearcut. The stream is 0.6 m wide and contains coarse streambed materials similar to the site examined at Gavin Lake. Flow in the creek was intermittent and did not appear to be directly accessible by Jacobie Lake fish. Well established alder and herbaceous vegetation provided almost total cover over the small channel. Conifer stocking in the RMA was estimated to be 700 well growing stems per hectare. Seedlings averaged 1.1 m in height and had leaders of 0.1 m. It was estimated that these trees would be free growing in 5 years.

All riparian functions for a stream of this riparian class were considered restored and the RMA deemed to be functioning properly. No rehabilitation activities are recommended.

Area 3. Jacobie Lake Site 6 Date Surveyed: 08/23/97

Riparian Stream Class: S3 Treatment: None required

Riparian Status: Proper Functioning Condition

Jacobie Creek is the outlet stream of Jacobie Lake and flows to the west of the lake (Appendix 1b). Disturbance to the RMA is minimal once beyond the recreational site located on the lake shore. The area adjacent to the stream has been selectively harvested and the area contains a mixture of alder clumps and scattered conifers ranging upwards to 30 cm in diameter. No rehabilitation measures are required as the area has been little affected by past disturbance.

Area 4. Antoine Lake Site 7 Date Surveyed: 08/24/97

Riparian Stream Classes: S6 Treatment: None required

Riparian Status: Proper Functioning Condition

The streams of interest in this area were found in older clearcuts to the north of Antoine Lake (Appendix 1c). Two streams were found in the area, but both were small intermittent S6 channels that flowed over fully reforested sideslopes north of the lake. The dominant forest cover in the area is a mixture of birch, aspen and conifers. No rehabilitation is required.

The road leading above Antoine Lake was a different matter. Drainage structures on the road have become dysfunctional and surface drainage is being diverted down the road and into the outlet stream of Antoine Lake (See Appendix 1c, Site 7A). Extensive erosion has occurred. Most is deposited on the meadow adjacent to the stream, but sufficient material is entering the stream as to be a significant sediment source. The road should be examined and actions taken to rectify the problem as soon as possible. This was the most significant sediment source identified during the course of this survey.

Area 5. Macauley Lake Date Surveyed: 08/24/97

Streams in this area were not visited as road access was not possible. There is significant forest harvesting on the south side of the lake, but like many of the other locations visited, cutover areas were well stocked with coniferous trees and all wet sites had good cover of deciduous trees, shrubs and herbaceous vegetation. Examination of the aerial photographs suggested these conditions were present adjacent to the streams of interest in the area.

Area 5. Parmiter Creek Site 8 Date Surveyed: 08/24/97

Riparian Stream Class: S2 Treatment: None required

Riparian Status: Functional - trending upwards

Because of lack of access in this area, Parmiter Creek was examined at the footslope of the valley bottom above the boundary of private land (Appendix 1d). No recent cutblocks are present in the vicinity, but the riparian area appeared to have been felled during a period of placer mining activity. At this time the stream itself was excavated for mineral deposits. Evidence of old placer works and tailings are visible where the stream flows across pasture land and joins Beaver Creek. The stream is thought to support rainbow trout, but no fish were observed during the survey. The stream is an illustrative example of the impacts of placer mining on fish habitat.

The stream has been excavated to a depth of approximately 2.0 m leaving the stream channalized over the section of stream traversed in the (Plate 4). In the surveyed section, the stream flows between relatively well defined cut banks and what appears to be berms along the channel created at the time of mining. The stream contains no deep water and is comprised of 80% riffle and 20% glide habitat. The bed is dominated by well sorted boulders, cobbles and gravels and flows at a gradient of 5%. Average channel width is 5.2 m. The riparian area is vegetated with a mix of large diameter coniferous and deciduous trees, but the second growth forest is still too young to provide the stream with a component of large wood. Thus, channel complexing is absent as are pool habitats.

All vegetative riparian functions have been restored to the stream with the exception of LWD. In the absence of LWD this stream with its higher flow capacity and abundance of gravel is at risk to degradation from hydrological events. The absence of large wood in the channel inhibits the capture of bedload necessary for floodplain development and promotion of pool and riffle complexes needed for productive fish habitat. While no riparian treatments are needed for the vegetated portion of the RMA the stream is a potentially productive trout stream and should be examined as a candidate for fish habitat restoration.

Area 6. Tyee Lake Site 9 Date Surveyed: 08/24/97

Riparian Stream Class: S6 Treatment: None required

Riparian Status: Proper Functioning Condition

The stream on the west side of the Tyee lake was assessed (Appendix 1e). This creek is an S6 stream with an average stream width of 1.2 m. Unlike all other creeks examined only the one side of the stream had been harvested and this was situated to the south. The vegetated RMA adjacent to the stream is shown in photo mosaic Plate 5. The stream is deeply incised and bounded on both sides by steeply sloping sidewalls. Both sides of the stream are well vegetated. On the side of the creek that was harvested the RMA is well stocked with pine and spruce at a density of approximately 900 stems per hectare. Seedlings are at or above the height of the competing vegetation. The north side of the creek is an non-harvested Douglas-fir dominated forest.

All riparian functions for a stream of this riparian class were considered restored and the RMA deemed to be functioning properly. No rehabilitation activities are recommended.

Beaver Creek Date Surveyed: 08/24/97

Riparian Stream Class: S3 Treatment: Consider

Riparian Status: Functional - trending downward

The majority of Beaver creek lies in private land, and as such was not viewed as a potential candidate for FRBC funded work in the riparian area. However, since it is the largest creek in the watershed and the stream was crossed in several places during the survey some comments on the system are warranted. In general the RMA of this stream runs through a series of interconnected hay fields and the stream cuts a meandering path on flat ground through fine-textured soils. The area has been under agricultural use since the turn of the century and the stream long used for watering and forage by cattle. Sources of LWD are limited and there is little potential for recruitment as the RMA has been converted to treeless hay fields in many places with riparian vegetation consisting of shrubs and herbaceous vegetation. The riparian functions of stream shade and small woody debris input are presently being provided by a strip of willow and alder cover which would be considered inadequate for management purposes on forest land. The actual amount of vegetation present was difficult to assess without gaining access to private land, but it can be seen to vary significantly over the length of the valley. In places upwards to 20 meters of shrub cover was provided on both sides of the stream, but in other areas the riparian area is sparsely vegetated. The stream in many places is deeply incised and cutting a meandering channel through fine-textured soils. While vegetated for the most part, the functionality of the riparian area has been significantly affected by human use. Areas of active bank collapse and erosion are indicative of an unstable system that lacks riparian attributes offered by larger trees such as stronger root systems, larger wood, and taller shade producing canopies. Remedial actions could be taken adjacent to Beaver Creek provided land owners could be persuaded to defray loss of hay production to the greater benefit of improving riparian conditions adjacent to the stream. It is possible that in some areas re-establishing riparian vegetation could be justified on the basis of simply preventing erosion of land area which would be in the best interest of land owners. The role of WRP and FRBC in dealing with private land issues would have to be explored. Another possible approach may be through the Habitat Conservation Fund.

OTHER CONSIDERATIONS

The only significant soil/erosion concern identified during the survey was the problem found at Antoine Lake where road surface material was actively washing out and being deposited on the active floodplain of the outlet stream to Antoine Lake. This site requires immediate road deactivation measures to prevent further deterioration of the site and sedimentation of Antoine Creek.

Lack of safe fish passage facilities on fish streams appeared to be a problem in the watershed. We examined enough installations to suggest that a culvert assessment for fish passage should be undertaken. The following summarizes notes taken at several key locations where safe fish passage should be provided:

1. Antoine Creek Access Road

Structure: 3 CMPs, one embedded

Gradient: 4 - 5% (moderate)

Q100: culverts observed flowing at 1/3 rd capacity during low flow, will not meet Q100 standards

Comments: These structure may pass fish owing to the single embedded pipe, but the structures are placed at a sufficiently high stream gradient as to likely not be passable at the high passage flow for fish. As currently provided juvenile fish will likely have access to upstream areas only during periods of low flow. The pipes were flowing sufficiently full as to be well sized below the Q100 pipe size required under the FPC.

2. Beaver Valley Road east of Robert Lake

Structure: 1, 1200 CMP pipe, perched 0.3 m with V of 2.0 - 2.5 m/sec.

Gradient: not taken (moderate)

Q100: would not meet Q100 standards

Comments: This structure was perched 0.3 m when first examined. A good plunge pool exists at the outlet which would enable larger fish to use pool hydraulics to assist in a leap into the culvert, however, velocities in the pipe appeared to be well in excess of the sustained swimming speed for rainbow trout. The perched condition was reduced to 0.1 on 8/24/97 following a rise in stream flow due to a heavy rainfall the previous day. At this time velocities in the pipe increased significantly suggesting that during the period of active spring migration rainbow trout movement would require burst speed to fully pass the structure. It is highly likely that adult fish passage is prevented at this time year. Juvenile trout are likely prevented from passing through the culvert at any time of year.

3. Old Gravel Creek Road west of the Horsefly Road

Structure: 3, 1200 CMPs

Gradient: 3% (moderate)

Q100: would not meet Q100 standards

Comments: These structures do not appear to be passable to adult trout and will certainly not allow upstream movement by juvenile fish. One pipe is blocked with sufficient gravel and organic debris as to be an obstruction to fish passage, a second pipe is perched 0.3 m, and the third structure is perched 0.5 m. A 4.0 m scour hole is washed out below the outlet causing significant widening of the channel and erosion of the stream bank. The degree of erosion below the pipe is partially a function of the blocked pipe forcing peak flows through the two remaining pipes. The resultant affect is to generate very high outlet velocities. These can be expected to occur during the time of spring migration and to exceed those that are passable by trout.

CONCLUSIONS

In general the impact of past harvesting activities on the crown lands of the Beaver Valley Watershed have been small. Timber harvesting is still in the first pass or just entering the second pass in most of the watershed and the majority of creeks adjacent to or within cutblocks are S6 to S3 streams. In general, harvesting has occurred from 5 to 15 years ago and the riparian functions of stream shading and SWD inputs have been restored with the re-establishment of alder and herbaceous growth in the RMAs. Past harvesting has removed the source of large wood from the riparian areas but reforestation activities have established sufficient stocking densities that a source of LWD and CWD will be re-established in the future. As such, we considered all of the areas examined to be in either "proper functioning condition" or "functional - tending upwards" for the riparian stream class and serial stage of vegetation present and a "desired future condition" for the stands will be established without restoration.

Thus, we concluded that a more exhaustive overview would not result in finding candidate sites for riparian restoration activities in the remainder of the assessment area. We do recommend, however, that consideration be given to issues concerning fish passage at road culverts and working with land owners to improve riparian habitats adjacent to "high valued" fish streams such as Beaver Creek.

 

Appendix 1. Location of study sites in the FRBC Watershed Assessment Area for Beaver Valley

1a. Solomon Creek Sites 1 & 2

1b. Gavin Lake Sites 3 & 4, Jacobie Lake Sites 5 & 6

1c. Antoine Lake Site 7

1d. Parmiter Creek Site 8

1e. Tyee Lake Site 9

Appendix 2. Photo mosaics plates 1-5 showing the condition of riparian stands adjacent to streams sampled in the Watershed Assessment Area for Beaver Valley.

Photo Mosaic Plate 1. Solomon Creek Site 1

Photo Mosaic Plate 2. Solomon Creek Site 2

Photo Mosaic Plate 3. Gavin Lake Site 3

Photo Mosaic Plate 4. Parmiter Creek

Photo Mosaic Plate 5. Tyee Lake Site 9

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Photo Mosaic Plate 1. Solomon Creek Site 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Photo Mosaic Plate 2. Solomon Creek Site 2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Photo Mosaic Plate 3. Gavin Lake Site 3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Photo Mosaic Plate 4. Parmiter Creek