2002 – 2006 Chase Creek Watershed Review · 2002 – 2006 Chase Creek Watershed Review ......

2002 – 2006 Chase Creek Watershed Review

[Okanagan TSA (SOTSA 22 4634009)]

prepared for Tolko Industries Limited

and BC Ministry of Environment

Prepared by

March 2007

Chase Creek 2002-2006 Review

FIA# SOTSA 22 4634009

2002 – 2006 Chase Creek Watershed Review

Okanagan TSA (SOTSA 22 4634009) 1. INTRODUCTION This report has been prepared to address the requirements set out in the contract documents provide in Appendix A. The project scope was to conduct a review of those restoration plans and activities carried out in the Chase Creek watershed, since 2002 that have been funded by the Forest Investment Account. The review includes a review of impacts of the expansion of the mountain pine beetle since 2002 and how conditions may have changed in the watershed. The scope was subsequently amended to include an assessment of the capacity of public and private road bridges along the main stem of Chase Creek including any on Charcoal Creek. 2. BACKGROUND Since 1995 the Chase Creek watershed has been receiving funding through the Forest Renewal BC program and more recently the Forest Investment Account program for projects related to watershed restoration activities. Projects undertaken during this period included assessments, prescriptions, data collection as well as physical restoration of specific sites. The Chase Creek watershed has also received considerable public attention and scrutiny due to flood damages on private lands as a result of extensive flooding in 1996. More recently forest health issues related to the epidemic expansion of the mountain pine beetle (MPB) and the potential for significant changes to the watershed hydrology as forest cover is lost have focused attention on the changes that may occur in the watershed. Specific concerns are related to the potential increases in streamflow and potential impacts on stream crossing and past restoration works. Local residents along the Chase Creek mainstem are also concerned about future flooding and bank erosion. Tolko Industries Ltd. (Tolko) in partnership with the Ministry of Environment, Kamloops (MoE)provided funding for this project to review the projects completed in the watershed from 2002 to 2006 including consideration of the effects of the MPB on the results and recommendations of these reports. In addition it was also requested that all road bridges, public and private, located along the Chase/Charcoal mainstem be reviewed to determine their capacity to pass high flows and whether or not they had sufficient capacity to pass the200-year flood (Q200) as well as the projected Q200 that would include allowances for the increased flow resulting from the loss of forest cover to the MPB. Table 1 summarizes the FIA (and other) projects conducted in the Chase Creek watershed that were reviewed as part of this project.

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Table 1. Forest Investment Account (and other) Projects completed between 2002 and 2006

Title Prepared by

Year completed

Prepared for

Chase Creek Restoration plan Silvatech Consulting Ltd. 2002 Chase Creek

Restoration Society Chase Charcoal Creek Water Levels Dobson

Engineering Ltd. 1999 - 2003 Riverside

Hydrology of the Chase Creek Watershed, Interpretive Report

Dobson Engineering Ltd. 2004 Chase Creek

Restoration Society CHASE CREEK HYDROLOGIC ASSESSMENT Impact of Mountain Pine Beetle Infestations on Peak Flows (Including Application of the Ministry of Forests’ Extension Note 67)

Dobson Engineering Ltd. 2004 Tolko/Riverside

Chase Creek Hydrology Update, 2005 Dobson Engineering Ltd. October 10, 2005 Tolko

Chase Creek Snow Measurements Henri Cornelson 2003 - 2006 Tolko 2006 Chase Creek Snowline Tolko/UBCO 2006 Tolko Charcoal Creek Meteorological Monitoring Station (2001 to 2006 Summary)

Alberto L. Orchansky 2006 Tolko

2004 to 2006 Hydrometric Data Summary for Upper Chase and Charcoal Creeks (annual Reports

Dobson Engineering Ltd. 2007 Tolko

Fish Passage (FPCI) Culvert Inspection Chase/Charcoal Creeks

Silvatech Consulting Ltd. 2007 –(Draft) Tolko

Engineering Reports for Structures Eligible for Replacement to meet Fish Passage within the Chase Creek Watershed

Terratech Consulting Ltd.

Not completed due to snow Tolko

Bridge Capacity for Public/Private crossings in the Chase Creek Watershed

Dobson Engineering Ltd. 2007 Ministry of Environment

3. REVIEW OF PROJECTS COMPLETED BETWEEN 2002 AND 2006

The review was conducted, and presented, in the order listed above. The following paragraphs are brief summaries of those reports.

3.1 Chase Creek Restoration Plan (2002 Watershed Restoration Program – Silvatech Consulting Ltd.) This report summarizes the general conditions existing in the watershed at that time. Draft Guidelines prepared by the Watershed Restoration Program, Provincial Coordination Team (May 15, 2000) were followed in the preparation of the restoration plan. The report identifies restoration components (i.e. channel, hillslope) for the each of the sub-basins and prioritized them based on conditions at that time. Sub-basin, component, and site level objectives were also summarized. The condition of the Chase Creek watershed was described by sub-basin, upper

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Chase Creek, Charcoal Creek and for the residual areas, Middle Chase Creek Residual Area and Lower Chase Creek Residual area. The Chase residual area was split into two areas to better represent the differing issues (i.e. salmon access in lower Chase Creek only).

The following is a summary of the conditions and recommendations presented in the 2002 WRP report.

Upper Chase Creek Sub-basin (Priority 1)• Channel Condition - Poor – frequent unstable large woody debris (LWD) jams storing

sediment, bank erosion/slope failures contributing sediment • Riparian Condition - Good – intact with the exception of some encroachment by roads • Fish Habitat/Populations - Fair – may have been impacted by degraded channel conditions

near slides, pools and LWD jams provide some habitat • Road Conditions - Poor – road related landslides on north slope • Hillslope Conditions - Poor – connected/coupled to channel, unstable, natural/development

related slides Recommendations: • Stabilize 13 landslides • Deactivate ~650m of high priority road section • Stabilize ~145m of stream bank Charcoal Creek Sub-basin (Priority 2) • Channel Condition - Fair – diminished riparian, bank erosion • Riparian Condition - Poor – private landclearing • Fish Habitat/Populations - Fair – rainbow trout present, habitat aggraded in Blanc Creek and

riparian clearing along Charcoal Creek • Road Conditions - Fair – roads in upland areas may have contributed to slope failures, some

deactivation • Hillslope Conditions Fair – landslides and debris flows on steeper upland slopes, Recommendations: • Streambank and channel stabilization below China Reservoir spillway Middle Chase Creek Residual Area (Priority 3) • Channel Condition - Poor – bank erosion, braided, temporary sediment deposition • Riparian Condition - Poor – private land clearing, • Fish Habitat/Populations - Poor – rainbow trout present, habitat aggraded, lack of pools,

reduced vegetation • Road Conditions - Good – paved roads, generally well buffered from road related sediment

delivery • Hillslope Conditions - Fair – landslide near Miller Lake, alluvial fans, hillslopes disconnected Recommendations: • Stabilization of stream bank at two sites adjacent to previous works • Repairs/Improvements to 7 high priority sites

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Lower Chase Creek Residual Area (Priority 4) • Channel Condition - Poor – bank protection, channel control works, alluvial fan, deposition • Riparian Condition - Poor – riparian vegetation sparse • Fish Habitat/Populations - Poor – accessible to salmon, habitat simplified by bank protection

and loss of riparian • Road Conditions - Good – paved roads, storm sewers • Hillslope Conditions - n/a Recommendations: • Investigate restoration opportunities available Other Recommended works not prioritized • Conduct annually a Routine Effectiveness Evaluations/upgrades at restoration sites. • Preparation of a revised restoration plan was recommended by 2004 after other works. A “Chase Creek Restoration Plan Map” was included with the report and identifies some of the sites listed above. Sha. For a detailed list of the priority sites identified in the 2002 WRP Report refer to Appendix B.

3.2 Chase/Charcoal Creek Water Levels (2002/03 – Dobson Engineering Ltd.)

In the spring of 2002 at the request of Riverside Forest Products Limited, Dobson Engineering Ltd. established a program to collect freshet water levels at two locations in the watershed. Local residents were hired to collect daily water level data at the Chase-Falkland Road crossings at upper Chase Creek and at Charcoal Creek. This program was continued in 2003. The purpose of the project was to determine the timing of the peak flows out of upper Chase Creek and Charcoal Creek relative to the peak flow at the Water Survey of Canada stream gauging station Chase Creek above the Mouth (Sta. No. 08LE112). It was not known if the peak flows from upper Chase Creek and Charcoal Creek were synchronized or desynchronized, or if the runoff from only one of the sub-basins generated the peak flow at the mouth. Preliminary results from the limited data indicated that peak flows from upper Chase Creek and Charcoal Creek were synchronized. This suggested that it was likely the snowmelt runoff in both sub-basins that produced the peak flow at the mouth. It should be noted that this project was discontinued after the 2003 and was replaced by the installation of automated continuous water level recorders at the two sites (refer to 2004 to 2006 Hydrometric Data Summary for Chase and Charcoal Creek, summarized in Section 1.7).

3.3 Hydrology of the Chase Creek Watershed (2004 –Dobson Engineering Ltd.)

This report summarizes the results of Phases I and II of the Chase Creek Interpretive Report regarding the hydrology of the Chase Creek watershed undertaken between 2002 and 2004. The intent of this project was to develop a better understanding of the hydrology of the watershed

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based on the actual stream flow data available. The results of this project could also be used for future hydrology modeling when an appropriate model becomes available. The report includes a summary of the available stream flow data collected by Water Survey of Canada on Chase Creek since 1911 as well as the water level data for two stations operated for Riverside Forest Products Limited in the upper watershed from 2000 to 2003. A literature review was conducted for all reports completed prior to 2002. The following is a summary of the conclusions: • The spring freshet usually occurs between April and June but has commenced as early as late

March and as late as early to mid-July. • For WSC station 08LE005, the date of the annual maximum daily discharge typically occurred

in May or June. However for station 08LE112, which was established in 1996, the date of the annual maximum daily discharge occurred in May for all recorded years.

• The minimum daily flows typically occurred in August and September for both stations. • The mean daily discharge data for period 2 (1963 – 1968) indicated that the start of the

freshet occurred on day 116 (~ May 10). For period 3 (1996 – 2002) the data indicated that the start of the freshet occurred on day 105 (~ April 29), suggesting that the timing of the freshet had advanced (i.e. the freshet was starting earlier over time).

• A review of the hydrographs of mean daily discharges for each period indicates a trend of increasing peak flow over time as well.

• A review of the scatter plot data did not identify a discernable trend with regards to the length of the peak flow period.

• A review of the data set does not suggest any potential trends with regards to increasing or decreasing minimum flows over time.

• A graphical analysis was completed of the mean daily discharge by month in order to identify potential trends with discharge increasing or decreasing over time in any particular month. Unfortunately for period 1 (1911 – 1930) and period 2 the data is limited to the April to September period only. Analysis of the mean daily discharge for April and May identified potential increasing trends in discharge over the three time periods. No discernable trends were identified in the months from July to September.

• It was determined that a single manual water level reading was insufficient to accurately determine the synchronicity of the flows between upper Chase Creek and Charcoal Creek.

• Precipitation data for weather stations #1166945 and #166R45 at Salmon Arm was examined for the period 1912 to 2001. Examination of the data as total annual precipitation (plotted as 5-year moving averages) indicated that there was an increase in annual precipitation over the period of record.

• Other climate studies also indicate increasing trends in precipitation throughout the central and southern interior (source: Environment Canada 2001.). Statistically significant increasing trends in minimum daily temperatures were also noted across BC, while the trend of increasing maximum daily temperatures is only statistically significant in southeast BC (Kamloops, Summerland, and Cranbrook).

• It is likely that the apparent increase in the magnitude of peak flows is due to the differences in the data collection methods (i.e. once or twice per day manual water level readings vs. automated continuous water level recording).

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• Factors effecting the advancement of the start of freshet flows include climate change. Potential increasing trends for precipitation noted in April and May may be one explanation. Increased minimum temperatures that typically occur in the evening may also be a contributor to an earlier start of the freshet period.

• Peak flow trends in Chase Creek are not significantly different from other watersheds in south central BC1 and are consistent with expected changes that are predicted from climate change scenarios. This suggests that the Chase Creek trends may be related primarily to climate change.

• No recommendations were presented with this report.

3.4 Chase Creek Hydrological Assessment - Impact of Mountain Pine Beetle Infestations on Peak Flows and 2005 Update report (2004/05 – Dobson Engineering Ltd.)

For the purposes of this review the Chase Creek Hydrological Assessment and the Impact of MPB infestations on Peak Flows completed in 2004, and its corresponding update report completed in 2005 were reviewed and are presented as one summary. These reports proposed to quantify the potential hydrologic impacts of the loss of forest cover as a result of the expansion of the mountain pine beetle in the Chase Creek watershed. The first report (2004) summarizes the results of loss of forest cover and peak flow impacts from two unique scenarios.

• Scenario 1 illustrates the “worst case” for peak flows should all the susceptible pine succumb

to the mountain pine beetle and assumes the loss of all mature lodgepole pine within the snow sensitive zone of the Chase Creek watershed.

• Scenario 2 illustrates what the expected impact will be as a result of the loss of currently identified infested pine (2003) within the timber harvest landbase portion of the snow sensitive zone.

Current conditions for the Upper Chase and Charcoal sub-basins and the residual area, and risk analysis are also presented. The 2005 report includes updated ECAs, the Tolko Retention Plan and the forest development proposed by Tolko. It should be noted that due to the expansion of the MPB in the watershed only Scenario 1 was considered in the update report (2005), and therefore summarized here. The equivalent clear-cut area (ECA) evaluation presented in these reports utilize the results of the Ministry of Forests, Forest Sciences Program Extension Note 67 (Schnorbus et. al. 2004) investigating the influence of forest development on the quantity of flows in a snowmelt hydrologic regime.

1 Leith, Rory M.M. and Paul H. Whitfield. Accepted June, 1998. Evidence of Climate Change Effects on the Hydrology

of Streams in South-Central BC. Canadian Water Resources Journal. Vol. 23, No. 3, 1998, P. 219.

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An office and ground-based field review was conducted in the Chase Creek watershed in May 2004. In the 2005 update was an office exercise only. The following is a summary of conditions, identified by sub-basin.

Upper Chase Creek • Upper Chase Creek has been disturbed by past landslides and bank failures through the lower

and middle reaches. • Several of the slides initiated from an old road adjacent to the channel on the north slope. • The Upper Chase Creek Landslide Inventory (Turner 1996) indicates that there are at least 73

landslides in the upper Chase Creek sub-basin. • Overall, the mainstem channel is moderately robust with boulder-dominated substrate and is

slightly to moderately aggraded. • Road related impacts have been extensive throughout the sub-basin, but many road sections

are now deactivated. • The sub-basin is considered moderately to highly sensitive to peak flows. • The potential water depth increase was not expected to exacerbate the channel condition • Peak flow related channel disturbance was not observed

Charcoal Creek • Charcoal Creek is stable and robust in the headwaters, but has been disturbed through the

middle reaches by riparian harvesting on private lands and grazing • The lower reaches by have been impacted by landslides and the failure of the spillway below

China Lake dam • Hydrogeomorphic (flood or landslide derived) disturbance was observed in the middle reaches

at site 9. • The Charcoal Creek mainstem is low gradient, sinuous, gravel dominated, and slightly to

moderately aggraded through the middle reaches • Through the lower reaches, the channel is cobble/gravel dominated, slightly to moderately

aggraded, and moderately to highly sensitive to peak flows • The potential water depth increase was not expected to exacerbate the channel condition • Peak flow related channel disturbance was not observed

Residual • Chase Creek through the residual area is gravel/cobble dominated and unstable through the

upper and middle reaches. • Moderate channel aggradation and braiding was observed along with severe bank erosion • Forest development likely has not been a factor in terms of potential peak flow increases, as

the current snow sensitive zone ECA for the watershed is low • Minor channel recovery was observed • The channel is more stable through the lower reaches where riparian vegetation is intact and

the channel gradient is greater • Overall, Chase Creek through the residual area is sensitive to peak flows. • The potential water depth increase was not expected to exacerbate the channel condition • Peak flow related channel disturbance was not observed

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The potential peak flow impacts have been assessed with consideration for the results of the research carried out in the Upper Penticton Creek watershed by the researcher staff with the Southern Interior Forest Region and reported in Extension Note 672, as well as channel conditions listed above, and related analysis. The estimated hydrologic risk ratings for the projected ECA levels that will occur over the next few years as the pine dies in the snow sensitive zone is summarized in Table 2 below. These risk ratings were based on judgment. In assessing the risk, the current channel conditions were considered and the estimated increase in shear stress on the bed material.

It should be noted that he Peak flow hazard, and the resulting risk in the Upper Chase sub-basin identified in 2004 were downgraded from high to moderate in both categories respectively in the 2005 update. The consequences within the Upper Chase sub-basin are considered moderate since the channel is confined and there are limited private lands that may be affected.

Table 2. 2005 Hydrologic risk ratings comparing no harvesting to harvesting + retention in

the snow sensitive zone

Increase in Peak Flow (%)5

10-year 50-year Sub-Basin/ Watershed

Risk1

Peak Flow Hazard

Consequence2

ECA3 (%)

ECA4 (%) No

Logging

With Logging

No Logging

With Logging

Upper Chase

Moderate Moderate Moderate 44.9 48.0 12 13 21 23

Charcoal High High Moderate 64.3 70.4 21 24 30 33 Watershed Very High High High 59.0 63.7 18 21 27 30

1-Risk = risk of hydrologic impacts, i.e. channel instability, as a result of increases in peak flow 2-Consequence = channel sensitivity to changes in peak flows 3-ECA for area with reduction in forest cover due to MPB + harvesting to December 31, 2005 – no proposed harvesting 4-ECA for areas proposed for harvest + past harvest + retention 5-Approximate increases in the 10-year and 50-year peak flow events compared to baseline of 0% ECA based on results of Technical Note 67.

The 2005 report also compared the harvesting/retention strategy to no harvesting/natural regeneration. The recovery curve in Figure 1, for no harvest/natural regeneration (Qn), suggests full hydrologic recovery would be achieved in approximately 60 years. Seemingly, harvesting infested stands followed by early replanting has the advantage of advancing the hydrologic recovery of the harvested area by several decades as compared to areas left to recover naturally. The removal of beetle-infested stands through forest development should cause negligible additional peak flow impacts compared to leaving the dead stands.

2 Extension Note 67, Schnorbus et al, Ministry of Forests, Forest Sciences Program, 2004

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Figure 1. Potential impact of management options on incremental increase in the 50-year peak flow

Incremental Change in 50-Year Peak Flow

0

5

10

15

200 10 20 30 40 50 60

Years after Logging

% C

hang

e in

Pea

k FL

ow

Qn

Qh+l

Notes: Qn = Incremental increase in peak flow with no harvesting, pine areas left for natural regeneration Qh+l = Incremental increase in peak flows with combined effect of proposed harvesting + retention

The following is a combined list of the recommendations identified in the 2004 and 2005 reports

• All options to aggressively suppress beetle expansion should be considered to minimize the future spread of beetles and subsequent peak flow impacts.

• Riparian vegetation should be retained, where practical, to maintain channel stability in reaches with highly mobile alluvial substrate, particularly in basins with high ECAs. In addition, these reaches should be explored for side channel access to relieve flood stress.

• For future beetle suppression activities in riparian areas, the need for wood recruitment as in-stream large wood, should be assessed during the site plan stage based on the specific channel requirements.

• Consider remedial works at the toe of landslides at high risk from increased peak flow levels within the Charcoal and upper Chase sub-basins to reduce further erosion.

• minimize the potential impacts of roads on peak flows, To ensure this, ditches that are directly connected to the channel network should not extend beyond the immediate gully drainage, cross-drains should deposit flows onto the forest floor, and roads should be deactivated as soon as possible following development.

• The results summarized in the extension note should be applied only to the snow sensitive zones of watersheds in the Southern Interior with morphologies similar to Upper Penticton Creek.

• The proposed harvesting and retention plan proposed by Tolko should be implemented as soon as possible starting with those blocks that have confirmed high levels of infestation and/or dead pine so that these areas can be planted and aid in promoting the reduction of peak flows.

• Where possible roads should be constructed as temporary structures and rehabilitated as soon as harvesting is completed to reduce the disturbance to natural drainage patterns

• The recommendations provided in the 2004 report still apply. • Planting of harvested blocks should be scheduled as soon as practical following harvesting to

promote the reduction of peak flow impacts. • For those areas where windthrow may be a concern along leave area boundaries, it is

recommended that a 1-2 tree height feathered buffer of pine be left to reduce the risk of blowdown in the adjacent stands.

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3.5 Snow survey Measurements in Upper Chase/Charcoal Creek (2002 to 2006 – Henri Cornelson)

Snow course measurements have been conducted in the Upper Chase Creek and Charcoal Creek watersheds for a many year. In discussions with Rita Winkler3 it was determined that the last summary of the snow survey data was completed in 2002. Currently (2002 to 2006), snow survey data is being compiled and archived for a later review.

3.6 Extent of Snow Cover During the 2006 Spring Freshet (2006 – Dobson Engineering Ltd.)

In May of 2006, Tolko funded an aerial snow cover survey for the Chase Creek watershed (part of a larger study being conducted by UBCO involving several watersheds). The deliverables included a summary of the Methodology, table of results, photographs, and a snowline map indicating the snowline elevation at each of the flight dates.

One line was mapped during each flight; a line representing the area of complete snow cover labeled 100% (actual cover ranged from 75% to 100%). During the overview flights, oblique photographs were obtained to aid in the determination of the final mapping of the snowline location. Snow survey flights were conducted on May 3rd, 10th, 17th, 22nd, and 30th, of 2006. Table 3 is a summary of the results of the 2006 snowline survey for the Chase Creek watershed.

Table 3. Results of 2006 Snow Line Survey

Date of flight

Average snow line Elevation (m)

SWE* at Mission Creek (2F05P) at 1780m elev. (mm)

SWE* at Brenda mines (2F18P) at 1460m elev. (mm)

2006 Peak flow Q m3/s As per WSC Stn # 08LE112

May 3, 2006 1410 570 160 5.71 May 10, 2006 1450 540 60 4.65 May 17, 2006 1540 416 20 11.1 May 22, 2006 1610 300 0 9.55 May 30, 2006 1680 229 0 7.92

• - SWE extrapolated from graphs on Ministry of environment website, refer to the supplied link; http://www.env.gov.bc.ca/rfc/river_forecast/graphs/spd2f18p.html

It should be noted that a graphical comparison of snowline elevations versus peak stream flow/snowmelt data was beyond the scope of the project. No recommendations were presented.

3 Rita Winkler, Research Hydrologist, Kamloops Forest Sciences

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http://www.env.gov.bc.ca/rfc/river_forecast/graphs/spd2f18p.html


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3.7 2001 – 2006 Charcoal Creek Meteorological Monitoring Station (Alberto L. Orchansky)

The charcoal Creek Meteorological station has been operational since the end of November 2001. It is located at approximately 700m above sea level in the Charcoal Creek Sub-basin, 600m Northeast of the intersection of Blanc Creek Road and B200 Road. This station collected hourly and daily data generating physical measurements for:

• Solar radiation, • Rainfall • Air temperature/Relative humidity • Snow depth • Soil temperature • And wind gusts • Vapour pressure deficit

Although the station is designed to run with the minimum of maintenance, routine service is mandatory to ensure the flow of quality data with limited data gaps or losses. Two service visits were conducted in 2006, in May and September. The Multi-annual and annual monthly mean statistics for incoming global solar radiation from December 2001, to September 2006 are identified in the report. The annual monthly mean exceeded the multi-annual mean in July of 2003 and 2006, both months were the driest on record. Wintertime measurements are not considered accurate at this station due to snow/ice formation on the sensor of this relatively unattended site. In agreement with the solar radiation data, the monthly mean, mean maximum and absolute maximum air temperature in 2003 and 2006 were higher then any other year on record. Accordingly, the vapour pressure deficit during the summers of 2003 and 2006 were higher then in other study years. The 2004/04 winter was identified as the coldest, and 2005/06 was the mildest. At no point did the soil temperature go below the freezing level. Snowpack and rainfall values are calculated as multi-annual and annual means. Snow depth measurements should be studied in conjunction with other snow pack data collected in the area (manual measurements). Snow free dates at the station were identified as April 20th, 2002; April 9th, 2003; April 3rd, 2004; March 8, 2005; and April 19, 2006. The largest rainfall event was recorded on May 22, 2004 at 34.9mm/day. The highest intensity rainfall was recorded on June 25, 2004 at 12.9mm/hr. The summer of 2004 had approximately 50% more rainfall then in 2002, and 150mm more then in 2003. No recommendations were presented within the report.

3.8 2004 to 2006 Hydrometric Data Summary, Upper Chase/Charcoal Creek (2006 Dobson Engineering Ltd.)

This is an annual report summarizing the hydrometric data collected continuously (during open flow periods) at Upper Chase Creek and Charcoal Creek stream gauging stations from 2004 to 2006. The stations provide stream runoff data that could be used to determine the timing and magnitude of annual peak flow events by sub-basin.

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The quality of the data is verified by conducting regular discharge measurements at the stations and comparing with the stage discharge curves derived from the channel cross-section for both sites. The mean monthly discharges were calculated using the hourly field data (water levels) and the corresponding discharge values derived from the stage/discharge curves. The total monthly yield was calculated in cubic meters and converted to acre-feet. The period of record for the stations varies from year to year depending on field conditions (ice conditions), however data is typically collected from May 1st through October 31st. The following tables (4 and 5) are a summary of the data collected to date:

Table 4. Mean Monthly Discharge (2004-2006)

Mean Monthly Discharge (m3/s)

Data Apr. May June July Aug. Sept. Oct. Upper Chase 2004 - - 0.85 0.21 *0.06 *0.19 0.22 Upper Chase 2005 - 4.4 0.98 0.36 0.10 0.05 0.69 Upper Chase 2006 - 3.51 1.47 0.198 0.038 0.045 0.039 Charcoal 2004 - - 1.78 0.31 0.08 0.12 0.07 Charcoal 2005 - 1.4 0.85 0.43 0.09 0.08 0.43 Charcoal 2006 - 2.48 1.09 0.207 0.079 0.073 0.073 WSC Chase 2004 - 3.6 2.2 0.39 0.10 0.36 0.44 WSC Chase 2005 - 4.9 2.4 1.1 0.12 0.22 1.4 WSC Chase 2006 - 7.70 2.79 0.326 0.048 0.116 0.197

*Values estimated - Chase Irrigation District was diverting water from August 26 to September 27, 2004.

Table 5. Monthly Yields (2004-2006 Data)

Monthly Yields (AF) Data Apr. May June July Aug. Sept. Oct. Total Upper Chase 2004 - - 1,789 460 *120 *407 472 3,248 Upper Chase 2005 - 9,498 2,065 776 226 103 1,505 14,173 Upper Chase 2006 - 7,627 3,093 429 83 95 85 11,412 Charcoal 2004 - - 3,732 682 176 246 146 4,982 Charcoal 2005 - 3,140 1,785 934 192 169 928 7,148 Charcoal 2006 - 5,379 2,294 448 171 153 159 8,604 WSC Chase 2004 - 7,904 4,581 856 221 746 945 15,253 WSC Chase 2005 - 10,705 4,983 2,452 251 471 2,960 21,822 WSC Chase 2006 - 16,720 5,863 708 104 244 428 24,066

*Values estimated - Chase Irrigation District was diverting water from August 26 to September 27, 2004.

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The Recommendations made in the 2004 to 2006 Hydrometric Data Summary were as follows

• The operation of the two gauging stations should continue through 2007. Understanding how

the runoff characteristics for the these two sub-basins may be altered as a result of the loss of forest cover due to the mountain pine beetle can be used to help make better forest management decisions.

• Continue to measure stage and discharge and carry out routine inspections of the sites during the open water season.

3.9 Fish Passage (FPCI) Culvert Inspection Chase/Charcoal Creek (2007 Draft -

Silvatech Consulting Ltd.)

Two draft reports for “Fish Passage Culvert Inspection for Chase/Charcoal Creeks (FPCI)”, completed by Silvatech, were made available for review. The first report was completed on behalf of Tolko through FIA funding; Ministry of Environment funded the second report. For the purposes of this review the two reports are presented as one, however the results and recommendations have been kept separate as private /public land issues are not fundable under FIA regulations.

The reports consisted of tables of priority sites, photos, maps and field cards. The reports identified a total of 20 stream crossing structures reviewed to determine if a FPCI could be conducted, Of the 20 sites, 16 were identified in the FIA report and 4 in the report completed for Environment. The following is a summary of the results/recommendations presented in the two reports: Maps identifying the sites were included in the report. The following tables (6 and 7) are a summary of the results, by site, identified in the two reports.


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Table 6. FIA Funded FPCI Results and Recommendations by Site

Site ID

Stream Existing Structure

Q100 Area Required

Structure Sizing

Fish Barrier Score Rank Recommendation Funding Eligibility*

C1 Blanc Creek

2000mm cmp 3360mm Undersized Rainbow Partial 43 1 Replace Yes

C2 Blanc Creek

1200mm cmp 3050mm Undersized Rainbow Full 38 3 Replace No

C3 No Data No Data No Data No Data No Data No Data No FPCI - None - C4 No Data No Data No Data No Data No Data No Data No FPCI - None -

C5 Charcoal Trib

1200mm cmp 1600mm undersized Other Full 22 3 Further Investigate No

C6 Charcoal Trib

1000mm cmp 1700mm undersized Other Undetermined 32 3 Further Investigate No

C6a Charcoal Trib

900mm cmp 1500mm undersized Rainbow Undetermined 29 3 Further Investigate No

C7 No Data No Data No Data No Data No Data No Data No FPCI - None -

C8 Charcoal Trib

600mm cmp 900mm undersized Other Full 19 3 Further Investigate No

C9 Charcoal Trib

600mm cmp 900mm Undersized Other Full 22 3 None No

C10 Charcoal Trib

600mm cmp 700mm Undersized No FPCI No FPCI No FPCI - None -

C13 Lisa Creek

1600mm cmp 1900mm Undersized Undetermined Not a barrier No FPCI - None -

C14 No Data No Data No Data No Data No Data No Data No FPCI - None - C15 No Data No Data No Data No Data No Data No Data No FPCI - None -

C16 Blanc Creek Trib

500mm cmp 1100mm Undersized Other Full 33 3 Replace No

C17 No Data No Data No Data No Data No Data No Data No FPCI - None -

* FIA eligibility requires a score of >39

In Summary: • 10 of the 16 sites are identified as undersized for Q100 and 5 of the 10 are full/partial barrier to fish. • The remaining 6 sites had no data available, no FPCI conducted. • Three culverts recommended for replacement • One site (C1) was determined to be eligible for funding based on FIA requirements


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Table .7 FPCI Results and Recommendations by Site funded by the Ministry of Environment

Site ID

Stream Existing Structure

Q100 Area Required

Structure Sizing

Fish Barrier Score Rank Recommendation Funding Eligibility*

C11 Charcoal Trib

400mm cmp 700mm Undersized Rainbow Full 28 3 None No

C12 Charcoal Trib

500mm cmp 800mm Undersized Rainbow Partial 32 3 Further Investigate No

C12a Charcoal Trib 800m cmp 800 Undersized Rainbow Full 28 3 Remove filter fabric No

C18 Charcoal Creek Bridge No Data No Data Rainbow No No FPCI - Repair Bridge No

In Summary: • 3 of the 4 sites are identified as undersized for Q100 and full/partial barrier to fish • The fourth site was recommended for bridge repair • Other recommendations included the removal of filter fabric and to investigate fish presence further


FIA# SOTSA 22 4634009 4.0 BRIDGE CAPACTY FOR PUBLIC/PRIVATE CROSSINGS ALONG CHASE/CHARCOAL CREEK

As requested (and funded) by the Ministry of Environment, and as part of this report, Dobson Engineering conducted a review of accessible bridge crossings on Chase/Charcoal Creeks for their ability to pass a 200-year hydrological event (Q200) including the potential influence of the MPB on increased peak flows. Bridge openings were measured for area calculations and applied to stream data (bed and bank texture, gradient) to determine the general capacity at each site. Manning’s “n” values used to determine the roughness of the channel are based on judgment, and range from 0.03 (rounded cobbles) to 0.045 (angular boulders/rip-rap). It should be noted that snow and iced over conditions prevented accurate measurement at all sites, estimations of depth below snow/ice to stream channel were required. To acquire access to bridge structures on private lands, the Chase Creek Watershed Committee committed to contacting residents along the Chase/Charcoal mainstem channels seeking approvals from landowners with bridge crossings. At the time of the field assessments (March 9th and 10th , 2007) five properties responded with approval for access. Four of the five properties were assessed; an address for the fifth was unable to be located along the Chase-Falkland Road. All public bridge crossings, a total of 11, along the Chase/Charcoal mainstem channel were accessible and measured.

Table . 8 Bridge Crossing Capacity Assessment

Crossing Identification Opening Capacity (m3/s)

Q200 **WSC Stn08LE112 Max Inst.

(Based on % increasein discharge at worstcase scenario –50 yea

(m3/s)

**Q200 + MPB

r (m3/s) Peak flow) Upper Chase 23% Charcoal 33% Watershed 30% Max Inst. (m3/s)

Q200 + MPB+ Bedload(1.5x)

Meets Capacity requirement for all factors

Upper Chase Creek at Chase-Falkland Hwy 255 41 50 75 Yes

Paxton Valley Road Crossing 151 41 50 75 Yes

Charcoal Creek at Chase-Falkland Hwy 244 27 36 54 Yes

8120 China Valley Rd - Charcoal Creek 30 68 88 132 No

2561 Chase-Falkland Rd 55 68 88 132 No

Chase-Falkland Hwy - Public Crossing 169 68 88 132 Yes

910 Chase Falkland Hwy 183 68 88 132 Yes

840Chase Falkland Hwy - Pozzobon 140 68 88 132 Yes

Skimikin Rd - Public Rd 535 68 88 132 Yes

Highway #1 at Chase 960 68 88 132 Yes

Paquette Rd at Chase BC 207 68 88 132 Yes

Chase Town Rd - Chase BC 178 68 88 132 Yes

Chase Creek at Shuswap Avenue - Chase BC 266 68 88 132 Yes

Chase Creek at Walking Bridge - Chase BC 186 68 88 132 Yes

Chase Creek at Third Avenue - Chase BC 265 68 88 132 Yes

Table 8 identifies the bridge sites accessed with a comparison of the capacity versus flow. The Q200 is estimated to be approximately 68m3/s, based on a frequency analysis of the 10 years data collected at

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WSC Station 08LE112 (Chase Creek near the Mouth) using maximum instantaneous flows for each year of record. It should be noted that with only 10 years data, 2 years of which appear exceedingly high, the percent standard deviation of the mean is at 60% thus widening the range of possible flows (range between 57m3/s to 88m3/s – refer to frequency distribution curves located in Appendix C). It was also assumed, based on the hydrometric data summarized in Section 1.8, the Upper Chase contributes approximately 60% of the peak flow discharge while Charcoal contributes the remaining 40% and flows for bridges near these locations were adjusted. To include the potential increase in Q200 flows due to the MPB infestations the Q200 was adjusted based on the increases identified in Section 1.4, Table 2. Additionally, the flows were increased by 50% to account for bedload material moving through the mainstem channel from past landslides and bank failures in the Upper Chase sub-basin and below the china Valley reservoir. Of the 15 bridge crossings reviewed, only two (8120 China Valley Road and 2561 Chase-Falkland Road) were identified as having a capacity lower then the calculated 200-year flood (Q200 – refer to Appendix C for Bridge cross-sections and stream flow data). At 8120 China Valley Road, on older crossing is rotting and appears unsafe for vehicle passage (a Danger sign is posted). The structure itself appears to have sunk, decreasing flow capacity. The bridge crossing at 2561 Chase-Falkland road is channelized through a corner with a log crib wall on both sides. Undercutting is occurring along the east wall (outside corner), deposition is occurring along the west wall.

East Bank

8120 China Valley Road 2561 Chase-Falkland Road

At both of these sites, and others, maintenance issues such as debris build-up at the crossings will likely occur during higher flows, further decreasing the flow capacity of the structures and increasing the potential for flooding and erosional undercutting along stream banks. It should be noted that none of the sites assessed in this section are eligible for funding through FIA.

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5.0 DISCUSSION From the results of the literature review it appears that the condition of the watershed, in hydrological terms, appears stable and unchanged between 2002 and 2006. This conclusion is based on the similar channel conditions presented in the 2002 WRP report (section 1.1) and the 2005 Hydrological Update report (Section 1.4). The reader should also understand that this is a general condition along the mainstem channels, and does not consider the individual priority sites identified in the 2002 WRP report (these sites have not been monitored, as recommended in the 2002 WRP report). Watershed health however, as identified in Section 1.4, has degraded since 2002 with the rapid expansion of the MPB throughout the Upper Chase and Charcoal sub-basin. It is apparent from the reports reviewed that regardless of the ‘harvesting or no harvesting scenarios” presented there are going to be hydrologic impacts as a result of the loss of the mature pine from the MPB infestation. Climate Change may also further add to potential increases in peak flow, particularly in terms of localized extreme weather events. With this in mind, FIA and other projects completed since 2002 appear to be focused on gaining a better understanding of the watershed hydrology through data collection (i.e. stream flow gauging, snow /meteorological data) and the application of research data (Extension note 67). The data collected to date constitutes valuable supporting data for modeling exercises and other initiatives. The meteorological data collected is also a valuable tool when combined with snow depth/density data collected manually at the Blanc Creek and Upper Chase Creek snow measuring stations. To date, no works that were recommended in the 2002 WRP have been conducted within the watershed, including Effectiveness Evaluation Monitoring. As such, the actual condition of the priority sites, or the current trend (stabilizing or degrading) at these sites is unknown and may no longer be applicable. It should be noted that only priority sites in the Upper Chase Creek sub-basin might be eligible for FIA funding. Priority sites identified in the Charcoal sub-basin and residual areas are located within private lands and are not eligible for watershed restoration through FIA. With regards to the fish passage/culvert inspection completed (Section 1.9, Table 6 and 7), 13 of a total of 20 inspected were considered undersized and unable to pass the Q100, of these only one was eligible for FIA funding. The Q100 at these stream crossing structures was calculated using the procedures identified in the FPC Community Watershed Guidebook and stream measurements identified at individual sites. These measurements do not account for the potential increases in peak flow due to the loss of mature pine from the MPB infestation. Care should be taken during the design phase to replace any undersized structure with an appropriately sized one that will pass the Q100 plus any potential increase in peak flow due to the MPB infestation. Additionally, a 20% increase should be included in the sizing of any tributary stream crossing to account for bedload movement. The bridge capacity assessment (Section 2) completed on public/private bridge crossings was conducted with the potential increase to the Q200 (design flows for public crossings) from the MPB infestation in mind. When compared with the current opening capacity at each site only the two were identified as unable to pass the Q200 (plus beetle impact and bedload movement). Furthermore, debris from erosional undercutting will likely cause initial concerns (i.e. logs/trees) at any bridge crossings prior to actually exceeding any capacity only issues, although this is a maintenance issue and not a design fault.

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6.0 RECOMMENDATIONS • Continue the collection of all data sets identified:

- Stage discharge at Chase and Charcoal Creek - Snow pack measurements in Upper Chase and Charcoal Creek sub-basins - Meteorological data

• Consider establishing snow measurement sites within a MPB infested stands

• Summarize archived snow measurement data since 2002, utilizing all other data sets as supporting

information.

• Designs for bridge crossings along the Chase Creek mainstem channel should include the potential increase in peak flows due to the MPB infestations as well as large bedload transportation (up to 50%).


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Appendix . A Priority Sites Within The Chase Creek Watershed (as listed in 2002 WRP) Priority Sub-basin #1 – Upper Chase Creek Restoration Objectives

Recommended Site Works Primary and Secondary Priority Components

Sub-basin Level Objectives

Component level Objectives Site Level Objectives Group Priority (Map ID)

Site Description

1 (19) Slide 21

2 (16) Slide 14

3 (17) Slide 15

4 (20) Slide 24

5 (4) Slide 2A/2B

6 (25) Slide 65

7 (26) Slide 68

8 (18) Slide 19

9 (15) Slide 8

10 (27) Bank erosion

11 (28) Bank erosion

12 (29) Slide 36 toe

13 (24) Slide 27

14 (21) Slide 27

15 (22) Slide 29

Hillslope Channel

Reduce sediment Delivery from hillslopes Improve water quality

Prevent new landslides or re-activation of existing slides Reduce sediment input from existing slides directly connected to the creek Restore natural hillslope drainage Reduce bank erosion along toe of unstable slopes and existing slides Increase stability of materials stored in the channel

Stabilize remaining active slopes directly connected to mainstem Reduce the erodibility of exposed soil surfaces on landslide deposits and scarps Reduce bank erosion along toe of unstable slopes and existing slides Increase crossdrains along maintained and roads not fully deactivated Use in-stream unstable rocks and debris to protect stream banks along unstable sections Increase stability of LWD through positioning, ballasting and/or anchoring

16 Rd J1.36 (450m)


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17 Rd J0.70 (200m)

Priority Sub-basin #2 – Charcoal Creek Restoration Objectives Recommended Site Works Primary and Secondary Priority Components


Component level Objectives Site Level Objectives Group Priority (Map ID)

Site Description


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Channel Riparian

Reduce sediment Delivery to mainstem channel Improve water quality Restore riparian function

Reduce bank failure/erosion along lower Charcoal Creek Reduce inputs of fine sediment and sources of increased turbidity along mainstem Accelerate recovery of riparian areas using fast growing species Exclude cattle from riparian area Preservation of riparian areas through education Encourage continued volunteer and community based efforts towards recovery

Stabilize channel and banks below China Lake Spillway No site level objectives for the secondary component were identified

1 (5)

Spillway channel below China lake reservoir eroding/failing

Priority Sub-basin #3 – Middle Chase Creek Restoration objectives Primary and Sub-basin Component level Objectives Site Level Objectives Recommended Site Works


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Group Priority (Map ID) Site Description

1 (*4) (Timmermann – site 0110-P1) Bank erosion

5 (*8) (Gasser – Site 0113-P1) Cattle fencing at past works

6 (*13) (Strang – Site 0124-P1) Beaver damage to LWD management structure

7 (*1) (Pozzobon – Site 0107-P7) Erosion below previous works

8 (2) (McLearon – Site 0109-P1) Bank erosion upstream of bridge

9 (*3) (Twerdochilb – Site 010-P6-PA) Failure of bar stabilization works

10 (9) (Burles – Site 0113-P6) Continued bank erosion, previous works at site

11 (*12)

(Lauren – Site 0116-P4-P6/P7) Previous works not completed at previously prescribed sites

12 (10) (Cornelson – Site 0115-P0A) Braided channel section

Channel Rparian

Improve channel and bank stability Improve water quality Restore Riparian function

Decrease sediment input to channel by protecting/stabilizing key areas of bank Retard the downstream movement of sediment and reduce the active channel width through bar stabilization Accelerate recovery of riparian areas using fast growing species Exclude cattle from riparian area Preservation of riparian areas through education Encourage continued volunteer and community based efforts towards recovery

Site level objectives listed as same as component Site level objectives listed as same as component

13 (11) (Cornelson/Kosolowkski – Site 0115-P5) Bank erosion

* - Signify locations of past work that requires maintenance/repairs or completion of works. Priority Sub-basin #4 – Lower Chase Creek Restoration Objectives Recommended Site Works Primary and Secondary Priority Components


Component level Objectives Site Level Objectives

Group Priority (Map ID) Site Description


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Channel Riparian

Although Primary and secondary restoration components for restoration were identified for this residual area, no other objectives or priority sites were noted. Recommendations were made to investigate further the limiting habitats and the likelihood of success for the direct restoration of fish habitat in this residual area

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